Does anyone know how many hops (backhaul links) the GPS sync should be able to be extended from one CMM?
Using the sync output from a BH-slave or SM can only be used for one extra hop, and only if the two hops use different frequency bands.
Using CMMs you should be able to go as many hops as you’d like using the same frequency band – even the same frequency. The co-located BHs should either both be masters or both be slaves. A CMM would be needed for every co-located pair of masters:
CMM-BHM<==>BHS-BHS<==>BHM-CMM-BHM<==>BHS-BHS<==>BHM-CMM