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Beware Of 2.4 GHz Interference
RobinX writes: "If you have any combination of cordless phones, wireless ethernet, wireless video, or Bluetooth you could be having problems. I've got two different 2.4 GHz phone brands that are interfering with each other and with my home 802.11b wireless ethernet network. It seems that the 2.4 GHz range isn't licensed so companies are free to do their own thing. Check out this article for more." I've been noticing problems recently as well, between phones from the same manufacturer and the WaveLan cards.
Microwave ovens operate in the 2.4 GHz band, and are poorly shielded high power transmitters. Wireless lans and other ISM band applications are low power transmitters, but many microwave ovens (especially older ones) radiate (read: interfere) more power than these low power transmitters are allowed to do, because of their poor shielding. I would be very sceptical to use equipment running in the 2.4 GHz for "mission critical" work. 5.7 GHz ISM band equipment would be a better choice.
RFC1925
Another often overlooked culprit around this frequency band is the microwave oven. These run in the neighborhood of 2.45 GHz (give or take). Even a small leakage from the RF shielding can produce a detectable signal on or about this frequency.
Also, the the band from 2.3 GHz to 2.45 GHz is (and had been for quite sometime) used by amatuer radio operators. A higher powered ham tramsmitter could also be a source of interfere with this equipment. Technically, low-power consumer equipment should have been located on another band.
Poorly designed equipment can "mix" signals on different bands and hear interference on their operating frequency, also.
So your argument is that just because we don't have conclusive proof that there is indeed a cause and effect relationship, we shouldn't care?
As time goes on we are relying more and more on RF equipment. We are bathing ourselves in EM radiation. Have long term exposure studies been done?
What about non-cancer effects? The brain is nothing more than a large, wet, electochemical device. It is suceptible to EM feilds. We have known for more than 50 years that EM feilds in the microwave range can cause psycological effects.
So...these are low power...I understand that, but what about long term effects. We are fast aproaching a world where we will be exposed to this stuff to chronic low levels.
I simply mean to point out that we have evidence that there may be health issues involved and that this really needs to be considered. People should be informed so that they can ecide for themselves about the possibility of risk involved.
"I opened my eyes, and everything went dark again"
While neurons carry current, using chemical electrolytes, I don't believe that you can induce a current in a neuron via EM radiation. If that were true than everytime you were subjected to EM radiation or a high magnetic field you would start shooting lightning bolts around, and I haven't seen this yet.
-- Remember: Wherever you go, there you are!
Resonance of various frequencies with various materials is due to the length of a specific wave with material that consists of particles of the same size as the wave length. Let's say the wave length is 1 millimeter than dust with diameter of 1 millimeter will resonate with this frequency. The power of the wave also matters, since more powerful waves will hit the particles at higher speed and more waves are produced with higher power for equal time periods. 2.4GHz is a frequency and does not tell you what the wave length is, so we are missing the wave length to find out exactly whether this wave length is the same 'size' or length as a water molecule diameter. Now if a wave length of size of a water molecule is directed at some water container with frequency of 2.4GHz that water may boil in seconds because of the resonance, the wave will not go through the molecule (as would have happened if the wave was much shorter) and it will not go around the molecule (if the wave was much greater) but it will 'fit' the molecule size and will cause it to move much faster and faster moving molecules give out heat.
You can't handle the truth.
Could this just be a case of poor receiver design? I've seen this is VHF/UHF receivers. A strong signal will produce intermodulation distortion in the front end and wipe out any weak signals. A good receiver will have a linear front end with a wide dynamic range. This costs money, which probably means that the receivers in consumer grade equipment are a major cause of the problem.
Mea navis aericumbens anguillis abundat
This article gives very little detail on whats going on here. They don't even say if the author even tried adjusting the frequency settings of the interfering components. 802.11 has 11 (in the US) -non Frequency hop mode frequency settings (most of which overlap) and selecting another one might have helped a bit!
