PMP Synchronization Solutions User Guide
UGPS and CMM Configurations
PMP-0297 007v001 (January, 2017)
4-14
UGPS and CMM Configurations
The UGPS may be used as a GPS synchronization source for Cambium Networks CMM3 and
CMM4 (Cluster Management Module) units. The UGPS provides GPS synchronization to the CMM
unit via the CMM’s sync port. This allows any access points or backhaul masters connected to the
CMM to receive sync. This configuration requires that the CMM3 or CMM4 be configured to
“Slave” mode via the CMM GUI. When using the UGPS as a synchronization source for a CMM3
or CMM4, a special sync cable must be used. This cable may be constructed from an RJ-11 cable
using the pin configuration in
When using a CMM unit, the UGPS may also be used as a redundant sync source for the CMM. If
a CMM encounters an issue with the primary, coaxial-connected GPS receiver an operator may
remotely login to the CMM and set the synchronization source to “Slave” to begin receiving sync
from the UGPS (connected via RJ-11 cable with the pin configuration in section
PMP 320 Systems - When using both the UGPS for timing and a CMM4 for timing in a PMP 320
network (same AP site or an adjacent AP site), timing discrepancies between the UGPS and
CMM4 can cause interference between the sites. To address this issue, operators may opt to use
one type of timing in the network (either UGPS
or
CMM4). Alternatively, operators may contact
technical support to set up remote access to troubleshoot the AP units that are exhibiting the
issue. A future PMP 320 software release will address this timing issue.