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How Reliable is 900Mhz Wireless Internet?

Posted by Cliff on from the gauging-the-airwaves dept.

amrust asks: "I live in an area that currently is not being served by broadband in any way. Local ISP's are discussing bringing Wireless Internet into our area, and for some of the more difficult to reach places, they have mentioned 900Mhz being used. I was wondering how reliable/secure the 900Mhz spectrum is for Wireless Internet, and if anybody has some comments on experiences with 900Mhz wireless internet that they can pass on?"

67 comments

  1. It's so reliable by Anonymous Coward · · Score: 4, Funny

    That I'm currently typing this comment usi

  2. Frequencies by hackwrench · · Score: 3, Interesting

    Any frequency is just as secure as any other. It depends on the protocols that run over it.

    1. Re:Frequencies by Anonymous Coward · · Score: 0

      1. On topic
      2. Intelligent
      3. Correct
      4. ???
      5. Mod points!

      And I can't even say "you must be new here." :(

    2. Re:Frequencies by The+Clockwork+Troll · · Score: 1
      Good point.

      For the newer users, we have an example of an unsafe protocol.

      --

      There are no karma whores, only moderation johns
    3. Re:Frequencies by Anonymous Coward · · Score: 0

      Any frequency is just as secure as any other. It depends on the protocols that run over it.

      You'd be correct, except the topic is not security. It's reliability. Read the headline. And on that topic, no, some frequencies are more reliable than others due to legitimate overuse of that piece of spectrum, unintended interference into that piece of spectrum, and natural and man-mad attenuations on that piece of spectrum.

    4. Re:Frequencies by Anonymous Coward · · Score: 0

      You'd be correct, except the topic is not security. It's reliability.

      You'd be correct, except the original poster referred to both. But this is Slashdot, where we don't even read the summaries!

  3. Phone Frequency by rritterson · · Score: 5, Informative

    I don't have any personal experience with 900mhz, but i do know that it is the same frequency that cordless phones use. Some phones today use 2.4ghz and they cause interference with .11b and g (my friend's neighbor has a phone that is so powerful it knocks my friend offline everytime the neighbor turns it on.) There are many more 900mhz phones that 2.4ghz phones, so I'd assume the problem is worse.

    However, you are in a rural area, so maybe the congestion on that band will be somewhat less (We live in a major metro area).

    --
    -Ryan
    AUWYHSTOT (Acronyms are Useless When You Have to Spell Them Out Too)
    1. Re:Phone Frequency by Anonymous Coward · · Score: 1, Insightful

      900 Mhz phones have been on sale for far longer than their 2.4 gig counterparts. It's really quite safe to say "There are many more 900mhz phones than 2.4ghz phones."

      The world looks quite different when you're not quite so fresh out of diapers, so please go back to your Nintendo and leave the computers to the grown ups.

    2. Re:Phone Frequency by semanticgap · · Score: 1

      Your friend should report his neighbors to the FCC because any 2.4GHz cordless phone is supposed to use spread-spectrum and therefore will not interfere with 802.11b.

      --
      grisha.org
    3. Re:Phone Frequency by The+Clockwork+Troll · · Score: 1
      Nice try loser. Most phones use 2.4GHz now. And 5.8GHz phones are already out. Try reading more.
      Hi there, I'm from Merv Griffin Productions.

      We'd like to invite you to come try out for our forthcoming game show, Cordless Phone Jeopardy.

      By any chance can you arrange transportation to Go-Fuck-Yourself, Indiana for tryouts on July 26th?

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    4. Re:Phone Frequency by cdrudge · · Score: 1

      I thought only the digital phones used the spread spectrum. The analog 2.5GHz phones didn't have to be...otherwise, wouldn't they advertise the spread spectrum feature on the box?

    5. Re:Phone Frequency by Anonymous Coward · · Score: 0

      They will always use lower frequencies to reach places that are more distant. Think of it this way..

