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The Coming Time for 802.11a?
abhikhurana writes "
This article on 80211-planet.com predicts a real boom in the market for 802.11a in the coming year. An excerpt from the article:
In tests in my SOHO LAN, I found that in real world conditions, 802.11a averaged four times faster than 802.11b. In addition, with its 5GHz frequency, 802.11a avoids the interference slow-downs that b must suffer with microwave ovens, high-end wireless phones, and other 802.11b networks.
Also makes an interesting read for knowing about the technologies which maybe driving the wireless bandwagon in the coming years."
they begin making base stations that support both standards and card which support both. These stations and cards would also be able to do both at the same time (IMAGINE THE BANDWIDTH!). They are on different freqs so it should be possible! This would do wonders for terrain based coms.
--
WHO ATE MY BREAKFAST PANTS?
bigger faster better more, the endless pursuit "just because we can."
This just sucks... when can i buy it?
I just got may 802.11b installed last week. Curse this need for the latest and greatist!!!
All Troll + "offtopic" mods are meta moderated as "Unfair", because you abused the system.
Hell, I still use Wavelan for my wireless gunk and I see no need to upgrade.
"Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
lower range, houses with chicken-wire in the walls, still limited by the speed of your cable modem/DSL ....
Fresh starters may be more inclined to adopt faster, "cleaner" wireless, but the push will be moving people from 802.11b - having incompatible networks makes buying decisions harder...
Though some will probably opt for both, as many businesses use b, and won't want to spend the money to replace all the cards in all the laptops.
I wonder when Apple will produce 802.11a cards, and if they'll support a & b.
That what was all this school was for... to teach us how to solve our own problems. -- janeowit
This may be slightly off-topic, but it still holds water
How are we going to adopt a technology when MS is deciding for the users what is best.
How about instead of XP deciding to take over for all WLAN third-party software and FORCING you to use an encryption key, let's let the fucking USERS decide what THEY want to do and what software THEY want to use.
Ever since switching to XP (from Win2k) as the host for my WLAN (Dlink DWL-650s in ad-hoc) I have had nothing but poor connectivity.
XP has been reporting that the WLAN is down even if it is working just fine. It won't let me use third-party software to control the WLAN. It forces me to have a network key (it would be different if the range on these cards was over the 25' from the host machine to the furthest reach of the signal).
Just my fucking rant on how MS and their "users are dumb" is really messing w/ME!
How long should I wait to get wireless? I don't want to get trapped in an upgrade loop, like I've been in with computers.
Since '92 I've just been happy to stay 1-2 generations behind to keep the cost down.
Here is a nice comparison of B and A on 80211 planet. Also, a whitepaper for A is available at Proxim Communications. Also, don't forget the FAQ!
My personal feeling about this: The U.S. government should sponsor a 802.11a nationwide network, so we can all have cell phone and data access anywhere, and a provider can 'buy' an area from the government to charge wireless rates for. Kind of like the current system we have in place for land-line phones.
Everyone comes out happy:
the cell phone company has a local monopoly
the customer has access to wireless data and phone everywhere
the government 's pocket gets fatter.
If you don't know what Zoo Blacklisting is, click here.
Anyone care to comment on why this is not prone to problems? Sure Microwaves screw with 802.11b, and cell phones, etc. But who in their right mind thinks that as soon as 802.11a takes off there won't be other devices using that range, like cordless phones, etc... This is going to be a constant problem forever. Since as soon as one device has the right to use a frequency, other devices will be manufactured to use that same frequency...
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Programming is like sex... Make one mistake and support it the rest of your life.
The truth is about halfway down the article, where they acknowledge that 802.11g is coming down the pike with better range than 802.11a, plus backwards compatibility with 802.11b. Any of us who already have investments in 802.11b are going to be more than a little hesitant to rip out that infrastructure and replace it with another incompatible format - when we can get an even better format, with backwards compatibility, by waiting a few more months.
I don't even buy the argument that homeowners just now getting wireless should get 802.11a equipment: they can't take their wireless cards and use them at public or private 802.11b access points. Why pay extra for something you can only use at home, when you can get something cheaper that works all over the US? It would be like buying a cellular phone that only worked in your neighborhood.
What's your damage, Heather?
That being said I will probably switch to 802.11a when Apple supports it. I have a DLink 802.11b and DLink NIC for my (PC) Laptop and it's really fast. The Apple AirPort is slower than grandma driving to the "beauty shop". Kind of sad really, I get this sweet computer with wireless networking and still have it plugged in!
...) and a standard UI to boot!
Oh well, I really shouldn't complain. OS X is unbelieveable. It's like running linux but having real commercial apps available (Photoshop, Flash, Dreamweaver, InDesign, Acrobat(full),
..especially when you can use them to their fullest.
Other advantages of the 5 MHz frequency are that the same antenna you use for 2.4 can be used at almost double gain (as long as you're careful), since the wavelength is almost half as long you can use the same antenna. The thoroughput kills 11b by a factor of 5 to 1 at max.