:-(
Some background for the curious: 802.11 sends 'chirps' - the same bit is sent simultaniously on a range of frequencies, with some bits reversed. this is done to prevent interference, or blocking on one band from interfering with the transmition.
The channels look somthing like this (in ASCII anyway) (if this looks wrong, paste it into an xterm, or notepad, or somthing with a fixed-width font)
|
|............---7---
|..........---6---
|........---5---
|......---4---........---11---
|....---3---........---10---
|..--2---.........---9---
|---1---........---8---
+---------------------------------------------
frequency ----->
Note that the vertical axis doesn't represent anything, it's just used to stop everything going on top of everything else. The dots are there because slashdot slashes spaces, but leaves dots! Nor is this diagram accurate, or to scale or anything, it's just ment to give you the gist.....
Here each ---x--- is a range of frequencies over which the bits of the chirp are spread.
There only one set of 3 channels which don't overlap, so if you need more than 3 802.11 networks in the same place, you're our of luck.
If you run your network in frequency hopping mode, you only transmit one bit on one frequency at a time (chirps send about 12 bits), but change frequencies often, across the whole range (no channels) This means that interference on one range will only kill some of your data. You obviously than need to retransmit failed sends (by the time a retransmit happens you will have switched to a different frequency.
The quality of the hardware you use can also make a big difference. The better equipment uses two aerials, spaced apart, to prevent reflected signals and some other kinds of interference from silencing the signal. The idea is that if a signal and it's reflection interfere to create a minimum (no signal) at one point, there will be signal just a short distance sway.
Most devices just ship set to a channel, and it's nearly always the same one - surprise surprise - 1! I don't know about the phones, but they would probably be similar.
I guess no detail, or background research is about what we expect from ZDNet.....
1. If you are experiencing problems with your cordless phone, try adjusting the operating frequency of your access point. Any AP worth thier weight will allow you to choose different frequencys to operate on, all within the 2.4 GHz band. Most commonly: 2412, 2417, 2422, 2427, 2432, 2437, 2442, 2447, 2452, 2457, and 2462.
2. Access Point placement: Make sure to place your AP in a strategic location at your home/office. Central locations work best, and make sure your orientation is correct for the kind of radio you use. A bad place to set one of these things is next to your microwave (for obvious reasons)
3. Cordless Phone base placement. Minimize multipath transmissions by keeping your base station away from corners. Multipath transmissions from your cordless base station can and will take down your wireless network as it confuses your client radios on your other PCs due to all the 2.4 GHz traffic in the air.
4. The new Lucent 6.0 driver for their ORINICO WaveLAN cards has a new feature called "Microwave Oven Robustness." When this feature is enabled it prevents the radio from falling back to less than 2 MBit/sec when it thinks it is in poor coverage. This should only be enable in environments that will not experience fringe/poor coverage, however it should help your problems with interference if it is enabled in a good coverage area.
Numbers two and three are probably the most vital in getting multiple 2.4GHz devices to co-exist, so try many different placements! Try not to get discouraged, it does work!
-- Ian
This reminds me of RC car days, when you carried 3+ crystal sets on you so you could change freqs that your servo/transmitter used. If someone else had your same freq at a race, and neither of you had spare cyrstals, SOL to one of you..
Same thing here, pretty much. A (semi-)open band, and people are gonna use it for pretty much everything they can. History repeats itself as always, go figure. Wish I knew more regs on this so I could say how things are supposed to be.
bash: ispell: command not found
This sig left intentionally blank.
I saw a while back on Ars-Technica that some pagers and cell phones share the same freq as the master oscilator in AMD boards. When the pager went off, the computer would die! I think the guy fixed it by building a grounded box around the chip.
I'd rather you do it wrong, than for me to have to do it at all.
Jeroen
Secure messaging: http://quickmsg.vreeken.net/
You're right. Note also that direct sequence 'chirps' and Frequency hopping *shouldn't* interfere, as the FH signal should only be able to kill one bit of the chirp at a time... leaving the other 11(?) or so to get through intact.
