2.4GHz-Friendly Phones?

da3dAlus writes "When I first bought my 2.4GHz wireless phone system several years ago, it was a rather new technology, and wi-fi wasn't even on the scene. Now it appears that all wireless phones are on the 2.4 or 5.8 GHz spectrum, and I've got neighbors with wi-fi (with myself included). While checking out new phones recently, I've noticed some are carrying a "802.11 Friendly" sticker. The question is, are there any trully 802.11 friendly phones? Has anyone really ever had a problem with these types of phones interfering with their wi-fi network?"

Comments

900mhz?

[Anonymous Coward]

Mine 900mhz cordless phone even has spread spectrum. Works great, excellent range.

Re:900mhz?

[Anonymous Coward]

http://www.walmart.com/catalog/product.gsp?cat=397 7&dept=3944&product_id=2194569&path=0%3A3944%3A397 7%3A57909%3A128290

He is talking about cordless.

Re:900mhz?

[number11]

We're talking about cordless, not cellular. You furriners need to read for comprehension.

Some GSM cell phones run on the 900MHz band (880-960MHz).

Some US cordless phones run on the 902-928MHz band. But thanks for your insightful comment anyhow, AC.

Re:900mhz?

[SynKKnyS]

My cell phone (running on 900 MHz) has interferred with my CRT more than any 900 MHz cordless phone.

Re:900mhz?

[badasscat]

We're talking about cordless, not cellular. You furriners need to read for comprehension.

Pot kettle black.

Someone apparently doesn't know that 900mhz cordless phones exist, and all of them are wi-fi friendly. I myself have a Panasonic 900mhz digital spread spectrum phone and have no problems at all with my wi-fi when using it.

Re:900mhz?

[matth]

Ummm cordless phones do/can run on 900mhz! Please make sure you know of what you speak before you speak!

Re:900mhz?

[Ohreally_factor]

All the phones in my house are 900 Mhz cordless, so next time tell me something I don't already know. If you read the post to which I was responding, you'd see that stated that "900MHz is such a BAAAD idea... You Yankies may have 1900MHz GSM, but the whole of Europe uses 1800MHz and... 900MHz! Baaaaad!"

So excuse the hell out of me that you didn't read the greatgrandfather post for comprehension. But one thing I definitely agree on. We could all use more cowbell.

Re:900mhz?

[JWSmythe]

Try talking on a Nextel phone anywhere near a monitor or speaker.. :)

You'll hear an audible clicking out of anything with a powered speaker. That includes TV's, home stereo's, boom boxes, and even PC speakers. The speakers don't even have to be attached to a PC, they just need power. While you're talking (or 2-waying), you can hear the digital noise the whole time.

TV's and monitors freak out too. It looks something like the degausse feature, except it continutes in the same way the sound does.

To stay on topic, I've used a variety of 802.11b and 802.11g equipment with a whole bunch of different 2.4Ghz phones, and never had a problem. We do have one location that has problems, but it's from someone elses microwave equipment (like communications, not cooking). I had my laptop monitoring, and I'd see the noise jump up to 20+ dB in a sweeping pattern. I don't know who it is, but it's not 802.11?, I didn't get any data, just a jump in noise. It's enough to jam the 2.4 Ghz cordless phones, but it doesn't bother my directional 802.11b antennas.

And no, I know my equipment wasn't interfering with the phones, I unplugged all my networking equipment one day, just to prove to the office staff that it wasn't the problem.

Re:900mhz?

[Tmack]

I can always tell when someone in my office is about to get a call on their cellphone because of the noise coming out of my speakers from it. They start clicking and buzzing about a second before the phone starts to ring.

As a side note, cordless phones in Colocations do the same if the tech is close to an operational circuit/equipment. Was working with a CO tech once on a problematic T1 (problem was in something in the Colo), and as soon as I started a Bert pattern, I could hear it over the phone (CO tech had just physically changed a MUX card and was standing there looking at it while on a cordless phone talking to me). It made a nice digitized/buzzing type noise.

Tm

Re:900mhz?

[Sanksa Wott]

I've got an itch, and the only thing that can scratch it is.. MORE COWBELL! ...and a 900mHz phone.

Re:900mhz?

[Ohreally_factor]

Please make sure you read the post I was responding to before you speak.

I'm well aware that cordless phones can run on 900 Mhz. I own three of them.

Don't feel bad, you're not the only one that saw my post and didn't realize that the parent post had been modded down, and so was not visible.

Re:900mhz?

[jaavaaguru]

I have a BT XD500 DECT/GAP phone and it doesn't appear to interfere with WiFi at all. I'm not sure what frequency the phone uses though - doesn't mention it on the box.

Re:900mhz?

[matth]

Woops, my apologies!

Re:900mhz?

[Cliffy03]

And I will keep my 900 MHz Panasonic......until 5.8 phones aren't so ugly.

Re:900mhz?

[justkarl]

My cell phone (running on 900 MHz) has interferred with my CRT more than any 900 MHz cordless phone.

I've had similar experience. My house is wirelessly networked, and when I'm talking on the cellphone(all I've got) it really interferes the shit out of my network, and I generally have to reboot..
Although if i'm waithing for an important call, and I'm wearing my headphones or just listening to music on the computer, I've found if I put the phone right under the monitor, it makes an awful noise from the speakers when it rings, so I know it's ringing and don't just not hear it.

5.8

[cflorio]

The other question is, will the 5.8 interfere?

Re:5.8

[jayhawk88]

Not unless you find a way to run your wireless network at 5.8Ghz.

Re:5.8

[Glonoinha]

You mean like the 802.11a wireless networks?

But the first guy hit it right on the head. 900MHz phones are the best bet if you are running a regular wifi network and don't want interference.

Re:5.8

[imp]

No. 5.8GHz won't interfere with your wireless network. 802.11[bg] is at 2.4GHz, and 802.11a is at 5.4GHz.

Re:5.8

[jayhawk88]

Well technically 802.11a runs at 5Ghz; maybe that's close enough to cause interference, I don't know.

But the real question is, considering the speed and price of 802.11g these days, why would you ever choose to run 802.11a?

Re:5.8

[mattkinabrewmindspri]

Have you checked ebay for 802.11a devices recently? You can get a card for $10 and an access point for ~$25.

Re:5.8

[Aaden42]

From: http://www.vocal.com/data_sheets/80211a_fre.html

The 5 GHz U-NII frequency bans is segmented into three 100 MHz bands for operation in the US. The lower band ranges from 5.15 -5.25 GHz, the middle band ranges from 5.25-5.35 GHz and the upper band ranges from 5.725-5.825 GHz.

So odds are a 5.8GHz phone would mess with the upper range of 802.11a.

Re:5.8

[imp]

I have 5.8GHz phones. They don't interfere with 802.11[bg] at all. They don't even interfere with 802.11a because the frequencies there are approx 5.4GHz.

Re:5.8

[stilwebm]

The other question is, will the 5.8 interfere?

I have an AT&T 5840 phone that uses 5.8GHz but if you read the fine print in the specifications, it also uses 2.4GHz:

• RF Frequency Band (Handset to base): 2400 MHz - 2483.5 MHz
• RF Frequency Band (Base to handset): 5725 MHz - 5850 MHz

All 802.11b/g devices use channels within 2412 MHz - 2483.5 MHz, so there is quite a bit of overlap there. When shopping around, I noticed that many 5.8 GHz phones actually use 2.4 GHz as well. In my limited use of 802.11b in the vicinity of this phone, I noticed no interference, but ymmv.

Re:5.8

[Baricom]

I don't mean to troll, but I seem to recall reading something about frequency harmonics. When you're working with radio, don't you also need to consider frequencies that aren't adjacent to the one in question?

Again, if I sound ignorant, it's because I am :)

Re:5.8

[rerunn]

This absolutely true of most 5.8 phones out there. It takes more power to transmit at the higher frequency so in order to preserve battery life and keep the same range they handset actually talks at the 2.4 frequency.

Re:5.8

[Anonymous Coward]

I just bought the Panasonic TGA510 series phones from Newegg. This system communicates at 5.8 both ways (base to set, set to base) unlike the Uniden and V-Tech which communicate at both 2.4 and 5.8. I don't run wireless at my house (cat5), but I don't anticipate any problems if I install .b or .g in the future. Not sure about .a however.

Re:5.8

[rockmanac]

the harmonics are 2x, 3x, 4x, etc of the base frequency.

Ex: 780kHz, 2nd harmonic is 1560 and 2340 is the 3rd.

-A

Re:5.8

[illumin8]

I have an AT&T 5840 phone that uses 5.8GHz but if you read the fine print in the specifications, it also uses 2.4GHz:

I just bought that same phone and was pretty pissed when I read the specifications because it advertises on the box that it won't interfere with wireless networks. Anyway, after using it for a couple of weeks I've had no problems. I get 5 megabits a second down on my Cablevision line (through a Linksys WRT54G) whether I'm using the phone to make a call or not (tested using dslreports.com speed test). My theory is that when they say "Handset to Base" they are talking about the communication that happens when you push numbers and other buttons on the phone, which is only short, bursty, data communication, rather than a continuous stream of voice traffic. This would explain why it doesn't seem to interfere with my wireless network.

Nice phone, by the way. It would be nicer if you could customize or download new ringtones though, and I wish I could sync it via Bluetooth with my Powerbook... (hehe, never thought I'd want that many features in a cordless...)

Re:5.8

[Anomalous Canard]

I have a brand new Uniden 5.8 set and the packaging says clearly that the handsets transmit at 5.8. There's no mention of any other operating frequency on the box or in the manuals. I bought it just last week deliberately so as not to interfere with my 801.11g AP. I have surfed while talking on the phone and there is no evidence of interference at all. I'd be taking this puppy back to the store in no time if it interfered with my WLAN.

Re:5.8

[Glonoinha]

The 802.11A specification provides 12 nonoverlapping channels in the 5.8 GHz frequency range.

Given that, I expect some interference with phones in the 5.8GHz range.

If I had to guess, I would say that the 5.8GHz band is a fairly popular range, simply because it has been opened up for use in unregulated consumer grade devices, hence the plethora of wireless devices jumping to use it (just like the 2.4GHz band.)

Re:5.8

[JWSmythe]

Both harmonics, and how clean the signal is. Microwave ovens don't run at 2.4Ghz (it's 2.6Ghz, I believe), but if they're not "tuned" right, they can jam 802.11b/g equipment.

Where I grew up, our local police and hospital used a trunked radio system. It would frequently override local broadcast TV stations (Channel 49 specifically). It wasn't anything you could listen to, it was noise, but still... They weren't at that frequency, but I believe it was that they were broadcasting a very strong signal, and not a particularly clean signal. This was probably intentional, so slightly out of tune equipment wouldn't find itself out of contact.

It always pissed me off, because it always happened during important parts of the shows I was watching. (I was a kid, TV was important then)

Re:5.8

[Anonymous Coward]

Microwave ovens certainly do operate at 2.4GHz. The one I have at the office quite clearing says so. My $20k HP spectrum analyzer says my one at my house does too.

Re:5.8

[AKnightCowboy]

So odds are a 5.8GHz phone would mess with the upper range of 802.11a.

802.11a is deader than a doornail now that 802.11g is here so it's kind of irrelevent. Get a 5.8GHz phone and just use 802.11g. The only people that would go with 802.11a are the suckers who adopted it too early and are stuck with obsolete hardware.

Re:5.8

[TWX]

"But the real question is, considering the speed and price of 802.11g these days, why would you ever choose to run 802.11a?"

Multiple reasons:

• Less people on it. Channels will be available until the end of time, and even if everyone in your neighbourhood has an access point, you won't have network problems.
• Less interest with wardrivers. While "security through obscurity" isn't the best idea if you're going to pick only one way to secure your systems, if you combine the fact that most people aren't looking for 802.11a networks with the fact that there are tons of open 802.11b and 802.11g networks you won't be looked upon as a potential victim nearly as much. It's not the end of security, but it's a good beginning.
• No protocol issues. 802.11b and 802.11g frequently have issues sharing, where the "g" features dumb down to "b" speeds if anything "b" is talking. This is bad in my opinion.
• Few, if any consumer devices in the 5GHz range. Nothing running in the house on 5GHz means nothing interfering with the network. Since everyone seems to be making 900MHz and 2.4GHz devices, including microwaves, telephones, and other things, using the currently lightly-used 5GHz area makes a lot of sense to me.

I was really sad that 802.11a never really made it to prime time in Linux while it was still commercially viable to manufacturers. I'd have bought into it in a heartbeat.

Re:5.8

[jrockway]

Yup, they're suckers because they're sitting on their couch with 54Mbps of theoretical bandwidth, while you're NOT a sucker because you're sitting on your couch with 54Mbps of theoretical bandwidth.

What's the difference? Sure, you can't go buy a shiny new 802.11a setup, but it works if you have it. It's better than my crappy 802.11b here :)

(Although I have the cheapest AP imaginable [A "NetworkEverywhere" unit that I bought very cheaply a few years ago], I have AMAZING range. It works in every square inch of my house, and even the park across the street (although trees kill reception REALLY fast).

Now I just need to get it to work in the park on the other side of my house... 'cause they have a nice tree-less area to sit down :)

Re:5.8

[jaavaaguru]

I have a Linksys WRT54G WiFi base station and when I used to stay in a flat in Edinburgh, it worked everywhere in the flat (old tenament style with thick walls) and all the way down the street. Now I've moved to a house out of the city, it works all over the house, the garden, and outside the front door. It all depends where you choose to place your base station. I've got mine in the attic.

Re:5.8

[muckdog]

Speaking of microwave ovens. A friend of mine has a 2.4GHz phone from sony and you can't use it while the microwave is on. I still love old Sanyo 900 Mhz phone that 5 years old. I been able to talk on it a 1/4 of a mile away. I came across one of those $0 after rebate phones at Circuit City a few months back. 900Mhz from Northwestern Bell. What a piece of crap it is. It must have cheap cheap components. I am in the market for a newer 5.8 Ghz phone since former owners of my house only had one phone jack and I use 802.11b. One of the new multibase phones is looking much more appealing that running phone cable to each room of the house.

Re:5.8

[imp]

So odds are a 5.8GHz phone would mess with the upper range of 802.11a.

The upper range of the 802.11a is restricted to outdoor use only. Most of the 802.11a with internal antennas don't use those frequencies at all.

I've been using my 5.8GHz phones for some time now, and I've had no interference with my 802.11a network at all. My phone doesn't use 2.4GHz at all.

Re:5.8

[russotto]

You run 802.11a because the 2.4Ghz spectrum is so crowded. Or at least, that's why I run it. There's about 7 802.11b/g networks around my townhouse, not to mention neighbors' cordless phones and microwaves.

802.11a has three bands allocated for it; one is 5.8Ghz, which is overlapped by those 5.8Ghz phones, but the other two are in the 5.2Ghz range.

I have always had one or more of these wireless..

[Anonymous Coward]

I have always had one or more of these wireless phone without ever encountering any problems. I think this is a non story.

Yes, I have

[Lordofohio]

We had to stop using our brand new 2.4Ghz phones at work because our wi-fi stuff wouldn't hold a signal when the phones were in use. Keep in mind this was 2 years ago, haven't tried anything since.

Re:Yes, I have

[n1ywb]

I was browsing at a relative's house recently when the phone rang. The moment someone answered it I lost my 802.11 carrier. As soon as the phone was hung up, it came back. Coincidence? I think not.

Re:Yes, I have

[Anonymous Coward]

My parents quit using *their* 2.4ghz wireless phone (Siemens).. the WiFi stayed up fine, and in fact I only measured a speed drop from maybe 500KBps down to 450KBps or so, with the phone right next to the machine. But you can hear clicks and dropouts on the phone itself no matter where it is in the house. The WiFi acess point is in the basement, with antennas folded down (it's on a cabinet), while the phone base is upstairs.. so reasonably, the phone should work fine and knock out the WiFi when you're upstairs, since it's much closer. But instead, the WiFi screws up the phone. The clicks are pretty infrequent and minor when the wireless network isn't busy, but if someone's web surfing it clicks enough to be annoying. If someone is either spooling a print job, or reading some files off a samba file server I've got going there, or something, forget about it.. you can't understand what the other dude's saying. I think the person at the other end can hear you saying "What? What?" just fine though 8-). They have a Siemens, and I've heard they're infamous for this. They use a 900mhz Southwestern Bell Freedom Phone.. but they had a 900mhz Vtech and it worked great too, until it was dropped into a grease can 8-).

In fact, you can still find the old 49mhz phones sometimes.. They had great range, and I can tell you, since they aren't common any more, the old problem of either hearing someone else's call (the real old analog ones), or having your range drop off because of interference from another user on your channel (if it's digital) isn't much trouble anymore.

900MHz

[Anonymous Coward]

Although I'm not sure how many new ones are available today, my 900MHz cordless has never interfered with my wireless network. In fact, it always seems to get better range than my "better" 2.4GHz phones.

Re:900MHz

[Anonymous Coward]

Same here! My Uniden 900Mhz phone has always had better range than my Motorola 2.4Ghz. By the way I was reading D-Link router reviews on newegg.com and many people were complaining that each time their phone would ring their router would reset. I looked deeper into this and apparently D-Link came out with some firmware upgrades to solve these problems.

Why YES, I have had problems

[johncel]

So, I had a linksys wifi router and an AT&T 2.4 gHz phone... They fought like dogs! If the phone rang, wifi was out for at least 5 mins after you hung up. What a pain. I finally just bought a 5.8 gHz phone.

Re:Why YES, I have had problems

[bldrake]

Same problem. Haven't upgraded my phones yet though. I have Netgear wifi router and various cards in my pc's. Royal pain. Gradually switching to Linux ...

Re:Why YES, I have had problems

[prockcore]

So, I had a linksys wifi router and an AT&T 2.4 gHz phone... They fought like dogs!

