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Can 802.11 Become A Viable Last-Mile Alternative?
NikiScevak writes "As telco's around the world move from government hands to private investors the incentive for them to create compeition at the wholesale DSL level drops dramatically. The CSIRO in Australia are investigating the use of Wireless LAN technology 802.11b as a means through which to provide alternative broadband access, achieving range of up to 7km with standard components."
costs too much for third world, last mile included.
fp
I'm being forced to do this for a client who is 400meters outside of cable and DSL range.
Ya, 400meters. The stupid fucks couldn't use repeaters or use current technology to stretch the line. Nice to see a commercial ISP is doing it on a mass scale.
Feed the need: Digitaladdiction.net
There are several isp's selling wireless access for the last mile in North Carolina. Overall, I wouldn't touch it. The networks are generally insecure, sniffable by anybody and their palmtop with the right hardware/software. From what I have seen and heard from people is that it works, but some days it dosen't work as well as others. *shrugs*
Honestly, I wouldn't mind being able to drive around and have allways on access in my car or something like that, but wireless does not cut it.... Collissions, and cordless phones reek havoc with 802.11b. I use a 100mw ap at my office... when I'm on my cordless phone... my laptop says the link quality is 10-20%.... and the ap is 20 feet away...
In theory, if you are going to use 802.11b on a large scale wouldn't you eventually reach a point where you would 'saturate' the frequency range alotted to this technology? Also, couldn't this cause problems with other electronic devices - if used on a large scale again?
And, last but not least, the damm networks are (usually) insecure as hell - not by nature but by incompetent setup. I remember an article about a bunch of 'hackers' who drove around downtown london's financial distric with a laptop and a wireless card and where ablet o log onto all sorts of networks b/c of lack of security.
The power company in Japan has set up a wireless ISP that boasts broadband speeds.
A google search would probably turn up some interesting information.
I have been pwned because my
As someone living in the middle of nowhere in Western Australia, where I can get a 33.6kbps connection on a good day (usually its closer to 28k), it's good to see that the CSIRO are taking an interest in that sort of thing.
But out here 1km, (or even 7 as they claim to strecth it in the article) isn't really very far, so they would need a lot of repeaters to get from place to place, making this a fairly expensive project. (Read: ain't gonna happen).
Major reasons why 802.11 and its variants will not solve the last mile problem (soon):
1. No agreement on standards (802.11, 802.11b, 802.11c, bluetooth, etc) :)
2. 2.4 GHz is already full and prone to interference
3. Security (though walking through a neighborhood and cracking the wireless encryption does sound appealing)
4. Whatever else I can't think of at the moment
It also has to do with the psychology of being connected to the "grid" so to speak. People feel so much more secure knowing they are connected to a tangible object- look at broadcast TV vs. cable, cell phones vs. lan line phones, etc.
I'm not sure this makes sense. It works in those cases where there is no other way and the number of connected nodes is small and controlled. That's to say the least about FCC rules, which are very specific about this. To make this work for the "last mile", theoretically it would be cheaper to update the current system, especially with new VDSL systems. The problem is that it offers little return to the telcos and they don't want to invest; One way or the other.
As telco's around the world move from government hands to private investors the incentive for them to create compeition at the wholesale DSL level drops dramatically.
This is simply false. Legally enforced government monopolies have zero incentive to compete. The whole point of privatization is to increase competition (assuming it is done correctly, i.e. no market-splitting or corruption, which I believe was a major problem in the former USSR). Private investors and consumers create competition because, unlike taxpayers, they can take their money elsewhere. This type of economic illiteracy is bad enough coming from a normal poster, but even worse coming from the author of the article (who is also the submitter, coincidentally enough).
Cheers,
IT
Power corrupts. PowerPoint corrupts absolutely.
If I see that Mitsubishi commercial again, I'm going to rip the arms of that bitch and use them to beat the shit out of the synthesizer player.
Surely you mean "Last 200 feet." At least, that's what it's like in any remotely urban area.
-b
But try this in the valleys of South Wales and you'll soon realise that copper has its advantages.
I'd be down for this. Where I live I've been having all sorts of cable line problems with att broadband. Not in my house, but the cable they have running to the neighborhood. So if I could get 802.11b, I'd probobly go for it.
This seems similar to the hawaii article that ran on /. a while ago, but the implications here are more commercial. While I can see how the non-commercial aspects of the hawii thing would work out, I'm not sure how they're going to get different groups to work together in this case. Maybe it'll just slow things down.
