Do stations on adjacent channel adhere to csma/ca

[prc]

Do 802.11b stations on adjacent channels adhere to csma/ca protocol. TO be specific, there are 2 stations - station1 on wlan1 on channel 11 and station2 on wlan2 on channel 10. Both the stations and their associated access points are visible(not hidden) to each other. Can these two stations sense each others transmissions ?

Please help me in this regard. Thank you very much in advance.

PRC.

[spiderbite]

yes. Every thing 802.11b is CSMA/ CA

Stay off of channel 10 though.. it is too close to 11 use either 6 or 1

[prc]

spiderbite,

I agree with your point that everything in 802.11b is csma/ca. If both are on same channels this is true. But can a station in one channel sense the carrier in the other channel and back off its transmission (if the other is transmitting too)?

[aspicer]

spiderbite,

I agree with your point that everything in 802.11b is csma/ca. If both are on same channels this is true. But can a station in one channel sense the carrier in the other channel and back off its transmission (if the other is transmitting too)?

I don't think anyone knew or could find the answer to that question, and it's been a long time.

Some 802.11 Pre-N stuff, Turbo and such speeds, were really bad at first because they used double channels or additional 2.4Ghz bandwidth than standard 802.11b/g gear. Later releases reportedly solved these problems and the gear was supposed to be more "friendly" to adjacent 802.11 networks and would not clobber them.

From what I've learned, without doing any MORE research I think that Standard 802.11 gear doesn't "sense" other channels other than the one they are locked onto. Any other overlapping channels would appear to their receivers as noise. That noise if strong enough would cause problems degrading performance of an 802.11 b/g access point or client. It wouldn't be sensing or determining what other channel it was coming from, it would be just noise the same as if it came from non-802.11 gear such as a microwave oven or 2.4Ghz cordless telephone.

That's my take on it.

---
Alan Spicer (a_spicer (at) bellsouth.net)
http://telecom.dyndns.biz/

[M/Q]

Somewhat funny as this subject has been popular this week. We have been ACI on another thread. I thought you might be interested in this article, somewhat old, but it tends to agree with your assessment about the receiver considering ACI as noise rather than in band signals that it needs to deal with.

http://focus.ti.com/lit/ml/sply005/sply005.pdf