I have 3 towers all within a 3 mile radius of each other. All AP’s and BH’s are 5.7, but I have no frequency issue. Each tower has its own CMM for timing. Can there be a timing issue if they are each seperately timed, and not timed together?
Accoding to when I asked motorola, even with seperate cmm’s they will still all sync the same. Other may have different answers but from my experience I havent had any issues.
DougVonDoom wrote: I have 3 towers all within a 3 mile radius of each other. All AP's and BH's are 5.7, but I have no frequency issue. Each tower has its own CMM for timing. Can there be a timing issue if they are each seperately timed, and not timed together?
I there any possibility to use one CMM for more than one cluster? (each 6 AP)
Exactly. But this is not recommended by motorola 
You can receive sync thru radio interface, and pass it via sync port.
You can build Y sync cable to pass the sync for more than one unit. As the sync
is one way data communication, you can have more than 2 leafs
Motorola does support timing an AP or BH-master from an SM or BH-slave, but only when the connected units are different frequency bands (e.g., 5.2 & 5.7).
Timing an AP off a BH-slave unit in the same band (e.g., 5.7 & 5.7) sometimes will work, but Motorola doesn’t support that configuration. Connecting timing ports together apparently adds a small timing delay so the units are not precisely synchronized. The out-of-sync transmission from the AP potentially can desense a co-located SM’s or BH-slave’s receiver.
When using CMMs at each cluster, the source for the timing is always a GPS signal. The CMM might also add a delay, but the delay would be identical from every CMM. Every connected AP and BH-master in the entore Canopy network would then be truely in sync.
Motorola’s suggestion for DougVonDoom would likely be to swap out the 5.7 BH units with 5.2s – even if he’s not currently experiencing a problem.