The short answer is that the X10 Video Sender is a piece of ca-ca and was the source of all of the problems. The other 2 devices do frequency hopping and spread spectrum transmissions to avoid (and compensate for) interference. The cheesy X10 device just blasts away on a fixed frequency with a very low quality transmitter that spills all over adjacent frequencies.
The best answer I found was to stick to 900 mHz phones and run a wire for video. I boxed up the Video Sender and gave it to my Dad. It was just a bad idea all around.
Shut up and eat your vegetables!!!
Tis true, and sorry that I obviously did not make myself more clear.
As you say, the problem is not what frequency it is on. The problem is that everything seems to be moving up here.
However, it does not matter whether it is spread spectrum or not. Yes, that is going to help, but it is not the total solution, either.
First, there are a limited number of frequencies there at 2.4 that can be used. Add to this that not all devices work on each of these frequencies. They may use 1, 2, 5, 10, or 20 of the frequencies. Next, even if they are frequency hopping there is a limit to the number of things that can be on a given frequency at the same time.
You mentioned that some devices don't frequency hop. True. So, if a device is in use and it does no hopping, that frequency is pretty much useless for devices that do hop.
We are seeing so many things using RF nowadays. And we are going to see many many more. Hell, I love wireless things. But I also realize that the more things I own, the more the possibility that they are going to start colliding. That is why I try to spread out between the different bands.
You don't need a license for the 2.4Ghz ISM band.
This is the band that your microwave oven works in (though that is supposed to be shielded)
Really, it's only licensed for spread spectrum use, either FHSS or DSSS.
And yes, it is possible for the two to smash each other. fhss devicess will tend to not smash each other.. and dsss won't either, as long as power levels are reasonable, but if you mix them.......
Unless you have a pre-GSM analog phone, which I know nothing about, then no, cellular phones in the UK don't transmit a 3-5 times the power used in the rest of Europe. Handheld units for GSM 900 output up to 2 watts, and GSM 1800 up to 1 watt. In reality the power is usually less than that, and it's determined by the network based on the strength of your signal when it's received at the tower (ie it's going to be really low if you're really close to the tower, and much higher if you're far from the tower and/or there is something blocking your signal).
This is very interesting.
Now I know the power output is nothing like that of a microwave oven but, it does make you think. There have been links made between putting cell phones next to your head and brain tumors...
Beyond that... it is well documented that electromagnetic waves in the microwave range can cause psycological effects in humans (in fact, I believe this was one of the many things that certain government agencies did some research in to see if they could use it to modify behavior)
I have to wonder what the long term effects of "imersing" yourself (for lack of a better term) in a "bath" of low power microwave rane EM radiation is.
Interestingly, health risks are exactly the objection that a co-worker of mine cited when we talked about deploying wireless ethernet in some places around campus...his background? Well he is a HAM radio operator and said "I know the risks and I voluntarily use the equipment with that knowledge. What about people who just happen to be nearby and don't even know its there - they don't get a choice" (or some similar sting of words to that effect...was a few weeks ago)
Food for thought.
"I opened my eyes, and everything went dark again"
Back in the 70's some friends of the family had a remote control TV. Their little boy had a fire engine toy that rang a bell when you push it along the floor. Everytime the bell rang in the same room as the TV, the TV changed channels!
You can see why ultrasonic remotes went the way of the dodo.
Pope
Freedom is Slavery! Ignorance is Strength! Monopolies offer Choice!
It doesn't mean much now, it's built for the future.
Most countries in the world limit the 2.4GHz band - although it is unlicensed - by power output. The US gets 1 Watt max, UK and Europe get 0.1 Watts (France keeps changing its regs) and the Middle East still hasn't fully complied:)
Frog51
Frog51
Unfortunately, the 802.11 Frequency Hopping standard does not allow the device to learn which parts of the frequency range are interfered with. It would be nice, but it just can't happen, as it would screw up so many other parts of the standard.
