Wireless Congestion 130
AllMightyPaul writes "An article on CNN describes the congestion experienced by many users of wireless networks as more and more people begin to use them at home and at work. The unregulated frequencies between 902 and 928, where most Wi-Fi devices operate, sees a lot of traffic, apparently."
Sounds really familiar (Score:1)
Correction on WiFi freq (Score:3, Informative)
Re:Correction on WiFi freq (Score:3, Interesting)
It'd be interesting to see some mobile spectrum analysis of frequency usage over geographic areas, to see if that plans out -- map spectrum emissions and see if there's an aberrant concentration in spots. Might not be terrifically useful, but cool data.
Aside from broad deployment of spread spectrum for future RF-emitting gadgets (the ones not using it already), it'd be helpful if devices like 802.11b access points could indicate when they're having interference problems, so as to distinguish these problems from those of topography, incorrectly installed antennas, hordes of evil lurking microwave ovens, etc.
Re:Correction on WiFi freq (Score:3, Informative)
The three in common use you will notice are the lowest, middlemost, and highest channels. Lots of space in betwen.
Devices DO indicate if they are having problems.. they give you indications of signal strength.
Re:Correction on WiFi freq (Score:1)
The three in common use you will notice are the lowest, middlemost, and highest channels. Lots of space in betwen.
Hmm, okay, that makes sense. However, as transmitter density increases, that concentration ceases to be ideal.
Devices DO indicate if they are having problems.. they give you indications of signal strength.
Insufficient specificity. It doesn't discriminate between poor signal propagation and emissive noise on the channel, which are cured in different ways.
Another approach would be for devices to make channel recommendations by checking each for round-trip signal strength and passively-sampled noise on the channel. Or simply to pick one automatically.
Re:Correction on WiFi freq (Score:2)
The EM spectrum is a limited resource (Score:2)
--CTH
Re:The EM spectrum is a limited resource (Score:1)
Please read more carefully (Score:1)
Re:Correction on WiFi freq (Score:2)
I don't remember the name but there was a big hacker conference (2600 type stuff) over in the Netherlands that had soo many guys using wifi that they maxed out the spectrum. They also raised a weather balloon with ethernet attached and did a bunch of other wierd stuff.
Re:Correction on WiFi freq (Score:2)
Sour grapes (Score:1)
Re:Sour grapes (Score:1)
You can't deny the fact that with the limited frequency ranges and tons of adopting users, we will quickly approach critical mass. I would imagine that in some areas, where wireless technologies cohabitate in high concentrations, critical mass is already in the foreseeable future.
I often wonder how we can achieve this utopian wireless world (a Net connection in every citizen's pocket) with the overbearing FCC regulations we have to exist under right now.
Re:Sour grapes (Score:1)
We appreciate your input.
First, I doubt that anyone, including yourself, would believe for a moment that "shortsighted individuals" would be able to keep the wireless world from coming into existence
Second, the FCC obviously doesn't have dominion over the world. They're federal. They have dominion over the USA. Therefore, I retract a small portion of my original comment and rephrase it as,"I often wonder how we can achieve this utopian wireless USA (a Net connection in every citizen's pocket) with the overbearing FCC regulations we have to exist under right now."
Re:Sour grapes (Score:1)
Re:Sour grapes (Score:2, Interesting)
Now how am I to take seriously the rest of the points that the article makes, if even the one most obvious and easy to verify is wrong in this one instance?
Re:Sour grapes (Score:1)
Now is a good time for something to be done about that. There is an ITU plenary session in a few months. So now would be a good time to lobby the (national?) delegates to get wireless LAN and other portable communications official recognised and given rights to use spectrum space (rather than being permitted to use it subject to accepting interference from, and prohibition of causeing interference to, other services.)
Re:Sour grapes (Score:1)
Tell that to the students at the college I work at (as telco admin). None of them want to be limited to their room by a wire for phone calls, so they all bring either a 900 MHZ or 2.4 GHZ phone (the cheaper, the better, so most are 900 MHZ). Now, at 120 students per hall, with 3 halls in close proximity to each other, there's a hell of a lot of students complaining to us that they're hearing other people's calls from time to time, and they want us to fix it.