I'm willing to bet that the linksys you've got is the first generation BEFW11S4. I had problems with my 2.4ghz phones but when I upgraded to linksys's 802.11g router, all my problems went away.

I'd recommend upgrading because if a 2.4ghz phone causes your router to die, then its likely that your router won't play well with others. If your neighbors get 802.11b/g, your router will die a horrible death.

Re:Why YES, I have had problems

[thegoogler]

hmm, i have 2.4ghz phone and it never compleatly knocks down the network, it just slows to about 5.5mbps(i have 802.11g)the trick is to get an older(about 2001) panasonic phone, my friend got one of these and it never takes his network down either(same one i have)

Re:Why YES, I have had problems

[andreyw]

Uh well the BEFW11S4 has no problems playing with other APs. My neighbors just got an 802.11b network and my BEFW11S4 is just fine, thank you.

Just because the router dies because some *other* non 802.11b device is blaring on the same frequency, doesn't mean it won't cooperate with in-spec devices.... Duh!

Re:Why YES, I have had problems

[mindriot]

Hmm weird... here in Germany (all of Europe, in fact), most wireless phones operate using the DECT standard at 1.9 GHz. At least those don't interfere with any Wi-Fi equipment (afaik)... how come your phones are using a different standard at 2.4/5.8 and not DECT? What type of standard is used on your phones? Some googling indicates that it seems to be called DCTS. What are its advantages? How come DCTS and 802.11 are allowed to operate and interfere in the same frequency range? Can someone shed some light on this please?

Re:Why YES, I have had problems

[NeuralAbyss]

2.4GHz is an unlicensed band, and as such, any devices are permitted to use it, provided they stay within any power regulations. For example, over here in Australia, 36dBI EIRP is the limit for unlicensed transmission in the 2.4GHz band. Phones were the first users, IIRC, but 802.11b started to use the band as well.

Re:Why YES, I have had problems

[jrockway]

What you really need is a pringles can. Then you can be multi-homed :)

Re:Why YES, I have had problems

[Igmuth]

Well, the reason people in the US don't use the DECT standard is that it is a standard by ETSI.

Re:Why YES, I have had problems

[jht]

Interestingly, many of the 5.8 GHz phones (like the one I use at home, it's an AT&T) actually only receive from the base station at 5.8 GHz. In order to save on their power budget, they transmit back in the good old 2.4 GHz band.

Though they do play much nicer with 802.11x than older generation stuff did.

In general, I've seen that newer phones coexist nicely, and also 802.11g devices seem to be less interference-prone than 802.11b. Also, 900MHz phones play pretty nicely because they aren't even in the same neighborhood.

Re:Why YES, I have had problems

[Mhtsos]

This has to be 802.11 friendly.

Re:Why YES, I have had problems

[mpe]

here in Germany (all of Europe, in fact), most wireless phones operate using the DECT standard at 1.9 GHz. At least those don't interfere with any Wi-Fi equipment (afaik)... how come your phones are using a different standard at 2.4/5.8 and not DECT?

Probably a case of Not Invented Here syndrome. Which is so notorious with North American telecoms that the manufacturers of telephone switching systems even divide their product lines into "NANP" and "rest of the planet"...

It doesn't interfere, silly

[Anonymous Coward]

It interoperates. If it finds an open port on your wifi network, it will handover and use VoIP to complete the call.

This saves you money in the long run because VoIP is much cheaper cost-wise than typical cell service.

The main thing is to make sure that the phone is SAR-approved. You don't want those microwaves heating up your neural tissue! :-)

Re:It doesn't interfere, silly

[Anonymous Coward]

Heh, my bad.

I thought this was in a technologically advanced country and we were talking about 3G service.

Re:It doesn't interfere, silly

[Anonymous Coward]

Ridiculous. Mod parent down.

Re:It doesn't interfere, silly

[jayhawk88]

Thank you, BOFH.

Re:It doesn't interfere, silly

[screwedcork]

Are the mods here this stupid? He's joking around!

Phones

[JelloG3]

I have had interferance with a phone to phone, but i have two wireless phones in my house, a cell phone, plus an airport wireless network, and have not had any problems between the phones and the connection of any devices to the wireless hub

Re:Phones

[JWSmythe]

That's odd, but expectable.

In the colo that I frequent, there are probably a dozen cordless phones. All of the ones I have looked at are 2.4Ghz. There are also no less than 3 802.11b/g access points, and everyone carries a cell phone. It's a location that absolutely *should* have too much 2.4Ghz interference.

The only problem I have with phones in the colo is the noise from the fans and air conditioners. It makes it hard to hear. :)

Cell phones don't work very well in the colo, but it seems to be a fringe area, probably because of the nearby skyscrapers (downtown LA), local broadcast equipment, and the colo is about 30 feet underground. Cells don't work very well at ground level either.

Are they nuts?!

[Pan T. Hose]

24GHz?! Who the hell would need such a fast phone is beyond me! I have a 500MHz AMD in my desktop (Debian) and it works just fine, thank you.

Re:Are they nuts?!

[SkaterGeek]

Oh, please tell me your kidding, Do you not realize that this is a joke?

Re:Are they nuts?!

[maskedbishounen]

Finally, I can play Doom 3 on my phone! ;P

Re:Are they nuts?!

[Anonymous Coward]

Yeah, it is really amazing the way the telecommunications industry has surpassed the computer industry in recent years. While 24 GHz phones are out on the street today (it was only a few years ago I bought a brand new cordless with a 900 MHz processor!), you probably won't be able to get an AMD or Intel system that fast for at least 8 to 10 years. The fact is, the telecom giants just have a lot more money to spend on R&D that leads to the rapid progress we have seen.

If you think this system is out of whack, we ive in a democratic system, so write your Senators and Congressmen and tell them what you think. The sooner the DCMA is abolished and John Ashcroft is out of the White House, the sooner open source will be able to start competing on a free and open market.

Best way to fix the problem...

[xneubien]

I have found that the best way to fix the problem with my 2.4ghz digital s.s. phone and my Airport Extreme is to use a corded phone. And to also use the oven instead of the microwave. I gotta get me one of those "802.11 friendly" phones

Re:Best way to fix the problem...

[len_harms]

I found the best way was to get a 900mhz phone. I have yet to find a 'decent' 2.4ghz phone. There is just too much stuff fighting for that space. Plus since 900mhz is 'old stuff' you can get em fairly cheap.

Re:Best way to fix the problem...

[bhtooefr]

Here's an 802.11 friendly phone.

It's free for the phone itself, and it can even be cheaper to get one of those over a "802.11 friendly" 2.4GHz cordless phone plus local+long distance phone service if you don't have dial-up, DSL, TiVo, or DirectTV. And, it's (IIRC) 1.9GHz, so you're safe there.

Hmmm

[SonicBV]

I've never had a problem with 2.4GHz phones and Wi-Fi. I guess that's like saying your stapler won't interfere with the operation of your TV.

Re:Hmmm

[Dachannien]

That depends on where you throw the stapler.

Re:Hmmm

[JWSmythe]

Staplers don't bother my TV much, but my coworkers duck frequently. :)

Interference

[L3on]

I had a 2.4ghz phone that I got about a year ago and it does interfere with my wireless connection. I tried setting the channel of the phone all the way t the highest end of the setting and the basestation all the way down and it helped some. Eventually I got a new 5.8ghz system and it's been alot better, no interference noticable.

v-tech

[Anonymous Coward]

I recently bought a pair of 2.4GHz V-Tech phones ($69 for 2) that had a "Wi-Fi Friendly" sticker on it. I use my 802.11 constantly at home (in fact, my whole Internet connection is 802.11b) and I'm yet to have either of them interfere with the other. I'm also posting this wirelessly on the same network.

WiSIP Phone

[Anonymous Coward]

Have you looked at VOIP handsets like this?

Not a myth.

[genixia]

My inlaws' 2.4GHz 'phone (sorry, can't recall the brand) totally screwed up their Linksys WLAN until I changed the WLAN channel (now it degrades link quality but doesn't drop it).

OTOH, My Panasonic 2.4GHz 'phone has never interfered with my Netgear WLAN.

I suspect that the 'phone brand has more of an effect than the WLAN brand.

Re:Not a myth.

[peculiarmethod]

wish i could change the channel and get the airplanes flying overhead to stop knocking my wi-fi network offline.. sheesh.. who decided to move directly under the flight path, anyhow?? oh. yeah. me.

pm

Re:Not a myth.

[jrockway]

I think that the flight path will change if you start pointing this high energy RF gun at the planes overhead. At least they'll fall out of the sky or something.

Has anyone tested this? Reply if you have!!

Re:Not a myth.

[Stinking Pig]

I agree, though I've had different experiences. I just canned a 2.4GHz phone branded by Virgin (hey, it was the cheapest piece of junk at Target with a headset jack and a mute button). This phone had significant trouble communicating with its base station in a room with two WAPs (one D-Link, one NetGear).

The replacement phone is also 2.4Ghz, but it's a Uniden (a brand I've had good luck with in the past). No interference observed to date in either direction.

To finish off my sad story of cordless phones, I've also owned a few Panasonics (generally crap) and Sonys (okay, but the batteries die very quickly).

Vtech

[jcostantino]

We just bought a Vtech 2.4ghz phone system - two handsets, one base w/ answering machine and a base with a charger. The system said "2.4ghz Friendly" and it replaced a Vtech 2.4ghz phone bought earlier in the year (and subsequently killed during a storm) which would knock the 802.11 offline unless I set my AP to channel 6.

I haven't bothered to change the AP to a different channel but so far it's working fine.

Worthy of mention is that the new handsets come with speakerphone and use three NiMH AAA cells instead of a shrinkwrapped battery with a lead. Plus they sound great and I don't have the problem I used to have on the older phone where the microphone was too sensitive and I heard background noise at too high a level in the earpiece.

Re:Vtech

[Anonymous Coward]

We just bought a Vtech 2.4ghz phone system - two handsets

The $40 deal from Sam's Club. My wife just bought this yesterday-what a coincidence! I have an 802.11b Iblitzz router (and that's why I'm posting anonymous the shame :) and with the older cordless vtech we had it sounded staticy but with the new ones, you can barely hear any static. It's still there but very minor. So I would say, yes it's way more "wifi friendly" than their predecesor. Parent forgot to mention also the Intercom feature where you can call one phone to the other or even transfer a call to the other headset! A great value indeed.

Re:Vtech

[LuxFX]

I've got a VTech 5.8 Ghz phone system -- also two handsets (the system supports up to six) and one base (w/o answering machine). It rocks. My VTech 2.4 Ghz phone had problems going through aluminum siding, but the 5.8 Ghz phone has tremendous range, through all of the trouble-spots I had before. And if you're using 5.8 Ghz, you know you're not going to hurt your 802.11? connection.

Re:Vtech

[swatoa]

Yes - changing the channel on my d-link solved the problem, completely. Before, I would get frequent interruptions in connection - every few hours, my connection would go through a routine of connecting and disconnecting, as if it was confused about something. It would repeat this periodic behavior up to 10 times, which was a pain in the ass.

E-mailed d-link customer service (which I find surprisingly knowledgeable/helpful) and they suggested changing channel.

So yes, 2.4GHz phones mess wireless LAN up.

My microwave

[geek]

Kills my wifi. My 2.4ghz phone does not however. Kinda strange.

Re:My microwave

[khrtt]

kills my WiFi...

I'd get an RF meter and check the shielding on the microwave with it. Don't want it to heat *me* when I'm sitting there hungry, watching my yestarday's pizza warm up.

Re:My microwave

[John Miles]

Household microwave ovens spew a lot of 2.4 GHz energy all over the band (enough that after looking at it on a spectrum analyzer, I no longer feel like pressing my face up to the window to see if the cheese on my pizza has melted yet).

However, they radiate only on alterating half-cycles of the 60 Hz line frequency. There may be a config option in your WLAN hardware's client utility to make it more resistant to microwave-oven leakage by forcing transmission of smaller packets. You'll lose some performance if you enable it, but it should keep your WLAN from going down altogether.

Re:My microwave

[Anonymous Coward]

Thats cuz you are supposed to take your router out of the microwave before use!

Re:My microwave

[urlgrey]

For the longest time my gf thought I was crazy for saying the microwave caused issues with the cordless phone (a 2.4GHz).

After being laughed at repeatedly for fleeing the scene anytime I started the microwave while I was speaking with anyone on the cordless, through extensive trial and error, I've succeeded in proving conclusively (well, at least in our case) that the safe range to have both the cordless and the microwave running is something greater than about three meters.

Anything less than three meters and the phone has a clear "POP!" every couple of seconds, and unlike some types of phone interference that can only be heard by one party, both parties can CLEARLY hear the 'POP'. Grrrr.

No more skull-to-the-microwave-window pressing for me either.

Re:My microwave

[Smurf]

No more skull-to-the-microwave-window pressing for me either.

Uhh... but you DO press your skull against the phone handset, which allegedly transmits a stronger signal (at least at that frequency)...

May I recommend a tin foil hat? ;)

Re:My microwave

[j1m 5n0w]

Interesting - that gives a window of about 8.3 milliseconds. (1/120th of a second, if I understand you correctly.) A full size packet takes about a millisecond to transmit at 11mbps, plus a few hundred microseconds for the ack. That should be well within the window.

Unfortunately, after repeatedly losing packets, most 802.11 gear will probably drop the transmission rate to its slowest rate: 1mbps. 1500*8 bits at 1 mbps is about 12 milliseconds (plus a few hundred microseconds for the header), which no longer fits in the window. In other words, by falling back on a more reliable transmission mechanism, 802.11 shoots itself in the foot.

Maybe if you can pin the rate at 11mbps and enable short headers (an option in the 802.11b standard supported by some hardware) it could work reasonably well, but fragmenting packets should help as well.

-jim

Re:My microwave

[MrBlue VT]

Who cares? It's not like the microwaves harm you. The only reason they can heat the food is because the metal interior sets up standing waves that amplify the signal at the wave's interference points. You can't be harmed by any microwaves that escape the oven.

Re:My microwave

[Detritus]

Your post is completely wrong and dangerous.

You don't need standing waves to couple energy from the magnetron to the food. High-power microwave devices are dangerous if not properly designed and operated. If you don't believe me, try standing in front of a high-power search radar.

Re:My microwave

[Anonymous Coward]

Surprisingly, not so much. The microwave leakage's about 20 dB (= 100X) stronger. About 1-2 watts in the near field, I imagine.

Re:My microwave

[eingram]

Whoa, cowboy. Put that metal grating back on your microwave and quit using it to mod your new G5.

Re:My microwave

[lachlan76]

That's because microwaves put out the best part of a kilowatt of RF, and Wi-Fi output is measured in millwatts. I know the microwave whould be shielded, but you MIGHT want to test it for leaks.

Re:My microwave

[jrockway]

And the danger is that it burns your eyes out. You'll notice if your arm is burning off, but your retinas don't tend to notice that they're being burned. No pain receptors there... So please be careful, at least keep your eyes out of the microwave beam.

Re:My microwave

[urlgrey]

Yep. Scareeeey stuff.

And that, my friend, is exactly why I always wear a headset.. ;-)

Besides, I've never been one for tin-foil hats--makes it too hard to shampoo.

Re:My microwave

[JWSmythe]

And what happens when you strip out the emitter from your microwave oven, and mount it on your outdated satellite dish (like a 15' dish)? You can knock out WiFi for miles. hehe

I always wondered if this could be used as a DDoS attack against satellites. With enough people blasting enough noise at a particular satellite, would it block the legitimate traffic?

Re:My microwave

[lachlan76]

IIRC, sattelites use 10GHz+ radio links, so this wouldn't work very well.

Re:My microwave

[JWSmythe]

Time to retune those microwave oven emitters. :)

Re:My microwave

[Anonymous Coward]

Microwave exposure leads to premature glacoma.

Re:My microwave

[Anonymous Coward]

and 6Ghz....
Does anybody have a list of uplink SATCOM freqs?

As far as frying the bird, you have to remember that they do the same thing up there that you do down here. They focus on a very small point on the surface, both to get the proper gain and for selectivity. If you mounted your uplink very near to an established ground station, that would probably mess things up, but then, somebody might notice your dish setting there as well.....

2.4 GHz phones == bad idea

[Anonymous Coward]

I've gone back to the older 900 MHz phones since installing a WiFi network at home. The WLAN didn't interfere with the 2.4 GHz cordless phones we had, but the phones knock the network down hard. I haven't heard anything about "802.11 friendly" labels on newer 2.4 GHz phones, but I'd be skeptical. If they work at all, they work by adaptively locating an empty part of the 2.4 GHz spectrum, and around many crowded residental areas, there ain't no such thing no mo'.

You can also get 5 GHz phones, too. Either 900 MHz or 5 GHz is fine, just keep 'em off 2.4 GHz.

Re:2.4 GHz phones == bad idea

[bigbigbison]

I agree. I've never had a bit of problem with my 900 MHz phones. I suspect the only reason they came out with 2.4 GHz phones is to get customers to use the "2.4 gig is bigger than 900 meg, so it must be better!" line of reasoning.

Re:2.4 GHz phones == bad idea

[bhtooefr]

Isn't sound quality better on the 2.4s, but range much shorter?

(greater bandwidth, but shorter signal distance at higher frequency, right?)

Re:2.4 GHz phones == bad idea

[Clueless Moron]

Isn't sound quality better on the 2.4s, but range much shorter?

Sound quality has nothing to do with the carrier frequency used. Consider broadcast FM; it's at around 100 MHz, or 0.1 GHz, yet I'm sure you'd admit it sounds quite a bit better than your cordless phone does.

You are correct that higher bandwidth == higher fidelity, but my point is that bandwidth is independent of the band you choose to use, as long as the bandwidth is available on that band. And it is on both 900 MHz and 2.4 GHz.