Disadvantages... At 5 MHz, walls are a factor. Objects start to interefere more. So on a campsite, 11a will be amazing. In an office, you'll need repeaters. Hardware costs more right now, on par with what 11b cost at first.. then again, you can get 11b cards right now for under $50.. even Orinocos for under $60.
I used to be someone else. Now I'm someone better.
Real life is underrated.
I think we have reached the 'good enough' point with wireless networking. 802.11b is faster than any internet connection I will have in the forseeable future, and performs perfectly well for the small day to day file transfers over the LAN. It doesn't work for large file transfers, but when I need to do those, I pull out the Wi-Fi card, walk the laptop over to the hub, and plug a spare cable into it's ethernet port.
I won't be upgrading until there is a compelling reason, and I can't see there being one for at least the next 3-5 years.
-josh
It's in dual band devices such as this one from linksys http://www.linksys.com/Products/product.asp?grid=2 2&prid=452
Doesn't "b" come after "a"?
Why does this "a" thing sound newer?
My multimedia machine in my living room runs off 802.11b with a music server in another section of the house. When my 2.4 GHz phone rings, the music pauses nice and automatically (well after the buffer runs out). Its a great feature!
Seriously, webcams, phones, baby monitors all can clobber 802.11b pretty badly. I can't wait for affordable dual mode so I can put the multmedia machine at least in the 5 Ghz range. Home users with lots of tech toys are going to be much happier with 802.11a. 802.11g will do nothing for them.
That is my two cents. Of course, the big variable is when 802.11g recieves finalized specs. 802.11a is already there.
One more question for the grou: I have read a lot (for a Business Analyst) about wireless networking and have yet to see a place which explains the "lettering system" used by the 802.11 products. Why are a, b, and g given those names? Are there 802.11c and d awaiting consideration?
Until the 5 GHz band becomes just as crowded as 2.4?
802.11a is not the wave of the future. It's going to be a nice for those hardcore who absolutely need obscene speed and live in an interference-prone environment.
It has to compete against the HUGE installed base of 11b hardware that is *far cheaper* than 11a and is more than adequate for 90% of the people out there.
I was thinking of upgrading to 11a since I happen to be a power user - But that means that the card I bought would be useless on most networks I might roam to (such as my former college's wireless network). In the end, 11b won out because:
a) I already had some 11b equipment
b) My parents had 11b equipment
c) I have never had problems with 11b interference - Spread spectrum is pretty resistant to CW interference (Microwave ovens - People could run microwaves all they want in my apartment and I wouldn't notice any difference on my network.) and 900 MHz analog is "good enough" for me in the cordless phone arena, which means that the most famous 802.11b interference culprit (2.4 GHz phones) isn't present.
d) 11b hardware was a helluva lot cheaper than 11a hardware.
retrorocket.o not found, launch anyway?
A 10 mbit 802.11a can cost as much as a gigabit NIC, which isn't too favourable if you're not going to do much roaming. The fact that you have to buy several Wi-Fi cards to get a wireless network together makes the proposition daunting for homes and small businesses. It doesn't have to be fast (or even secure, that's what ipsec is for), but for the technology to become truly ubiquitous, it needs to be priced at commodity levels, say around £10 to £15.
Personally I'm hedging my bets on systems that offload most of the processing to the host CPU like the stuff Microsoft is working on. It allows not only for cheaper hardware, but also gives more flexibility and upgradability (care to upgrade your Wifi setup to 100mbit with a software update?) The only thing that could potentially go wrong with this technology is if Microsoft tries to abuse its position and fails to release open specs for the hardware or releases proprietary (or no) drivers for non-Windows operating systems. However, given their commitment to FreeBSD it's quite possible that they'll go ahead and release some BSD-licensed reference drivers for FreeBSD which can be ported to other architectures.
I belive that you cant legally run 802.11a in the UK or europe
intel had to get a licence for London Fashion Week where they did video streaming of differant shows
not sure about china or taiwan anyone know
regards
John Jones
If I was sitting normal in a chair and using the computer, no problems.
I see this a a bigger push from 802.11b, as the 11a components will now demand the high price, 11b components will drop even more.... eeeexcellent Smithers.
This is not the sig line you are looking for... -- Old Jedi Sig Line Trick
I was a beta tester for a 802.11a product in early 2001. I was attending school at RPI and our test product did not reach through the dorm walls. I couldn't, on high power, reach to the dorm next door. However, with the same company's 802.11b system, it would go all the way around the building. The issue is that 5ghz drops off faster than the 2.4ghz equipment.
The real world:
That said, a small office or home that can be covered by a single unit should work acceptably. I would wait for 802.11g before installing a large number of units based on 802.11a, especially for any core business use.
I rbought a nifty sponsored 54mbit wlan card along with my laptop at university; in return university installs wlan routers throughout buildings and other 'hotspots' to try out this new technology. To be honest, i would prefer the use of standard 100mbit with a normal utp cable. .. it still has a long way to go ..
Wireless connection get dropped by windows(XP) at random intervals, and connectivity is poor; i find myself connected at 12mbit regularly even though im sitting next to the router, and am the only one that makes use of it.
