View Full Version : WLAN: Fixed vs. Automatic Channel Selection

2009-08-29, 03:58
Hi all,

All my SBs beside a boom box are connected via ehternet cables. The boom box is connected wirelessly to either an Asus router with dd-wrt firmware (details below) or an additional access point (details below)(same SSID, same WPA key).

Because of the additional access point, I want to set the radio channel of both WLAN access points to distinct frequencies to avoid interferences.

But when I set the channel to ANY "fixed" frequency on the Asus router (disabling "auto" mode) the connection to the boom box drops at high bitrates (FLAC).

Connected to the Devolo AP, the fixed channel does not seem to affect the WLAN stability. FLAC audio is streamed flawlessly.

All other WLAN devices (WLAN-VoIP-Phone, Notebooks, Cell-Phones with WLAN) do not seem to bother on whether the radio channel is set to "fixed" or "auto" mode.

Now my questions are:
Is there a bug in the boom boxes WLAN electronic? Is it a bug in the dd-wrt firmware, that appears only in combination with the boom box?

Is it possible to leave one/both APs in the "auto" channel mode, without causing interferences?

Is it due to electromagnetic pollution, that "auto" mode performs better because it automatically choses the best channel (allthough only one other WLAN from the neighborhood is visible. The devolo APs area is certainly not less noisy).

Any hints on how to track down the issue?
Thanks in advance,

Primary Router Model: Asus WL-500g Premium
Firmware Version: DD-WRT v24-sp2 (07/21/09) vpn - build 12533

Secondary Acess Point: devolo dLAN 200 AV Wireless G

2009-08-29, 09:20
Further investigations show, that also with wireless channel set to "auto" the connection drops but by far more seldom.

And I connected a SB3 classic wirelessly: The same issue here: FLAC files cause the connection to break every few minutes.

All devices are very close to the router (about four metres).

So, I think it might be an incompatibility to the dd-wrt/Asus router... I propably flash the original Asus firmware back to the router...

2009-08-29, 12:36
I tried to alter a lot of settings on dd-wrt: And I might have foud the cause for the WLAN drops: The encryption algorithm.

Now that I've changed it from TKIP to TKIP+AES the connection seems to be stable.

I may also set the channel to a fixed frequency without getting troubles.

My first observation, the correlation with the transmission channel seems to have been misleading...

Then I found another thread on this:

This brings me to the belief that the TKIP implementation on the squeezeboxes and the boombox is somewhat "sensible"...