There isn't any significant inherent difference in range either (note, lurkers, I said significant), but 2.4 GHz phones tend to be lossier than 900 MHz phones. That is, their power output tends to be lower and their receive sensitive not as good for stuff designed for the same money.

So, yeah, 900 MHz phones are pretty good. The older 49 MHz phones are sucky in that the inherent wavelength is over 6 meters, and so their antennas are notoriously inefficient. At 900 MHz, the wavelength is just 30cm, making it really easy to build efficient omnidirectional antennas, and 2.4GHz doesn't really have much of an advantage there.

Re:2.4 GHz phones == bad idea

[Anonymous Coward]

It is really difficult to find non-analog 900 MHz phones these days. Even harder to get DSS ones. Marketing-driven manufacturering can be annoying when the market drives products being sold without significant tangible benefits overs their predecessors. Does a 2.4 or 5 GHz phone really offer more than a 900MHz DSS one?

Re:2.4 GHz phones == bad idea

[Anonymous Coward]

Sound quality is fine on current generation 900MHz digital spread spectrum phones. Don't confuse them with earlier analog phones.

Bandwidth is a function of the width of the band, not the carrier frequency. Thus the name.

Wider bands are available at higher carrier frequencies because of regulatory issues, mostly because higher frequency technology used to cost more, so there was less competition to use those frequencies. But there is no reason that a higher carrier frequency might not use a narrower band, and thus have less bandwidth. Another example is that all NTSC TV channels use exactly the same bandwidth, no matter what the carrier frequency.

Re:2.4 GHz phones == bad idea

[jrockway]

3 words (that will increase the range of your 2.4GHz phone): pringles can waveguide

^_^

Re:2.4 GHz phones == bad idea

[bhtooefr]

Ahh... that's where I got that idea. Thanks...

Re:2.4 GHz phones == bad idea

[nmos]

There isn't any significant inherent difference in range either (note, lurkers, I said significant), but 2.4 GHz phones tend to be lossier than 900 MHz phones. That is, their power output tends to be lower and their receive sensitive not as good for stuff designed for the same money.

While it's true that the range should be similar in an open field, 900MHz tends to go through obsticles better.

My Experience

[dborod]

I had a 2.4 GHz phone that I really like, unfortunately, I also really like my 802.11g base station. They didn't get along and I replaced my phone with an 800 MHz model.

2.4ghz phones not good

[p0z3r]

I set up a lan at my Parents house using some off the shelf Linksys router. For a while my brother's computer would lose connectivity and we could never figure it out. Then just by chance my Parents had their 2.4ghz phone upstairs from their office and when it rang in and they picked up the call, all our wireless computers lost connectivity. It may just be that router that was manufactured, but I'd still watch out for this when planning on implementing your own wifi network.

Wireless phones?

[Anonymous Coward]

I still don't have a wireless phone. When the power goes out for the eastern side of north america I prefer to be able to still reach people. Cell phones and wireless phones just can't do that.

Re:Wireless phones?

[Anonymous Coward]

When the power goes out for the eastern side of north america I prefer to be able to still reach people.

Then you'd better get into ham radio, or something. Wired phone or not, you can't count on Ma Bell when the shit hits the fan.

Personally, I run my cordless phone on a UPS, so it continues to work fine for an hour or so after the power goes out.

Re:Wireless phones?

[WhatAmIDoingHere]

Cell towers usually have backup power sources. Such as generators. I know that when the power went out in my town I could still use my cell.

Re:Wireless phones?

[reiggin]

I don't know about you, but I have more than one phone outlet in my house. So I keep both. :-/

Re:Wireless phones?

[stilwebm]

When the power goes out for the eastern side of north america I prefer to be able to still reach people. Cell phones and wireless phones just can't do that.

I have a wireless phone with a base that contains a charging bay for a second handset battery. If this battery is fully charged and power is lost, the battery will allow phone calls to continue for up to 2.5 hours of talk time. On a recent sunny afternoon a construction accident (remember, call before you dig!) killed the power while I was on the phone on my balcony. I never noticed until I saw all of my appliances with clocks needed reset. I also have a wired phone just in case.

Important stats to remember: the North American wired telephone network has uptime of 99.999%. Cellular telephone networks have uptime averages of 98%. Also, most cells can only support a maximum of 32 calls (depends on the technology). Exceed that and expect dropped calls, no service errors, or "all circuits are busy" errors. If the power fails over your entire cell, expect others on your network to be relying on their cell phone too. If the power outage is extended, expect the backup power source for the cell towers to fail. Central offices for land lines are not as wide-spread and thus it's easier to deliver additional fuel for backup generators.

Problems with wi-fi cards and cordless phones

[darin3200]

Has anyone really ever had a problem with these types of phones interfering with their wi-fi network?"
I've never actually tried these phones. My 2.4 ghz phone right now is terrible though. If someone calls me and my phone is within 10-15 feet of my laptop it will just kill the wi-fi signal (no very good when you have 695mb of a 700mb linux iso). I would like to see how these phones would work, they could possibly operate on a very high 2.4ghz frequency but I still question how effective this would be. Here is a good little article
on the issue.

Re:Problems with wi-fi cards and cordless phones

[everett]

A very high 2.4ghz frequency? Reminds me of that thinkgeek shirt 2+2=5 for extremely large values of 2.

Re:Problems with wi-fi cards and cordless phones

[jrockway]

Just use wget to download stuff, then you can continue when your wifi dies...

wget http://example.com/file.iso

*net connection dies*

wget --continue http://example.com/file.iso

By the way

[jcostantino]

Link to the phone:

http://www.vtechphones.com/vtechui/shop/productdet ail.cfm?itemID=1299

Wireless phones and wifi

[Anonymous Coward]

I work on wifi systems all day long, at multiple customers houses. I have seen 2.4 phones cause interference with their wifi, but I usually just change the channel on the router and its fixed

Re:I have always had one or more of these wireless

[Gonarat]

I agree. In fact, I am able to use 802.11b at my sister-in-laws at the same time she is on the phone. The phone is a fairly new 2.4 GHz cordless -- so perhaps that is why it works. BTW I am on channel 6 on the wireless -- not sure of the exact frequency of the phone.

Uniden

[pluggo]

I've got a dual-handset 2.4ghz Uniden cordless phone and a Netgear 802.11b Cable/DSL router... they seem to work fine together, but I haven't tested it very extensively yet.

WiFi and 2.4GHz Don't Mix

[pbwiz]

WiFi (802.11b) and 2.4GHz Phones almost always will clash -- but there is a good article on wifi planet that gives some things that can be done to lessen interference.
http://www.wi-fiplanet.com/tutorials/article.php/2 191241/
Of course, the best solution is a 900MHz or 5.8GHz Cordless Phone.

Re:WiFi and 2.4GHz Don't Mix

[Anonymous Coward]

I can't get that site to return the entire page, which is odd. Here's the Google cache of the article.

Re:WiFi and 2.4GHz Don't Mix

[spinkham]

As you may note from the article you point out, there are a number of DSSS 2.4 GHz phones coming out, that don't interfere like FHSS phones do...

Re:WiFi and 2.4GHz Don't Mix

[Stinking Pig]

great article all right, three blinky ads and a big blank spot.

Interestingly enough, the URL you gave is the same as the URL I found from Google, but the link is FUBARed when going through Slashdot. It's probably all Taco's fault.

Here's a Google link, click the first article titled "Interference from Cordless Phones."

No problems in my house

[DesertJester]

I have used my 2.4ghz phone while on my 54g wireless net with no issues. In fact my microwave messes-up my phone more than it does my wireless. I have two Linksys AP's running on a mostly wired net. They give me great coverage, sometimes too good... damn nieghobr with NetStumbler..oh well.

Re:No problems in my house

[jwcorder]

Not to nig your post here, but there is no way he cracked YOUR WAP with NetStumbler unless he just left it for about 2 months.

The way NetStumbler works is that it looks for "special" packets that have weak keys. Once it gets enough of these (a million is a good number) it can crack your WEP. The only problem with this is that the average home with one or two wireless connections would have to send constant data for months and months before there would be enough packets sniffed to crack it.

A business would do it in a week probably if they had say 25-50 wireless users, but 1-3 wireless connections wouldn't be enough data to even bother sniffing out.

Not like I know ANYTHING about doing this kind of stuff though....

Re:No problems in my house

[DesertJester]

I'm not saying that he has cracked it, but he does tell me that he picks up my signal when he is in his back yard. One of my AP's is near the back of ym house.

Re:No problems in my house

[Graemee]

Turn off SSID AND encrypt.

Re:No problems in my house

[Anonymous Coward]

I pick up gobs of wifi's when I just walk around the neighbourhood with my Zaurus SL6000.

But most of them are using WEP. The Zaurus tells me that they're there, but they're of absolutely no use to me unless I were to spend a few months collecting enough data to break into them.

Fortunately, about 20% are open. I don't know if it's because of ignorance or benevolence, but it's nice having them around.

Re:No problems in my house

[mcknation]

Last time I checked NetStumbler itself certainly didn't do any WEP cracking. It will give you a whole bunch of info about the WAP. However collecting packets and cracking the "weak" packets was not something it was designed to do.

-/McK

Re:No problems in my house

[Trukster]

You are thinking of Airsnort. Netstumbler is wardriving software that does nothing but log access points it detects, and Airsnort is the wep cracking software.

And for what it's worth, Airsnort has the ability to save its place so you can stop and restart at a later point, so it doesn't have to be a continuous month long cracking session, and if it's a neighbor I don't doubt that they could leave it running in the background enough to crack a wep key. It's in his house, so it's not like anyone is going to notice a van sitting in front of their house all the time.

Re:No problems in my house

[Anonymous Coward]

Mod parent up, he's right, and the other is wrong

Wifi problems

[isaac338]

I have a Panasonic 2.4GHz phone which I hardly ever use anymore, because everytime the thing even so much as rings it knocks every wifi computer off the network. Sometimes you can change channels on the phone and it'll fix it until you hang up, but that's not really a good solution because you still get knocked off for the few seconds it takes you to change channels on the phone.

Definitely problematic.

[Kufat]

My uncle had both a wifi setup and 2.4ghz phones; when the phones were used, the signal strength decreased sharply. So he gave me the phones, and then they interfered with my network, even when I changed the channel that they were operating on. (This reduced the interference but didn't eliminate it.) It looks like computers will win 2.4ghz and 5.8ghz phones will become more popular.
The microwave problem is also a common one and one which I've experienced firsthand.

Uniden 8865

[Anonymous Coward]

Buy a Uniden 8865 (-2). 5.8 Ghz, meaning no WiFi <--> phone interaction.

Works _great_ with Vonage (which is why you want the 8865; no answering machine, so the message indicator lights work off the Vonage voicemail waiting signal).

Works like a charm through old plaster and metal wire walls.

Re:Uniden 8865

[WhatAmIDoingHere]

I don't think you really understood the question. When I first installed my wireless network, the battery life of our 2.4ghz cordless phones was about 15 minutes. I went out and bought some 5.8ghz phones, and they work great with no problems. I think he's looking for phones that can co-exist with a wireless network without each other causing problems.

I get interference

[BrianWCarver]

Yes,

My D-Link 614+ wireless router has a heck of a time communicating with my wife's iBook whenever we use the 2.4GHz wireless phone.

I've read suggestions that the intereference will lessen if you set the wireless router to Channel 11, but we've tried that and only seen small to no improvement.

My plan is to buy a 5.8 GHz phone, which is widely reported to clear this up.

Re:I get interference

[joel8x]

I've had the interference problem with a Linksys 802.11B router and now an Airport Express with a Seimens phone and an AT&T phone (both 2.4GHz).

When I change the routers to channel 11, I get no problem whatsover. I guess you just need to find the right combination of gear.

Re:I get interference

[Cyberop5]

I've tried a few 5.8ghz phones. They have horrible range and still pollute 802.11a. The quality is better, but not being able to leave the room with the base antenna doesn't really help.

Just stick to 900mhz for the best range and wireless reliability.

Re:I get interference

[jcostantino]

What do you consider range? My 2.4ghz phone (see my post above) can get about 120' away from the base and still have somewhat decent signal (somewhat being I have to orient myself towards the antenna for it to be usable).

Re:I get interference

[japhering]

Typically if you set you AP to channel 11 and buy a phone with a "change channel" you can work with a 2.4GHz network. I end up changing channels on my phone 1 or 2 times per day.

At most, you lose a few packets while changing the channel

Re:I get interference

[CaptBubba]

Honestly, it may not be all the phone's fault, it could be the D-Link. If one of your friends has a Linksys WAP, or some other brand higher up than D-Link, you may want to try it out and see if the problem doesn't improve.

In my experience, D-Link's APs seem to be easily confused. In situations where a Linksys, Cisco, or Vivato WAP will keep on going, the D-Link will just drop the connection. This could be some sort of old firmware issue though, and is honestly an unfair comparison (at least with the Cisco and the Vivato).

Re:I get interference

[numark]

Likewise with the Airport card in my iBook, a Linksys router, and a Vtech phone. I kept getting low bandwidth and outright disconnections until I switched the channel to 11. From then on it's worked perfectly.

Re:I get interference

[Cyberop5]

My suggestion, if you have the money to spend, is an engenius. We use a pair at work and aside from a flakey power system they get great reception and distance. Analog I believe. We get through 5 stories of concrete building plus the perimeter and into the neighboring buildings.

We tried most consumer products before purchasing these and nothing came close to the performance of these. The 5.8 ghz phones, from panasonic, could hardly get reception down the hall. All of the 2.4 ghz phones we tried couldn't reach another story. The 2.4 ghz I use at home can't reach to the other end of the house while our 900mhz (digital) can penetrate the house and surrounding acreage.

Finally, I can tell when my father uses our 2.4 ghz phone when I'm on the perimeter of the linksys 802.11b/g border. Depending on what my signal strength is, it'll drop or weaken.

Re:I get interference

[lordDallan]

I followed the engenius link, was reading about the product, and started to get really excited... Then I noticed that the engenius has been discontinued, and the only phones they had available were the same crap available at office slax or wurst buy. Too bad.

Adaptive 2.4ghz is probably why

[rtilghman]

I haven't looked into it too much, but from what I understand newer 2.4ghz phones use an adaptive frequency response to get around interference from other devices. In essence they detect other devices on "locked" channels and maneuver their way through the mine field without causing any real problems for everyone else.

As for actual signal strength, the phones aren't usually the problem. 2.4ghz phones have 2.4ghz transmitters in the base station, but the phone itself is often just 900mhz. That being the case positioning the phones base unit away from any WIFI equipment can help, the same way positioning WIFI gear away from a microwave does.

You can probably just find more about the newer adaptive 2.4ghz stuff by doing a search with google...

-rt

Absolutely!

[md17]

A while back every time someone at my house used the cordless phone, my 802.11b network would get hosed. I ended up finding a channel which doesn't get hosed as badly, but there is still packet loss.

why 0.9Ghz is better

[infonick]

900Mhz phones:

1) are inexpensive;
2) do no interfere with the 5Ghz and 2.4Ghz wifi channles;
3) do no interfere with Bluetooth;
4) are inexpensive;
5) will get better range because of the lower frequency used.

Re:why 0.9Ghz is better

[CMRichar]

i think you forgot:

6)are inexpensive.

Re:why 0.9Ghz is better

[jwcorder]

"5) will get better range because of the lower frequency used."

Sorry but not true. If this statement where true, companies would stick to 900mhz. T0he 2.4 and 5 Ghz offer more range that's the whole point of upgrading. That's also why when you walk away from the base of your 2.4 Ghz phone and reach it's transmission limit, you can still hear the person on the other end long after they can no longer hear you. From the base to the phone is 2.4, from the phone to the base is 900. 900 has a shorter range.

Re:why 0.9Ghz is better

[iantri]

Christ, does the difference really matter? I can carry a 900mhz phone all around my property and it is an acre of land!

Re:why 0.9Ghz is better

[psyconaut]

Sorry, but I don't think you know too much about RF. All things equal (same effective power output, same obstacles), low frequencies travel further.

This is part of the reason why low frequency radio has such a reach (well, that and it can be bounced off the ionosphere whereas higher frequencies often break-through).

-psy

Re:why 0.9Ghz is better

[disappear]

But 900Mhz phones:

1> Don't support caller ID call waiting
2> Rarely have caller ID displays at all
3> Aren't widely available with multi-handset base stations
4> Don't have useful phone book modes

Which is what stopped me from downgrading to 900mhz and made me upgrade to 5.8ghz instead.

Re:why 0.9Ghz is better

[shadypalm88]

Actually, one of the few times I've watched TechTV, they had an explanation of why 900MHz phones can get better range. It's the same reason why if you hear music playing in another room, you usually hear the beat. The lower-frequency sound has an easier time making it through the walls. Likewise, 900MHz phones can have an easier time getting through walls than 2.4GHz or 5GHz.

Re:why 0.9Ghz is better

[Anonymous Coward]

"5) will get better range because of the lower frequency used."

"Sorry but not true."

It may be that range out in a wide open space MAY be larger for some 2.4 GHz phones, but 900MHz DOES penetrate walls and non-metallic obstacles MUCH better than 2.4 GHz which DOES increase the useful indoor quality and range vs. 2.4GHz.

For myself, my 2.4 GHz phone I used before I got rid of it because it interfered with 802.11 had about the same range my current 900MHz phone has.

Re:why 0.9Ghz is better

[tlacicer]

yes they do, I have one, panasonic makes it. It has everything except the multi-handset feature.

Re:why 0.9Ghz is better

[jwcorder]

I don't know much about RF, but I know alot about cordless phones. Considering I worked at Circuit City selling them for a living for 4 years in college. If they don't have a further reach and are more apt to noise then why would companies sell them?