It's in dual band devices such as this one from linksys
The device you point out is an access point, not a card. Buying a combo 802.11a/b access point means you have to have 802.11a access *cards*, or else your money on the a/b access point was wasted - and you should have just gotten an 802.11b access point. But if you have 802.11a cards, then you can't use them at the public/private access points away from your house/job - like at coffee shops all over the place these days. So these combo access points really don't help much.
What's your damage, Heather?
microsoft has a commitment to freebsd?
did i miss the memo? the only thing i know that connects microsoft to freebsd is the fact that they used portions of the tcp/ip code in win2k.
stored on computers from birth to the grave
The Federal Bureau of Acronyms has announced that all desirable acronyms have been used.
A new scheme postfixing a letter after an FBA-assigned five digit series of numeric characters is now in place.
This space for rent.
I'm just wondering...does 802.11a not operate in the 5.8 GHz range? I know there are three chunks of the 5 GHz area, so is 802.11a going to work in the low and middle bands only (5.15 -5.35)?
I ask because I know VTech (and so other manufacturers, probably) are selling 5.8 phones now, which I assume are operating in the high band.
Fortran programmer...oh yeah. Array math for life!
does anyone actually know of a PCMCIA card that does both Bluetooth and 802.11b ?
that would make alot of people Very happy
regards
john jones
p.s. bluetooth phone dialup when your not in the office and 802.11b for when you are
Double the frequency of 802.11b means a shorter range. For those of us who've been building cantennas and such, there's really no point in switching to 802.11a, unless we like the "challenge".
I own two D-Link DWL-650 cards. The range was never all that great (even in Linux). I assumed it was the fact that I was communicating card-to-card.
Things became much better when I started using a proper AP.
Later on, I needed a WLAN card for my desktop. After a BAD runin with a D-Link DWL-520 that I promptly returned, I tried a Orinoco and PCI carrier. The PCI adapter didn't work to well on my desktop. (Fine under Linux, useless in Windows) I returned the PCI adapter, but because the Orinoco had seemed to give slightly better performance and was supported by Netstumbler, I kept it.
A few weeks later I pulled out the D-Link once again for comparison - At that point I realized just how bad it was.
Side-by-side in the same place, the Orinoco blew away the D-Link. Orinoco reports a "good" signal strength upstairs. The D-Link barely gets signal. Downstairs, the D-Link reports low signal strength IN THE SAME ROOM AS THE AP! The Orinoco is pegged at full strength in this case.
I'm sticking with Orinocos from now on...
retrorocket.o not found, launch anyway?
There's like ZERO FUCKING RANGE on these things.
and not compatability either.
I was running a Dlink card with a netgear base -- hah! I couldn't get a connection better than 1k. And that was with a range of 2 feet.
The range on these sucks. You can't get much past 30 feet in a home.
The old Freq Hop method was much better. I was regularly getting 100 feet, changed to the DSS and it's down to 30 feet.
I can't imagine how piss-poor 802.11a would be.
But there's just no justification in spending hundreds of dollars for something that is little better than bluetooth or IRDA.
Wireless is over-priced, under performing, and just pretty shitty.
I don't think I can even justify buying the 802.11b now that they are getting dumped off the market for CHEAP.
It's just bad technology.
It took just a little bit of troubleshooting but after switching to channel 7 on my Linksys Wirelss AP/router, I have NO interference from my Sony 2.4 ghz phone or my microwave. Of course the tinfoil armor around the phone and microwave might have something to do it...
Honestly is the interference such a problem w/ 802.11b? It sure isn't in my case. Maybe it's jsut part of a marketing push for 802.11a so the manufacturers can concentrate on one standard. Anyone here have any experience w/ HomePlug? I'de love to hear about it if you've installed it.
I have quite few problems since installing SP1 for XP. XP now insists that the wireless connection is down even when I'm sufing the net and periodically I get conflicting IP address errors that only rebooting my Linksys router can fix.
I'm sitting here using my computer at work over Remote Desktop (yes, stuck using Windows crap, but as Windows goes, this remote desktop stuff is pretty trick). Wireless network is pretty much pegged between this and local stuff. I'm showing solid green (excellent signal), and I'm sitting here on my DSSS 2.4ghz cordless phone.
Now maybe if there were other phones or something in the area it'd be a problem, but I'm just not seeing it.
Hey Guys... a small correction. When I posted this article I wanted the subject to be coming of time for 802.11a? :-)
So hey, sorry for the ommited of
What's under yellowstone?
So you ARE going to tell us about the pros and cons of switching back from 80.11a to 80.11b? I, for one, wold like to hear them.
So as the 'new wave' of 5 GHz devices come out, the next phones will again mess with wireless. You get rid of the microwave, but not phone. Personally, I have not experienced problems with 802.11b and interference.
Range will, however, be hurt. Wireless becomes pointless as the range diminishes. Range matters in some ways more than excessive bandwidth. Beyond 11 Megabit, it certainly doesn't matter much. For 95% of the applications out there, the extra bandwidth is unnecessary. I am able to stream extremely high quality video content through that to a handful of users on a single access point. Accessing things through network shares are still a pain in the ass at 100 megabit, so the added pain of 11 megabit most of the time isn't enough to make the sacrifice. As they say, 802.11g looks more promising, but in any event I can for about a hundred bucks set up a wireless system and client with 802.11b that suites all my needs. Why bother?