      Let's say you have some really loud music in one room. You leave that room and close the door. You go and sit in the next room. What do you hear more over any other tone in the music? The bass, aka the lower frequency. Lower frequencies can travel through things much better than higher frequencies can.

  4. I would assume... by twiztidlojik · · Score: 3, Interesting

    That it would be more reliable to use the higher spectrum. If you can transmit 900 million waves/second, then you probably can't fit as much error correction in the stream as the protocols used in 2400 million waves/second communication due to the lower bandwidth of the 900MHz band. Then again, I'm just guessing. Any radio geeks want to take a stab at this?

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    1. Re:I would assume... by rritterson · · Score: 2, Insightful

      I don't think this is true. Bandwidth is not directly proportional to frequency.

      It's not 2400 million waves/sec it's 2400 million peaks per second on a single wave.

      The major differnce is the depth to which the signals will penetrate, and their loss over distance.

      --
      -Ryan
      AUWYHSTOT (Acronyms are Useless When You Have to Spell Them Out Too)
    2. Re:I would assume... by dJCL · · Score: 4, Interesting
      Based on my phone experience, I've owned and generally used both a 900 and a 2.4 phone. The 2.4 sounds better close in and can get a good secure connection to the base station within about 100+ meters of my base station. On the other hand, my 900 was quite capable of connecting to me when I was over 250+ meters away. The connection quality was pasable, but the range was great.


      The reason they are probably using 900 is for connection distance. The same equiptment will cover more users with probably less bandwidth, but that is a price to pay.


      As someone else noted, security of the connection has nothing to do with the frequency, so just discuss that with the provider. As it is, still 80% of the wireless networks that I run into are even setup with WEP(mine is not, but I have other ways) and most are default settings, so if the provider even tries to put in some security, no one will bother with them unless they have a reason.


      Enjoy!

      --
      On Arrakis: early worm gets the bird. Magister mundi sum!
    3. Re:I would assume... by thebigmacd · · Score: 3, Informative

      Bandwidth IS directly proportional to frequency. Baud Rate (in the scientific sense) is exactly twice the frequency. @ 900 MHz, the bandwidth is 900 MHz, the maximum switching rate (BAUD) is 1800 MHz. tha Shannon Channel capacity, assuming 60 dB signal-to-noise, is 900e6log_2(1 + 1,000,000) = 17.9 Gb/s. obviously, this is extremely high. it is technically possible to hit this raw rate of data transfer. and it is impossible to exceed this value without data compression

    4. Re:I would assume... by Anonymous Coward · · Score: 3, Informative

      When they say "transmit at 9OO MHz" of course you can not send any real data if you transmit ONLY at 900MHz. Because that would be a single unvarying siqn wave at 900 MHz.

      Instead, you are allowed to vary around 900 MHz. I think the standard 900 MHz is really 900 MHz to 914 MHz.

      So 14 MHz is the WIDTH OF THE BAND, otherwise known as BANDWIDTH.

      At any particular center frequency you can set a wide or narrow range around it.

      I'm not even a ham or anything, come on guys I learned this by osmois somehow. You should know this.

    5. Re:I would assume... by unitron · · Score: 2, Informative

      If the bandwidth is 14MHz then the center frequency above and below which the carrier will vary would probably be 907 MHz. However 14Mhz is wide enough for about 2 and 1/2 regular television channels, so for a telephone call, which only needs 0.0027 Mhz of bandwidth, I expect that only a small part of that 14 MHz is used with the rest available for other cordless phones in the same area.

      --

      I see even classic Slashdot is now pretty much unusable on dial up anymore.

    6. Re:I would assume... by innosent · · Score: 4, Informative

      The important factor here is how efficiently the signal can pass through a medium, and how directional the signal is. We don't live in a vacuum (if you didn't know this, you might need to get out once in a while :P), and therefore any signal sent has to travel through any objects in its path, including the air. Not sure exactly off hand which law of physics covers this, but lower frequencies lose less energy when passing through a medium, and are also less directional. Think about sound here, a low frequency (bass), say 40Hz will have relatively no problem passing through an object, like a car driving in front of your house at 2:00A.M., but a high frequency (treble), for example 10kHz is highly directional and has great difficulty traveling through objects.
      I believe this is due to the fact that to pass a signal through a medium, the particles in the medium must be excited to the same frequency as the signal, and it takes significantly less energy to excite a material at a lower frequency than it does at a higher one. Higher frequencies give higher fidelity, but are less resistant to signal loss.