0 21 0
http://slashdot.org/article.pl?sid=02/03/13/194
The costs to the service provider may also be significantly less than using the full Telstra ADSL or ISDN service. In some areas they may only need to put an antenna on the roof of their office and pay Telstra for the connection to the backbone (instead of having to also rent wires to their customers).
I'm amazed by the number of people in Australia who ditch their ISP due to poor quality connections, and then have the same problem with the next ISP - and don't realise that everything is coming down the same wire controlled by the same telecommunications company.
To all those who are confused as to who Telstra is, it is the formerly government owned, half privatised telecommunications company that owns most of the communications in Australia. The remainder is owned by Optus/Singtel, a mainly Singapore government owned telecommunications company, which has a few lines, provides cable TV and broadband to a few small areas and has a mobile phone network. These half privatised companies have most of the worst aspects of both goverment (a we rule you attitude) and private enterprise (more charges for less service all of the time). The way they are heading, full privatisation will turn them into monsters that make the worst multinational mining corporations look like a charities. Therefore, anything that increases the choice here is good.
All the other telecommunications companies mainly just rent space on those two networks.
Everything is on 2.4GHz, theres not much to go arround though! wireless networking, last le, bluetooth, wireless video senders, cordless phones
Put it all together and none of it will work, except the microwave.
Security isn't what I'd be worrying about for this sort of application -- you have to assume that packets going out over Cable modems and DSL links are going to be sniffed by everyone and their little brother anyway. Use those VPNs if you're looking for security.
(The air gap isn't what it used to be, is it?)
"It is our blasphemy which has made us great, and will sustain us, and which the gods secretly admire in us." - Zelazny
standard components...
...like pringles cans?
Seriously, as a consumer, I would have serious doubts about security, but I suppose I might just be underestimating the security of my current access.
.sig last updated Jan. 14, 2000
As others have pointed out there are numerous technical problems with wireless if used at a large scale. It is all the more irrational knowing that there is already a good last mile in place: the local loop. Mostly it has been paid for with tax money, i.e. you could say that everyone owns its own local loop.
Thus, it is only logical to separate the local loop from the service providers. Create a non-profit (public owned) company that maintains the local loop and offers it at cost price. The telecom companies can compete to offer service over this public infrastructure.
Just like the road system (which is mostly public in most countries). Everyone can use them for a relatively small amount of money. Imagine the situation where there would be no public roads, but the 'local transport company' alone would build and own roads and offer their transport services (trucks, taxis) in one package; since you can hardly have 3 different roads leading to your house, you would be dependant on 1 or maybe 2 transport companies if you want to use the road leading to your house.
Would privatization solve such an absurd situation? No, since no true competition can't exist even if the transport companies would be privately owned (i.e. strive for maximum profit).
The only solution is to have a public infrastructure, and have private companies compete using this public infrastructure.
The polititians that essentially gave away the local loop to a privatized telecom operator (i.e. they gave away something that the public has paid for) made a huge mistake. This must be corrected.
There are atleast 3 ISP's doing this in India.. ut not using standard equptment, they have specially modified high-power directional antenna.
;)
Besides the favored method is to do Wireless to a roof-mounted antenna at a commercial (or apartment) complex and then do a 10baseT ethernet switched network inside the complex.
So the last 0.99 mile is wireless but the last 0.01 is yet copper
consume.net in the UK are pioneering this kinda thing. There's also a whole raft of other community based wireless links at Wireless Anarchy.
Al.
HantsWireless - Hampshire Wireless
SurreyWireless - Surrey Wireless
I think i'm close to the average price of a 802.11 tranciever. Back to my point, I can buy 1000 feet of cat5 for $50 dollars a box. Maybe 2.5 boxes per last mile? In quantity it would be cheaper of course.
So i'm lookin at $125 dollars per mile VS $200 dollars per mile and i'm asking myself, ARE THEY COMPLETELY OUT OF THEIR MINDS? How hard is it to run a cat5 cable over someone's fence? Hell I share my DSL with my neighbor that way (Pesky teenager d/l on kazza screwin with my CS games)
So point is, this is what I would classify as an overengineered idea. Too expensive, too much stuff can go wrong, no no no no. Look at what happened to metricom a.k.a. Ricochet. Same plan basically and it died because they needed something like 300,000 subscribers just to cover their equipment costs.