I can't. Not much else I can say except to try getting a newer 2.4 GHZ phone to try to transfer some of the load from the 900 MHZ channels, or else use the landline. Yes, a cordless phone is a great benefit.
But the issue at hand is far from "FUD" and "No problem exists".
Re:Sour grapes (Score:1)
Re:Sour grapes (Score:1)
Now as for cell phones, those are in use too, but the only problem with that is kinda weak signals. We've talked to the various cell providers time and again (this is US, so there's abut 5 major providers using as many different types of networks), but nothing has come out of it.
BTW, the most popular cell phone on campus now seems to be Nextel with the Direct Connect feature (everytime I hear someone's chirp, I reach for mine.) Must have something to do with how colege students love to use chatrooms and instant messenger.
Now if they'd only make other colege activities portable...
802.11a fix? (Score:1)
Re:802.11a fix? (Score:2)
Re:802.11a fix? (Score:1)
Re:802.11a fix? (Score:2)
Re:802.11a fix? (Score:2)
It's not fundamentally any different.
It is no more or less prone to interference than 802.11b.
It may be that there IS less interference because it's a relatively new band, but it's no less prone to it.
Re:802.11a fix? (Score:1)
802.11a uses a technology called Orthogonal Frequency Division Multiplexing (OFDM), which significantly increases channel availability, mostly due to its ability to split them into seperate, more unique channels. It manages to create more independant channels by combining low speed subcarriers into a larger high-speed channel.
Check out this good article about this:
Proxim Article on OFDM and 802.11a [proxim.com]
Re:802.11a fix? (Score:2, Informative)
Apparently the 5GHz band is cleaner than the 2.5GHz band, so at least the background noise will be less, and hopefully the transmitters in the range will all use a common media access protocol so that the interference that is there will be more cooperative and not just straight radio interference. One possible solution to this problem might be a configuration protocol is created to allow different access points in the area to automatically negotiate which channels they will use, so there isn't even the collisions that happen when to WiFi devices share the same channel. I've never heard of anything like this before, however.
-Patrick Bridges
access points negotiating settings (Score:1)
Re:802.11a fix? (Score:2)
Re:802.11a fix? (Score:2)
Perhaps if he read
IEEE 802.11, 1999 Edition [ieee.org]
IEEE 802.11a-1999 [ieee.org]
IEEE 802.11b-1999 [ieee.org]
IEEE 802.11d-2001 [ieee.org]
he would be more informed...
Re:802.11a fix? (Score:1)
Re:802.11a fix? (Score:1)
Re:802.11a fix? (Score:1)
Re:Is this safe? (Score:1, Funny)
Anyone with some letters behind their name care to back me up?
Uh, ok... (Score:2, Funny)
There have been reports of people being kidnapped by space aliens.
But barring any evidence, neither seems to be true.
Re:Uh, ok... (Score:3, Insightful)
disruption will occur in living tissue as a result of
proximate emission of radiation. While the evidence
of causation is anecdotal, it is also quite persuasive
in some cases, as when the form of a tumor mimics the
form of an applied device. The bulk of research on the
subject is currently funded by interested parties, so that
inconclusive results are unpersuasive.
Eventually, the common-sense conclusion that some level
of cancer incidence is directly tracable to body-hugging
microwave transmitters will probably be borne out by
specific statistical analysis of the accumulating mass
of case studies. In the meanwhile, I use a headset, on
the belief that it's much easier to get a hip replaced
than a big chunk of cerebrum. I am sufficiently reckless,
however, to sit with a wifi card in my lap most of the day.
May God Almighty bless my gonads.
Few things. (Score:5, Informative)
2) Of course it's going to be congested! There is a REASON the 2.4Ghz band is where it is. It's dirty, and unlicensed. It was designated in the first place as an ISM band because it's dirty; it's not as commercially attractive as other bands in the same area. The fcc regulations REQUIRE you to accept interference from other devices.