XML is like violence. If it doesn't solve the problem, use more.
ok, i read ages ago about a trial in cardiff (i think) about a radio network where each home was a node and sumwhere there was a internet POP... surely this is the future? as it grows u end up with a massive network in itself, areas link up as more ppl join and before u kno it there is no definition of where this WAN and the international WAN that is the internet join. anyone can host, there can be less censorship (no ISPs) and no one can limit what anyone else can do. It also makes the whole thing even more fault tolerant. or at least thats how i see it. /me cowers from flames.
what he said.
Distance affects usability, of course - if the thing can't talk from the living room to the bedroom, that's a problem. But speed isn't enough to justify the extra cost for most home users.
Business is a different matter - there you often have enough machines sharing a server in the same building that total bandwidth matters.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Using 802.11 at the moment (thanks whom ever is running this public service.) Two good bad things, untill it comes with a adapt.method, significantly wider range and a much cheaper asking price modems will still roll out. 802.11 blows prity badly under linux (wich blows in of it self). Why not use a SPL (secure protocall link ) that transparently uses GPG or PGP, transparently rotates frequentcy, and has a 2-3 mile (6 Kilomoter) range? toss in stability for up to three repeters, (18 kilomiters) using any device PASSIVLY, that's in range and you've got win win, starbucks is more inclined to continue to tollerate people borrowing spare bandwidth cicles (it is thier backbone),banks cellphones, etc can sleep tight knowing that max_user is max_user, thus if they have say 5 spare_slots in max_user.method, and or up to 2 megs free joe next door has 3 you'll dynamicly hopbetween all of the above. Oh wait this is the GPL crrowd, and that's not the android you want. Untill then I'll tolerate my 20::month internet service.
Actually, 802.11b has better penetration at the same power, mainly becouse 5GHz iterferes with concrete walls even more than 2.4GHz
Maybe a microwave oven will force you to go as low as 1MB/s, but for sharing a ADSL connection (what I use it for) it is more than enough, plus I get the extra distance. 802.11a born dead...
I agree. It works fine for me. I'm using it at home with one or maybe two laptops for surfing the net or grabbing a (small) file.
I need the wireless"ness" more than access to larger pipe.
I came. I bought. I'm done.
NOPE.
going from 801.11b to 802.11g not even going to touch a. The vendors have interoperability issues with a.
If your microwave is interfering with ANY 2.4Ghz product then REPLACE IT ASAP. A microwave in good operating condition should not leak any 2.4Ghz radiation as the entire chamber should be properly sealed and the screen on the front of the microwave should keep the radiation in. Some people freak about cell phones and wlan devices, but the max power output of an 802.11b radio is 100mw for a client card, while a microwave over has radiated power in the hundreds of watts.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
okay, i've never squawked about moderation before, but here goes:
that's not flamebait. flamebait would be *complaining* that they used portions of the bsd tcp/ip code in win2k etc. flamebait would be imprecating them for that. flamebait would be using a dirty name or word. flamebait would be insulting the bsd license that allows such use.
i did none of the above.
i just simply stated what the only connection i know of between the two was. i suppose i could get linkage to illustrate, but it's pretty common knowledge.
i don't know if they currently use the stack in xp. haven't tried ftp on it.
i am still curious to know what commitment microsoft has to bsd. i've never heard of such a thing. they've had an off-and-on commitment to SCO (flamebait warning: yuck.) but that's the closest they come, i think.
stored on computers from birth to the grave
But some definately are. I have a coworker that has an 802.11b network and a 2.4 GHz phone - His network gets *clobbered* when he uses his phone.
retrorocket.o not found, launch anyway?
I don't see this happening with 802.11a. The range for a is MUCH shorter than the range for b, and even b is rather short. There would need to be some way to put out a much stronger signal with a to make this effective. Simply put, I don't see a government nationwide wireless network happening for another year or two. The technology still is not there yet. Of course, the rate of change is getting faster by the month now, so my prediction may be more out of date than 640k in 6 months, but time will tell.
"I may be quite wrong." - Socrates
microsoft of all people did the right thing. they won't WHQL certify an 802.11a device that does not also have 802.11b backwards compatibility.
buy an 802.11a device today and you have something that you can't carry with you anywhere you go and expect to work. buy an 802.11b device and you can connect to 40 different APs on the way to work.
Buy a combo device and you've got the best of both worlds.
While you can use other software with XP, XP makes it VERY, VERY difficult and just *loves* to conflict with said software, making using WLAN in XP an absolute nightmare. (Orinoco firmware updates not working reliably is a perfect example of this. Also, while you CAN use Orinoco's client manager, it is a BITCH to set up.)
I nuked XP in favor of Win2k on my laptop and have been happy ever since. Wireless works great, I have infinitely more control over SpeedStep (XP's built-in support has hardcoded profiles that result in it being *impossible* or at least extremely difficult to force slow speed when on AC), and my laptop can now wake up from suspend. None of those worked properly under XP, in at least two cases (wireless, SpeedStep) it was because XP tried to do it for you but did it very badly.
retrorocket.o not found, launch anyway?