Secondly, if you don't believe my little test, ask your mom to use the phone and then have your girlfriend (the real one) call you. Then walk away from the base. Somewhere in the middle of the freeway near your house, you will still be able to hear her and she won't be able to hear you. Now get out of the road.....

Now if the base transmits at 2.4 and the phone at 900...which has a better range??? Hummmm....looks like 2.4.

Re:why 0.9Ghz is better

[zbuffered]

I'll be happy when I can take my cordless phone several miles from the base station via wireless repeating, and act as a wireless repeater for other phones.

Re:why 0.9Ghz is better

[Anonymous Coward]

"Considering I worked at Circuit City selling them for a living for 4 years"

Thanks for the warning I will be sure to not beleive anything you say then.
Seriously saying you sell/sold something simply tells me that you don't have the knowledge/ experience to work on them . The best computer software and training salesmen I know (my Father and Step-mother) are completely clueless in physics and computer use/ operation. and to give you an idea of my father's level he was teh sr salesman for the 2nd largest software company in the world at the time litterally selling contracts ion the hundreds of millions of dollars, still can't install his own OS or reconnect his computer when his router goes down.

Re:why 0.9Ghz is better

[andreyw]

And all of this is a consequence of using .9GHz instead of 2.4Ghz or 5.8Ghz as the signal carrier?

*sigh* Dumbass!

Re:why 0.9Ghz is better

[bromodrosis]

Mine has caller id that works fine. It also has a phone list of the last 10 calls that is very useful as a 'phonebook'. However, most of the people I call, I know their numbers already.

Re:why 0.9Ghz is better

[Anonymous Coward]

Free space loss for radio transmissions (in dB):
L(f,d)=20.log(f*d)+92.5
(got it from http://www.geocities.com/senol_gulgonul/linkbudget /formula.html, which is a list of formulas for calculating link budgets for satellite communications, but it's the same physics as for a cordless phone...)

f is frequency, d is distance.

So obviously L(2.4GHz,d) > L(0.9GHz,d). Meaning lower frequency leads to less loss (further reach).

Re:why 0.9Ghz is better

[Smitty825]

My personal experience with phones suggests that 900MHz is better because it tends to travel through walls better, thus making it appear like it works further away. If you only used your phone outside, or in a large empty warehouse, then you'll likely find that the 2.4GHz phones work equally well.

(IIRC, a few years ago, 2.4GHz phones were allowed to operate with more power, thus making those phones appear to work better...however, (again IIRC), the FCC up'd the max. allowable power of the 900MHz phones a few years ago)

Re:why 0.9Ghz is better

[shess]

Repeat after me: At the same power level. At the same power level. At the same power level.

All of you guys wearing your Big Brains on the outside: would you expect a base station plugged into an essentially infinite source of power to transmit with more or less power than a handset probably carrying 3 A or AA cells?

And, beyond that, what's the likelihood that the FCC has authorized 2.4Ghz and 900Mhz operations at the exact same power levels?

Re:why 0.9Ghz is better

[Anonymous Coward]

Considering I worked at Circuit City selling them for a living for 4 years in college.

a)you're admiting this on /. ?
b)I think that proves that you don't know what you're talking about, not the other way around.

Re:why 0.9Ghz is better

[lpp]

Remember, he said "all things being equal"...

Hmm... base, plugged into wall outlet, plenty of power... handset, running on battery, probably using less energy for transmission in order to conserve energy.

I'd say the transmission power *might* play a factor in there somewhere. And I, too, recall that lower frequencies tend to travel further.

Re:why 0.9Ghz is better

[psyconaut]

Good lad :-) RF is RF, as you mention.

-psy

Re:why 0.9Ghz is better

[avdp]

I wouldn't brag about working at Circuit City as a skill or source of knowledge. No offense, but being able to repeat the marketing text written on the boxes is not that impressive. As an electrical engineer, I can vouch (from real knowledge) that he's correct about lower frequencies and range. Not to say that there aren't other benefits to the higher frequency phones, but range is not it.

Re:why 0.9Ghz is better

[disappear]

Not just caller ID... call waiting caller ID. As in caller ID for that annoying beep, so you can decide if you'd like to answer it at all.

Re:why 0.9Ghz is better

[disappear]

Did I say that it was a consequence of using the band, or only that phones using those bands were not available with those features?

It's (obviously) not due to the choice of bands, but the expectation on the part of manufacturers that 900mhz phones are low-end products. I'm guessing that nobody's revved their 900mhz phone chipsets in five years at this point.

Or are you suggesting that I should be leet enough to design my own 900mhz phone with all of the features I'd like?

Re:why 0.9Ghz is better

[bogie]

Companies went with 2.4GHz so they could sell the same products to people again. Although the latest 2.4 phones are probably ok for years 2.4GHz phones had shit reception compared to their 900MHz predecessors. There is zero doubt in my mind that most 2.4GHz phones were not equal to their 900MHz counterparts when they first came out. I used to hear echo and bad reception constantly on 2.4GHz phones while 900MHz just worked. Plus even now 2.4GHz models can have a nack of interfering with wireless which you and especially your neighbors probably won't like.

Re:why 0.9Ghz is better

[Steve Cowan]

You hit the nail right on the head. Speaking as an RF technician I can verify despite some others' opinions that 900 MHz will almost always propogate better than 2.4 GHz.

Apart from seeming more impressive numerically (after all, a 2.4 GHz phone is 1.5 GHz more than a 900 MHz phone), there is NO advantage to 2.4 GHz.

The 2.4 band has been set aside for unlicenced, low-power, public spread-spectrum use. Blutetooth uses it too.

I think it's only a matter of time before the cordless phones talk directly to WiFi routers anyway via VoIP, and then this whole thing will be moot - and phone companies will be very upset.

Re:why 0.9Ghz is better

[Anonymous Coward]

I have one from Uniden that supports everything you mentioned, plus has 2-line support from handset and base, speakerphone, etc.

It's not a matter of the frequency, just what the designers put into them.

Re:why 0.9Ghz is better

[Anonymous Coward]

Check this one out:

http://www.uniden.com/productpop/00_productpop.c fm ?prd_code=EXI2926

Re:why 0.9Ghz is better

[bwalzer]

Free space loss for radio transmissions (in dB): L(f,d)=20.log(f*d)+92.5

...

So obviously L(2.4GHz,d) > L(0.9GHz,d). Meaning lower frequency leads to less loss (further reach).

Which is true, but misleading. Fascinating RF engineering trivia follows;

The variable L is often called "free space path loss". This sort of path loss increases with frequency. But where is the actual loss? This is supposed to be in free space, i.e. vacuum. Since there isn't anything in vacuum to heat up or whatever the loss can't be in the actual path between the antennas (which is why the "path loss" bit is misleading).

It's because of the antennas. An efficient omnidirectional transmitting antenna will radiate pretty much all the power you feed it. An omnidirectional receiving antenna will receive power proportional to it's size. Obviously larger antennas will collect more power. Rather than giving each antenna a separate transmit gain and receive gain the RF engineering types just fudge it with the idea of "free space path loss".

So yes, you will end up with more signal at the receive antenna of a 0.9GHz as opposed to a 2,4GHz phone. The formula is correct in that. After all the receive antenna is 2.7 times bigger. That's a whole 8 dB more signal. Of course the larger antenna will receive noise that much better too (and there tends to be a lot at 900MHz). The 900 MHz antenna will probably be so large that you will only be able to get one in a handset (some 900MHz phones actually have an extendable antenna). If the 2.4GHz faction puts more than one antenna in their handset and then has the phone pick the one with the best signal, they will probably win in practice.

Real path loss caused by things like building materials and trees does tend to go up with frequency. OTOH higher frequency signals can squeeze though smaller holes. It's all a bit complicated. I personally suspect that free space path loss isn't a significant factor in the actual range you end up with.

Re:why 0.9Ghz is better

[jonbrewer]

900Mhz phones:

0) Are available only in places where 900 MHz isn't already in use by GSM.

Forget all this competition thing. Use a 2.4GHz WiFi phone w/ a VoIP gateway and be done with it.

Re:why 0.9Ghz is better

[Anonymous Coward]

I'd like to buy 900 Mhz, but all the cool features are going in the other lines.

Re:why 0.9Ghz is better

[0111 1110]

You are almost right. Low frequencies only travel farther (transmissions are attenuated less) when there are obstacles involved. Higher frequencies are better for line-of-sight transmission. Since most people (at least the ones who buy cordless phones) don't live outside on flat open land, microwave transmitters are less efficient for cordless phone applications. The use of 5.8 Ghz for cordless phones only makes sense if you live in a studio (one room) apartment.

Re:why 0.9Ghz is better

[antirename]

Mine has that... and it's a cheap vlink I got at Best Buy about 5 years ago.

Re:why 0.9Ghz is better

[Anonymous Coward]

> 6) are inexpensive.

7) Profit!!!

BenK

Re:why 0.9Ghz is better

[Anonymous Coward]

companies sell 2.4, 5.8 MHz phones for the same reason the idiots at Circuit City sell 3.2 GHz P4's to 60 yr. old women that just want to check email on a dial up modem. B/c idoits always think that higher numbers == better product. OH MY GOSH, manufactures use marketing, TELL ME IT AIN'T SO! You sir, are a fuck. But you already know this, and if you don't go do a little reading and then if you still don't understand please do not post on /. again. And if you do realize that you are a fuck, please note that on the rest of your posts.

Re:why 0.9Ghz is better

[bareshiyth]

Uh, I like your signature motto, the "quote" by Einstein... and sympathize (or is that "empathize"?), BUT, what was the source? I ask, cuz, truth is, Einstein never did think the universe is infinite. In fact, his conclusion that it had a beginning (is finite) led to the "Big Bang" theory, and his certainty that it was both finite (not infinite in expanse) and had a timed future led to his "cosmological constant", which he soon denounced but hopeful scientists, everywhere, resurrect in hopes of defining and explaining the finite universe!.

Notice, there is no such effort regarding human stupidity... though politicians everywhere build careers on their certainty about you and me, and tell us how they have infinite wisdom and thus solve our problem(s).

Re:why 0.9Ghz is better

[jwcorder]

I wasn't bragging ass munch. I was stating a fact that because I had to depend on them to eat, I knew alot about them. I also never argued against the point that lower frequencies travel farther. I was simply stating a fact that the range is better on a 2.4 ghz phone. I never stated why. Every other smart ass on here assumed I was saying because the frequency was 2.4. That wasn't what I stated. Any 3rd grader who passed general science can tell you that lower frequencies travel farther. What no one of here has been able to do is tell me why the 2.4 gives better distance. Once I get a valid explanation for that, I will move on to the next post.

I never stated that working at Circuit City required skill or knowledge, it's not exactly brain surgery, but it does require product knowledge and that does involve more then just "repeat(ing) the marketing text written on boxes". If it was just that, any "Engineer" like yourself wouldn't require salesmen or CSAs for product help and assistance. No offense, but I am sure that Electrical Engineering job does require the ability to read.

If it was going on frequencies alone, we would still be on the 47mhz phones that were popular 10 years ago. But what do I know, I worked at Circuit City for Christ's sake.

Re:why 0.9Ghz is better

[avdp]

The re-read the post you were replying to. You'd notice that frequency is ALL he was talking.

An engineer like myself has NEVER EVER needed a salesman from Circuit City other that go find the product. I avoid that place like the plague specifically because of annoying sales people that actually think they know anything at all of use. I doubt an engineer has EVER asked "how does it work?" about any phones. I think you know squat about phones considering you've probably never seen a non-display working model outside of a shrinkwrapped box (other than the one of two phones you may have bought for yourself with the employee discount). And you should know that the specs of a product written on the box rarely counts as "facts" - if they did, then you wouldn't have a zillion review sites on the net to test products to see if they meet expectations.

As far as why some 2.4GHz may have better range than the 900MHz phones - go read the rest of the posts. Frequency is only one part of the equations. 2.4GHz have better range in spite of their frequency, not because. The whole point of the thread is that frequency is a marketing ploy. It means very little.

Lovely language by the way, did that get your far at Circuit City? Just wondering - that kind of language rarely impress anyone when trying to have an argument.

Re:why 0.9Ghz is better

[xrayspx]

I've never seen Tom Smykowski's point more elegantly demonstrated than right here in that post.

You can't have clients talking right to the engineers, engineers have an overwhelming tendancy towards dick-headedness, and a proclivity towards know-it-all-itude.

This kid might not know as much as an EE about how cordless phones work. BUT, keep in mind that, in the course of selling them for four years, he would have tons of anecdotal evidence about which "work better" under whatever conditions. Customers come back all pissed about why their phones don't work well, occasionally he might hear positive comments, whatever.

He'll be more in a position to be an authority than your average consumer who doesn't get that kind of feedback daily.

After saying that, yes, it's true, that most of the salesdrones I've had the fortune to bump into at Big Box Stores have been about as useful as, and slightly less welcome than, a sock full of quarters to the head.

"I'm a PEOPLE PERSON, what the HELL is wrong with you people?"

Re:why 0.9Ghz is better

[CMRichar]

Where else would I find a highly inaccurate and misattributed quote? that Intar-web thingie, of course! the source of large amounts of highly erroneous information since AOL went live...

Re:why 0.9Ghz is better

[jwcorder]

I wasn't trying to have argument. A wise man once stated that having an argument is like being the the Special Olmypics....Even if you win, you are still a retard.

I also must have missed the global announcement that stated that EE were suddenly god of all products that require power. You are right though, you would never require help on ANYTHING, because it's obvious that you know it ALL!

You also assume that I learned everything I know about life from Circuit City. I said I worked there for 4 years while in college, mainly because I happen to be a pretty decent salesman and the job was commission based. So as a 19 year old college student, I was raking in about 35k a year.

Thankfully, I am not in the business of having arguments for a living. Because when someone comes across as an ass munch, I call them one. I think you are definitely in this category. It's not your fault though. Most engineers aren't people friendly because you think you know it all which might be true...but knowing how to apply it all in the real world is were most of you guys fail.

God knows how many times I as an analyst have had to fix something that an engineer did.

If you really want a test, try engineering a way to remove your head from your rectum.

Have a great day!

Re:why 0.9Ghz is better

[avdp]

Oooohh... An analyst... Fancy word for someone with no marketable skills. I'm impressed (yeah right). I got news for you, being an "analyst" is a built-in feature of being an engineer.

EE are not knowledgeable on anything with power. But the concepts here are RF 101. A sophomore EE could tell you you're full of it.

I don't doubt you were able to con clueless people with your pseudo-knowledge at Circuit City and make a decent living out of it (another reason I never go to Circuit City: commissioned predators). I've seen it happens in many such stores countless times. Sometimes it takes everything I got to keep a straight face when I overhear a salesman dazzling its unsuspecting prey.

Get over yourself. You know squat about phone other than what batteries to put in them and which has the shiniest box.

I will have a great day, thanks.

Re:why 0.9Ghz is better

[jwcorder]

No marketable job skills?...my boss needs to know that. Especially since I was just named Employee for the Quarter for a Fortune 50 company.

Once again, I bow to your superior knowledge.

yeah, dont...

[Anonymous Coward]

dont buy a 2.4ghz phone... i had a $20 900mhz vtech phone that was clear as day all the way to my mailbox about 200ft down the road from my house.
unless your back yard is larger than a footbal field noone needs a 2.4ghz phone unless its a penis extension.

Link to related article

[rtilghman]

Quick search found the following:

http://www.dectweb.com/News&Views/Features/0302R TX .htm

Not the most impressive site or source, but we're not looking for NASA level input and I don't think anyone's going to be lying about this stuff. :)

-rt

vice versa

[zontroll]

My Wi-Fi was interfering with my 2.4GHz phone. This was especially bad after I upgraded from 802.11b to 802.11g for some reason. I would always hearing these clicking noises on the phone. I got one of these "Wi-Fi Friendly" phones and my problems were solved.

um... you haven't specified any of the frequencies

[Anonymous Coward]

saying you have all those things means nothing at all if your cordless phones are 900 mhz or 5.8ghz. your cell phone is a non-issue since it operates at 850 or 1800/1900mhz (whatever the US is). wifi operates at 2.4mhz.

Then There's 900 MHz

[W. Justice Black]

We saw the interference problem coming, even before we went wireless with the network, so we thought ahead and bought a 900 MHz DSS phone (with digital answering thingy) a couple of years ago. Thus, no issues with 802.11 or even the older Proxim Symphony stuff we used to have.

I don't know if Toshiba still sells the SX-2981, but it's a great phone... Headphone jack, good range, DSS for clarity/security, etc. Answering machine is sometimes a little unclear (unsure what audio codec they use for voice recording), but it's not too bad. All in all, it's an 8/10 phone.

my 802.11g and 2.4ghz phone hate eachother

[Anonymous Coward]

We have a dlink 802.11g access point in my apartment along with a 2.4ghz wireless phone. Whenever I pick up the phone to make a call (or the roommate makes/answers a call) I am promptly lose my network connection.

I'm glad to see 'friendly' 2.4ghz devices are coming out!

Re:I have always had one or more of these wireless

[PabloJones]

Maybe a small handful of people will have problem with older phones and wireless networks, but I'd be willing to bet that this is just a gimmick to sucker people into choosing their phones over the other guys'.

No problems

[onebuttonmouse]

I've got three Linksys WAP11s, two of which are positioned within 1 metre or so of the base station of my 2.4GHz phone. I've never observed any kind of interference, Airport monitor on my PowerBook says the signal to noise ratio stays the same with or without the phone, even if I make or receive a call.

900mhz phones are your WiFi friends, folks.

[thedarb]

That's right. Stick with your 900mhz phones. Stores here in the Seattle area still carry several models in the 900mhz range. Do you really *need* the higher frequency for your phone? Save your money and buy these older phones.

