Query About Co-Ex Value Reliability for Channel Selection in SAS Deployments

[heisenberg600]

Hi,

I’m using SAS for deploying radios and have been relying on the Google Co-Ex value for channel selection. Recently, during one of my deployments, I noticed that the Co-Ex values for some channels were marked as 0. Initially, we avoided those channels based on this value, but found that channels with higher Co-Ex values performed worse.

Eventually, we switched to using channels with a Co-Ex value of 0, and surprisingly, their performance was significantly better.

This has made me question the reliability of Co-Ex values for channel selection. Could you clarify:

1. How reliable are Co-Ex values for making channel selection decisions?
2. What exact method or heuristics are used to calculate the Co-Ex value?

Your insights would be greatly appreciated.

Best regards,
Saurabh

[James_S]

@heisenberg600 

There are multiple tools in the Coex tab of the SAS Portal. Could you please clarify what tool you are asking about, and what field within that tool? Specifically, are you asking about EIRP, or are you asking about the channel quality score?

[heisenberg600]

The channel quality score was 0 for those channels. I am talking about the channel quality histogram under the co-ex tab. 

[James_S]

@heisenberg600 

Channel quality is a combined score of available Max EIRP + predicted interference levels. If you see a channel quality score of 0, but full EIRP available, it means that the SAS predicts that there will be  interference from other CBSD operators in the area on those channels. More information on channel quality can be found here.