MacBook and MacBook Pro competing for airwaves

Question

Howdy,
I have an Airport Extreme set up as wireless router, i.e., the cable modem is plugged into the Extreme. Elsewhere in the house, an Airport Express is set up to extend the network. We have both a MacBook and a MacBook Pro, both running Leopard. When both laptops are accessing the web, it seems as though they were competing for the connection because the MacBook systematically gets slower connections, lags, and sometimes gets disconnected entirely.
Following some advice I found elsewhere in these forums, I downgraded the firmware of the Airport Extreme to 7.3.1. Here are its main settings:
- participate in a WDS network
- radio mode: 802.11n (b/g compatible)
- channel 11
- security: WPA/WPA2 Personal
- DHCP server distributes addresses between 10.0.1.2 and 10.0.1.200
Both the Extreme and the Express use the same channel. I tried changing it with no success.
Upgrading the firmware does not resolve the issue. The MacBook Pro is never disconnected; it always comes ahead of the MacBook. The two laptops are not dealt the same IP address, but somehow, there is a competition. When the MacBook Pro is turned off, say, and not accessing the web or anything else, the MacBook does not get disconnected.
Has anyone seen such a situation before? I might have misconfigured something.
Thank you in advance for any suggestions.
Dom

Answer 1

In a WDS setup, everyone uses the same channel (in your case 11).
If you can run an ethernet cable from the Airport Extreme to the Airport Express you can eliminate the WDS mode and instead configure your 2 base stations for WiFi Roaming, and you can put the Airport Express on a different channel (eg. Ch1).
The Airport Express gets its connection to the router via ethernet. The Express is configured into "Bridge Mode". The Express is given the exact same SSID as the Extreme. The Express is given the exact same password as the Extreme. The Express is set to a different channel (Channel 1 would be a good choice, unless your neighbors are using that, in which case you want to be at least 5 channels away from your Extreme and any neighboring base stations with strong signals).
This will give you a Roaming setup where as your move around the house, your MacBook and MacBook Pro will automatically switch between the strongest base station, but because everyone is using the same SSID and Password, you do not loose your connections.
And each base station is using its own channel.
If you do have neighbors with strong signals, you can use something like "AP Grapher", iStumbler, KisMac, MacStumbler, etc... to see your neighbors, the chanels they are using, and the relative WiFi signal strength so you can choose the channels with the least interference.
If you can not run an ethernet cable between the Extreme and the Express, but you really like the idea of a Roaming network, then you could look into PowerLine ethernet adaptors for getting an ethernet equivalent between the 2 base stations.