*TheDarb

Re:900mhz phones are your WiFi friends, folks.

[reiggin]

Yes, if privacy is an issue, you do need the 2.4 or 5.8 phones. But not b/c of the freq. but b/c they have models with Digital Spread Spectrum. That's a much more reliable way to keep people from picking up your phone conversations. IIRC, 900mhz phones don't offer DSS. So when purchasing a phone, make sure it has DSS if you want security. Otherwise, it doesn't matter one way or the other. In fact, if security isn't a concern, 900mhz phones do have better range in buildings with many walls. 2.4 and 5.8 ghz signals don't travel as well through obsticles.

Re:900mhz phones are your WiFi friends, folks.

[Anonymous Coward]

My 900mhz Sanyo CLT-926, aka The Super Phone, does have DSS. I purchased it back in 1997 and it works great with an incredible range.

Re:900mhz phones are your WiFi friends, folks.

[slashbot]

My Panasonic KX-TCS970-B is 900MHz with DSS. It was bought back in the 90's. A new battery every couple years and it keeps going strong.

I've had very little interference since Ricochet shut down - damn antenna was right across the street.

Re:900mhz phones are your WiFi friends, folks.

[thedarb]

Yes, it's a fantastic phone. I got mine in the late 90's and still haven't had the battery give up yet. Where do you get your replacements, incase that day comes up for me?

Re:900mhz phones are your WiFi friends, folks.

[slashbot]

I get the batteries at Radio Shack. They're a standard item.

Re:900mhz phones are your WiFi friends, folks.

[AKnightCowboy]

But not b/c of the freq. but b/c they have models with Digital Spread Spectrum. That's a much more reliable way to keep people from picking up your phone conversations. IIRC, 900mhz phones don't offer DSS. So when purchasing a phone, make sure it has DSS if you want security.

My 900Mhz Panasonic cordless phone most certainly is digital spread spectrum (DSS logo right on the box when I bought it a few years ago). I specifically avoided 2.4GHz phones because I had a wireless network and have had zero problems. Hell, buy one off of eBay if you have to.. why torture yourself and risk the problems?

Wireless Sony speakers

[DigiShaman]

I've been told that Sony has some wireless home speakers available. And of course, they run at 2.4Ghz. From what I've been told at work, they are most often used in appartment complexes not to mention along with Wireless 802.11 b/g stuff.

I guess 2.4 is only going to get more crowded as more and more devices offer wireless ability on this spectrum. Maybe I will have a need to go back to 10/100/GB Eithernet soon :( Oh well, at least I will have a constant connection *shrug*

Digital or analogue 2.4GHZ

[Atticka]

I had that problem with my first 2.4ghz cordless and my wifi connection, fixed it by buying a "digital" 2.4ghz set (Panasonic KX-TG2216). Earlier 2.4ghz phones used analogue technology (dont ask, I thought that being 2.4ghz meant it WAS digital...apparently not), new phone's will actually say "digital" on them or "wifi friendly".

Take a look at the KX-TG2216, very nice phone and doesnt cause issue's with my wifi.

Here's an example of unfriendly

[w3weasel]

I have a D-link 614+ that will reset each time my Panasonic 2.4Ghz phone rings.

Changing from factory default channel 6 to channel 10 clears the problem up

My 3 year old Sony 2.4 ghz Phone Disables 802.11b

[Lioner]

If someone picks up a handset in my house I lose 802.11b and now 802.11g signal. I think some of these phones use spread spectrum and don't obey all the freq hopping rules.

No problems here

[Night Goat]

I've got a Linksys WRT54G router and a Panasonic 2.4GHz phone. Haven't had any problems yet, and they're both in the same room. In fact, as I type this, my laptop's directly in between the two. I think if you make sure not to use both devices on the same channel, you should be all set.

Personal Exp /w cordless 2.4GHZ joystiick

[Anonymous Coward]

I have a 2.4ghz logi freedom/2.4

1 thing i have noticed is that our uniden (2.4?) phone will actualy kill my wireless joystick if left off hook/carrier detect(dialt0ne). Oh so many times i was all 'WTF' i crashed how? only to realize i hit the 'talk' rather then off button my phone and it was still "on". Our other phone's talk button turns it off so its a somewhat common occourence.]

Ps: everything works *fine* if the phone is actualy in a call (or so it seems).

Phones & WiFi

[damnal]

I've got a VTech VMix and a LinkSys WiFi setup and they play nice together despite the lack of a "WiFi" friendly sticker. Have minor reception problems with the phone occassionally, but a simple press of the channel button fixes that and it's only when the one laptop is using the WiFi.

Short answer: yes

[kbielefe]

I had to set my wi-fi to channel 1 in order to prevent interference with my 2.4 GHz spread spectrum phone. I thought I was just having random driver anomalies until one day I couldn't connect at all while my wife was on the phone then finally connected the instant she hung up. Watching the signal to noise ratio when I turned the phone on and off finally proved it.

What a lot of people don't realize is that both 802.11 and cordless phones are part 15 devices, meaning they have no spectrum allocated to them, they can't generate any interference to licensed users of that frequency, and have to accept any interference from other sources.

Much of the bandwidth that 802.11 uses is allocated to amateur radio, meaning that I can transmit up to 1500 Watts on those channels and legally interfere with any wi-fi stations that are in my way.

Lucky for everyone, Hams are nice guys that like computers and wireless internet too, and do everything in their power to avoid such interference even though it is their legal right.

I don't get it

[elnoble]

Is there a common-sense reason for companies to be producing 2.4 and 5.8ghz cordless phones? I've always thought this was a 'bigger is better' marketing ploy, where people simply buy phones like they buy processors: higher frequency = better. Personally, I would think lower frequencies (say, the old 40mhz cordless phones that came out a decade ago) would do a better job propagating through walls and other objects typically found where these phones are used, as opposed to the relatively line-of-sight limitations of microwave band devices.

Re:I don't get it

[Secrity]

Greater bandwidth is available at 2.4 and 5.8 GHz than is available at 900 MHz. With the bandwidth requirements for WiFi and the high usage in some ares, bandwidth is a much greater advantage than wall penetration. In practice, reduced wall penetration does not seem to be a major problem for 2.4 GHz. If there actually is reduced wall penetration at 2.4 GHz or 5.8 GHz, that attribute could actually be considered an advantage as it would tend to reduce interference and could improve security.

Re:I don't get it

[Detritus]

Lower is better, to a point. The problem is designing an efficient antenna at the frequency that is in use. Normally it should be a quarter-wavelength or longer. A quarter-wavelength at 900 MHz is about 8 cm, which is a reasonable size for a handset antenna. At 40 MHz, a quarter-wavelength is about 190 cm, which is way too large for a handset. There are ways to electrically shorten the antenna, but you give up a lot of performance and efficiency.

There is also the problem that there are fewer channels available in lower frequency bands, making interference more likely. There may also be additional restrictions on modulation methods and bandwidth, which can reduce audio quality and make it easy for eavesdroppers to listen to your call.

Re:I don't get it

[0111 1110]

Yet another reason why 900 Mhz is the best frequency so far allocated to cordless phones. It is high enough to allow reasonably short antennas and open space propogation efficiency, and low enough to still penetrate multiple walls at reasonable power levels.

My 900 Mhz handset seems to use a reasonably efficient 3" (~8cm) 1/4 wave antenna, while my base uses a nice 6" 1/2 wave antenna. Of course 2400 Mhz allows antennas that don't protrude out of even a small handset. In some applications, like very small handsets, this could be a significant design advantage, especially outside in rural areas where building penetration is least important and open space range most important).

For the old 46/49 Mhz phones the only privacy feature that I can recall is "frequency inversion" which produced Donald Duck quacking noises instead of speech. Some Uniden phones used this. However, such speech could still be monitored with the use of commonly available frequency inversion decoders. There were better "rolling" frequency scramblers for which decoders were not so easily available, but Uniden was not using those.

Keep in mind that the 46/49 Mhz phones were so low in power in comparison to modern phones that an eavesdropper needed to be much closer and/or have a much more sensitive receiver to pick up the broadcast. When 900 Mhz phones first came out they were regarded as less private until the first digital and then digital spread spectrum models were released. I am not aware of any viable method to eavesdrop on DSS calls.

Never had a problem

[majkqball]

My new Uniden 2.4GHz phones work great with WiFi. Put the phone next to the WiFi card and I get no interference. Granted, the base station is 15 feet away from the WAP, and the microwave is 30 feet away from the WAP, but I've never noticed any interference at all. The WAP is a Linksys WAP54G, BTW.

It would interfere with my Wifi

[NoxiousB]

..... if i ever got called.

More problems ..

[miketang16]

I have a Uniden 2.4 GHz cordless phone from like a year or two ago. There's two problems with my D-Link DI-624 Wi-Fi router and it. One, if I use the cordless phone anyway remotely in the same area of the house as the router, I get an audible rapid clicking. Also, I discovered that by turning the phone on, and placing it next to my wireless card, it drops the signal. AND then Intel's ProWireless software says an unknown device is trying to communicate with the card. Go figure... =p

Uniden 2.4 GHz sucks rocks

[Anonymous Coward]

I bought a 2-phone system because I liked Uniden's cordless interface and Home Depot had the system on sale. It sucks rocks. The phone and the TiBk do not work at the same time. Pick up phone, no Airport. Switching the phone channel helps about 50%. Then I have Airport and a scratchy sounding phone.

900mHZ

[Anonymous Coward]

We have a nice, dual line, spread spectrum 900mhz phone. It works all the way down the street, is spread spectrum so no one else can pick it up, and doesn't interfere with any of our wireless stuff.

Bluetooth

[andrewjj20]

are there bluetooth phones availble, if there is it seems that bluetooth would be wifi friendly as it frequency hops after a packet has transfered making it interfere only for a very small while. however I have never heard of a bluetooth wireless phone, has anyone else?

Somewhat related issue with 2.4GHz phone and PC

[bhtooefr]

I think the phone is this. It came with a warning that it shouldn't be near a PC. I thought it meant something like not near a WiFi base station. Well, when I used it near one, the static was REALLY bad - even when the computer had no component running anywhere near 2.4GHz (466MHz Celeron, 66MHz FSB (which means 66MHz RAM), 33MHz PCI bus).

Why do we keep going higher?

[Anonymous Coward]

That's right. Stick with your 900mhz phones. Stores here in the Seattle area still carry several models in the 900mhz range. Do you really *need* the higher frequency for your phone? Save your money and buy these older phones. *TheDarb

No, you don't. In fact, I don't understand why phone manufacturers keep using higher, higher, and higher frequencies. I guess "overcrowding" was the initial reason; however, the higher you get in frequency, the shorter the RF wavelength, which only means your signal will not travel as far. 5 GHz??! You've got to be kidding me! Those are some crazy microwaves! I don't think I'd want anything running on 5 GHz that close to my head. I think it is time that phone manufacturers go back to using the 49 MHz band (digitally modulated, of course), now that almost all of the older (original) cordless phones that use that band are no longer in use.

Interference Robustness

[mrbrown1602]

I have a PowerBook G4 which is equipped with an Airport Extreme card. The Airport Extreme (802.11b/g) has a feature called "Interference Robustness" which prevents any problems I would normally encounter using my 2.4GHz phone. Does anybody have any insight into how this works and does anybody know if any other wireless adapters include it?

900 mhz!

[Grimster]

This is why when I recently bought new cordless phones, I bought 900mhz phones instead of 2.4 so I couldn't have any worries. I've never been at all displeased with 900mhz and the range is excellent.

Re:900 mhz!

[akac]

I just want a nice 900 Mhz 2 line phone but they aren't made any longer :(

I know that

[Pan T. Hose]

24GHz?! Who the hell would need such a fast phone is beyond me! I have a 500MHz AMD in my desktop (Debian) and it works just fine, thank you.

ARE YOU NUTS? Obviously they left out a dot on the frequency. The frequency your phone transmits on has nothing to do with speed like a processor. Get out of here.....

I know there are other important speed-wise factors as well, the most important one being not the clock frequency itself but whether the chip has 64 bits or not. Nevertheless, I don't think anyone would ever need more than 640MHz.

Re:I know that

[zbuffered]

Brilliant sir. Brilliant.

Re:I know that

[crayz]

I know there are other important speed-wise factors as well, the most important one being not the clock frequency itself but whether the chip has 64 bits or not.

I took my G5 and soldered on a few extra bits I found in a computer repair shop. It now has 73 bits, which makes it even more of a supercomputer than before

Re:I know that

[cmowire]

You know, it's a shame to waste old DEC PDP-10 parts like that. ;)

Re:I know that

[Anonymous Coward]

I took my G5 and soldered on a few extra bits I found in a computer repair shop. It now has 73 bits, which makes it even more of a supercomputer than before

What are you nuts? You have to solder on only a number of bits that's a power of 2.

Re:I know that

[ikegami]

The GHz for cordless phones refer to frequency of the radio waves used to communicate between the base and the phone, and not to microprocessor speed. It's similar to the MHz used to identify radio stations, but it's totally unlike the MHz/GHz of computers which refer to how fast the CPU is running. Do phones even have a central processor? I imagine they have a whole bunch of chips doing the work that needs to be done.

Wireless network friendly = 5.8ghz

[ccjernigan]

I was just recently looking for a 2-line cordless phone for my Vonage and landline phone service. What I found was that phone manufacturers claiming their phones are "computer" or "wireless network" friendly are selling 5.8ghz phones.

Interestingly, I found a Uniden 5.8ghz phone at Sam's earlier today that claimed that it was not only 802.11b and g friendly, but that it also would not interfere with 802.11a networks. I find that hard to believe.

I have found that our existing Panasonic KX-TG2730s 2.4ghz phone creates a lot of interference with other 2.4ghz devices. Annoyingly, the Panasonic phone base continues transmitting even when the phones are not in use. So my 2.4ghz Amphony wireless headphones won't work more than about 3 feet from their transmitter. The Panasonic phone generally doesn't interfere with my Bluetooth keyboard, mouse, Tungsten T3, or Logitech headset unless someone is talking on the handset in the same room as those devices. The Panasonic phone also dramatically reduces the speed and reliability of the 802.11g network in the house.

So what about a Wi-Fi phone, those are Wi-Fi friendly...

Re:I have always had one or more of these wireless

[MrAndrews]

I actually found a conflict between the wireless phones and wifi to be rather widespread. At my house we had a problem where if you were closer to the base station with your laptop than the phone was to its base station, the phone wouldn't always ring --- and then if you were further away with the laptop the phone would drop your internet while it was ringing. Can't say I've checked out newer phones... we've switched to iChat AV and cell phones for all our telecommunications needs :)

This ain't tech support

[Anonymous Coward]

Next thing you know, people r gonna ask if fat free cheese is really fat free?

3.141

[Anonymous Coward]

So your router goes to 11, huh?

will you people stop buying 2.4GHz phones!

[Doppler00]

You are doing nothing but using a low bandwidth device to pollute a frequency range that is better used on 802.11 networks.

2.4GHz phones does not mean that:

1. The sound quality is better. This is entirely dependent on the encoding algorithm the phone uses (if at all). The 2.4GHz is simply a carrier signal.
2. You get better range. You don't because 2.4GHz doesn't propogate as far.

And also, given that some 2.4GHz phones probably don't use spread spectrum, they are likely to interfere with several channels. At least bluetooth devices hop frequencies fast enough and are low power so they don't interfer.

The use of higher frequencies on phones I think is simply a product of marketing. You have people who hear about "2.4GHz" computers and think a similar increase in "GHz" will benefit their phone.

Good high quality 900MHz phones are out there, just keep looking.

Check the specs before you buy

[spudmcduck]

Our family bought some AT&T 3358 5.8 GHz phones to clear out the 2.4 GHz band a bit. The problem is they transmit in 5.8 GHZ but still receive in 2.4 GHz. They are good phones apart from this issue. So much for impulse buying...

Yep - seen it often!

[King_TJ]

I'm lucky that right now, I own a Panasonic (KX-TG1000N) 2.4Ghz cordless phone, and it never seems to cause my wi-fi network any problems at all. (I'm using a Linksys WRT-54G router, but also used a Lucent RG-1000 residential gateway before that, and had no problems with it either.)

A good friend of mine, also using a Linksys WRT-54G has terrible problems with a 2.4Ghz cordless phone at his house. (I don't know the model, or I'd post it.) I was over there on his wi-fi network, and as soon as you'd pick that phone up off the hook, the whole network would instantly disappear! I couldn't even redetect the router, much less get a good connection to it. It came right back upon hanging the phone up.

Where I work, we've had issues too. A mortgage company moved into the office next door to us, and we discovered our 2.4Ghz phones were knocking out his wi-fi network temporarily, every time they rang. (He was using some type of US Robotics router.)

The problem seems to be a lot of 2.4Ghz phones are being really "sloppy" about transmitting across multiple frequencies at the same time. The wi-fi cards just can't seem to step out of their way.... I guess the phones with this new sticker on them have been built to tighter tolerances.

It's a hit and miss combination

[nettdata]

A friend of mine has an Apple Airport, and an AT&T 2.4 phone, and whenever the phone was turned on the wireless network disappeared TOTALLY. You could be 10 feet from the Airport and it would still disappear. They did not work and play well together at ALL. You could occasionally force a new phone channel and it would have minimal effect, but still an effect. (The 802.11 connection would flicker in and out of existance). All in all, it was quickly a learned behaviour that the network was not available when his wife was on the phone. ;)

That being said, I have a LinkSys and an Airport WAP co-existing with a Panasonic 2.4 cordless phone, and there is absolutely no discernable interferance between them.

Personally, I don't know enough of the details of the frequencies used to figure out why, but all I know is that it works.

I am my own neighbor

[froh]

I've got neighbors with wi-fi (with myself included).