Sorry to disappoint
Frog51
Frog51
Yes but you dont need to induce the power into the enginge. Mess up the controls and you could get a freghttrain to run amok. It has been done with planes ( cellphones, you know the rest ) Perhaps you should enlighten us? How exactly _did_ such a low-power radio such as a cell phone mess up the _controls_ of an aircraft? No, you are horribly and woefully misinformed. (or you completely lack understanding in this area, in which case you shouldn't say anything) What happens with cell phones and aircraft has nothing to do with the controls, but the navigational equipment that recieves radio signals. Since these devices are likely to overlap in the frequencies they use, it's not such a huge leap of logic as to why such navigational equipment might not be very accurate under these circumstances. It's also worth noting that freight trains do not need radio navigation equipment to find their way. You shouldent underestimate the strangeness of things that can happen when dealing with HFEM radiation. Riiiiiiight. Seen any funny lights in the sky lately?
---
"No problem. I have the capacity to do infinite work so long as you don't mind that my quality approaches zero."-Dilbert
And on most wireless phones and LANs there's only ONE preset frequency, and since it's neatly set at EXACTLY 2.4 GHz, ofcourse they'll interfere...
I don't know about wireless phones, but wireless LANs (at least 802.11b) usually have the option of 11 frequencies in the 2.4GHz band in the US. Other areas of the world have different restrictions. Usually a 5 channel separation will eliminate interference from other 803.11b devices, so if you are using channel 6 and your neighbor is using channel 1 and your other neighbor is using channel 11 their shouldn't be a problem.
This is supposed to be great art. So why does it look like a bunch of decapitated naked people? -- Calvin
This generally shouldn't become an issue, as the 802.11 standard allows for intelligent loadsharing (assuming rf coverage by more than one AP).
Certainly, we like to overlap quite heavily in industrial areas - continuous coverage by 3 AP's for any mobile device pretty much guarantees robustness (for hw fail or congestion) - of course using Voice over IP over 802.11 rf does mean we need nice fast routers in there as well:)
Frog51
Frog51
Well, the phones have a whole stack of problems in their own right. First, any idiot can tune in to them (no encryption). Second, they interfere with each other a lot. You're not likely to notice the second, unless you live in between a college dorm and a college sorority, like I do (thank you God). At any rate, I'll keep the 802.11, and I'll keep the phone, since nobody really cares what I am getting on my pizza.
Eh...
Man, first its kids getting all hopped up on "Placebo", now this "Wireless" stuff!? When will the madness end?!
It's 10 PM. Do you know if you're un-American?
I have a rack of machines with FM tuner cards that recieve and stream FM radio for local radio stations on the net. The things are all hooked up to a cybex KVM switch (AutoView 200) with a "longview" extension that runs the video, kbd, mouse, etc over a piece of Cat5 200 feet away.
For some bizzare reason, the Longview box spews all over 107.9MHz making it impossible to recieve that radio station inside of the office (I had to go with a roof-mounted antenna)... The other funny problem with 107.9MHz was that whenever I tuned one of the radio cards in the rack to the station, one of the computers would crash! I taped a piece of lead foil around the chassis. I think it was screwing up the SDRAM (whose oscillator was probably a little bit funky and going at 107.9MHz!)
~GoRK
Actually all frequencies can interfere and resonate with your various body parts. It has being established that in experiments with rats and mice frequencies on which US cell phones operate cause the rodents to develop disorientation and worsens their further learning abilities. Of-course rats and mice are not people but in some respect mice are the closest human cousines, they have the DNA closest to the humans (after the primates of-course). So it's not only your wireless network that is suffering, it could well be your wireless brain too.
You can't handle the truth.
http://www.wirelessethernet.org/
'nuf said.