      --
      --That's the point of being root, you can do anything you want, even if it's stupid.
    7. Re:I would assume... by n9hmg · · Score: 3, Informative

      Bandwidth IS directly proportional to frequency
      What?
      <SARCASM>Wow! I can do morse code at only about 8wpm (which equates to about 40 baud) on 80M. Does that mean that I can do 856wpm on 70cm?
      ...and WOW! I can crank up my 1200baud packet system to 3600baud by just switching from 2M to 70cm. Thank you, oh great radio genius!</SARCASM>
      Sorry, but that's such an offensively ignorant statement from a member of a very technically-savvy group that I have to go off on it a bit. Frequency occupied by a signal indicates how much data could be fit in it. Depending on your modulation scheme, you'll reach some significant fraction of that bandwidth. In a perfect propogation environment, with perfect components on both ends, that fraction can asymptotically approach 1. For relatively-reliable real-world links, you'll be running well below 50% of the theoretical throughput, to make it easier for the receiver to discriminate the actual states of the transmitter. Ethernet is an example of a protocol expecting near-perfect transmission. Ever had a 100MBps link fail back to 10 because of crappy terminations, or had any link degraded? That's because individual packets are simply not getting resolved by the receivers, due to substandard signal-to-noise ratio - noise leaking into the cable and/or signal leaking out.
      That's why 802.11 links drop in speed, so the reciever can sort of go "Is that bit off or on? It sounded on, but it's really not much different from the static. Well, it keeps looking like it's on. Yes, that's definitely '1'", while at higher speeds, there's less chance to discrimnate the signal from the noise.
      Have you ever worked in a really loud factory? You can't understand anything coming over the PA system, but the signal tones sent over the same system at the same volume in the same environment are perfectly understandable.
      Now, if systems used everything from DC to their operating frequency, a 2.4Ghz system would have about 2.5x the potential bandwidth as a 900Mhz system. In fact, however, the systems use a slice of spectrum in the range of their stated frequency. I don't know the amount of spectrum used by these systems, but I know some things about the frequencies and the environment they work in.
      First: In general, path loss increases with frequency. My beam has nearly 3 times the gain on 70cm as it does on 2M, but using the same power, I can work stations much farther away with 2M than 70cm.
      Second:there are specific absorptions in different frequency ranges. Since the early 1970s, at least, many households have made use of the strong water absorption band around 2.4Ghz to heat food in microwave ovens. That means two things A)2.4Ghz performance is significantly affected by humidity. B)There are ubiquitous high-power ISM devices in the band. Why do you think most 802.11b gear has a setting to work around microwave ovens?

      In the end, you're probably going to be using a system with throughput capability many times larger than the amount you are to receive, which will allow for big sags in performance to not hurt you unless they coincide with peaks in demand. I would recommend going for the one with the smaller collision domain. I bought into Sprint Broadband Direct, which uses large swaths of licensed spectrum (no significant interference). This system operates from single central systems covering vast geographic areas - mine is a mountain 16 miles away, and i'm near the fringe. That's 804 square miles. Half of it is blocked by the mountains behind it, but the sector it does cover is heavy population (north of Denver). That means that even though the RF transit time to the tower is insignificant, My unit has to wait in line for a long time for its turn to transmit, giving me ping times ranging from 100ms (quite acceptable) to 5 seconds (no interractive work over VPN, I can tell you). Mesa networks has come into the area now, using 802.11B and gain antennae. Base stations are on poles (cell sites, phon

    8. Re:I would assume... by jafuser · · Score: 1

      Heh. My 2.4GHz phone got interference whenever someone used a microwave oven nearby. =)

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    9. Re:I would assume... by jafuser · · Score: 1

      I'll admit I don't know a whole lot about this, but can't you get more than 1 bit per baud by using something like QAM?

