Adaptive Antennas and Interference

There is quite a nice discussion going on over at GT Hill's blog about Adaptive Antennas.

One part of the discussion centers around interference rejection of such a system, by "controlling" the RF signal. This serves to increase signal gain for the intended client and reduce interference in most other directions (I agree on these points). My contention is that in a multi-cell architecture, as is typically found in most enterprise, education, healthcare, and [especially] high density environments, the increased signal gain also results in increased interference (or more aptly "contention") of other neighboring Wi-Fi cells in the path of the newly shaped signal. And, different than directional antennas, the path changes with every client that the Adaptive Antenna system is transmitting to. So, with an omni-directional coverage area and clients distributed throughout that area, interference will impact all other Wi-Fi cells around it. Not at the same time, but at different points in time depending on traffic patterns downlink to clients.

What I'm getting at is that Adaptive Antennas simultaneously reduce interference in some directions and increase it in others. I'm not saying that one outweighs the other, because I don't think anyone can predict that unless we know the specific deployment scenario and network design. My point is just that we need to acknowledge the presence of both effects (not just one, while ignoring the other).

Hopefully this makes sense. It does in my [admittedly jumbled] mind ;)

I would normally just post this in the comments section on GT's blog, but I would like to include a drawing to help convey what I'm talking about. (I'm a great artist BTW. Can't you tell!)

Adaptive Antenna's Simultaneously Decrease and
Increase Interference In Different Directions

GT - Hopefully this clarifies my opinion. Sorry to take the conversation away from your website.

Readers - please comment directly on GT's blog to keep the conversation thread in one location.