Do some research in the area you are deploying into.  Drive around and look at some towers. See what types of equipment others have deployed.

If you have access to a spectrum analyzer spend some time doing scans from towers at various times of the day. There is a little bit of a learning curve using these but you can always hire a consultant to help. This is money well spent.

If you don’t have a spectrum analyzer take some of the equipment on your shortlist.  Pick a location or locations and install this equipment like you would if you were going to deploy it.  Use this as an evaluation over the course of several days to a week.  Keep a record of the noise floor and if the equipment supports it logs of the spectrum analysis.  This will give you real world insights into what the spectrum looks like. An omni is a good way to tell because it picks up 360 degrees of noise.  If the spectrum is fairly clear with an omni then sectors will be that much better. Make sure to change the channels to see how clean the overall spectrum is.

The main frequencies people deal with are the following:

900MHZ
2.4GHZ
3.65GHZ
5.8GHZ

Each one has it’s distinct advantages and disadvantages.  There are also tricks ones can do to mitigate interference. We will talk about those in our next installment.