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    10. Re:I would assume... by gregeth · · Score: 1

      One thing to add, though, is that the higher the frequency, the more "noise" you will have to deal with. I'm not really sure at what kind of filtering processes are used to combat this, but I have noticed that some 2.4Ghz phones have a lot more static than the 900 ones.

    11. Re:I would assume... by jafuser · · Score: 2, Funny

      Ok, after reading up on this and re-reading the post I responded to, I am offically declaring my reply stupid. =)

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    12. Re:I would assume... by ChaoticLimbs · · Score: 1

      you don't know anything about RF. This is the CARRIER FREQUENCY (900MHZ). The data rate in bits per second (baud) determines the deviation and band-width of the signal. In no circumstance have I EVER seen bandwidth exceed 1/8th carrier frequency for free-space signals. To get 17GB/s you would need a carrier deep in the microwave spectrum, and an extremely efficient DPSK or QPSK digital modulation. Your mathematical analysis is nice, but completely based on you plugging in numbers without knowledge of what those numbers represent in the real world. And sure, you could probably deviate a signal to 17.9gb/s but at 900Mhz you would be using every bit of the spectrum from 1 hertz to around 2 gigahertz. It just can't be done in a practical way. How do you design a resonant circuit that will resonate at one hertz as well as 1800 megaherts? and every frequency in between? And how do you tune your transmit antenna so you don't reflect waves back into your amplifier? The formula you use here is completely useless in the RF spectrum. What you have there seems to be designed to calculate bandwidth based on transmission in a cable or waveguide, and clearly states that RC where R is data rate and C is channel capacity.

  5. It's perfectly secure by anthony_dipierro · · Score: 5, Funny

    All the sniffing software is written for the 2.6Ghz range, so you can rest assured that no one other than you and the intended recipient will be able to read the message.

    1. Re:It's perfectly secure by Anonymous Coward · · Score: 1, Informative

      Nice troll.

      But I'll bite.

      First of all, its the 2.4Ghz range.
      Second, security through obscruity is complete rubbish, 'no one other than you and the intended recipient will be able to read the message' is a load of, quite frankly, bollocks.

      Mod this down.. no need to give trolls karma.

    2. Re:It's perfectly secure by anthony_dipierro · · Score: 0, Offtopic

      Nice troll.

      Thanks.

      Mod this down.. no need to give trolls karma.

      Or if you're going to mod it up, at least go for +1 Funny instead of +1 Interesting. Stupid moderators.

    3. Re:It's perfectly secure by bobthemonkey13 · · Score: 3, Informative
      1. IIRC, 802.11b is 2.4GHz.
      2. It's a question of hardware, not software; most current wardriving software has support for other systems such as 802.11a and g as well as b. In theory, they could also sniff on 900 MHz if there were 900 MHz cards that supported the right software interfaces.
      3. Remember that there's much more to a secure connection than just the "last mile" from your ISP to you. Depending on the network itself for security is risky at best. To really ensure security, you should always assume that your neighbors, your local bank robbers, and the NSA are all snooping on you, and simply encrypt anything important. And please use a good algorithm; WEP doesn't count (this is aimed mostly at the 802.11b crowd, obviously).
    4. Re:It's perfectly secure by anthony_dipierro · · Score: 1

      To really ensure security, you should always assume that your neighbors, your local bank robbers, and the NSA are all snooping on you, and simply encrypt anything important.

      No, to really ensure security, you should always assume that your neighbors, your local bank robbers, and the NSA are all snooping on you and they have your encryption key.

      If it's that important, you shouldn't be transferring it over the internet at all.

    5. Re:It's perfectly secure by bobthemonkey13 · · Score: 1
      If it's that important, you shouldn't be transferring it over the internet at all.