I don't understand how in a forum like this people can assume that all network bandwidth is only used to connect to the greater 'Internet.' Part of the reason I've not invested in any wireless networking equipment up to now is that I like moving data around the various machines in my house at Fast Ethernet data rates. I would NEVER want to go back to regular 10baseT bandwidth, nor any wireless method of about the same speed. When I'm moving big chunks of data, which is what networks are for, I want the bandwidth there to do the work for me. When I'm playing Pysol on a NetBSD box, displayed on my W2K box with eXceed, I don't want to watch the pixels redrawn.
about a month ago (D-Link DWL-6000AP). We have 802.11b in the other building and I decided to try 802.11a down here to see how they compared.
.11b and hard barriers (concrete walls, walls with a lot of steel, etc.) seem to attenuate the signal much more quickly. I don't get nearly the range with 802.11a here as I did a couple of years ago when we tested 802.11b here (before moving it to the executive building.) Speed drops off much more quickly, too: I get about 40-50 feet here in the office at full speed and then it drops off very quickly to 802.11b speeds beyond that, before finally quitting altogether at about 90 feet.
.g comes along: .a seems like a -very- interim technology with few advantages and some serious faults.
802.11a has a noticably shorter range than does
If it were me, I'd stay with 802.11b until
On the plus side, all of our Thinkpad notebooks with built-in 802.11b work effortlessly with the D-Link access point. I've got three systems (two notebooks, one desktop) with the 802.11a cards in them and half a dozen Thinkpads with 802.11b either built in or with cards and it all works very well.
Hello...Sorry to post as AC, but...
.11a, so we are waiting for their update.) Any ways.... 30 Laptops per "Cart"
.11b... and if .11b did... BUT Thats not our need, so it works great for in the room, wireless networking... If I do line of sight, I can get a few hundred feet down the hall between the WAP and the laptop before I loose signal (although down to about 20MB...)
.11a,
:)
(BTW, this is in a elementary school environment)
We just got 7 Wireless Laptop Labs, all with 802.11a built in (well, not yet, PCMCIA now..
the drivers didn't work because of bios on the
built in
2 WAPs (Wireless Access Points for newbies) and
a 10/100 Switch to tie it into our existing network in the room(s)
The teacher wheels in the cart, pugs it it, and
hand out the laptop to the room full of students
and ~Bingo~ they are on the network running about 58-75MB. A Learning program that keeps student data on the Server, Program is local... Kinda overkill... 802.11b would have worked except with
so many students at once it was a bit of a slow down on network login, printing, etc...
Now.. Downside... Coverage... I can only get about 1/2 the coverage as with
it involves rooms with concrete walls up between them, then it doesn't work as good as the
Just a sampling... All the wireless is Proxim... I don't know if they are the only folks for
but thats who's equipment the school got with the package. No... I'm not gonna bait thread with the company that puts it together, I'm sure if you look around google you'll find a few...
now, if someone could make wireless power so I can
get rid of ALL the cables in my other classrooms...
I have been using an 802.11b network in my house for almost 4 years. I first started with a Breezecom AP and PCMCIA card. I had range that would allow me to roam around the house at 3 Mbps. I could even roam outside by the pool with a little drop in performance. The ISP I worked for setup these same units on a near by hilltop and with a larger antenna and an amplifier we were able to send Internet access out to customers up to 8 miles away. I had an external antenna receive the signal outside my house and drop it off to a BSD router with three NICS. One for incoming wireless form the hilltop, one to my switch and the third for my internal wireless network.
Two and half years ago I upgraded my internal network to a Cisco AP and got a new PC Card for my laptop. Shortly after that I upgraded from the wireless network to DSL from the same ISP. I left the run of LMR400 that runs outside. I replaced the 18 dBi directional antenna with a 9 dBi omni. Now I can browse the Internet down the street at my neighbors. The BSD router is still in place and considers everything on the wireless Ap outside the network and requires a VPN to gain access to the network, just like the Internet side.
Recently I helped a friend that lives a block down from me install an 802.11a network including an external antenna so he can use his wireless by the pool. I can get better through put from my wireless in his backyard than he can get standing right next to me. Granted his speed inside his house, especially in the family room, where the indoor antenna is located, is far and away faster than what I can get even next to my AP. Initially he had a dead spot just outside the sliding glass door. As soon as it was shut he went dead until he walked out 10-15 feet towards the pool. With a little adjustment of the exterior antenna it was eliminated. That wife of his insisted that it not be out in the open where everyone could see it.
Now he just needs to decide what he values more, limited distance and greater speed or greater roaming ability with limited speed. Those are the tradeoffs.
Old7
Well, 54 Mb/s is about 5 times 11 Mb/s. But abhikhurana only saw a 4x improvement. This lines up well with my own tests show 3 - 4 times improvement.
So that 54 Mb/s rate sounds like about 1/2 of a 100 Mb/s ethernet. But in reality you will only get about 10 - 15 Mb/s under optimum conditions, and it is shared bandwidth, not switched.