At least the cable can be recycled for scrap metal. Not sure what you can do with a 802.11 basestation.
--My Sig is a warning that it's 1:30am and I can't be held responsible for this ramble because i'm pretty flipped out.
Perfect case for RTFA.
CSIRO is not a company, its a government funded research institute
One and half years ago at least nortel, most likely the others had a last mile box in the making. To be more exact a real last mile box. For the last mile between the patch board in the street and the customer house. At least the Nortel project was a DSL/Voice/ISDN concentrator that was supposed to be deployed in the street as a replacement for those grey ugly distribution boxes most telcos use since the days of Bell. Concentrate close to the customer premises and carry over fiber or vDSL to the exchange.
Most of these projects got cancelled during cost cutting exersies. You know the drill: it is something new, so you should not do it and stick to the areas of "core expertise".
If they were not cancelled the question of "out of range" would have quickly stopped to exist. Same for line noise and line-to-line interference (the usual problem with DSL).
Just comes to show that some cost cutting exercices during the dot-com burst have been outright stupid...
Anyway, back to the 802.11 topic. Once sanity is back and some startup (or the classic switch vendors) starts putting these out the 802.11 broadband will be as dead in the water as wireless local loop. It is not something that can be used to beat the telcos at their own game. It is a great office network, hotspot filler, neighbourhood network but broadband it aint.
Baker's Law: Misery no longer loves company. Nowadays it insists on it
http://www.sigsegv.cx/
Two comments have been made in this discussion that warrant reply. The first is that 802.11 cannot be used because of signal problems. Nonsense. Those who read the article would realize that you're going to use antennae that focus the signal (i.e., use hyperbolic dishes). This lessens noise and increases signal strength. For those in the Bay Area, a great example of this can be found in The Exploratorium, where two people can sit *inside* a pair of hyperbolic dishes about 40 ft away from each other and hear each others' whispers.
In addition, this nonsense about being afraid of wireless access to the Internet due to security is *silly*. You're connecting to the Internet. What sort of security do you expect on a normal *wire*? Want real security? Use IPsec, TLS, or ssh.
Remember, here in America we have our own troubles with last mile access, the cost of getting into COs and all that fun. This is a good alternative in other countries where access is even more impeded.
It's not clear that the problem making wireless more attractive for the last mile is the equipment cost. Everything helps, I suppose, but installation and ISP transmitter costs (antenna rental, Internet hookup) are likely to be more costly. See sprintbbd.com for one venture that has been put on hold.
Dude, you read an article about sniffers? Wow, can I touch you? Yes, this is a flame because I'm sick of hearing such bullshit.
Here's ignorance taken to a new degree. I once heard a story about the whole internet being insecure, a place where all sorts of "hackers" could break into all sorts of machines. They even were able to phreak the phone system. And this new fangled email? Thanks to poor implemetaion, I'm told that the very internet itsel was shaken (routers destabilized) by a silly VB script. Can you believe it? Who would use such an insecure media? I'm sure glad no one ever persued those crazy things!
Want security? You can start by tossing out your M$ crap. You might then consider the virtues of encryption routines, such as provided by OpenBSD and used everwhere people have sense. If you really really don't want anyone to see something, don't write it down. In the long run, it would be adventageous to get governments to extend mail fraud and tampering laws to electronic formats. Remember those things that protect your precious documents from those bold enough to rip open an envelope?
Run along and play in traffic now.
DMCA, Hollings, Palladium. What might have sounded like paranoia is now common sense.
An amazing organisation. Depsite the vagaries of public funding it is a network of insitutions with a proud history of discovery and invention.
:-P
The specific research in question here is to determine the feasibility of the idea and to answer (with facts rather than BS we have seen here) the question of whether the wireless technology is viable. And despite the erudite position of some of the "interesting" slashdotter's, I'll take CSIRO's results before their opinions any day
"The first thing to do when you find yourself in a hole is stop digging."
The use of wireless to solve the "last mile" problem has been growing at a steady pace since around 1997. At least in the mid-south. A small company called www.aerosurf.com started using the equipment to provide broadband access to small rural towns in the south. A close friend of mine recently took advantage of the unique characteristics of grain elevators to provide Broadband access to practically anywhere. It is/has/will be an excellent alternative to an otherwise poor communication infrastructure that rural areas have now.