      Right, but that kinda defeats the purpose of the question. ;-)

      But yes, I do agree that crypto is nowhere near a bulletproof suggestion (literally, if you're talking DoS attacks). For it to be of any use, you still need basic smart computing practices: don't give out your passphrase, don't install a Trojan horse, keep your computer in a secure physical location, etc. But the fact of the matter is that just using SSL for credit card transactions puts you above the low-hanging fruit (in this case, people sharing their financial data on KaZaA or Windows fileshares, or emailing it in the clear). If you're plotting world domination over the internet, that's another thing.

    6. Re:It's perfectly secure by Anonymous Coward · · Score: 0, Offtopic

      Maybe the moderators are trolling.

    7. Re:It's perfectly secure by anthony_dipierro · · Score: 1, Offtopic

      Good point.

    8. Re:It's perfectly secure by lizrd · · Score: 1

      WEP isn't for protecting data. It's for giving the war driving script kiddies a reason to use my neighbor's wireless network instead of mine. Wireless security is a race to the bottom and as long as you aren't running downhill as fast as the rest you're pretty safe.

      --
      I don't want free as in beer. I just want free beer.
    9. Re:It's perfectly secure by jrockway · · Score: 1

      I can relate to #3. I can ARP-poison the gateway of my ISP (wireless over 802.11b) and get EVERYTHING. Passwords, mail (someone's using our mail gateway to relay spam :), IM, you name it. Worse, my school doesn't let me have encrypted POP/IMAP sessions, so I can't make my data safe. Time to setup some SSH tunnels, I guess :(

      What worries me more is that anyone with a pringles can and a wifi card can sniff the connection!

      --
      My other car is first.
  6. Try Google groups by klui · · Score: 4, Informative

    Just picking up from the first page yields some tidbits. Range, reliability; Interference.

  7. Wait for it to reach the 1 GHz range... by Anonymous Coward · · Score: 0

    You'll be able to boast to all your friends then.

    1. Re:Wait for it to reach the 1 GHz range... by Anonymous Coward · · Score: 0
      Oooh, can I overclock my cordless phone? I have the special conductive silver goo to bridge that sneaky laser cut lead!

      Better yet, can I underclock it and make my own radio station?

  8. 900 mhz is just as good by r00tdenied · · Score: 4, Informative

    Most WISP's use 900mhz where there is a substantial amount of tree cover. 900mhz can penetrate the tree canopy much easier than 2.4ghz because of the wavelength.


    2.4ghz has a problem with dense water, and in tree leaves their is significant amount to cause multipath reflection. Multipath reflection is caused when the wavelength of any given radio signal is short enough to be relected by the water molecules.


    At 900mhz the wavelength is much greater than 2.4ghz so it doesn't have as much difficulty.

    --
    Platinum Networks Hosting www.platinum-networks.com
  9. Oops by Anonymous Coward · · Score: 5, Funny

    It's so unreliable that I just stole this guy's password and am now posting as him.

    1. Re:Oops by rasteri · · Score: 1

      You stole Anonymous Coward's password?? You inconsiderate clod!

  10. Anecdotal by Jahf · · Score: 5, Informative

    I listened to Bill Joy talk at a conference in Aspen where he went into fair detail about the 900MHz system they had installed there long before 802.11b came about (if anyone remembers seeing a story about an Aspen cabby with a totally connected neon taxi cab, he was using this system for his net access).

    Anyway ... for long distance penetration through anything other than air, 2.4GHz plain sucks (I'm using a WISP now and occasionally when strong winds hit I have to give up working for awhile ... shame). Mr. Joy did mention that they weren't able to get more than a few hundred Kb/s out of their system, but that was acceptable for a few dozen people sharing a single T1 and the system sounds like it was rock solid stable.

    If you only have one choice (or if you consider a normal dialup line a choice maybe 2) then that is definitely not a bad one. I think I would actually prefer my 2.4GHz ISP to offer 900MHz as an option. Instead they're switching to 5GHz for high-end use ... though since their 5GHz access point doesn't have trees between it and myself and it is far less war driven I will probably switch to that anyway.