Also consider that the range is greatly reduced. Keep in mind that in 802.11b the farther out you are, and the more interference there is, the lower you rate is. It will switch from 11, to 5.5 to 2, and then 1 as the signal gets weaker or more corrupted. The same is true for 802.11A, accept the range is way smaller, so you will get a reduced rate at ranges where 802.11b is still running at full rate.
Unless you are really trying to squeeze more bits down the pipe and your range is small it probably doesn't make sense to upgrade.
There are companies out there who use this 5 ghz unlicensed band to do reliable 50+ mile shots using 6-8 foot dishes. Radio stations also use it for digital studio to transmitter links.
Andrew makes a line of dishes for this band that are very popular.
China, Europe etc all have issues with Radar interference in the 5Ghz band. Only when the military people in each of the various markets sign on will there be widespread 802.11a penetration. The technology is there, no question about it, it's the regulatory issue that is the holdup. Lobby your govt in the respective countries to get it approved. Until then, volume manufacturing will always favor 802.11b/g for now.
802.11a devices are not powerful and have difficulty with any objects that would obstruct the sight. to get near maximum speed, you have to sit in line of sight around 10-15 meters from the
device. Bandwidth deteriorates quicky as you move behind walls.
That was my experience with 802.11a. There should be intermediate solution @ 3.2 ghz or around there, so people can get better range out of their devices. 802.11a, is to be used as replacement of inhouse networks, nothing more.
I guess this is great for cafes and alike due to reduced range, they don't have to step on each
ones toes...
2c,
p.
Very loosely speaking, I see the triad of 802.11, 802.11b, and 802.11a as being like the triad of Ethernet, FastEthernet, and GigabitEthernet.
There was once a time when everyone had Ethernet, and all was good, if a tad bit slow.
When FastEthernet came out, there was some initial hand wringing, but pretty much everyone has moved to FastEthernet and declared it The Standard. Since it was the prevailiing technology at the time that computers with integrated networking were starting to come out in droves, FastEthernet has achieved critical mass.
Now, Gigabit Ethernet is out, but no average home user will ever see it in his computer. He's not likely going to need that high performance, and is certainly not willing to pay for it. It's a specialty application product.
Similarly, the older 802.11 wireless cards (2 MBit) was a good thing at the time they came out; but they were still a bit too slow.
When 802.11b came out, the performance reached a good level for the most common wireless use. And the price is pretty darned good. And since most laptops with integrated wireless come with 802.11b, it is achieving (has achieved?) critical mass. (Or is that critical mess?)
Although 802.11a is now available, they are too expensive and have not yet achieved the interoperability track record of 802.11b. And, besides, if you have a portable wireless network application, you probably don't need the higher speed. Really now, when was the last time you compiled your kernel over wireless? Or streamed video from a server to watch it on your laptop while you're seated at your comfy couch?
The world got along fine with Plain Old Telephone Service for a 100 years.
Now, wired FastEthernet, and wireless 802.11b is the "pretty good and cheap" solution for the masses.
vortex with a static warp shell.
Only on slashdot do you see things like "Score:0, Interesting"
You're probably right... 802.11g is able to tout "backwards compatibility", and it will probably have some component commonality with b, so it will be cheaper. Thus it'll take over the home market and such. I see some troubles with that.
All the technology reviews I've seen indicate (please correct me if I am mistaken) that 802.11g takes up the whole available 2.4GHz spectrum. This poses a few problems. In my situation, I may be getting into a house down the road. My plan would be to drop one or two AP's inside, as needed for coverage. Then another cell out the back, with an omni antenna to roam the backyard and porch. With g, interference might become a severe factor in such a multi-cell configuration. I could install a/b AP's, but then my girlfriend's Powerbook might lose out, considering all the rumors that Apple is about to get all g'd up. Protocol wars are such fun...
The other concern I have with g is if it retains the good wall-penetrating capability of b, and does take up the whole spectrum, apartment dwellers might be in for a bad time. I've seen apartments where 802.11b users are pretty dense, requiring shifting channel assignments around. g might not have that flexibility.
And the 802.11 Planet articles mentioned elsewhere here brought up a potential mess with RTS/CTS packets in a mixed b/g network. So far I'm liking 802.11a a lot better technically.
It looks like your post received a (Score:0) itself. One thing of note however is that your pathetic post did not garner the "Interesting" clarifier.
This seems to be the conventional wisdom, but the technical specs indicate that at a given range a is faster, and that they both drop off at roughly the same range.
Can anyone point out any docs that show why a should have a shorter range in practice? Is it just because 5GHz is not as effective at penetrating barriers?
-Peter
Exactly.
Let's see, would I rather dl Win2k SP3 from microsoft 3 times, or 1 time and copy it to the other two computers at 100Mbps? Tough question.
Bandwidth to the internet is not always a bottleneck.
People seem to also be overlooking the fact that 802.11a does not work with 802.11b antennas.
802.11b and 802.11g use the same antennas, same frequency.
