GPS Sync Deployment and hardware options

Hi everyone.

I want to know how we can go about deploying a GPS Synced solution. Im aware of the Cambium recommended ABAB solution with 4 90 degree sectors - 2 radios opposite eachother re-use the same frequency with 5Mhz guard bands, but i would like to know what has been done when 360 degree coverage is not a requirement. I'm looking at 4x 60 degree horns to cover a 240 degree area. Has anyone deployed something similar to this with success? My main concern is the isolation required in the ABAB solution and what is its criticality towards a successful GPS Sync deployment.

Also, what are some GPS Sync solutions that are being used in regards to vendors/technologies? I'm looking at powering PMP 450i, ePMP 2000 and eventually ePMP 3000 once its realeased.

Let me know what yous think.


In this case, you are right, that there may be concern that the front-to-back isolation is insufficient because the antenna side lobes may create interference for a neighboring sector (that is not facing the opposite direction).

I would recommend ABCD in this case, with as much separation of freuqency between adjacent sectors as possible.  With 450, you don't need any guard bands, and with ePMP at least 5 MHz of guard band is recommended.

Both of these systems can be synchronized, and now can be timed together (using the latest ePMP software) where needed.

Hi Matt,

I am after some clarity on how the ePMP and PMP 450 sync. I have been informed that you must share a single sync source (via a CMM4) to achieve tower sync - but then i also have some information that points the other way which says that you can recieve sync across all access points via the GPS timing pulse from the satellite using individual pucks on each access point. Can you shed some light as to which is correct.