    --
    It is more productive to voice thoughtful opinions (reply) than to judge (moderate) others.
  11. Many types of "900mhz wireless" by RALE007 · · Score: 2, Informative
    There are multiple wireless standards that operate within the 900mhz range. Without knowing which standard at 900mhz your local ISP's are considering, one cannot comment on the security or reliability of the unknown methods of communication that may be implemented in your area.

    I would recommend digging a little deeper to see what standards are being considered, then visiting this very informative page at IBM.com pertaining to current and emerging wireless standards. Once you know the exact standard the ISP's are considering, you should be able to have your questions concerning security and reliability answered on the IBM link provided.

    --
    Beware blue cats moving at .99c
  12. Totally different approach. by WasterDave · · Score: 3, Informative

    [disclaimer: the following is based on research, not personal experience]

    So, I've been looking at using 900MHz for some low bandwidth stuff. Primarily because 2.4GHz can be a PITA to deploy - near line of sight (over distance), trees, rain etc.

    Anyway, it appears that the products available round 900MHz have taken a completely different, and much more "agricultural" approach to the problem. Basically they're 900MHz FM radios with a modem bolted on. No clever multipath resolution, no time division, no orthogonal frequency division (outside that which the modem does). Consequently the amount of bandwith available is about seven eigths of fuck all - a claimed 115Kbit (being the limit of the RS232 connectors they use) - with something rather worse being the practicality of situation.

    Security is kinda interesting though. Quite a lot frequency hop across a range of channels within the spectrum. It appears that you need to get both radios, from the same manufacturer, and put them on the same hopping scheme before they'll talk.

    Dave

    --
    I write a blog now, you should be afraid.
    1. Re:Totally different approach. by battjt · · Score: 1

      waverider.com claims 2 Mb on their hardware and ranges of up to 2 miles without antennas.

      --
      Joe Batt Solid Design
  13. good and cheap by akb · · Score: 3, Informative

    Ricochet ran a well regarded service over 900mhz. They claimed 1 mile range from base stations, w/o line of site. So it is certainly possible to build a reliable service.

    Urban environments have a fair amount of 900mhz interference, in a rural setting you are probably much better off. Heck, w/ all the 2.4ghz phones being sold I wonder if 900mhz is clearing up some.

    There's a whole lot of cheap equipment around. I got 3 900mhz DEC Roamabout pcmcia nics for $12 (inc shipping). They are 2mbit and the linux driver worked perfectly.

    Many houses have old directional antennas for UHF TV that aren't used anymore because of cable / satellite. I've found a fair amount of these range up to 900mhz. So maybe you've already got an installed antenna and cable run in your house. If not you probably know someone who has one they aren't using or can pick one up for cheap.

    1. Re:good and cheap by JonnyRo88 · · Score: 1

      Where did you purchase the cards from?

      -Jonathan

      --
      The Ro Factor - Jeep/Linux Weblog
    2. Re:good and cheap by akb · · Score: 1

      Ebay.

    3. Re:good and cheap by David+E.+Smith · · Score: 1
      Note the keyword "claimed" to have one mile, even without LOS...

      I'll be honest, I never worked with the Ricochet stuff. Right now, though, my company (small local ISP, we also do wireless) does have some of the Waverider 900MHz hardware deployed. We have FOUR customers using it, as opposed to several hundred using the 2.4GHz stuff. Heck, I'm about half a mile away from one of the Waverider CCUs (basically, their equivalent of an access point), and I have to deal with the competition for my broadband because the 900MHz stuff just doesn't cut it, and (as I don't own the property) I can't put up an external 2.4GHz antenna.

    4. Re:good and cheap by ophix · · Score: 1

      oddly i work for a WISP not far from the hometown of mvn.net ... and we use the waverider stuff. we have good luck out of it, most of our customers are on it as opposed to the 2.4 (although 2.4 definately has more bandwidth to play with). dont use the damned 6db internal window mount antenna and you will be fine.