External antennas make all the difference with these low-power devices. For $70 you can get cable and a decent antenna and solve most install problems - IF you get units that support them.
I have yet to see a dual-band (5 and 2 at same time) antenna.
It doesn't get the distance that 2.4GHz does, and the further you get away from the AP the faster it drops speed because of that. So you'll be lucky to get 802.11b speeds out of it unless you are sitting on top of it, what's the point of being wireless?
Speaking of radiation. If you use that 802.11x card in a laptop and use said laptop, ahem, on your lap... by all means WEAR YOUR FARADAY UNDERPANTS! Thank you.
nice troll but 802.11x is a security standard.
LAN bandwidth is important enough to me that, upon buying a new house a few months ago, I pulled cat5e into all the rooms rather than going wireless. It was a pain in the ass but I'm hoping that gigabit switches will come down in price soon so I can go gigabit at home. All the current gigabit products are obviously meant for big office backbones, not home usage. I guess I am alone...
wordclock records
If you want to use slightly more stable drivers for the DWL-650, go pull a set from the manufacturer Intersil. I'm using their generic Prism 2.5 drivers with my card (don't know what the 3.0 set does) and they're WAY more stable than the ones on the DLink website. (In my case, the Signal Strength meter actually runs on Win 2K instead of BSOD).
I can only imagine that the XP drivers would be better from them than DLink.
That is the reason I bought 802.11b instead of 802.11a:
I need the extra bandwidth because I use the wireless to stream video (divx) on a daily basis. 11 Mbps is barely adequate and often causes jerkiness in high quality video. So I did some reasearch on 802.11a to find the one best supported by Linux. The result? There is *no* support for any 802.11a cards as far as I could tell. So I didn't buy any.
Some of these companies need to figure out that early adopters are also people likely to use Linux...
Sure, you're weird (:-) So are many of my friends, like Hugh, whose house is "mainly insulated with copper wire". But when you're talking about mass-market adoption of a product, that's not who buys most of the millions of units - it's the people who probably have multiple computers and don't want to wire their house with Cat5E and fiber, but most of the computing horsepower is in the house is the kids' game machines and maybe the adult's work laptop. Business usability is a different matter (that's why the word "home" is in the subject line :-), but businesses probably won't be really mass adopters until the security issues are fixed. 802.11a prices have started to come down enough that in a new business installation it's almost certainly worthwhile, but for mass-market home use the main reason for it is better coverage (or sharing with your neighbors.)
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Yeah but having a cable attached to my laptop isn't nearly as nice as wireless .... trust me sitting on the porch doing a little programming is a beautiful thing.
Before modding this down as a troll, please read the whole thing:
802.11a is horrible. The testing I've done for my company indicates that the highest actual throughput you'll get with an access point is 8Mb. The highest you'll get ad-hoc is 18 (which is actually pretty good).
The problem is that kind of throughput is only possible when the system is right next to the AP or when the two systems are practically touching. If you walk a few meters and have line-of-site, you'll be able to get +10Mb throughput with the two adapters in ad-hoc, but if you go around a corner it drops off radically.
Now, why does 802.11a have such a problem with corners? Because the higher frequency transmissions will not bounce as well. Rather than diffracting like 2.4GHz transmissions do (diffraction is the bending of a wave around an obstruction), the radio waves bounce, diffuse, etc. Basically, the signal breaks up.
802.11b, though (and 802.11g) will route around obstructions better because of the lower frequency. The lower the frequency, the more diffractive the signal. I predict 802.11a will be passed over for 802.11g. Especially because 802.11g is backwards compatible. The real panacea will be cards that work with 802.11a/b/g. They'll have to have two different antennas, but they'll be kick-ass.
I just finished writing a networking book and tested 802.11a and 802.11b equipment in my home/office. 11a had much less range than 11b. I was really rooting for the 11a too.
I bought a setup of 802.11a products a few months ago to test out and setup a network at a friend's house. The range is so limited by what is currently being offered for 11a products that I doubt it will catch on except when the networks will be confined to a single room. I found that that the signal dropped at less than 30 feet in many cases and calls to tech support (Dlink) revealed that they openly admit that the range of current generation .11a products is very limited and that the claim that 5ghz can go farther than 2.4 ghz as it often says on the box is a massive dose of wishful thinking. The price/performance is just not up to par.
XP seems to be (oddly) missing support for Prism2 (i.e. DWL-650, SMC, Linksys, etc.) cards - My Prism2 wasn't detected by XP.
But if you want to use decent hardware (Orinoco), XP has built-in drivers and you're in for a fight.
retrorocket.o not found, launch anyway?
I had a problem with a .11b product, bought a .11a setup, got a replacement .11b setup, and decided to keep it and run both.
.11b network, but if I even try to go next door on my .11a network I get dropped.
.11a vs. like 4-5Mb on .11b using 64 bit WEP.
.11a drop while in my house (inside its limited range), whereas I can be right next to my .11b AP and get dropped because of interference. This is important; there is tons of traffic/noise in the 2.4 range.
.11b card to go next door, and use my .11a card while at home. Either way I am still on my LAN. Plus, I am set whichever way the industry goes (until the next big thing). I am thinking about doing the PDA thing soon too, so it's nice to know I can run it on my .11b network if it won't support .11a.
