Does anyone know what encoding schemes Texas Instuments and Itersil were fighting over to be the standard for 802.11g? I personally don't think it will do well because .11a will be already in place and no one would want to upgrade.
Personally I think 802.11g is a better way to go for wireless because it is backwards compatible with 802.11b, and just about every wireless installation out there right now it 802.11b. 802.11a is fast and all, but you can't walk down to your local starbucks and surf with a .11a card, as you can with a .11b card and will be able to with a .11g card.
Not to mention that .11b cards will work with .11g base stations.
Personally I know people with 802.11a cards and basestations and they hate the distance they get with it. 802.11b has a lot better range then .11a and .11g will have even better range then .11b. Not to mention it is backwards compatable. Oh and one last thing, when PV hits 5 GHz it will interfear with the .11a standard
<strong>It probably won't end up costing much extra to have dual-band wireless standard anyway...</strong><hr></blockquote>
Yes but trying to take 802.11b and .11 g with only 54Mbps creates a lot of traffic depending on the amount of nodes. The interframe gap is smaller and this helps but the base station would have to switch between sending and receiving on the .11b and sending and receiving on the .11g which would create less that spectacular speeds for more than 15-20 users.
Yes but trying to take 802.11b and .11 g with only 54Mbps creates a lot of traffic depending on the amount of nodes. The interframe gap is smaller and this helps but the base station would have to switch between sending and receiving on the .11b and sending and receiving on the .11g which would create less that spectacular speeds for more than 15-20 users.</strong><hr></blockquote>
Huh? 802.11g is supposedly already backward compatible with 802.11b, so all this hoopla about congestion = quixotic. I was talking about dual-band 802.11a and 802.11g
Linksys and others already have dual-band 802.11a/802.11b products.
Huh? 802.11g is supposedly already backward compatible with 802.11b, so all this hoopla about congestion = quixotic. I was talking about dual-band 802.11a and 802.11g
Linksys and others already have dual-band 802.11a/802.11b products.</strong><hr></blockquote>
Dual Band means that it's using one antenna for .11b and one for .11a. We can assume since neither is able to use both antennas that maximum throughput speeds will decrease as well as effective transmission area and redundancy. As far as processing, I believe that it can only process input or output from one at a time, so only .11a or .11b would be able to talk at any given time. This equipment may have totally separate controllers, but if they do not, this is another congestion problem. I don't know exactly what the specs are with the linksys stuff but I can tell you if they have separate processors, buffers, etc, then they are truly dual band. If they just share the same backbone and processor, but have different antennas then the congestion WILL occur. Please, correct me if I am wrong.
Macubus, this seems like the least of 802.11's problems considering the that 802.11 is simplex I know for a fact that 802.11b is simplex, but I'm not totally sure about 802.11a. Only one side can talk at a time. It's like a walkie-talkie. It sends something out, stops sending, waits for a response. 802.11b is not capable of sending and receiving simultaneously.
Because this limitation already exists at the core of each standard, there probably won't be any big problems with cross-talk, congestion, whatever. Since I have no idea what components Liksys uses in its dual-band access point, I can't really tell you how many parts of the device are shared and creating a bottleneck.
<strong>Macubus, this seems like the least of 802.11's problems considering the that 802.11 is simplex I know for a fact that 802.11b is simplex, but I'm not totally sure about 802.11a. Only one side can talk at a time. It's like a walkie-talkie. It sends something out, stops sending, waits for a response. 802.11b is not capable of sending and receiving simultaneously.
</strong><hr></blockquote>
They operate in two different bands and use two antennas (didn't check). The problem is, that ONE antenna can't receive and send at the same time. That's why the CSMA/CA (Collision Avoidance) protocol is used in 802.11. It's no problem to create a device that can send and receive in different bands at the same time (take a b and an a AP and put them into one box).
However, there are problems with these dual band devices. Because of the small range of 802.11a, you have to put them close together. Short distances are bad for the 802.11b network, because you only have 3 channels. Chances are good that two APs using the same b-channel are so close that they can see each other. As a result, half of the available b bandwidth is lost (because of CSMA/CA).