  14. That's what Metricom/Ricochet used.. by nesthigh · · Score: 2, Interesting

    so I'm sure it's doable..

    TechTV article about Metricom modems
    next

  15. ISM by Detritus · · Score: 3, Interesting
    900 MHz is an ISM (Industrial, Scientific, Medical) band, like the 2.4 GHz band. Unlicensed devices may not cause interference to licensed users and they must accept interference from other devices. This means that you are at the bottom of the totem pole in a "junk" band. If you can't use your unlicensed 900 MHz device due to interference, tough shit, that's the price you pay for unlicensed operation in an ISM band. Devices designed for ISM bands are usually designed with low cost as the primary design goal. That often means that there is no shielding and the RF electronics function poorly, or not at all, in a hostile RF environment.

    The end result is that you should keep your expectations low. If it works, great, if not, try something else.

    --
    Mea navis aericumbens anguillis abundat
    1. Re:ISM by Muad'Dave · · Score: 3, Interesting

      Amen to that, brother! As a part 47 user of 902-928 MHz, I have to deal with part 15 users noise. My local power company, Dominion Resources (aka VA Power) just installed some Schlumberger C1SR meters in my area. They're the kind that transmit usage data on 910-920 MHz as a part 15C device. As far as I can tell, they broadcast their info every min or 5 min instead of being polled - aargh! My whole neighborhood now has lots of meters blasting away for 99 44/100% of the month when there's no meter reader truck around to hear them. I could be a nasty boy and demand their removal if they interfere with my part 47 use - we'll see how bad it really is after I get a chance to quantify the interference.

      Of course, searching for manufacturer code F9C, product ID C1R-1 on the FCC Product ID Search page returns little useful info regarding the exact freqs and modulation techniques in use. They asked for and received confidential status on the most interesting bits. Ugh.

      PS - The FCC product ID search page can return all sorts of useful info on any product with an FCC ID. For instance, the info on the electronic key for my car returns schematics, data format info, etc. Sweet!

      --
      Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
  16. I use my house to University! Restrict use, maybe? by Fu+Ling-Yu · · Score: 2, Interesting

    I have found 900 mhz to be very reliable. I connect to network at University from home using 900 mhz network equipments. Sometime service is down for an hour here or there but this may be more because of problems at the University network.

    In China, we have ways of making sure wireless space becomes not over crowded. Crowded could be a big problem because of the population, billions of people! Only top academic, scientist and politican can use wirless networking in my city, because otherwise it'd be overcrowded. Perhaps similar laws could be applyed in your area, so that overcrowding of the frequencys does not occur?

    --
    -- Dr. Fu Ling-Yu, Internal Technology Consult; Tongji University, People Republic of China.
  17. Thank you by Jucius+Maximus · · Score: 1
    for asking this question. I am considering setting up my own WISP on 900 MHz in my area.

    I live in a broadband-less rural part of Canada lots of hills, forest, rabbits, etc. and 2.4 GHz probably would not stand a chance.

  18. Go for it by Anonymous Coward · · Score: 0

    The CPU on my older box is 900 MHz, and it has been quite reliable.

  19. I'm currently with a 5.2 GHz WISP by leifw · · Score: 2, Interesting

    My home internet connection is with a terrific WISP. I believe they use a 5.2 GHz radio band that is 128-bit encrypted. The service has been reliable; much more so than Southwestern Bell's DSL, but slightly less so than @Home's cable modem. The speed is also good (~85 KB/s) and resonably responsive (~80 ms ping to various points on the net).
    So while I can't comment on the 900 MHz band specifically, I can say that a WISP in general can be a good choice.

  20. Re:I use my house to University! Restrict use, may by ArsonPerBuilding · · Score: 1

    Billions? All 1.1-1.3 billions of people. Anyhow I don't think a law or regulation like that simply would fly, because laws that Americans disregard are practically unenforcable.

    --
    1 tequila 2 tequila 3 tequila floor
  21. How do you spell ass u me? by ls-lta · · Score: 1

    Impossible, no, line of sight with antennas at angles could exceed this value.