Bottom line(s):
1. 802.11b has WAY more range - I would say like almost double. I can go next door (and to my pool) on my
2. 802.11a has is WAY faster - I get a solid 25-30Mb over
3. I have never had my
-------------
Anyway, the setup works well. I can just throw in my
dmiessler.com -- grep understanding knowledge
I need to deploy it eventually, but my main concern right now is users hooking up an access point to their PC and using internet connection sharing or some other hack to give access to our network. So far, threat of death is working, but I can't rely on that. (We disabled ICS in AD GPOs but some users have admin rights to their PCs....)
Does 11a or 11g provide any improvements in security? All "advice" I've read about seems useless (like turning off SID advertising, easily gotten around using kismet, for example).
Do 802.11a or 802.11g fix the lousy security of 802.11b? I mean, no wireless network will ever be secure as a wired one because making it secure requires key management, but at least I should be able to expect that if I do my key management correctly, other people can't break in.
"Quick fix will let one avoid interfering with the other"
The ACA has some interesting ideas about the 5.2/5.8Ghz spectrum that don't quite agree with the FCC. For example 5.2 can't be used outdoors and the 5.8 can't be used in the long haul point to point modes and the max power leves seem to be 1/2 of what the FCC allows. The worst part about this is that the only references I can find are proposals about what they intend to do with the frequencies.
The reason for this madness is that some satellite is using 5.2 for an uplink. Considering how well regulated the frequency is in most of the countries between here and Japan, I would think it would be a very bad idea to keep a sat on a frequency that lots of people will be using.
My school (small private school in upstate New York) was 100% wireless last year with 802.11b. This year they switched to 802.11a. They were boasting a minmum speed of 54 mbps and a max of 108. It rarely gets up to 54 and never goes higher. In addition there are 4 Access Points in each housing unit. I had the one closest to me go out, leaving with another one which was about 30-40 ft. away. The signal was terribly weak and my connection suffered. Also there is a constant refresh, very noticable in multiplayer games. Every minute or 2 there is a half second of connection loss. Personally I would rather have the old style RJ-45 connection, but I guess this will do. I get somewhere around a ping of 12 to pretty local game servers. The school is still working on it and I am not trying to pre-judge it. They still have fixes to make
faster!!!! That is my only complaint so far with my new mac (G4 Tower). OS X is great! They should put me in one of those damn switch commercials, I mean hell I meet the requirements: I'm ugly, I am a nerd, I'm weird (come on I live in Oklahoma BY CHOICE!!!), I regularly visit the local apple store (Willow Bend Mall in Frisco aka Dallas), I have 3 Macs now 4 months after buying my first one, and I've bought every OS since 7.6 off eBay in the last 3 months!! (My wife is pissed off, hope our trip to New Orleans cheers her up or I'm (not) screwed!)
Apple OS X == Unix + Great UI (this is the unique part)
BTW dont buy a fucking Belkin KVM, mine is a piece of shit. If I type too much it shits out (which comes in really handy when playing online games). And I only have 2 computers hooked up to it (2 are monitor only b/c the Apple converter for ps/2 is a waste + I like the apple keyboards and mice).
Oh wait, that's out of order...
maybe the research group is just messing with our minds.
-rt
I see no reason that the 5 gig "a" frequency won't become just as crowded as the 2.4 gig "b" frequency is now. Ultimately, we all need technologies that let us live in unregulated frequency spaces. If we don't develop them, the "gov" will do it for us. BV
First, maybe I'm paranoid, but I just don't like the thought of placing a 5Ghz device in my office...probably next to my desk.
Second, 5Ghz is quite high.....if you had line of sight problems with 802.11b, they will only be worse with 802.11a. If you *need* more wireless bandwidth (and I doubt you do....if you do, perhaps you should rethink what it is you're trying to do) go with 802.11g. 2.4Ghz AND 54Mb/sec......best of both worlds....speed, and the ability to penetrate something thicker than a piece of paper (but not much more).
the monkey lives. i've tried it.
Large print giveth, and the small print taketh away
802.11a devices all have a radiation warning in the documentation:
/ pdf/8x50man01.pdf
"It is the responibility of the installer and users of the Harmony 802.11a PCI Card Model 8150 to guarantee that the antennas are operated at least 20 centimeters from any person. This is necessary to insure that te product is operated in accordance with the RF Guidelines for Human Exposure which have been adopted by the Federal Communications Commission."
http://www.proxim.com/support/all/harmony/manuals
802.11b devices run at a lower power and do not have that warning.
How do you keep a PC Card 20cm from your body?
It's my understanding that the range of 802.11a transmissions is significantly shorter than 802.11b. Couple this with the fact that 802.11g is the 54mbps standard that was approved, and I think that 802.11a is actually on it's way into nothingness. DO you REALLY need 54mbps? Is your internet connection that fast?
People who think they know everything really piss off those of us that actually do.
I'm posting from two streets away using my wifi router!! Mwahua ha ha ha! Who cares about 802.11a?