There is a C&W song called "I'm My Own Grandpa" http://users.cis.net/sammy/grandpa.htm
, but i've never heard of someone being their own neighbor.

wireless keyboard

[Arngautr]

Not WiFi but my wireless keyboard (or reciever) is affected by my new cell phone, if the phone is near it (like 4 feet or so) it often causes keys to rrrrrrepeat or skp. I think it has to do with a DoS on the feedback but I don't really know much in this area.

802.11 friendly is possible

[KB1GHC]

i don't know, i don't use a 2.4 Ghz phone,

but i'm pretty sure it is possible to have 802.11 friendly phones because it just uses a slightly difforent frequency, however it's not perfect, because of harmonics, etc. so it's NOT 100% friendly, but it won't completly wipe out your network when your on the phone.

this DOES NOT mean it hooks up to your network. and it SHOULD NOT interfere with your network.

802.11 friendly

[Anonymous Coward]

Phones that are in the 900Mhz range are considered 802.11 friendly

Overclock it

[Proc6]

Why not just overclock your phone? Put it up into the 20 ghz range and trump anyone who tries to start a conversation about them overclocking their Athlon. Weaklings.

Nope, wrong again!

[Penguinoflight]

^Quoting Rafiki from the lion king... The base has longer range because it has a higher power output. The physicaly properties of EM waves dictate that a 2.4ghz wave requires more energy to produce than a 900mhz wave. This is in part why AM radio stations are lower power, and the range is a lot better.

Phone gets onto the network.

[InternationalCow]

Really, it does, at least here in Europe. My father had this Nokia cell phone that he brought into my (then, now it's a Cisco router) Airport network. It did not exactly interfere, instead, it hopped onto the network (it wasn't a WAP phone or whatever, it only made calls you know) and appeared as a kind of zombie client. It was present but didn't do anything. Weird. He got another phone later on (a Siemens) and I never had that problem again. Seems that European dual band cell phones also operate in the 2.4 GHz range :)

Joining the 900 MHz crowd..

[cmowire]

The cordless phone manufacturers have been playing quite a game over the past decade. They keep trying to get you to upgrade phones to a "higher" megahertz phone because they know that you are already being told by Intel to upgrade your CPU to a "higher" megahertz CPU.

So, here's the thing. It's a general rule that as you go up in megahertz, the ability to penetrate walls goes down. Thus, the higher the megahertz, the lower the effective range. Consumer Reports did some tests here and showed that this carries over to reality. This is also why Verizon Wireless tends to have better reception -- they are primarily on the 850 MHz band instead of the 1900 MHz band.

So what have you gotten by upgrading to an "advanced" 2.4 or 5.8 GHz phone? Less range, although generally enough range to make it around a "normal" house.

Now, in order to produce a device that works in the 900 MHz, 2.4 GHz or 5.8 GHz band without a license the FCC requires you to be spread-spectrum.

There's some upsides and downsides here. First, some of the spread-spectrum devices, most notably older ones, didn't use very good spread-spectrum methods.

Second, in *theory* if everything's optimized properly, you can use some number of devices and they will all be perceived as "noise" to all of the other devices. So as you add more functioning devices in general, they will all start to experience interference. The problem is when devices using conflicting spread spectrum techniques are in use.

Third, microwaves and other such RF-heating applications, are covered underneath a different set of FCC rules, which generally are built around not causing your eyeballs to be fried overeasy (your eyeballs are the first thing to suffer damage from microwaves, which is why staring at the microwave window is not the world's brightest idea) Microwaves are supposed to be Faraday cages, but sometimes there's a leak. I'd start to wonder about my Microwave's safety if it started interfering with my WiFi, mind you.

Fourth, if there's interference and undesired performance, you have essentially no recourse. I've been thinking that they really should have allocated a frequency band that's reserved for only devices using a 802.11-standard protocol, but that decision really should have been made a long time ago. Oh, and if you start interfering with something important (That's the "Harmfull Interference" they speak of on the FCC warning on the back of a device) you can and will have government folks knocking on your doorstep. There have been documented cases of equipment interfering with aircraft navigation signals from the ground, which makes the airlines very unhappy and tends to get investigated. ;)

I'm really wondering what the "Wifi-Friendly" cordless phones are actually. Especially given that VTech is the folks who are advertising it. As I've mentioned above, in *theory* any device on the 900 MHz, 2.4 GHz, and 5.4/5.8 GHz ISM bands (they are actually the same thing) shouldn't prevent each other from working and should just be perceivable as noise Also, *in theory*, one could "do better" by listening for 802.11b/g activity and actively routing around it. This is the big difference between Bluetooth 1.1 and 1.2. But that's more circuitry, so I'm not entirely sure if they are actually doing that, or they just put them in a test lab to see what happens. They'll probably insist that it took years of engineering time and it's a special feature, even if it's more the second. ;)

I personally have just stuck to 900 MHz phones. Like I said, all things being equal, they tend to have longer range. Plus, I figure that having absolutely no interference is better than having a measured amount while the phone is in use. ;)

Sure my WiFi uses 802.11b, which is 2.4 GHz, but there's some darn good reasons for why one should keep 802.11a around.

The main one is that 802.11a is usually faster than 802.11g at close range. So I have a halfassed

Re:Joining the 900 MHz crowd..

[Servo]

When I went from 900Mhz to 2.4Ghz portable phone, my range went to crap. Where are you finding these 900Mhz phones? Nobody seems to make or carry them anymore. I ended up getting another 2.4Ghz multi-extension phone and this one hasn't interfered at all.

Re:Joining the 900 MHz crowd..

[cmowire]

I picked up a Panasonic KX-TC1486B from Target a few weeks back.

Re:Joining the 900 MHz crowd..

[0111 1110]

Good post. I was going to mod you up, but I'd like to make a minor correction instead. As many have stated, the "penetration ability" of RF waves is inversely proportional to frequency (proportional to wavelength). For getting through building structures the best are 46/49 Mhz phones followed by 900, 2.4, and 5.8. What no one has (yet) mentioned is that higher frequencies do give better range for unobstructed line-of-sight transmission. Higher frequencies require less power (especially important for handsets) to propogate through empty space. The problem lies with obstructions like walls.

Anyone who has tried to use a handheld GPS while hiking in dense forest has seen that even 1227 or 1575 Mhz is a high enough frequency to have difficulty penetrating the leaves on trees (at least at such low power).

So as long as you can actually see your base a 5.8 Ghz cordless phone (RF transmitter) will give you the greatest range, but in any situation with obstructions it will give you the least range per unit of output power.

46 Mhz is such a low frequency that it penetrates walls easily without losing much power, but it is less efficient at open-space propogation (per watt). 900 Mhz seems to be a nearly perfect balance (perhaps 450 Mhz might be better). The frequency is high enough that open space propagation is very efficient, but still low enough that it will penetrate walls with some effectiveness.

Spread spectrum is not a form of "frequency hopping" in most cordless phones. It is a form of "wideband" transmission. It does not actually "hop" per se (although there are exceptions). It does allow for greater power and range. The longest range cordless phones for most people who live indoors in a multi-room house is a 900 Mhz spread spectrum phone.

I bought as many of these as I could because I knew that MarketSpeak would win over RF theory and that truly long range cordless phones would probably become unavailable.

Re:Joining the 900 MHz crowd..

[0111 1110]

Are you sure that Verizon uses 850 Mhz? Verizon wireless is a CDMA company. I have never heard of 850 Mhz CDMA, although I have heard of 850 Mhz GSM. I have heard of 800 Mhz CDMA, but I was not aware of anyone was actually using it in the US. I thought everyone was using 1900 (PCS channel). If you are right, then that is indeed an advantage when using the cellphone indoors or in the city.

AT&T was using an 800-something Mhz TDMA system until they recently switched to GSM (which technically is a form of TDMA). I had thought they were the only ones in the US with digital 800 Mhz cell phones.

Re:Joining the 900 MHz crowd..

[Anonymous Coward]

Almost correct. 1 watt is 1 watt at any frequency. Tell hams that lower frequencies won't carry as far but stand back if you don't want get get wet from the laughter you get back. What higher frequencies do is allow higher gain antennas with less space. The least, effective, antenna is 1/4 of the wavelength of the frequency (with ground plane) 1/2 without a ground. Frequecy goes up wavelength goes down. To make a 1/4 wave antenna at 49MHz you need over 4 feet. The same 1/4 wave antenna at 900MHz needs only 3/4 inch. 900 MHz is a very good balance for cordless phone. High enough frequency for small antennas, low enough to penetrate walls and such. Also the FCC allow greater power output at higher frequencies. 4 watts EIRP (1 watt into a 6db gain antenna) at 2.4GHz and 16 watts at 5.8 GHz. The requirements at 49MHz are much lower.

Re:Joining the 900 MHz crowd..

[0111 1110]

Based on the free space loss equation (where signal loss is proportional to frequency), and based on e=k*f where energy(e)in a EM wave is proportional to the frequency(f), I must say that you seem to be correct.

My belief to the contrary came from a number of sources I deemed reliable, but it seems that the idea that higher frequencies take less energy to propogate a given distance is just a myth. So I guess there is absolutely no reason (aside from antenna size and bandwidth) to transmit at higher frequencies. There seems to be no real benefit at all.

Re:Joining the 900 MHz crowd..

[grumling]

Oh, and if you start interfering with something important (That's the "Harmfull Interference" they speak of on the FCC warning on the back of a device) you can and will have government folks knocking on your doorstep.

No, the FCC's role in modern government is to enforce copyright laws. If anything, there is going to be much LESS regulation of airwaves in the future!

Re:Joining the 900 MHz crowd..

[cmowire]

Well, other than there being more high frequencies to work with.

Re:Joining the 900 MHz crowd..

[cmowire]

850 is a synonym for 800, when you are talking about cellular.

Either way, it is the frequencies of 824-849MHz and 869-894MHz. It's just that the GSM folks added a 50 to the 800 to be more precise.

This is why you really need to snicker when Sprint advertizes that they are the "nation's largest all-digital all-PCS network". AT&T and Cingular have some presence on the 850 band. Basicly, Sprint's advertizing that they got to the party late and that they suck. The big thing that AT&T and Cingular have been up to lately is getting rid of TDMA service on the 850 band and using GSM instead.

The big thing is that there's room for 2 providers (A and B, if you ever used an old cell phone) in the 850 band, but there's room for 6 providers in the 1900 band. Part of why it makes sense for AT&T and Cingular to merge is that they will be able to combine their respective 850 bands and will, especially when they get UMTS (which handles the sorts of multipath you find in cities as well as CDMA does and GSM does not) rolled out and potentially give Verizon a run for their money.

Re:Joining the 900 MHz crowd..

[cmowire]

You wish.

The FCC's regulating just as much as they did before because they are beholden to congressional smack-downs paid for by incumbent broadcasters, their traditional responsibilities, and the potential to look really good by taking people's unused spectrum away and auctioning it off.

There's a big one happening once they get rid of analog TV and get everybody to use HDTV.

Mandating the broadcast flag and wiretapping is but a tiny piece of the FCC's present and future jack-booted thug job.

Don't use 2.4GHz

[AgentAce]

900MHz cordless phones are more than sufficient for home use and I bought one to ensure that there isn't any kind of interference among my access points and my phones system. The only room for 2.4GHz "cordless" phones that I can see now is to set up an Asterisk box in your house and get a WiFi IP phone.

Unfortunately, I am only aware of these phones manufactured by Cisco...and Cisco can suck my balls.

Okay with Dlink 802.11b

[macklin01]

I use a Uniden 2.4 GHz phone in the same apartment as with a D-Link 802.11b AP (model DI-614+) and adapters (airlink plus, so it goes at 22 mbps, rather than 11 mbps). I haven't had a problem with wireless performance, even with the transmission strength turned down to 12.5%. (to reduce the strength of the transmissions leaving my apartment)

However, I have noticed a pulsating clicking sound on the phones caused by the wireless network. Usually, changing the channel on the phone helps with it.

Now, do keep in mind that the 802.11g units will be much more sensitive than the 802.11b units. -- Paul

Easy

[paul248]

Just find someone's credit card, and buy ten 4.8GHz wireless routers, and your interference problems will be solved.

Reccomended model Southwestern Bell GH3028NB

[Stonent1]

It looks quite similar to this but is bronze colored. It was fairly inexpensive and it was purchased at Lowes. It was initially bought for my house by someone who knew nothing about computers and I gasped when I saw the 2.4ghz logo on the box. Amazingly, it has not affected my wireless setup one bit. I can sit 1 inch away from the phone with my laptop and my connectivity never drops nor does my speed. If I am on the phone and move near my WAP or laptop occasionally I'll hear a click every once in a while but the person on the other end never hears it.

Here's a novel idea

[Solder Fumes]

Make a telephone that plugs directly into your network, with handsets that actually communicate over 802.11. That'd be Wi-Fi friendly! In fact, do away with the phone base station and phone line altogether, and use VoIP wireless phones. You can even get ones that automatically switch between VoIP and cellular. One *ring* to rule them all....

Baby Monitors

[z4ce]

I put wi-fi at my sister's house, and nothing was a problem except for a video baby monitor. Turning it on would cause interference in both the 2.4ghz phones and 802.11g AP, practically disabling both. So instead we just used a 900mhz non-video baby monitor...

Ian

900 MHZ Interference

[OYAHHH]

Given,

All of the 900 mhz advocates on this thread seem to think there is no interference I would like to interject and say that I do have interference issues with my 900 mhz phone and my 801.11 B equipment.

More specifically, I have a Panasonic 900 mhz gigarange telephone with some sort of digital spread spectrum technology (KX-TC1891B). The phone does not seem to impact my 801.11b equipment's (Linksys WRT54G) connectivity.

But, connectivity isn't everything.

As soon as I hooked a Hawking omnidirectional attenna onto my router I suddenly started hearing a beep on my computer speakers about every 5 seconds.

It about drove me nuts one day when I took the phone handset off the base unit and placed it in another room. I didn't realize that my phone was causing my computer to beep.

I thought something was dieing on my computer or that some program/virus was playing a cruel prank on me.

I must have rebooted that computer 20 times that day trying to isolate the cause of the beep. Never did.

Next day, put the phone back on the base unit and the beep went away.

Having discovered the source of the problem, I couldn't believe it, I turned the sound off via the computer's O/S, picked up the handset and no beep.

So, nowadays I have to turn the sound off on my computer before I answer the phone. Very annoying. But I paid a bundle for the two line phone, for which my wife was sorely irritated, so I guess I'm stuck.

Re:900 MHZ Interference

[lachlan76]

That beep was the RF interfering with your sound card. Haven't you heard what a mobile phone does when it goes off near a computer?

none

[DesiGuy421]

On the 2nd floor of our house, we have our 2.4 ghz wireless router and a 2.4 ghz phone. I always hear interference on the phone when I use it, but who knows, the phone could just be crappy.

Interference

[pr0nd3xtr]

Sure thing - when we first rolled out 802.11b in our office, we had to troubleshoot why the wireless network kept going down. Low and behold, when someone made a call all the wireless clients lost connectivity. Solution was to just trash the cordless phones.

Can't we all just get along?

[j1m 5n0w]

What's the deal with 802.11 and cordless phones intefering anyways? I thought this was the problem spread spectrum was supposed to solve: Direct sequence radios should be relatively immune to narrow band interference, and frequency hopping radios should not be affected much by direct sequence signals.

If they work at all, they work by adaptively locating an empty part of the 2.4 GHz spectrum

IIRC the FCC part 15 rules forbid this: for frequency hopping radios, they must hop to every channel in the hopping pattern with equal frequency. Or are cordless phones usually direct sequence?

-jim

In addition

[IncohereD]

In support of the comments about the handset running off batteries, and therefore having a shorter range, why do you think they're running 900 on the way back, and not 2.4 both ways? Because 900 takes LESS power to get the same range!

Thank you, come again.

Re:In addition

[Detritus]

The electronics for 900 MHz are cheaper and consume less power than the electronics for 2.4 GHz. It is also cheaper to build a cross-band phone (900 MHz/2.4 GHz) than it is to build a single-band full-duplex phone. The manufacturer is more concerned about costs than range.

Oh yes ...

[PhilipPeake]

When my 2.4GHz phone was in use it would completely squash my 802.11b -- wich was very unfortunate, since its a 1 mile link to the nearest spot at which broadband is available, so when that goes, my Internet connectivity goes.

The answer was to buy an new 5.8Ghz phone.

I was tempted by the "802.11b friendly" phones -- they were a lot cheaper. But I didn't want to take the risk. All works just fine now.

The Other Common 2.4GhZ Device

[Lord Byron II]

The other common 2.4GhZ device that we all have is the microwave. My brother used to be in an apartment that by bad luck and poor planning had the microwave between his bedroom and the jack where the cable modem was installed. Everytime you'd go to microwave a burrito, you'd loose the Internet. As an interesting sidenote, he had a neighbor start running an unsecured node on the same frequency. Their signal was weaker usually, but once somebody touched the microwave, their's became the stronger and the wifi card would automatically switch over.

Actually, I've had the opposite problem

[randy_harvey]

Rather than a problem with the phoneinterfering with the WiFi link, I had the opposite issue. Everytime my "Call Waiting Caller ID" signal was triggered on my phone, it would result in a piercing feedback-like screech. This would only occur if my 802.11b router was powered up.

Why 47 MHz is even better

[Outatime]

47 MHz phones (you remember them, right? -- the *original* cordless) may be your best option yet! They're on such a low frequency that they don't have a chance of interfering with anything in your house, except maybe your neighbor kid's walkie-talkies or the garage door opener, and those are both very unlikely. Get a set with voice scrambling and you've got some privacy too. And lastly it has a terrific range and because it's analog, sounds good even when the reception is getting poor (you will get a little static, but that's better than drop-outs).