  22. frequency != bandwidth by js7a · · Score: 2, Informative
    @ 900 MHz, the bandwidth is 900 MHz

    On the contrary, as has been pointed out, frequency is not bandwidth.

    it is technically possible to hit this raw rate of data transfer.

    Actually, it is possible to approach the Shannon channel capacity the way you calculated it, but impossible in practice to achieve it. Technical possibility is not the same as theoretical maximum throughput.

  23. Mod down for being misleading by pr0ntab · · Score: 1

    If you could commandeer all RF 0-900MHz, then you could transmit 900MHz worth of signal. You need bandwidth to convey the information, and the channel capacity is the width of the band. If you aren't baseband, you modulate. 900MHz phones use frequencies near 902-928MHz (I forget), divided into 80 discrete channels of 25 kHz each. Each cordless actually uses two channels to acheive full duplex mode, and not all manufacturers use all 80 channels in each phone, so collisions are possible.

    Anway, the phones don't push more than 16kbps on those channels. So a wireless internet service using those bands would have to swamp out the cell phones in transmission power for it to occupy those bands.

    --
    Fuck Beta. Fuck Dice
  24. Don't need no steenkin' subject by heck · · Score: 1

    People have addressed the differences of 900 Mhz fairly well, but I thought I'd chime on my experience with 2.4 Ghz

    First, you will have to determine what you have in your house that is at 900 Mhz. I know all 4 of my cordless phones are 900 Mhz. I know this because I was having interference on my connection (40 percent packet loss) until I found the culprit. (the culprit was my X10 camera. We moved it to the new baby's room - we use it to check on the baby without opening the door - and the new nursery was 10 feet closer to my antenna. Oops. Changing the channel didn't matter - the piece of shit causes interference across all of the channels)

    Secondly, what are you going to do INSIDE your house. That's important. I have both wireless (again at 2.4 Ghz) and CAT5. Generally, I leave the wireless off; when its on, I have to be careful which of the 11 channels I use or we're back to an interference problem.

    For the most part, my connection has been reliable and fairly speedy. I get 1 Mbps down at almost all time; and can pay more if I want a faster rate.

    As far as security - the signal is encrypted, and after that you're dealing with your normal network security.

    They're saying they're going to upgrade my area to 5.2 Ghz due to interference problems (and some days I do get random interference even though I have clear line of sight and very little around me) Some people say they have a problem with wind, but I live in a windy area (insurance companies charging extra for wind damage now. Grrrr) and have never experienced a problem.

  25. My Experiance by pr0c · · Score: 1

    I've been using wireless 900mhz net for about 7 months now. I've never had downtime due to the wireless itself. Weather has never been a factor and I live in Michigan. I have a 786/786 connection and i pay 30 dollars a month.. not to bad at all as far as i'm concerned! And i get every bit of my bandwidth.

    My cordless phone does stop my net but all i had to do was press 1 button on the phone to change the channel... no big deal.

    My latency is just as good as on cable.

  26. I've had no problems with it at all by Doc316 · · Score: 0

    When RR came and installed wireless internet on my laptop I was very nervous at first thinking that ok if I go so far I'll lose my connection and everything I've been looking for. So since I live in Albany NY up in the mountains I've decided to check it out I went to my back yard good so far then all around the house just carrying my Laptop reading slashdot net no problems what so ever then I went out front and walked to the corner no problems still hmmm well from there I'm convinced I've say about 10 yards is all I didn't want to go any further was reading very interesting info about wireless internet.

    --
    For all of those that had witness let me give you one of my favorite sayings "Ph34r My M4d Skillz"
  27. to the dweed who modified this by Doc316 · · Score: 0

    ok jackass here you go and listen up the bottom line is what I said was true and if you can't understand the fact that yes I said the wireless internet worked then you have mad issues my friend well then f u for messing up my karma and when im done i'll be banging you sister and mom tonight have a great day

    --
    For all of those that had witness let me give you one of my favorite sayings "Ph34r My M4d Skillz"