The use of wireless to solve the "last mile" problem has been growing at a steady pace since around 1997. At least in the mid-south. A small company called www.airosurf.com started using the equipment to provide broadband access to small rural towns in the south. A close friend of mine recently took advantage of the unique characteristics of grain elevators to provide Broadband access to practically anywhere. It is/has/will be an excellent alternative to an otherwise poor communication infrastructure that rural areas have now.
It continues to amaze me that people are astounded that a 2.4ghz signal could manage to travel more than 500 feet, this article speaks as if 7km is something to brag about.. I've personally setup 20 mile links with "standard components" without any problem.
As for the last mile, I sincerely doubt it will happen on a medium that the telco/cable co cannot fully control, and last time I looked there wasn't any frequency space near the 2.4ghz ISM band available for national use (in case an ISP decided they wanted to use their own licensed frequency).
Just because you disagree doesn't make it offtopic or flamebait.
In Denver Colorado, If you drive around sniffing, your can find that there at least 4 seperate isp networks running around.
The first is MileHigh Online. It appears that they have about 400-500 customers. Another is one from idcomm (but they don't advertise it) and appears to have about 100-200 customers. idcomm is also insecure.
Another is techangle. But they seem to have shown as having traffic with idcomm, but not anymore. Another insane insecure network though. Haven't figured out the fourth one yet.
I use a wireless net in my house because I like to be able to move around with my laptop. My experience has been this: even with just me on the net, low ping times and fast transfers are only attainable by wire. Sure, wireless is great for browsing and other misc. taks, but if you get somebody that games, don't expect it to happen. Also not good for too much past entry-level DSL. If you're a wireless ISP, cool - there's a place for that. But I'd shudder to see everybody trying to make this a standard last mile...
SIG: HUP
Are there some signal amplifiers that one can get? Because, as last I heard, 802.11b only had around a 300 foot range... not 7km.
I ask because i'd love to have a good wireless setup in my college dorm... maybe with the cooperation of some other students, so we could walk around (at least parts of) campus and still have connectivity...
links?
What comes first, finding a teacher or becoming a student?
This is Australia after all.
I've yet to see a hardware AP that does SSH tunneling between nodes. I've yet to see any implimentation of any other encryption over a link. With the recent insecurity of the encrytion in 802.11b wouldn't it be a good idea for manufacturers to use alternate encryption in their products and still support the old encryption?
Wrong - at least in the case of Advanced Mobile Phone System (AMPS, the system still in use in the USA). In AMPS, a phone is commanded by the cell site to adjust its power as needed to maintain the connection to the cell site. In fact, you have to do this for almost any radio system with multiple transmitters (more on this later).
The problem was the granularity of the control and the rate of control - in AMPS the phone only had a very small number of power steps (like about 5) and was only commanded to change on the order of once every few seconds - in GSM, the power is adjusted much more finely (like many tens of steps) and much more quickly, and in CDMA the power is adjusted hundreds of times a second, and over hundreds of levels.
You have to do this for any system with multiple transmitters, otherwise the more powerful signals will dominate the receiver at the cell tower, and the weaker signals will be lost in the IF noise (the technical term for this is "desense"). It's bad enough with Frequency Domain Multiple Access systems like AMPS, where each conversation is on a different frequency, but it gets worse on Time Domain Multiple Access systems like GSM (because the receiver has to react in microseconds to the different power levels of each signal), and it will KILL Code Domain Multiple Access systems (where a strong signal will wipe out all the other signals - no amount of code gain will pull them out from that far under the noise floor).
Besides - I've been to the UK, and I've watched people cuss at their GSM phones as they drop calls. The double-edged (no pun intended (inside joke for folks in the cellular industry)) sword is the fact that GSM digitizes and compresses the voice, unlike AMPS - when the signal is weak, GSM will error-correct and continue with little degredation until the bit error rate exceeds the forward error correction capability, then BAM! you drop the call. In AMPS, you will hear the signal to noise ratio increase (the static in the background), and you will have an idea that you are losing the signal before you get dropped.
www.eFax.com are spammers
I attribute the success of 802.11 to its catchy name. It promises to sell even more units than the wildly popular IEEE-1394.
Karma: Good (despite my invention of the Karma: sig)
... we walked 5,280 feet to school! Without any shoes! In the snow! Took over 5 boxes of 1000ft Cat5 to lay a cable so we could find our way home again! And we STILL came up a football field short of the front door! But we LIKED IT!
