Chapter 1: Product description
Wireless operation
Page 1-27
•
PTP-SYNC: One PTP-SYNC unit is connected in line in the drop cable between the AC+DC
Power Injector 56V and each Master ODU, close to the AC+DC Power Injector 56V. The PTP
SYNC hardware option can synchronize an isolated or standalone cluster of PTP-SYNC
units without a GPS receiver. An optional GPS receiver can be added to provide network-
wide synchronization.
•
CMM5: One CMM5 Power and Sync Injector provides power and optional synchronization
for up to four ODUs. The Universal GPS (UGPS) receiver is always needed in synchronized
networks, and network-wide synchronization is always provided when CMM5 is used for
TDD synchronization.
•
Direct connection between two ODUs: Two PTP 670 Master ODUs may be synchronized in
a standalone configuration using a direct cable connection between wired Ethernet ports.
There is no option in this case to synchronize with a GPS receiver, and so no possibility of
network-wide synchronization. This option may be useful in an isolated 2+0 link, or at the
centre point of a relay of two links using the same mast. For this option, the PSU could be
the AC Power Injector 56V, the AC+DC Enhanced Power Injector 56V, or the CMM5.
PTP-SYNC
Up to ten PTP-SYNCs can be connected in a chain to share the timing signal from one timing
reference.
PTP-SYNC provides two deployment options:
•
An isolated or standalone cluster of PTP-SYNC units, without an external timing reference.
In this case, one ODU acts as a reference for other collocated units. The associated ODUs
may be synchronized with each other, but will not be synchronized with Master ODUs at
other sites.
•
One PTP-SYNC unit, or a cluster of several PTP-SYNC units, connected to an external
timing reference, which is typically a GPS receiver. In this case, all of the associated ODUs
may be synchronized with a network-wide reference, and thereby synchronized with other
Master ODUs in the network. The timing reference can be from any timing system that
provides a 1 Hz signal, accurately synchronized in frequency and phase with a network-
wide master timing reference. GPS timing receivers are a very practical way of obtaining a
suitable reference. The PTP-SYNC is compatible with the Trimble Acutime™ GG and
Trimble Acutime™ Gold GPS receivers.
Caution
The PTP-SYNC is compatible only with the AC+DC Power Injector 56V.
The AC Power Injector 56V and CMM5 will not work with a PTP-SYNC, and it is likely
that a fuse will be blown in the PTP-SYNC if this is attempted.
PTP-SYNC is not compatible with standards-based power-over-Ethernet (PoE).
Cluster Management Module (CMM5)
The CMM5 Power and Sync Injector distributes a one pulse-per-second (1 pps) signal from the
associated Universal PGS (UGPS) receiver to each of the connected ODUs. The Injector
supports up to four ODUs. The synchronization signal can be daisy-chained between multiple
CMM5 Power and Sync Injector units for installations with more than four collocated ODUs.