The only WiFi Friendly phones are WiFi Compliant

[Anonymous Coward]

Why not just get a VoIP phone that uses WiFi?

Yes

[Anonymous Coward]

Sometimes it worked sometimes it didn't. We had to go for ours with out the net when our grandparents would call us!

I usually like to find out the weather in England online, so I dont have to ask the same lame question every time.

Ours goes up to 11

[whorfin]

I've got a Linksys 802.11g base station, and a Sony 2.4 GHz phone setup. I live in an apartment, where the arm of my couch is my desk, so the phone is often just inches from the computer I'm using.

Every time we used the phone, I'd lose my wireless network. So I fiddled around with my base station, and set it to broadcast on channel 11, which apparently nudged it just far enough away from the phone's noise band that I haven't lost signal since.

YMMV

Re:Ours goes up to 11

[Anonymous Coward]

Also set my Linksys 803.11b to Channel 11 and solved the big problems with the two 2.4 Phone systems in the house. (Vtech and Sony)

Have to say the new Microwave though really helped. We use the microwave often ... and getting a newer microwave seemed to help the situation.

In the past, I always had too much trouble with 900mhz phones in my area (too dense?) noise and other peoples conversations would quickly overpower the signal any moderate distance away from the base station. The 2.4 phones have greatly solved that issue. (I haven't tried the 5ghz phones yet ... I haven't needed to.)

That and going back to a 900Mhz phone that doesn't have multiLine support or multihandset support just would be silly.

Works for me...

[ErnieD]

I have a GE 2.4GHz phone and a Netgear 802.11g WAP. I've never noticed a problem between the two when talking on the phone.

I often have my laptop out in the living room via the wifi, and my wife will be talking on the phone, and the laptop's connection doesn't even hiccup.

Perhaps my phone detects that channel 11 isn't the cleanest channel it sees, and chooses another to operate on for the call?

Panasonic good, Motorola bad.

[Anonymous Coward]

I have a panasonic which works fine. It wasn't until I got a Motorola cordless that I noticed clicking and that the caller ID wouldn't show up in the room that has the AP.

Feature wise, the panasonics are pretty good also.

AT&T 2455

[ccarr.com]

No longer being produced but you might be able to find it on ebay.

I can't say that it doesn't slow down my wifi network, but I've never noticed a problem.

What I really like about it is that it's the only 2.4 phone I've used which has a clear sound even in proximity to a wifi network.

Why 900mhz phones are the SPAWN OF SATAN

[hamsterspeed]

Repeat after me: 900mhz phones will screw up your DSL.

I don't care if you've had that phone forever and it's never been a problem before. I don't care if there's a microfilter on it. I don't care if there's five microfilters on it. I don't care if it's plugged in all the way on the other end of your house. I don't care if you've got a CAT5 homerun from the demarc (unless you've installed a frequency splitter to go with it, and if I'm talking to you, YOU HAVEN'T).

I DON'T CARE. Throw your 900mhz cordless phone away. It is why your DSL keeps disconnecting and the speeds are slow.

-hamsterspeed provides excellent customer support for a Major Independent Broadband Provider

Re:Why 900mhz phones are the SPAWN OF SATAN

[Anonymous Coward]

I've had DSL for 5 years, 900mhz phone for 7. The 900mhz phone is positioned above the DSL modem on my desk, and their lines run parellel. No problems at all.

Re:Why 900mhz phones are the SPAWN OF SATAN

[hamsterspeed]

Yes, and I'm quite certain that this is true for many, many, many people. I even had one myself for a bit that never ever caused a problem.

What I do know, from hundreds of customer troubleshoots, is that when a line that's been working for ages suddenly goes intermittent, the DSLAM stats show substantial signal strength fluctuation on the downstream side but no variance on the upstream side, and the MLT shows a clean loop from the CO, 9 times out of 10 the problem will be fixed by disconnecting a 900mhz phone.

I'm not saying it always happens with every phone, I'm just saying that this symptom set correlates strongly with these devices allowing HF onto the phone copper (sometimes after years of no problems). Mostly this was a "nobody understands me" rant about a unique element of my job.

I'm amused to see I got modded troll... I guess I deserved that.

-hamsterspeed

Re:Why 900mhz phones are the SPAWN OF SATAN

[AgentAce]

correlation != causation

Re:Why 900mhz phones are the SPAWN OF SATAN

[hamsterspeed]

correlation != causation

Of course not. In fact, people often infer the inverse case: "the phone has always been there, and, sometimes when I'm on it I don't have this problem." I'm actually talking about a repeatable, demonstrable phenomenon wherein intermittent, transient DSL sync loss can be caused by a telephone devices with an HF electronic element.

When this occurs, removing the device successfully prevents recurrence of the sync loss, as verified by extensive monitoring of noise margins on affected circuits. Took me a year of doing this stuff to find the correlation, and quite a number of test cases before I became somewhat comfortable with the hypothesis.

After a couple hundred carefully monitor examples, it starts to look like a causal relationship :)

Sony SPP-A968

[trentfoley]

This phone has everything except for the multi-handset base station. I've had mine for years and it is a good phone.

Re:Sony SPP-A968

[disappear]

I just checked the Amazon page... it appears that the phone has caller ID, but not call waiting caller ID (ie, caller ID for those calls on call waiting).

Re:Sony SPP-A968

[trentfoley]

I just checked the Amazon page... it appears that the phone has caller ID, but not call waiting caller ID (ie, caller ID for those calls on call

Well, the phone does indeed have call-waiting caller-id. I use it regularly.

You can download the manual from this link:

http://www.iq.sony.com/srvs/sosdocs/default.asp? sr c=sonysupport

Search for SPP-A968. Look on page 46 and all will become clear.

Re:Sony SPP-A968

[Anonymous Coward]

Amazon.com has this to say about the SPP-A968:

This item is not stocked or has been discontinued. :\

My 2.4 GHz solution

[yroJJory]

I have Panasonic 2.4 GHz phones and 802.11b WiFi routers. I've had many problems with interference, but did finally find a solution that seems to work. I set the 802.11b AP for channel 11 and the phones don't seem to jump to that channel.

Ever since I did that, I've had no internet outages that were phone-related.

Channel 11

[Hoch]

My cordless phones are mostly 2.4 ghz of different brands. They all have channel settings, but none check to see if the channel has trafic on it before broadcasting. Stupid phones. They would kick me off when the channel on the phone hit the wifi. The trouble with the phones is that they would pick a channel at random. I did some searching and found out that channel 11 on the wifi would fix this problem. It did and I didnt have to stop using the 2.4ghz phones. Use channel 11!

Never have any problem with 2.4GHz

[WrongDecision]

I've never had a problem with my 2.4GHz Panasonic phone and 802.11b Linksys WiFi. However, my 900MHz phone couldn't make it out of my apartment, whereas my 2.4GHz phone has at least a 1/4 mile range in my urban environment. I used to carry it with me shopping, dining, and at the movies befor I got a cell phone. As in most things in life, quality does make a difference.

5.8 is 2.4? In some cases, yes.

[Stalin]

The following text is from http://telecom.hellodirect.com/docs/Tutorials/5.8G HzFrequency.1.031903.asp. It is a decent article, targeted towards consumers, that explains the difference between 900Mhz, 2.4Ghz, and 5.8Ghz phones and why the different bands exist.

Output wattage

To keep neighbors from constantly hearing each other's conversations, the FCC initially limited the output wattage for cordless phones to just .001 watt. But when digital and spread spectrum technologies (SSTs) made eavesdropping a less valid concern by scrambling signals or dividing them across multiple bandwidths, the allowable wattage for cordless phones was increased to 1 watt. This action made for clearer calls and increased a cordless phone's range three- to fourfold. Meanwhile, the increased wattage covered up the fact that higher-frequency signals require more power to transmit.

When 5.8 GHz phones were introduced, the allowable wattage was not increased--and here is where the buyer must beware. Because transmitting signals at a higher frequency requires more power, some 5.8 GHz phones use the new frequency only for the base-to-handset transmission. Then, to make sure a handset's battery has a reasonable life, handset-to-base transmissions are sent on the older 2.4 GHz frequencies.

Re:5.8 is 2.4? In some cases, yes.

[0111 1110]

From the article: If such logic stands, one would assume that a cordless phone utilizing the 900 MHz band would perform better than one using the 2.4 GHz (or 2400 MHz) band. Not so.

Unfortunately this is so. This article is misleading. 900 Mhz SS is superior technology to 2400 Mhz SS for the typical cordless phone usage pattern. 900 Mhz will be attenuated far less traveling through walls than 2400 Mhz. In open space 2400 Mhz will give better range, but for communicating through structures, 900 Mhz is more efficient. 2400 Mhz was a step backwards. Any real life testing will demonstrate this.

The same reasoning they apply (about filling a room with more RF waves) applies to 5.8 Ghz as well. So by that reasoning a 5.8 Ghz phone should be superior. They clearly have lots of 2.4 Ghz phones (the current standard) to sell but no 900 Mhz phones. So of course 2400 is the ideal frequency.

Their point about antennas is valid though. Higher frequencies allow for more efficient recievers with the ultra-short antennas that are typically used nowadays.

Re:5.8 is 2.4? In some cases, yes.

[Stalin]

I figured there would be a lot of marketing involved with it. The biggest thing I was trying to bring to light is the 5.8Ghz phone is more than likely not going to operate at that frequency is most instances. /me really doesn't know anything about the whole matter.

Simple Solution...

[goMac2500]

Buy a WiFi phone. :)

2.4GHz band is THICK in my neighborhood

[major.morgan]

I live in downtown Seattle, in a fairly dense apt/condo area. Just sitting on my couch NetStumbler comes up with about 20 AP's. I can't even imagine how many 2.4 cordless phones are out there.

I'm not that concerned with how MY phone and AP are going to get along - it's my hundreds of neighbors that I'm worried about!

My plan: 900MHz for the phone and 5GHz for the WiFi, I'll just stay the hell out of their way.

Had bad interference until...

[penginkun]

...I bought an antenna. It's nothing much, just a 4db jobbie I got for $20 at Frys (mmm...Frys...) but it's solved the problem of my phone interfering with my wireless.

What it doesn't help with is the microwave. Our microwave is between the router and the PC (they're on opposite sides of the tiny box we call our home) and when it's on, my 'net connection goes bye-bye. Which means there's a leak in the box somewhere. Come to think of it, we should probably buy a new microwave soon. Now if you'll excuse me, I need to find some lead-lined underwear...

dual specrtum

[KMonk]

as other people have pointed out they do definitely interfere however, beware the 5.8ghz phones too - some of them are dual spectrum, they receive at 5.8 and transmit to the base at 2.4. The uniden true 5.8 series is good but expensive, I have a cheap AT&T 5.8 that works great, and had many problems with the panasonic 2.4. Linksys WRT54g router.

Problems? Oh yes.

[localman]

My 2.4Ghz model would cut my network off neatly from the moment it rang to the moment I hung up. For some reason (my think skull?) it actually took me several weeks to realize this was what was happening. I guess because I would stop what I was doing when the phone rang, usually. Then if I tried anything while I was on the phone -- no dice. And after I hung up most of my ssh sessions would be dead.

Anyways, I went out and got a 5.8 and I've had no problems since. YMMV.

Cheers.

My phone interferes with my WiFi network.

[Aqua OS X]

My kitchen phone interferes with my WiFi network all the time.. it's really annoying.

From time to time it selects the same channel that my desktop computer is on, and I have to switch phones because damn thing doesn't have a channel button on it.

I should probably go out an buy a new phone. But the problem only occurs once or twice a month, so I never really remember to do anything about it.

Re:Problems? Oh yes.

[yagu]

..., For some reason (my think skull?)...

Thank Goodness you have a think skull!

could the interference be just static?

[yagu]

I have a set of cordless 2.4Ghz phones..., and have NEVER seen any cut out in my network. However, periodically when on the phone I get earth rattling static. Many times I have to re-initiate the phone call -- it becomes unbearable and indecipherable. Does anyone else experience this? Is it the interference from my linksys?

What brand & model?

[midg3t]

Any chance of you finding out and publishing the manufacturer & model of phone so we can avoid it?

Re:What brand & model?

[Anonymous Coward]

Any 2.4ghz cordless phone. Seriously, this is a rather pointless article. If you two devices use the same frequency, you can bet there will be interference. If your wi-fi equipment overpowered your phones, you would notice static in your conversations. Now, you can try changing the channel on your 2.4ghz phone and hope you are not interfering with your wireless gear too much but unless your AP is close to your wireless nic, you're SOL.

I found out my downstairs neighbor had bought a new 2.4ghz phone when my laptop would randomly drop wireless connections, this was because her phone overpowered my AP at longer distances. At work, we use 2.4ghz cordless phones which causes no problem with our wireless setup, however we cannot travel very far before our phone's lose their signal.

Re:um... you haven't specified any of the frequenc

[Anonymous Coward]

"wifi operates at 2.4mhz".. I wonder how they squeeze so much data out of bandwidth that narrow :P

Why not WIFI Phone

[lars_boegild_thomsen]

They are fairly WIFI friendly :)

Seriously speaking, currently a lot of new WIFI enabled VoIP phones are coming to market. I've been using one for the past few month and while they are still a little pricey, the technology do work.

Luddite.

[supabeast!]

That technology is SO twentieth-century. Just use cellular!

ISM bands

[elgatozorbas]

No surprise 'all wireless phones are at 2.4GHz': this is an international ISM band (industrial, scientific and medical). The other bands are around 900MHz and 5.8GHz (country dependent, I believe). You need no license to transmit in these bands, although the maximum power is limited. The downside is that you have to accept any received interference.

Z

Panasonic System and airport express. No issues

[OS24Ever]

I have the panasonic TGA-2000 family of phones. I have five handsets scattered across 2500 sq feet home. I also have two airport extreme base stations and one airport express.

I've had no problems being on the phone and on the internet at the same time, or broadcasting a song to my airport express.

My neighbors phone interferes with my wireless...

[sketchyDOTcom]

I know whenever my neighbor's phone rings I'm going to loose wireless connectivity when they pick up... At first I couldn't figure it out and then one day when the TV/Stereo wasn't on I heard their phone ringing just before I lost my connection. So yes, some phones can interfere, although I'm not sure what kind of phone they have as they don't seem to speak english and if I ask I may freak them out.

Answers

[Jahf]

I would answer with Yes and No.

YES ... that damned Panasonic 2.4GHz phone was the pits for wireless ... it would knock out not just my internal 802.11b but my directional 802.11b wireless ISP connection (the antenna was on the ROOF and on the outside of the HOUSE pointed AWAY from the phone's base and the Panasonic could kill it from the opposite side of the house). Whenever we would get a call I would have to answer it and hit the "channel" button

We have a sincere suspicion that my neighbor grabbed the phone from the trash or bought an identical model since when they get calls my net connection gets very fuzzy (but not gone).

No ... my Siemens gear does not interfere with anything. I've owned 2 different Gigaset base stations (first one got water damage from a snow storm) with 4 phones placed around the house and I can be on 2 different lines with handsets and have no trouble with either 802.11b network.

The Siemens gear is fairly expensive ($300 for the base I think and about $100 per handset) but if you work at home and require 802.11b it is a worthwhile contender.

The higher the freq, the more the effective range

[lhaeh]

When 2.4ghz phones came out and most people still were useing 900mhz so the 2.4ghz spectrum was wide open and their was little intereference. Since interference was low the signal could go further. This is no longer as much of a case for 2.4ghz phones as most phones sold now are 2.4ghz. 5.8ghz phones enjoy greater range for now as they are not in as much use.

My experience

[$exyNerdie]

When I decided to shop for a new cordless phone, I read about all those 2.4 GHz interference so my options were to go back to 900 MHz Digital (which was surprisingly more expensive than 2.4GHz due to limited demand)or analog or to go with 5.8GHz. I did research on 5.8GHz to make sure to pick up a uniden model that uses 5.8GHz both ways (base to handset and viceversa) because lot of 5.8GHz phones use 2.4GHz one way. I didn't have any problems with my selection in my wi-fi network...

Definitely Siemens

[Abalamahalamatandra]

I've had a Siemens Gigaset system for several years, and it works great with 80211b. My cordless base station is upstairs in the house, the Linksys is downstairs, and I can sit right next to the base station and surf with nary a burp on the call in progress.

Occasionally I'll be transferring a movie from my Linux server to my laptop while on the phone and you'll hear a slight hissing on the call (with 100% full throughput) but that's about it, and the phone call doesn't slow down the transfer.

You can get Gigaset systems quite cheap on Ebay these days. The really great thing is that the handsets use NiMh or Nicad AA rechargables instead of proprietary batteries, so when batteries go I can run just about anywhere and get new batteries.

My 900MHz *cordless* phone works great

[Anonymous Coward]

Not cellular. Cordless, as in a base station plugged into a POTS line. Spread Spectrum, so it doesn't have the eavesdropping problems of the earlier 900MHz analog cordless phones. Better range than the higher frequency phones. Cheaper, too.

Note to original poster: MHz, not mhz.

m is the symbol for milli, divide by one thousand
M is the symbol for mega, multiply by one million

What's a mere factor of a billion between friends?

Hz is the symbol for hertz.
hz is a meaningless two letter sequence, not a symbol for any unit.

Units named after people are in lower case, but the symbols are in upper case. The unit of frequency is hertz, with a symbol of Hz. Example units are volt, ampere, watt, farad, henry, and ohm. The symbols are V, A, W, F, H, and an upper case omega that I'm not going to try to type.

dect, pacs, phs

[demmer]

buy a phone that uses one of these standards (europe, usa, japan).. they work in 1880-1900, 1850-1990, 1895-1918MHz and will not interfere with wlan or bluetooth. thats why they made standards and reserved frequencies...

my 2.4GHz phone would bring my network down

[xshader]

I *used* to have a fucking 2.4GHz phone, but whenever it was in use, my network link quality would drop to 0%. I kid you not.