Fried ice cream is a reality. - George Clinton
...as long as a large Milo tin counts as `standard equipment', that is. One end of the link is a Milo tin in Osborne Park, the other end of the link is a half-omni in Lesmurdie. Standard cards. Good old Aussie `we won't know until we try it' technology. No worries. (-:
Mind you, there are people claiming to run DSL along barbed wire fences...
I don't know what the line quality is. I think `working' is good enough at that distance. (-:
Got time? Spend some of it coding or testing
I don't know about that. My cell phone bill the same price as my regular phone bill today, and I never use my regular phone. My cell phone includes extras on the land line (voice mail, caller id, and others that I don't use). It seems that even though wireless is expensive to get going, the costs are much less than wired for moderate bandwidth. When you need large amounts of bandwidth you need wires, but most of us don't use that much, so wireless is cheaper than running wires.
802.11 probably won't stand up to video, but it is enough for most internet users.
The only solution is to have a public infrastructure, and have private companies compete using this public infrastructure.
... I wanted to start running some Free Sites (freenet nodes) in my home and play around with some other server stuff that is difficult to do on my cable modem with its ever changing IP address (and I was greedy for more bandwidth).
... almost everyone I know has dumped Ameritech in favor of one cellular phone service or another, which means all those technically savvy people ... a prime market for Sprint's DSL service if there ever was one ... are disqualified from ever being able to buy their product.
That is exactly right.
I recently tried to acquire Sprint DSL (8 Mbit down, 1 Mbit up) in my home
I've had DSL in my home before (but it was expensive and slow in comparison), so it shouldn't be a problem.
It was.
I do not have a landline phone, having developed a sufficient hatred of our local Telco Monopoly (Ameritech) over the years that I will now only use a cellular service (currently AT&T, but I can change to whatever service I like whenever I like, in contrast to our local monopoly). This wasn't a problem the last time I had DSL installed, but apparently that has changed as the local Telco chokehold on the local loop has tightened.
The bottom line, if I don't buy phone service from the local telco monopoly, I cannot get Sprint DSL service. Period.
Quoting the correspondence I had with Sprint on the matter (for anyone else who is interested):
SPRINT:
I'm sorry I've been trying all day to get someone to tell me why another DSL provider was able to give you service w/o a phone number, but they said we have to have a phone number to service a location. Is there any way you could get a basic phone line just to have a phone number established to have the service installed?
ME:
No, I can't and won't do that. (I already have copper pairs going to my unit, having had DSL here previously.) My dislike for Ameritech is sufficient to avoid doing that, even if it means sticking with a cable modem. These services typicall charge installation fees, require people to take time off work to wait around for them (and then often don't show up when they are scheduled to do so), are expensive, difficult to work with, and then sell your contact information to telemarketers as a final slap in the face. I won't do business with them, period.
SPRINT:
I'm sorry that I was misinformed and told you we'd be able to set up service the way you said your previous provider did. I hope in the future if you ever get a phone line at home you would still consider us for home DSL service. Again I apologize for the miscommunication.
As you can see, despite having the copper already in my unit and having had a DSL service previously (despite never having had a landline telephone in that Unit, ever), it is apparently no longer possible to get DSL service (at least through Sprint) without buying telephone service from the local telco monopoly.
Sprint is losing $160/month on me alone because of either the local telco monopoly or their own incredible denseness, and I'm missing out on a DSL service I would like to have had. I doubt very seriously I am alone
It is past time for the government to break the local telco monopolies and nationalize the last mile of copper (local loop) exactly as you describe. Anything else is going to lead to a communications oligarchy that will stall the telco and broadband industry and likley stagnate the technology indefinitely.
The Future of Human Evolution: Autonomy
Can 802.11 Become A Viable Last-Mile Alternative?
* Burning1 posts from the new 1.5 megabit per second syncronous 802.11b wirless internet connection he's been beta testing for his local ISP (at no cost...)
Um... I'll get back to you in a year or so, when I've thoroughly tested this thing. ; )
We are a small independent ISP in a semi-rural Southern California town and we have several customers running via 802.11b at DSL speeds. Check out our very minimalist web page at www.ojaiwireless.com for ideas as far as price, etc.
Our latest challenge has been finding ways to deal with the "hidden transmitter issue" which can cause serious packet loss. This stuff DOES work though, quite nicely if you you know what you are doing.