<strong>... I personally don't think it will do well because .11a will be already in place and no one would want to upgrade.</strong><hr></blockquote>
In Europe, 802.11a is a no go (licencing issues). Extension 802.11h is needed, but .11g "will be already in place and no one would want to upgrade." One likely scenario is that in the US, 802.11a will have the biggest market share while 802.11g will be the standard in Europe.
Short distances are bad for the 802.11b network, because you only have 3 channels. </strong><hr></blockquote>
You actually have 11 channels, but to stop overlapping between access points, they should be placed 5 channels apart. Hence the reason the 3 recommened channels are 1, 6, and 11.
These are all great points, I'm surprised 802.11 standards got this much attention.
You actually have 11 channels, but to stop overlapping between access points, they should be placed 5 channels apart. Hence the reason the 3 recommened channels are 1, 6, and 11.
</strong><hr></blockquote>
Yes, I should have said 3 non-overlapping channels. 14 channels are specified, but you can't use all of them, 11 in the US (1,6,11), 13 in Europe (1,7,13), 1 in Japan (14). If all 14 channels were used, you could theoretically have 4 non-overlapping channels (11 and 14 being right next to each other).
What about security? Do the same security issues apply to 11g as 11b? I don't like the idea of someone cruising my neighborhood for wireless access and getting onto my network and either a) stealing (using) my bandwidth or b) getting into my Macs. If the only answer to this is to turn off file-sharing, then what's the point of a network? After all, networks were designed to enable file-sharing.
<strong>802.11b has a lot better range then .11a and .11g will have even better range then .11b.</strong><hr></blockquote>Is this true? I thought g had less range then b at max data rate, and about the same range at the same data rate.
<strong>Macubus, this seems like the least of 802.11's problems considering the that 802.11 is simplex I know for a fact that 802.11b is simplex, but I'm not totally sure about 802.11a. Only one side can talk at a time. It's like a walkie-talkie.</strong><hr></blockquote>
Actually, this is called half-duplex, not simplex. The latter means unidirectional, i..e one side is always the sender, the other is always the receiver.
1. Does an 802.11b client in slow down an 802.11g network/basestation to 11MB/s or is it like a "switched" environment?
2. Is Airport Extreme compatible to 22MB/s 802.11b+?</strong><hr></blockquote>
From what I've read it's been stated the base station slows down to keep the network compatible. Ergo, it appears that one 802.11b device on your network will deprive everyone of the 11g's speed...
Comments
Not to mention that .11b cards will work with .11g base stations.
--PB
A@ron
<strong>It probably won't end up costing much extra to have dual-band wireless standard anyway...</strong><hr></blockquote>
Yes but trying to take 802.11b and .11 g with only 54Mbps creates a lot of traffic depending on the amount of nodes. The interframe gap is smaller and this helps but the base station would have to switch between sending and receiving on the .11b and sending and receiving on the .11g which would create less that spectacular speeds for more than 15-20 users.
<strong>
Yes but trying to take 802.11b and .11 g with only 54Mbps creates a lot of traffic depending on the amount of nodes. The interframe gap is smaller and this helps but the base station would have to switch between sending and receiving on the .11b and sending and receiving on the .11g which would create less that spectacular speeds for more than 15-20 users.</strong><hr></blockquote>
Huh? 802.11g is supposedly already backward compatible with 802.11b, so all this hoopla about congestion = quixotic. I was talking about dual-band 802.11a and 802.11g
Linksys and others already have dual-band 802.11a/802.11b products.
<strong>
Huh? 802.11g is supposedly already backward compatible with 802.11b, so all this hoopla about congestion = quixotic. I was talking about dual-band 802.11a and 802.11g
Linksys and others already have dual-band 802.11a/802.11b products.</strong><hr></blockquote>
Dual Band means that it's using one antenna for .11b and one for .11a. We can assume since neither is able to use both antennas that maximum throughput speeds will decrease as well as effective transmission area and redundancy. As far as processing, I believe that it can only process input or output from one at a time, so only .11a or .11b would be able to talk at any given time. This equipment may have totally separate controllers, but if they do not, this is another congestion problem. I don't know exactly what the specs are with the linksys stuff but I can tell you if they have separate processors, buffers, etc, then they are truly dual band. If they just share the same backbone and processor, but have different antennas then the congestion WILL occur. Please, correct me if I am wrong.