-- From Denmark
I'm from Holland and like in every country we also got out television and radio stations, next to a line up of GSM networks. All of these have transmitters. The GSM's have small antenna's which are spreak among the country but the television and radio have one big antenna which allmost covers the entire country. And here the fun part begins.... People living there are having extremely difficult times in buying electrical equipment. Why? Because it hardly works and or acts extremely funny. And I'm not talking about weirdness like we all know from Windows. No; this is serious stuff. Like electronic stoves going crazy (hot / cold), microwaves which act crazy or not at all for no reason what so ever, electric trains which run out of their own; a copper wire is more then efficient. Things are so bad that most people just can't use any electrical devices such as computers; they don't work as it should. Things are so extreme that local re-sellers are refusing to sell these people electrical equipment since they keep claiming due to problems.
So basicly this article doesn't come as a surprise to me. There is more going on then people know, and all the radio waves out there are doing something. IMHO even more then most people realize.
I chose an ad hoc configuration, so there was no problem; the non-pro version of the driver should work to connect windows to Linux (in fact I'm using the standard aviator driver on one of my home machines, and the raytheon version of the pro driver -- for the same card. The only difference is the pro driver supports communication to access points used to bridge the wireless network to the ethernet. Instead, I created a separate subnet and use the Linux box as a router. You could, i guess, bridge if you wanted to set it up in your Linux kernel. I haven't tried it.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
There have been some past articles in slashdot about adapting Apple AirPorts (try a search) to a parabolic dish for extended distances. The aviators cards cannot be so adapted because their antenna is integrated.
I'm not sure, but think you may be using the term "bridging" somewhat loosely. If by "bridging", you mean to maintain a single broadcast domain but to segregate out unicast packets, I believe it can be done by configuring your kernels for bridging. However, I don't see much point in cluttering the airways with broadcast packets.
If you want to connect two networks, I would have a Linux box on each end acting as a router. The aerial link becomes another subnet. I wouldn't try running the laptops off the same subnet; I'd get an additional card on each end to handle the local subnet (because you replaced the antenna on the link card with a directional one).
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
2.4 Ghz , in respect to 802.11b and such, is actually a band from 2.4 to 2.49 or something.. I forget exactly.
Microwave ovens operate right in the middle of this.. and there is a reason....
that's why ISM is the Industry, Science, and Medical band..... and the reason it is unlicensed is mainly because of this.
2.4 Ghz has all kinds of industrial uses, so it's 'dirty'.
So.. first off, your microwave oven is 100% shielded basically... there should be absolutely no leakage.. (not that it would be a big deal if there was a bit).
I can operate a 2.4 Ghz DSSS router right next to 2 microwave ovens and it continues to pump out 11Mbps.
I install 802.11 networks by Symbol, Lucent and Telxon (Aironet/Cisco) and this is something I come into contact with more and more.
Frequency Hopping (FH) devices tend to kill the reception by Direct Sequence (DS) devices, mainly due to the differences in signal strength. Multiple DS networks can happily coexist, and run at 1,2,5,11 or 25 MBit/s while keeping the actual signal at below ambient noise strength (nice - security-wise)
FH networks just tend to upset all other 802.11 networks, and they only go up to 2 Mbit/s at the moment. The reason people use them is that they are very stable and solid. They just work, without tweaking!
With todays bandwidth demands, you have to go for the 25 Mbit/s gear (which gives you throughput roughly equivalent to a 40Mbit/s ethernet type protocol - due to use of CSMA/CA not CSMA/CD) so things should get better as more people use DS not FH:)
Frog51
Frog51
I'm really mystified by the cause, I'd appreciate anybody who know what the 'cause is because I really do worry about my brain getting fried by these things.
Well, he gives us the answer in his article. ... well, one can understand why there's just not enough of the bandwidth left. Just like with the 900MHz range, 2.4GHz is in the ISM band (Industry, Science, and Medical), the two options at this point are: change the 802.11b devices to 5.7GHz devices, or stick with 900MHz for the appliances to free up the 2.4 for the NICs.
