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View Full Version : Can 802.11b and 802.11g coexist?


Doctor Q
Jan 20, 2005, 04:09 PM
My coworker has 6 computers at home (a mixture of platforms), a two story house. He uses a Linksys WAP11 (http://www.linksys.com/products/product.asp?grid=33&scid=35&prid=563) 802.11b wireless access point connected to a firewall device connected in turn to his cable router.

Things work fine, except for his main computer upstairs, the furthest one away from the point of entry. He upgraded this computer to 802.11g and wants to get another wireless access point, such as the Linksys WAP54G (http://www.linksys.com/products/product.asp?grid=33&scid=35&prid=608). That way, this one computer will have a better and faster connection. He doesn't want to spend more money to upgrade the other computers.

The question is whether this will cause trouble for the WAP11 and the other computers. Can the two access points sit side by side and coexist peacefully? Can he use WPA on the WAP54G? Any other considerations?

Benj
Jan 20, 2005, 04:19 PM
egads that's technical!

I know this is not what you are asking, is possibly unhelpful, and you almost certainly know if already, but..... my airport express works with both airport equipped iBook and airport express equipped iMac all play nicely.

Littleodie914
Jan 20, 2005, 04:20 PM
I got a bit lost trying to follow the setup and how everything's connected, so I'll try and explain as best I can. (The problem's not your explanation, rather my being a bit out of it tday :rolleyes: ) Yes, 802.11b and 802.11g can exist perfectly together. They detect each other just fine, and sending files is exactly the same as using two of the same. The only drawback is that your network will operate at the speed of the slowest connection. (That is, if you're sending files from a B to G or a G to B, sending G to G will work at 54Mbps, even if there's a B on the network.) Any further questions, feel free to post 'em ;)

Mechcozmo
Jan 20, 2005, 04:51 PM
They will work fine. But B will not work at the G speeds. And if G is trying to connect to a B base station, it will go at only B speeds.

Not too confusing...

Doctor Q
Jan 20, 2005, 05:07 PM
Thanks for the tips, everyone.

A picture is worth a thousand words, so here's a diagram of what he has in mind (OLD=current setup, NEW=proposed setup). If the two types of connections can work separately (at their own speeds with their own security), that would give him the best result. If Computer6 would connect only at 802.11b speed, he'd lose one benefit he had in mind.

jadam
Jan 20, 2005, 05:28 PM
He could always get an airport express to do that.

therevolution
Jan 20, 2005, 05:40 PM
The two access points could listen on different channels and broadcast different SSIDs. Then, you just have computer 6 connect to the 802.11g router, the rest connnect to the 802.11b. Shouldn't be a problem!

Edit: Just make sure the channels are at least 5 apart. As I understand it, anything less makes interference more likely.

TEG
Jan 20, 2005, 06:54 PM
Definitely, you can make sure they stay separated by separating the channels. G on 1, B on 12. That will keep is safe.

TEG

Mechcozmo
Jan 20, 2005, 08:06 PM
Thanks for the tips, everyone.

A picture is worth a thousand words, so here's a diagram of what he has in mind (OLD=current setup, NEW=proposed setup). If the two types of connections can work separately (at their own speeds with their own security), that would give him the best result. If Computer6 would connect only at 802.11b speed, he'd lose one benefit he had in mind.

If Computer6 had a 802.11G card, that would work. At least, from my understanding of the network, it would work.

brap
Jan 20, 2005, 08:16 PM
I have both b and g clients on my home network, and it's fine. All connecting to the same base station (D-Link DSL-G604T - cheap cheap). No interference, no nothing. Why, though, keep the old b base station? G base stations are generally backwards compatible and able to handle all clients?

I honestly can't see a reason why having two SSIDs on two different adapters would be beneficial when one can do it really quite well enough... would you clue us in on why he wants to keep it so?

Westside guy
Jan 20, 2005, 09:52 PM
If an 802.11b client connects to an 802.11g base station, all the connections will be pulled down to 802.11b speeds (more or less). So if you do the two base station setup described above, be sure the b clients can only connect to the b base station.

Doctor Q
Jan 21, 2005, 01:26 PM
I corrected my diagram above and it now shows the protocols he has in mind.

cpjakes
Jan 21, 2005, 02:17 PM
What about the simpler solution of moving the original access point to a more central location so that everything can be happy without buying anything else? If it's DSL or cable, isn't there another phone/cable jack somewhere else? Just a thought...

The only other thing to look out for (if another WAP is purchased) would be which devices function as routers. If there's only one, then great. If there are two, there may be problems getting computers 1-5 to talk with computer 6 as you'd be jumping through different 192.168.x.x networks.

cpjakes

evil_santa
Jan 21, 2005, 02:37 PM
I can't see the benefit of having 1 computer on the 802.11g router & the rest on the 802.11b router. 802.11b is faster than most broadband connections, so the internet will not be any faster because of the 802.11g router. As the computer on the 802.11g router will have to go through the 802.11b router to talk to the other machines it will only work at 11 mbps for file transfers.

You would be better swapping the routers around, so the multiple machines on 1 hub can connect to each other at G speeds.

Doctor Q
Jan 21, 2005, 02:59 PM
He says that having the cable company move the point of entry would be hard so he doesn't favor that choice.

I asked him about computer-to-computer file transfers. He does transfer quite a bit of data back and forth between the computers, and he eventually plans to upgrade some of the other computers to 802.11g.

cpjakes
Jan 21, 2005, 03:06 PM
Another thought would be to move the computer (within the same room, rotating it even) to see if it gets reception. I would assume that one of the six computers is a laptop. I'd take it to the computer 6 room and see if signal gets there at all...

hulugu
Jan 21, 2005, 03:12 PM
I have both b and g clients on my home network, and it's fine. All connecting to the same base station (D-Link DSL-G604T - cheap cheap). No interference, no nothing. Why, though, keep the old b base station? G base stations are generally backwards compatible and able to handle all clients?

I honestly can't see a reason why having two SSIDs on two different adapters would be beneficial when one can do it really quite well enough... would you clue us in on why he wants to keep it so?


As I understand it a mixed network will result in all connections working at 802.11b, typically the base station can only handle on type of connection at a time, so you would need two base stations to get different speeds.

Doctor Q, the (new) diagram should work quite well to give the G computer the extra speed to the firewall and thereby the outside connection.