Re:Few things. (Score:1)
Re:Few things. (Score:1)
Re:Few things. (Score:2)
If water was resonant at 2.4GHz, you would boil all of the water out of your food within the first 10 seconds or so of cooking - not the desired result. You want the water to absorb the energy slowly enough to give the heat time to conduct into the rest of the food. See this [eskimo.com] and this [winstonbrill.com] article.
Ehh? (Score:5, Informative)
Headsets and other gadgets using the Bluetooth standard, newer cordless phones and microwave-powered, energy-saving light bulbs share the 2.4 to 2.483.5 gigahertz frequency range used by Wi-Fi. Household microwave ovens use radio waves in that range to heat leftovers.
802.11b Wi-Fi devices occupy the 2.4 GHz spectrum, not the 900 MHz spectrum as erroneously stated by the article submitter.
802.11a, by comparison, uses the mostly-unoccupied 5 GHz spectrum, making it less prone to interference. It also boasts about 5x the theoretical bandwidth of 802.11b.
Furthermore, there are additional 802.11 hybrids that occupy different frequencies and offer different bandwidths.
Re:Ehh? (Score:2)
Re:Ehh? (Score:1)
Re:Ehh? (Score:2)
Poor Equipment (Score:5, Informative)
IANAWE(I am not a wireless engineer), but I can't help but feeling that if we're to see the 'unlimited spectrum' as it's been mentioned before, then equipment manufacturers are going to have to do a hell of a lot better job of making wireless kit that minimizes signal bleed.
Re:Poor Equipment (Score:2)
This is also the reason that most microwave bands are regulated and licensed. Frequencies need to be coordinated. Equipment needs to meet certain minimum standards. Power levels need to be set at the minimum level that provides a reliable link.
Re:Poor Equipment (Score:5, Interesting)
With general network setups (eg: an office) many people have a tendancy to put an AP on the edge of the building, particularly in warehouses (simply because there is little else to support it). Semi-directional antennas (with 60-180 degree coverage patterns) are VERY useful for walls and corners, and usually have a higher gain in the direction you want (away from the wall or corner, into your business). The less signal that escapes your premesis, the less chance of interference, and also the harder it is to get an outside connection (ie: war driving).
If your setup doesn't allow for outside interference, and is very succeptable to it, you'll always have problems.
Re:Poor Equipment (Score:1)
IANAWE(I am not a wireless engineer), but I can't help but feeling that if we're to see the 'unlimited spectrum' as it's been mentioned before, then equipment manufacturers are going to have to do a hell of a lot better job of making wireless kit that minimizes signal bleed.
IAAWE, and you can't expect the equipment manufacturers to fix the problem, because as the specs are written all of the original equipment works perfectly. All of this equipment has to pass field tests before it can be manufactured and sold. The problem is that you get some clueless dork who either (A) doesn't know anything about wireless systems or (B) doesn't care, to plug in a amplifier and overdrive it into compression, at which point the signal bleeds into all the adjacent channels wiping out all the nearby networks (I can assure you a LOT of engineering work goes into controlling adjacent channel power, and it is VERY easy to destroy this by hooking up a crappy amplifier). End result, you end up with a powerful signal spanning the entire band (and for those who really don't care they plug it into an omnidirectional antenna to spread the joy...)
The root problem is that you have average people putting together an ad-hoc cellular network without any knowledge of how to do such a thing, and typically not working as a group either, but as individuals, with each individual wanting to have an optimum connection at the expense of the others. Now you could argue that equipment should be even lower-powered to avoid interference, but this only makes it more susceptible to real-world intereferers (the microwave ovens and rainstorms), and still doesn't solve the problem of the guy with the overpowered amp.
Unfortunately this problem will only follow into the 802.11a band, as it is irrelevant what particular frequency your using (again the root problem is network design). For now you just have to negotiate with your neighbors to get an optimal setup (assuming you can find them, simply explain that the connection will be better on both sides if your not stepping on each other).
As an aside, this has particular serious issues when you think about it in the context of UWB (ultra wideband) equipment .. can you imagine when UWB appears, how long will it be before someone tries to amplify that, and starts blasting ALL frequencies .. not pretty .. and I seriously doubt the FCC will be able to police it...