Avoid 2.4GHz phones at all cost!!!

Major service outages due to cordless phones

[riceboy50]

I work in a higher education environment and we have had so many problems on our 802.11b network from interference by 2.4ghz phones that it was necessary to outlaw them on campus. I agree with the many other posts on this topic that question why *exactly* it was necessary to migrate cordless phones from 900mhz up into the 2.4ghz and 5.4ghz ranges. I have held onto my older 900mhz phones and they work perfectly fine. P.S. That question is rhetorical. I already know that the migration to the higher frequencies was for meager performance gain and a marketing boon for the stagnating cordless phone industry.

spread spectrum hops

[Anonymous Coward]

There's no doubt about it.

http://www.sss-mag.com/ss.html

Wideband (like FM) is wideband, that's different.

Re:spread spectrum hops

[0111 1110]

Nice link. Frequency Hopping Spread Spectrum (FHSS) "hops" (jumps around to different frequencies). Direct Sequence Spread Spectrum does not. Direct Sequence is used more often on cordless phones. It is true that wideband is technically different, but Spread Spectrum could be seen as a form of wideband transmission since the whole point is to spread the signal over a wide range of frequencies to reduce detection.

Here's a quote from that article:
The use of these special pseudo noise codes in spread spectrum (SS) communications makes signals appear wide band and noise-like.

Re:spread spectrum hops

[cmowire]

Well, either case, you take advantage of Shannon's Limit. As you increase the size of the channel, you reduce the decibels of gain required to get information through.

I think you have things reversed. WiFi uses DSSS and cordless phones use FHSS, from what I was reading.

Now, the one suggested explanation I've seen about 2.4 GHz cordless vs. WiFi is that one device having FHSS and another having DSSS will tend to bring out the worst-case conflict behaviour. It sounds like FHSS doesn't look like the gausian noise that all of the spread-spectrum assumptions are built around to a DSSS radio. It sounds like, however, it's dependent on the exact implementation of FHSS and DSSS.

2.4 Ghz

[EtherBoo]

I have 2.4 GHz phones in my house, and it does not interfere at all with my wireless network. However, with a friend of mine's, whenever we have a LAN party, he takes his 2.4 GHz phones off the hook, because it kills the network whenever someone calls. It was funny when we were all playing a game of WC3, and someoen called, and half the players lagged out and dropped.

Never had a problem. Virgin phone

[dinodriver]

I have a 2.4 virgin wireless phone that I got for less than $30 at target (with built in answering machine). I have an ibook with airport card and a 802.11b microsoft wireless router. Have never had a problem. I can sit in the same room and use the phone with no loss of connectivity.

2.4 GHZ

[Anonymous Coward]

My radio shack 2.4 GHZ phone messes up my 802.11g every now and then if the phone rings when it is on my pc desk the wifi connection on my laptop drops

Or dropouts plus hits on network bandwidth.

[grnchile]

Could be. My 2.4GHz phone frequency hops. That seems to keep it from knocking out the wireless network when the phone is in use. However, if the phone hops through the channel the wireless is using when there's heavy network activity, I get background noise and/or brief dropouts on the phone. It was worse when I had the phone near the AP for a brief period.

I did some throughput tests on the network when I first installed the phone. There was a 10-20% hit with the phone active. (This was with a WaveLan 802.11b RG).

FHSS is what you want

[bono]

You'll find out on the market 2.4GHz phones that fall into 2 catagories.
DSS - Digital Spread Spectrum
FHSS - Frequency Hopping Spread Spectrum

The DSS ones will interfere with your 802.11b wireless connections.

The FHSS one will not interfere. FHSS changes the exact frequency that is uses, hops around, many times a second. So it's not on the exact frequency as your wireless base station long enough to cause any problems.

Panasonic does a good job on 2.4Ghz cordless phones and makes a number of models a that use FHSS technology.

My guess is that other company's that are saying they are 2.4Ghz-Friendly are using FHSS.

I've used Panasonic FHSS phones successfully with both 802.11 b and g wireless.

2.4 Ghz, Microwave and Router sitting next to each

[Darthmalt]

My router is located in the kitchen about a foot away from the microwave and we also have a 2.4 ghz wireless phone sitting next to it. I've never had a problem with my WiFi network. Even though we have had a NEW microwave (which recently died) And a several several year old microwave which is now sitting next to it.

Which 900 MHz?

[alexo]

What 900 MHz phones have better range and reception, the analog or the digital?

Re:Which 900 MHz?

[picman]

I would avoid analog unless you want your neighbors listening to your conversations. they can easily listen with an entry-level scanner. I understand that digital phones are much safer, but can still be cracked if you have sophisticated neighbors. I live in white-trashville, so I don't worry much about junior rocket scientists around here, but a lot of folks do have cb/emergency scanners.

After owning older 900mhz phones by vtech, GE, hitachi, panansonic, and a 2.4 ghz seimens gigaset (bad choice btw), I recently bought a Vtech VT 2931 )2-line for about $100). Works like a champ! It is digital with all of the bells and whistles that I need and it works great with my 802.11b network, and has great coverage in all of my house and for about 100 feet outside in all directions. It also works great with my plantronics headset, which is something I can't say for any of my previous phones.

Do 2.4 GHz CPUs cause interference?

[menscher]

This reminds me of going to a LAN party where someone had a see-through plexiglass case. We were wondering if their CPU ran at 2.4 GHz, and if so, whether it would cause interference with the wireless.

Anyone care to comment?

All 2.4 GHz phones should be 802.11x friendly

[Anonymous Coward]

Devices like phones that operate in SMR bands _SHOULD_ follow regulations for LIPD (Low Interference Powered Devices). If you find a problem with your wireless network and your phone "fighting" for the medium, switch AP to a different channel. Remember that when switching channels in 802.11b|g mode that they overlap, so you should switch to a different part of the spectrum (high to low. etc.)

Re:All 2.4 GHz phones should be 802.11x friendly

[Zilch]

Doesn't work.

Zilch

Huh? Phone?

[EvilStein]

What, you guys haven't all ditched your landlines in favor of cell phones and/or VoIP yet? :)

I rarely use my phone, so the cheap corded phone I got at Fry's works just fine.

Not everything needs to be cordless. *shrug*

2.4 Ghz Panasonic phones + 3 access points

[uvsc_wolverine]

We've got I think it's funny that so many people are commenting about how their 900 Mhz phones aren't interfering with their 802.11[b/g] networks. That seems fairly obvious to me that they wouldn't interfere with each other. The phone runs on 900 Mhz and the network runs on 2.4 Ghz. They're on different frequencies, therefore they don't interfere.

Re: 2.4 Ghz Panasonic phones + 3 access points

[uvsc_wolverine]

Stupid enter key, I didn't get to make my point. We have three wireless access points and four Panasonic Gigarange phones, as well as multiple Bluetooth devices. We've had Bluetooth, wi-fi, and the phones running (and I think someone was microwaving some popcorn, too) and none of the above had any problems...except maybe the popcorn. It also depends on the phones, too. The phones we have here are fairly new. We had a similar setup at my uncle's house, and he had an older model of the Panasonic Gigarange phone, and I could tell when someone was on the phone because my internet connection was gone. Apparently the earlier versions of the Gigarange phones were geared towards higher transmitter power, and overall sound clarity at a distance. But they also didn't play nice on the 2.4 Ghz band. If the phone decides that it wants to use the channel that your wireless network is on your network (at least until grandma gets off the dang phone!) is toast. These phones run at around 5 watts, while your average access point runs at something closer to 500 mW and will get totally swamped.

Use 900Mhz eh?

[John Siracusa]

Good luck finding a digital 900Mhz phone. I could barely find any inexpensive 5.8GHz phones when I looked. Digital 900Mhz phones seem to have dropped off the face of the earth.

No interference, no cooperation

[anon*127.0.0.1]

My phones and my computer network don't seem to be aware that the other exists. Which is a shame, because I'd *really* like to be able to use my computer to set up or modify all of my phone/answering machines features. Typing in names and accessing menus through an keypad and a couple of arcane buttons is a PITA. It'd be nice if I had a simple, clear menu-driven interface on my computer that would allow me to just type everything in. Then when I'm done, I can hit send and it'll program my phone.

Re:No interference, no cooperation

[Anonymous Coward]

In my experience in the last year acessing my former college's wireless network, I noticed that the base of my Panasonic 2.4ghz Gigarange phone would kill the wireless if it was near the WLAN reciever. Now the hanset didn't do this. As noted WAY above in a post, the 5.8ghz phones use 2.4 to transmit back to the base. Now in my testing, the hanset for my cordless transmits back in 900mhz. Now this makes sense. 2.4ghz travels farther in open space (see post way up as well) and if the base is transmiting it, you can put far more raw watts out with a power supply as opposed to a battery (not to mention battery life) and if you can crank the output watts on the base, you can compensate for the lose signal due to obstructions. (Plus as all wireless equipment isn't perfectly governed to a specific frequency, the base outputting that raw power could be another factor in overpowering the income wireless. aka bleed) However, on the return trip back from the handset, you want a low power option (for the conserved battey life. not to mention the inabiliy to get raw amps out of a battery) so why not choose 900mhz? its a fairly empty band so it makes sense. The 900mhz has less conflicts and it goes through barriers at less watts. This is what the testing I did with my phone and and a spetrum analyzer have yielded in my situation. If this little theory holds true with the 5.8ghz, who knows. In my experience as long as the base isn't in the same room as the wireless reciever, all is well. No complaints about this phone. Great range and quality.

Go DECT and be done with it

[Zilch]

Unless you are unfortunate enough to live in North America, just make sure you get a DECT phone. These operate in the 1880-1900 MHz range, and are actually standards based.

From what I understand this frequency range is reserved in the US - so bad luck. You are stuck with stupid phones and the imperial system :-)

I made the mistake of getting a Panasonic 2.4GHz phone. Complete crap, and has about 60% chance of killing your (and your neighbors) wireless LAN dead when you call someone. I'm just in the process of moving to DECT/GAP myself.

More info: http://www.dect.org/toptech.html

Ironically, this wouldn't be a problem for me except my stupid IBM Thinkpads think they are in the US, and won't allow me to use the extra channels that we are given in Australia. My WAP will go all the way up to channel 13 if I tell it I live in Australia - which is well out of the range the phone uses - but the Thinkpads limit me to max channel 11.

Zilch.

Re:Go DECT and be done with it

[kennedy]

That's funny. I've got a 2.4ghz panasonic cordless phone right here, and both my WAPs seem to work fine while i'm on the phone.

see the trick (and i know this is a hard one for lots of you to understand), is to have each 2.4ghz decide on its OWN channel. This really isn't rocket
science.

Re:Go DECT and be done with it

[Zilch]

Decide == device?

That doesn't work (and I know this will be hard for you to understand) with 2.4GHz Spread Spectrum phones because - you see - they don't use a channel. They are...ummm...spread spectrum.

Having said that, my phone only really kills my Wifi about 60% of the time, and hitting the channel button a bunch of times can sometimes get you back online, but it is a pain in the bum, and there is no way to tell the phone to stick to a particular channel.

Zilch.

2.4 GHz and Linksys Issues

[pluckyduck]

My 2.4 GHz phones would cause my Linksys wireless access point to stop sending/receiving.

The solution appears to be changing the channel the Linksys works on.

So I suspect if someone sets theirs up with an unused channel to begin with they'll avoid issues.

Re:2.4 GHz and Linksys Issues

[Anonymous Coward]

Thought I would post for the 1st time and give my quick little experience. After purchasing and setting up my dlink 802.11b router I finnally found out why I would only very rarely completely loose connectivity. I found out that one of my panasonic phones cannot be set to a specific channel; as a "security" feature it jumps to a different channel everytime someone actuallly picks up a call on that phone. Sooooo if someone picked up a call on that handset while somone was using the wireless network AND the next channel it would jump to was the one set on the router, down goes the network....I found this out by sitting there in front of my pc and just turning on the phone on the line and hangning up and every 21st time the network would go down. Anyway its so rare for that circumstance to happen that it doesnt really bother me but thought id share for all those other poor souls who are having the same issue :-)

Isn't this just like 'Dolphin Friendly' ?

[thrill12]

Where people think they buy good, safely captured "fish", only to find out the whole logo is thought up by some FHB that thought it would be good for marketing ?
What's next ?
Children-safe cleaning products ?
Furniture that doesn't harm the rainforest
??

Cordless and DSL

[Anonymous Coward]

When I got my DSL 2 years ago (Verizon here in PA), and was having some rather bizzare problems, one of the first questions asked was: "do you have a cordless base station nearby?". The answer was no, so I inquired further. Seems that there's also some potential problems with the 2.4GHz cordless phones and some of the DSL modems (Mine is a Westell). I have a 900 MHz phone, and have put off upgrading. Now that I also have a Wireless router for my notebook (NetGear 814), I'm REALLY going to have to look.
Anyone have any problems with the DSL modems and Cordless Phones.
So little bandwidth, so much information, what's a bit to do?

Why are you even still using telephones??

[Anonymous Coward]

Go check out the program Skype, you'll never need a telephone again just a microphone. Or a cisco IP phone.

Blame Iran

[nuggz]

Well we know Iran and their weapons of mass interference is causing this problem.
There really isn't any proof, but don't worry Bush is getting the CIA to look into it again and find evidence that Iran is lowering your DSL speed.

I got rid of DSL specifically because of pathetic witch doctor techs like you.
If the phone can put HF that interferes on the line, PUT A FILTER ON THE LINE.

AT&T and VTech phones

[Anonymous Coward]

I have seen a number of posts about VTech and AT&T phones in this thread. It should be noted that they are almost the same phones with different plastic wrapped around them. They are both made by VTech.

I'm sure someone has mentioned this already, but I believe what makes the phones 802.11 friendly is that they don't use the whole spectrum when a wireless network is detected.

Get a DECT phone from europe

[steve_l]

yeah, the panasonic one I had was death to wlan.

Having moved back to the UK, I now own a set of DECT phones which are the dogs bollocks.

Interference: zero. Range: Excellent. Scalability: superb. The DECT standard includes an open spec for adding new phones (from any vendor) to the same base station. So we have 3 phones off one one station, one per floor.

I dont know what frequency it runs on, and frankly dont care. It works. the WLAN works. that is all I need to know.

interference

[d0pp13r]

yes, ive had some interference. my philips DECT phone (1998) started to sound cracked when i moved large files via the original apple base (1999 model). however, the later airport extreme base (2002) seems more stable/less prone to interference. also, small data transfers like light browsing never bothered me with apple/philips equipment.

Uniden TRU8866

[tengu1sd]

I've been waiting for a 2 line 5.8 phone for almost a year, making due with a 900 mhz single line phone for the time being. With a home office, 2 phone lines and 802.11b the 2.4 ghz phones were out. Finally in stock is the Uniden TRU8866. Best deal on phone & handsets was Frys.

900Mhz Cordless Phones Consumer Reports "Best Buy"

[electricmba]

According to CR, The Panasonic KX-TC1484B gets both the #1 ranking in their review of 30 cordless phones (covering 900Mz, 2.4Ghz and 5.4Ghz phones). In addition, it receives the "Best Buy" designation, given that it rings in at $69.99 up here in Toronto...and a paltry, Froogled $29.99 right here: http://www.soundcitycorp.com/ECscripts/ECware.exe/ dcp?id=001&sku=Panasonic%20KX-TC1486&type=A1CN1&lc =EN for our American cousins. The CR comments indicated that in general, 900Mhz phones had the best sound clarity and battery duration (the Panasonic above lasts 16 hours).

Having this trouble at work

[Avatar8]

Not only do we have enough 2.4Ghz phones to fight each other for channels, but we also have a public 802.11a/b/g wireless network and a dedicated wireless (b) system for handheld scanners. Everything fights constantly.

Personlly, I've brought in an old 900Mhz phone to use, and it works fine. We're supposed to start using SIP phones on our network and that should remove most of the conflict.

This is one of those situations where the hot dog makers and the bun makers didn't get together before going to market.

Panasonic uses 5.8GHz exclusively.

[mr_death]

While researching this topic a few months ago, most phones did use both 5.8 and 2.4GHz. The exception was a Panasonic 5.8 phone, which was 5.8GHz only. It does not conflict with my wireless 802.11g network in the house.

If You can't beat them, join them.

[AndyCap]

Get a phone that's guaranteed wi-fi friendly, It actually uses wi-fi as a transport. You will of course need some additional hardware for interfacing with your phoneline unless you want to move to VoIP completely. Asterisk and a voice card would probably be nice in a linux box.

No problems for me

[angle_slam]

I have a 2.4 GHz phone and an 802.11b network. Plus, many of my neighbors have WiFi networks. I've never had any problems. Even now, with the phone base and router in the same room.

phone to wi-fi conection

[Anonymous Coward]

would you be able to retrive sound or data pakcets from a phone that interferes with wi-fi? Or would it not work because the acces point and the base staion of the phone are on diffrent channels.

Interference

[Anonymous Coward]

I've got a linksys WRT54G and a 2.4 GHz phone. When the wireless is on, my phone gets a faint "pop" every second or two.

802.11a and 5.8 GHz phones

[Andy Dodd]

Unlike 802.11b and 2.4GHZ phones which share the same 2.4 GHz ISM band, there are actually 2 or 3 rather closely-spaced (but not overlapping or even adjacent) ISM bands in the 5.4-5.8 GHz range.

All 802.11a communications is restricted to just one of these bands, while I believe the cordless phone manufacturers can choose any of the 2 or 3 ISM bands. So some of the 5.x GHz cordless phones can interfere, but some of them most definately are not overlapping.