I've seen similar statements around the forum and I'm also having issues with sync at a site with four Synced 2.4Ghz ePMP APs. We've tried new cabling, gps receiver, new injector, and new injector power supply. I feel like we have replaced every device contributing to the sync with the exception of the AP's themselves. According to the APs GUI, one second the sync will be up and the next it will be down. It doesnt appear to go down on all APs at the same time either with a couple of the APs seemingly worse than the other two. Any ideas what may be going on here?
Do you have these APs deployed with GPS antennas? If you do, have you attempted to switch the APs from "CMM" to "GPS" as synchronization source to see if this has an effect on the stability of the sync functionality?
Do the Packetflux SyncInjector has any indicators like number of satellites tracked, state of sync, signal-to-noise ratio, etc that would give you an idea on how stable is the received GPS signal is at the time an AP or APs are showing this issue? Sorry, I'm not familiar with the SyncInjectors.
The timing pulse into the device needs to have certain characteristics and stability for the ePMP software to be able to reliably maintain sync.
I opened up a ticket with Cambium support and their response seems to indicate that PacketFlux Injectors are not wholly compatible with ePMP...is this the general conesensus? Cambium Response Pasted below:
"Thank you for confirmation. Well I would hesitate to make an official statement here but personally I have seen many service providers running in to similar issues with packetflux and ePMP. Although there are few success stories, packetflux syncinjector never gave satisfactory test results (this is what I understand from feedback from ePMP development team). Please do not consider it as an "official" statement for now.
Also there is a fundamental difference of frame size for ePMP as compared to FSK or PMP450 APs (5ms as against 2.5ms for Canopy products).
I am surely forwarding your concerns and observation we have on your sites to ePMP development team. I will keep you posted with any developments in this regard.