Because this limitation already exists at the core of each standard, there probably won't be any big problems with cross-talk, congestion, whatever. Since I have no idea what components Liksys uses in its dual-band access point, I can't really tell you how many parts of the device are shared and creating a bottleneck.
<strong>Macubus, this seems like the least of 802.11's problems considering the that 802.11 is simplex I know for a fact that 802.11b is simplex, but I'm not totally sure about 802.11a. Only one side can talk at a time. It's like a walkie-talkie. It sends something out, stops sending, waits for a response. 802.11b is not capable of sending and receiving simultaneously.
</strong><hr></blockquote>
They operate in two different bands and use two antennas (didn't check). The problem is, that ONE antenna can't receive and send at the same time. That's why the CSMA/CA (Collision Avoidance) protocol is used in 802.11. It's no problem to create a device that can send and receive in different bands at the same time (take a b and an a AP and put them into one box).
However, there are problems with these dual band devices. Because of the small range of 802.11a, you have to put them close together. Short distances are bad for the 802.11b network, because you only have 3 channels. Chances are good that two APs using the same b-channel are so close that they can see each other. As a result, half of the available b bandwidth is lost (because of CSMA/CA).
<strong>... I personally don't think it will do well because .11a will be already in place and no one would want to upgrade.</strong><hr></blockquote>
In Europe, 802.11a is a no go (licencing issues). Extension 802.11h is needed, but .11g "will be already in place and no one would want to upgrade." One likely scenario is that in the US, 802.11a will have the biggest market share while 802.11g will be the standard in Europe.
<strong>
Short distances are bad for the 802.11b network, because you only have 3 channels. </strong><hr></blockquote>
You actually have 11 channels, but to stop overlapping between access points, they should be placed 5 channels apart. Hence the reason the 3 recommened channels are 1, 6, and 11.
These are all great points, I'm surprised 802.11 standards got this much attention.
<strong>
You actually have 11 channels, but to stop overlapping between access points, they should be placed 5 channels apart. Hence the reason the 3 recommened channels are 1, 6, and 11.
</strong><hr></blockquote>
Yes, I should have said 3 non-overlapping channels. 14 channels are specified, but you can't use all of them, 11 in the US (1,6,11), 13 in Europe (1,7,13), 1 in Japan (14). If all 14 channels were used, you could theoretically have 4 non-overlapping channels (11 and 14 being right next to each other).
I know, lots of questions
<strong>802.11b has a lot better range then .11a and .11g will have even better range then .11b.</strong><hr></blockquote>Is this true? I thought g had less range then b at max data rate, and about the same range at the same data rate.
<strong>Macubus, this seems like the least of 802.11's problems considering the that 802.11 is simplex I know for a fact that 802.11b is simplex, but I'm not totally sure about 802.11a. Only one side can talk at a time. It's like a walkie-talkie.</strong><hr></blockquote>
Actually, this is called half-duplex, not simplex. The latter means unidirectional, i..e one side is always the sender, the other is always the receiver.
Bye,
RazzFazz
[ 01-09-2003: Message edited by: RazzFazz ]</p>
<strong>Is this true? I thought g had less range then b at max data rate, and about the same range at the same data rate.</strong><hr></blockquote>
g definitely has smaller range at max data rate than b. Not sure if the max range has been improved over b, though.
Bye,
RazzFazz
1. Does an 802.11b client in slow down an 802.11g network/basestation to 11MB/s or is it like a "switched" environment?
2. Is Airport Extreme compatible to 22MB/s 802.11b+?
<strong>Here are my 802.11b/g questions:
1. Does an 802.11b client in slow down an 802.11g network/basestation to 11MB/s or is it like a "switched" environment?
2. Is Airport Extreme compatible to 22MB/s 802.11b+?</strong><hr></blockquote>
From what I've read it's been stated the base station slows down to keep the network compatible. Ergo, it appears that one 802.11b device on your network will deprive everyone of the 11g's speed...