Also, most newer firmware\drivers bypass the known insecure part of the WEP. This means that the standard wireless sniffing techniques will not work easily. I must note however, with others, that a determined attacker is gonna get through whatever the transport. Firewalls and VPNs would be required for any kind of sensitive data.
Have a Nice Day!
In the long run 802.11b like systems (fixed and/or roaming) are going to play a vital role in our communications infrastructure. On this subject I have no doubt whatsoever for a variety of reasons which I will describe in as much detail as possible. Please note that I do work for an 802.11b last-mile provider as a programmer for our edge-device. These are my views, not necessarily those of my employer.
1. It's cheaper; both now and down the road.
Step back and look at the history of telecom. In the beginning was the telegraph, and it was good. But it was point-to-point and we didn't have the technology to do proper routing. Then the telephone, whose basic design has not changed in any significant way. It's a point-to-point device by design with routing mechanisms and conventions (ala area code) added over time.
This is the really interesting part. *If* the telephone were re-implimented with modern technology how would it differ? It's a lot cheaper to build semi-intelligent edge devices now than it was. The number of homes desiring a telephone unconnected to the power grid is substantially smaller, presumably small enough to justify powering edge devices locally instead of carrying juice over the wire.
How about addressing/routing? If each phone has a unique identifier (ala MAC address), you could input whatever personal information you would like to have available to a regional database and impliment basic search functionality into the phone. The switching fabric of the network itself would actually be _simpler_ with ATM pushed all the way to the edge. Mixing data and voice over such a network would be cheap and easy. Phones would cost a lot more, but mass-production on those kinds of scales can do some amazing things (and it wasn't very many years ago that a phone cost 50$ and was only available from ma' bell).
I don't think anyone genuinely doubt that we could make a system many times better and cheaper (once operational) than the staus quo.
The question then turns to why. Why haven't we done it? To a degree we have. Cell phones are a big step between yesterday and tomorrow. Why don't 'normal' phones do everything cell phones can do? Because the cost of re-wiring is too great and our existing infrastructure is not sufficient.
It's a lot like writing software (I'm one of those freaky souls that sees everything as being a whole lot like writing software). We've got a huge amount of complex code written in an obsolete language. It works, but it's hard to modify. The only long-term solution is to rewrite. You must also accept the enduring facts. As technology progresses everything is eventually obsolete.
Back to the point at hand. The initial cost of setting up a nationwide wireless infrastructure is far from insignificant, just as the cost of our wired infrastructure required years of expense. Once a wireless infrastructure has been built it has one huge advantage that wire (sans fibre) cannot overcome. You can upgrade the edges.
A contemporary example. Suppose you have a 802.11b point-to-point link between your house and buisness. It's truckin' along at around 2-4mb (I know the press says 11 but they are ignorant, liars or salesmen). Technology marches on. A few years from now you pick up two 802.11x-like cards and upgrade both sides of your link. You'll probably need to upgrade the antenna as well (I doubt 2.4 will still be the best price/perform in a few years). Total cost around 500$ give or take for at least double the pipe. No change in ongoing cost of operation (maybe a few pennies a month more power).
Lets see any wired solution that's similarly expandable at anything close to those costs. We're playing at the edge of what POTS can do with xDSL. Demand is going up and presumably will continue to rise.
2. Empowerment
Why does your telephone company care about the software that is running on your computer? When you run a web server or a p2p node you're destroying the oversubscription model of their service. Every provider assumes that some portion of the people on their network arn't going to use the bandwidth they are paying for. There is nothing wrong with that. Build a model based on actual usage and ensure that your available bandwidth is sufficient.
Wireless has an inherent advantage with respect to oversubscription. It's a curious thing, but since the boogyman of radio is dropped packets (and the subsequent tcp/ip backoff) traffic shaping is actually simpler. The radio is accustomed to loosing a packet here and there and optimized to deal with it nicely. In the design of a radio system (particularly fixed) the maximum possible number of users is well-known. When that number is reached the system must be expanded (using new channels while it lasts then new towers). Available bandwidth is then a function of tower density (unless/until you reach RF saturation at which point fiber is the only viable solution).
3. Speed and latency
Every time 802.11 comes up on /. or elsewhere there is inevitably a thread about latency. Personally I'm rather fascinated by latency. In absolute terms (a perfect, noiseless system) latency is a function of distance. Any device that queues packets adds latency. Any device that doesn't queue packets adds noise/fragmentation unless it's faster than the datastream. Radio systems generally require reasonably substantial queues for both input and output (thanks to the tendency of packets to get mangled/lost in transit). The most popular form-factor for a computer radio is currently pcmcia. Despite it's numerous advantages this isn't really the 'right' solution. Far better would be mini-PCI (for example). No one will ever make a gigibit pcmcia card.