What?!? (Score:3, Funny)
Re:What?!? (Score:3, Insightful)
Yes, we can greatly increase the efficiency of spectrum utilization for some applications if we toss out all existing models of spectrum use and their associated equipment, spend huge amounts of money on software defined radios, develop new suites of protocols, and mandate cooperation between all users.
Re:What?!? (Score:2)
The only way to allow multiple use is with exotic directional antenna concepts like phased arrays. Sure, with a perfect directional antenna you can have as many transmitters as you want on one frequency; you just aim perfectly at the one you want to listen to. But of course directional antennas are unworkable for a mobile solution, and they are complicated and expensive to set up for a stationary one.
Really that earlier article was just an attempt to bash the FCC with some theoretical results that don't have much to do with the real world.
Re:What?!? (Score:1)
It would be REALLY nice if... (Score:1)
Re:It would be REALLY nice if... some people are (Score:1)
Ricochet??!!!??? (Score:1)
I think the author needs to get in touch with the times! ;-)
Re:Ricochet??!!!??? (Score:1)
Someone does
902 - 928 unreguated - wrong. (Score:1)
Re:902 - 928 unreguated - wrong. (Score:1)
Another ham band, 13 cm (2.30-2.31 GHz and 2.39-2.45 GHz), overlaps the Part 15 spectrum at 2.435-2.465 GHz.
Theoretically, hams (and everyone else) have priority over Part 15 devices, but just try explaining that to an angry neighbor.
The complete amateur radio regulations for the USA can be found here [arrl.org]. The USA is in ITU region 2, except for some Pacific islands in region 3.
One minor correction... (Score:2)
The Australian (Maybe another country) 2.4 GHz ISM band is a different story - There's an article for hams on hacking old Proxim Symphony cards that said that if you send in a photocopy of your ham license, Proxim would send you a card normally only legal in Australia.
Re:One minor correction... (Score:1)
check this page [qsl.net] for a howto too.
KG4AKV, John Brier
Re:One minor correction... (Score:1)
http://www.qsl.net/kb9mwr/projects/wirele
Does this remind anyone... (Score:1)
2.4 ghz Co-existence sucks (Score:5, Interesting)
We have a 2.4 ghz phone, with also works great, but when we're on the phone, the throughput on the wireless lan goes down, and similarly, if there's a lot of wireless lan traffic, the phone gets interference. Tried different channels.
Tried out a wireless video relay from Radio Shack which uses 2.4 ghz. The wireless lan (even idle) causes regular noise on the screen, making it unusable. It went back.
Most annoying of all, when our microwave is on, the wireless lan loses most packets, and is almost unusable in the kitchen (and some other places).
The frequency hopping and co-existence in this band doesn't seem to work out as well in practice as it does in theory, unfortunately.
-me
Re:2.4 ghz Co-existence sucks (Score:3, Insightful)
Re:2.4 ghz Co-existence sucks (Score:2, Interesting)
This is unfortunate actually, as a good fh radio would be much better at avoiding the interference.
As a side note, I work for a wireless company involved with all sorts of wireless networking from good old UHF and 902 MHz up to 802.11a. Even we suffer from the interference that our microwaves, lights, etc. generate. Maybe it's time to go back to a regulated spectrum...
Re:2.4 ghz Co-existence sucks (Score:2)
Screw the neighbors... :) (Score:1)
Screw the neighbors
WiFi is at 2.4 GHz (Score:3, Informative)
At 900 MHz Government and vehicle location are primary, and amatuers are among the secondary authorized users. Part 15 devices just add to the noise that other services must overcome.
In both bands, amatuer operations are swamped, if low power, by the increase in the noise floor. However, amatuers can operate on those bands with enough power using the same spread spectrum scheme such that the WiFi would be useless for PArt 15 devices. But its unlikely given the nature of the amatuer radio service (recently the FCC relaxed the allowable spread spectrum/frequency hopping restrictions on amatuers).
This is where that portion of the FCC regs. for Part 15 devices is critical, in that they must not create interference for the licensed users of the spectrum and must accept interference from them. Not an exact quote, but you get the drift.