In the 802.11b (the b is important) standard, he's using DSSS (Direct Sequence Spread Spectrum) radios as opposed to frequency hopping. This means he's able to get up to 11Mbps per device, but, it also means only 3 non-overlapping channels. While there are many channels (11 or 12, IIRC) in the 2.4GHz range, the DSSS 11Mbps radios lump multiple channels together (802.11 radios were 2Mbps because they only used one channel instead of groups of channels). Now, toss the Seimens Gigaset (which is also Spread Spectrum, I believe) and other wireless devices into the mix and
Just my thoughts.
For home use, you can save major dough by skipping the access point and using peer to peer ("ad hoc"). Cost is about $80 per node for 2MB access using the webGear aviator 2.4Ghz card, including two ISA PCMCIA adapters. The webgear aviator card is a relabelled raytheon raylink card, so you can get the "professional" features (mainly the ability to access an access point) by downloading the raytheon drivers for Windows.
The raylink drivers are also included in the all the recent Linux PCMCIA subsystems, as well as the Lucent WaveLan cards (much faster, shorter range); don't download any "drivers" from the WebGear site, they're stale. Under Linux, the card works like a charm, far better than under windows; I can pop the card in or out as necessary without my system hiccupping, whereas Windows tends to hang.
In any case, I can roam around the house or out into the backyard with no problem. I used it to share an Internet connection with our kitchen computer because for $160 bucks for a pair, it was well worth avoiding the hassle of pulling cable, and 2Mb/sec is plenty fast.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
Ofcourse this is expected to cause problems... What's concerning me is, as the article proposes, that the manufacturers do not seem concerned about this. In the old days when You bought an open fequency "commodity" (anything really), You could usually "tune" the set to a slightly lower or higher fequency (as You changed Your crystals). This option seems to be gone from most equipment You buy today. I tested a Wireless Video/Audio transmitter set, and it only had TWO settings for frequencies ! Suppose both my neighbors had the same set ? And on most wireless phones and LANs there's only ONE preset frequency, and since it's neatly set at EXACTLY 2.4 GHz, ofcourse they'll interfere... So what are we supposed to do ? Shield the transmitter and reciever in a cage ? Might as well go back to wires then.
No this is DEFINATELY up to the manufacturers to work out. if they want to sell their crap to us. They better make sure it works.
If you have any combination of cordless phones, wireless ethernet, wireless video, or Bluetooth you could be having problems. Not only will your bank balance will be suffering a from the debhilitating effects of continuous expenditure on unecessary geeky networking technologies, but your health will be in sever danger.
An article to be published in the Lancet later this month will show how people can suffer serious side effects from replacing all the cables in their house.
"It started happening after I went to one of those underground Linux install parties" reports a young man, who we'll call 'Alf'.
"At first, it was just phones. You know, people passing around some Nokia's and Ericssons, and it felt really good to be cordless. It was like I was with the in-crowd."
"After a few weeks though, people started getting out the infra-red enabled PDAs out. I didn't think anything of it at the time."
But, as the report shows, cordlessness is an unpleasant and addictive activity, and it's only a matter of time before the serious health implications start. 'Ben' has been in re-hab for three months now, getting used to staying in the same place when he talks on the phone, and being re-trained in Cat5 cabling.
"I can't remember much towards the end" says Ben, "I was really out of it. There was like about 4 of us in this house in Shoreditch, you know with serious 802.11b right through. It was like a permanent trip. We used to have these wild parties at weekends with loads of girls and booze, it was pretty wild, people doing it with like Psion5's and i-mode phones, really f**cked up stuff."
But although Ben is recovering, it's a growing problem thoughout London and the whole of the West. Dissatisfied with their parents' strict ideas of free love, home grown dope, and long skirts, the young generation are turning to hardcore wireless technologies, with street names such as Bluetooth, WAP and i-mode.
Next: The Goverment launches "War on Wireless" to stop this disturbing trend in our young people.