Exactly what is the bottleneck in 802.11b latency? We know it's not the transmission of the actual radio signal, though any 'extra' ACK'ing or handshaking that's required by the 802.11b protocol will certainly hurt. It's easily provable that wireless is equal in terms of pure information transfer (radio waves travels at c, electrons in copper propagate at c) so any 'extra' latency in radio must come from either the 'creation' of a radio packet or the decomposition of same.
The answer (I'm reasonably sure) is in the soft/firmware Radios have much more verbose error checking and wrap packets in quite a bit of extra protocol. As the hardware improves the time required to process this layer will decrease and we'll see radio latencies approaching wired latencies. Even now a good radio does about as well (in terms of latency) as a cheap NIC.
4. Security
Only morons have a 'problem' with wireless security. Sorry, had to toss in a little ad hominem to 'fit in' with the /. crowd. Seriously, whenever you're radiating information you should be sure to encrypt.
You wouldn't shout a private conversation across a busy lobby. You walk up to the other person and whisper. But nowadays that isn't good enough either. If someone wants to listen in they can use high-tech devices to amplify your whisper and eavesdrop. You're a little paranoid so you write down your message, hand it to someone you trust, they hand it to someone they trust, who hands it to the intended reciever. That's a wired network. There's nothing wrong with that and it has it's place. But are you going to stop talking and live our your life passing notes through people you've decided to trust? Especially when you can switch from english to a language only understood by you and your intended audience? (that's encryption) Sure, a really hot linguist might be able to figure it out (NSA). But again, how much paranoia can you really justify?
5. Noise, Microwaved packets.
As an experiment I setup a point-to-point link from one countertop, through a spectrum analyizer, through a cheap microwave oven, through an equally cheap wall, a few cubes to a lucent AP. I put a big glass of water in the microwave, cranked it up and watched the packets on either side. It was very interesting in a number of ways. First the microwave oven concentrates it energy into a relativly narrow band. It effectivly destroyed the first two channels. Within a few minutes (I was suprised to find that it took so long) the AP and radio hopped over to another channel and resumed transmitting. On the 'noisy' channel about 25% of the packets were garbled. Every licenced device is supposed to change channels to avoid interference (as far as the radio 'knew' the microwave was a transmitter already on that channel). I know for a fact that there are some cordless (funny how different 'wireless' and 'cordless' hit the brain) phones that don't play nice. The failures of telephone manufacturers to produce quality hardware should not be used as an argument against the development of 802.11b devices. Radio hardware manufacturers _could_ be as sloppy as the guys building the crufty phones. Then your phone wouldn't work instead of your 802.11b gear. That's hardly an improvement. This interoperability argument condemns the hardware that is doing the "right thing" in favor of the hardware that isn't. That's obviously an indefensible position in the long run.
I'm done. I doubt anyone will bother to read this as the subject is nearly off the main /. page, but it's good to rant it out every now and then. Apologies to anyone insulted, insults to any apologists.
SaskTel, the provincial Crown phone monopoly in the Canadian province of Saskatchewan, is investing CDN$80 million into starting a subsiduary that will provide broadband service to Newcastle, NSW, Australia.
See the link here. It's skimpy on details, but it's real broadband. Take it from a SaskTel customer, they're good ($22/month, unlimited (128k) DSL to $100/month for unlimited (3m) DSL)
God save our Queen, and Heaven bless The Maple Leaf Forever!
Doesn't anyone out there get concerned about all these high powered transceivers surrounding them?
Xrays and microwaves are a fair ways apart, but it is the same thing -- *these waves are going through your body*.
I guess it's like smoking, unless the negative aspect is immediatly apparent, no-one cares.
Enjoy your tumor!
It won't get quite the speed that the high-speed ADSL might be able to get, but it doesn't do line-sharing, and there's no need for a dialtone.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
I trust that you do not go outside at all. The sun gives you a much higher doseage than does 802.11. Likewise, be careful, we also have o2 floating around and in slightly higher concentration, we die. Without h2o, we die, but also, too much and we also die.
Life is one big balancing act.
See subject
There is no place like ~!