In a nutshell, if you use unlicensed devices in spectrum where other services are authorized for higher power, you get what you'd expect. Now 5GHz is a great place to be! BTW when I key up on 2.4 GHz with 10 watts, my 802.11b network shuts down pretty hard. With only 50 feet or so of seperation the front end of the WiFi receivers gets overloaded even though I am not all that close in frequency, it is just the radio circuitry in the WiFi devices is just barely adequate so they can meet their price point and comply with the FCC regs. Better frequency agile receivers could be put in the devices and most likely will be as more devices crowd in. Also automatic power control will get better and the potentially they'll create a third scheme for the spread spectrum use that is more adaptive and as such would accomadate more users.
Last, everyone knows that they can change the channel their network is on, right. I have found several swamped WiFi networks all clashing on channel 1 when there was plenty of usable spectrum up the band. (Powerbooks are great portable diagnostic tools even though the UI is cheesy for the Airport software and the third party tools are scarce due to lack of internal Airport info.)
That is why there is a choice of channels... (Score:5, Informative)
Whoops (Score:1)
Yet more snake oil (Score:1)
Yes - a cellular/trunked model will enable greater use of spectrum. This has been well known for the last twenty years.
Yes - spread spectrum/ultra-wide band allows re-use of the same spectrum.
BUT the price you pay (for cellular or spread spectrum) is gradual degradation of service with increased users.
Yes - radio waves do "pass through one another" allowing spectrum re-use, and that's been known since beam antennas came into use in 1919.
These presentations are simply examples of special pleading by commercial interests. Some corporations believe that the law of gravity could be repealed if they lobby hard enough. Everyone wants a chunk of the radio spectrum and non-one wants to pay for it or show responsibility to other users.
Hopefully this will mean more free-space optics :) (Score:3, Interesting)
The site I can't find quickly (anyone?) is one that I know has been mentioned on Slashdot a few times, home-built optical transmitters (In the Czech republic, IIRC) using modified ethernet cards and powerful LEDs to beam multi-kilometer distances
5 years ago I would not have guessed how widespread and cheap 802.11 stuff would be today; right now, you (point of reference, Americans in the lower 48) can get an 802.11 base station for under $100. Glut isn't quite the right word, but lets say there's *a lot* of somewhat decent, moderately versatile wireless gear available for what is in 1st countries not a huge chunk of disposable income, at least for folks middle-class-and-up. The cost of 7 cds gets a working base station
Wouldn't it be nice to see a similar flood of products for optical gear? Yes, there will be lawsuits (eye damage! you hurt my eye!), and ugly warning labels, and ISP crackdowns for retransmission and who knows what else, but
timothy
Re:Hopefully this will mean more free-space optics (Score:1)
Searching 'ronja' on
Re:Hopefully this will mean more free-space optics (Score:1)
RF interference? (Score:2, Interesting)
Zhrodague WiFi Mapserver (Score:1, Interesting)
Welp thats the end of un-regulated air space.. (Score:1)
Left to their own, people dont share..
Usurf (Score:1)
Well I used to work for them and they were trying to bring WiFi to the consumer at about the same rate per monthas DSL/Cable.
It's funny that it didn't take off, but mismanagement of company resources and firing your entire Tech. Support Dept. Doesn't help.
It seems like many of the microwave devices are of somewhat low quality anyway, I recall the connection was supposed to have 1.5 MBps up and down, but was never faster than a 256/256 DSL. On top of that data loss and corruption was prolific.
I think these companies should leave WiFi to Cisco (w0rd to your 802.11b) and research even higher frequencies so that in 10 years when the demand increases we wont all think back to the days of AOL 3.0 and it's loverly 26.4 KBps connections...
Re:obligatory mirror (Score:1)
Re:wireless at home? (Score:1)
Some of us actually like to live in a clean environment, a concept that many hygienically challenged people can't quite comprehend. Walking over cords is probably no big deal for someone who's used to stepping over animal feces while walking from one room to another. But for those of us who aren't "ghetto", wireless is a nice option.
No fun.... (Score:1)
But that's the fun part.....
Re:wireless at home? (Score:1)
I use wireless at home exclusively for my laptop. I can use it by the pool, I can use it in my bedroom, I can use it in my living room...