-----
- ETS 300 328
- ETS 300 826
The later standard is used for Bluetooth applications; from what I understand all equipment must abide to ETS 3090 328.The fact that the Siemens Gigaset and X10 are noisy could be that the ETSI standards actually allows them to do prett much what they want to; it could also be the case of bad design of the X10 or Gigaset equipment. I have seen plenty of cases where equipment from wellknown manufacturers claims to be approved according to CE emissions standards (EN55022/23), but when measured up proves to be way of.
Regarding Bluetooth, it is my understanding (after working with it for one year from a hardware designer perspective) that BT is designed to work in "noisy" environments. BTs frequency jumping scheme is designed to make the most of the frequency band, even if there are cordless phones and wireless LANs using the spectrum also.
Also, BT is a low power technique in contrast to IEE802.11 and possibly the cordless telephones.
I have followed some threads regarding possible interference between IEEE802.11 and BT, and the latest information is that they do not interfere and thus can coexist.
Standard disclaimer: I may be wrong
The author of the linked article is obviously inadept at grasping the reality of what he was witnessing.
The 802.11 cards and Siemens phone system are frequency-hopping. By switching frequencies often, they reduce overall interference at the expense of a little bandwidth (there's plenty of room at 2.4GHz for these things to co-exist). Some types of frequency-hopping "spread spectrum" devices will dynamically learn trouble-spots and avoid them, bringing bandwidth back up to a point approaching ideal (unless that entire block of spectrum is completely hosed).
So, the phone system and wirelss LAN should work fine together. There will be a slight (measurable, but imperceptable) decrease in bandwidth for the LAN while phones are in use. The phones, if they're poorly designed and/or the CODEC is intolerant of errors, may suffer an occasional (and very brief) dropouts; due to the real-time streamed nature of the device, retransmissions aren't possible as they are with 802.11. I don't suspect these dropouts would be overly bothersome, or even noticable in most instances.
Interestingly, the X10 video-sender box was the last thing he threw away. Oddly enough, that's the device which should have gone away *first*. It's cheap - too cheap to use any of the present-day bandwidth-reducing digital coolness of most other 2.4GHz devices. So, it spews forth broadband analog video - likely using *more* bandwidth than a TV station to avoid expensive modulation/demodulation parts - destroying the 2.4GHz for the rest of the household toys. Remember the remark above about the spectrum being completely hosed? This is probably a better example of an RF monster than anything else available to a consumer today.
Had he turned off the bargain-bin X10 stuff first, I strongly suspect he would have had no further difficulty (and would continue to enjoy the hideously-cool phone system).
That all said, I really don't see the need for moving to 2.4GHZ for *everything*. It offers more bandwidth for a given slice of spectrum, which is nice - and really not needed for things like telephones. I prefer to get my cancer from tobacco, standing too close to the microwave, and hanging out by 600,000 volt transmission lines - not talking on the phone.
Kid-proof tablet..
I recently bought a siemens gigaset, however I have this terrible problem with a loud oscilating ring and echo noise. I was wondering what kind of interference could create an _echo_? I thought it was rather strange... I should try to turn off our microwave see if that helps.. but its built into the house so that's easier said then done.. it means flipping the circuit breaker for 1/2 the kitchen...
These problems are no different than when you go to Radio Shack and buy some of their radio controlled toys. The toys are plainly marked what frequency they run on. If you get two cars that are on the same frequency and try to run them at the same time, of course they are gonna go wacky!
We are going to see more and more devices up at 2.4 GHz. What is the solution? Quit it! It is that simple.
These same problems everyone is gritching about is how it was with the early 49 MHz phones. Someone would get one then their neighbor would get one and they would inevitably take them back to the store because "they were broken". Well, sorry, but they are not broken, it is just that someone else is on that frequency also.
Look around your house and check out how many wireless devices you have. Do you need 3 cordless phones? Do you need wireless TV transmitters and ethernet cards too? Yeah, they are nice, but when you start getting interference between them, well, I hate to say it, but there is only one person you can blame for it.