User's Manual

3–9
PacketMax 5000 Installation and Operation Manual, 10007678 Rev J
Chapter 3. Installing the Base Station IDU
PacketMax Base Stations have the capability of synchronizing with each other by
using and sharing the common reference signals: A 1Hz sync signal and a 10 MHz
reference clock. This allows them to synchronize all of the adjoining frequencies, pro
-
viding maximum efficiency of bandwidth utilization. The two clocks used for synchro-
nization can be either externally generated (by a GPS receiver) or internally generated
by the PM 5000 BS itself. Internally generated signals are available on the PM 5000s
SYNC Output and 10 MHz Output BNC ports.
NOTE: For proper synchronization, the frame size and upstream/downstream frame
parameters must be the same for all synchronized BSs.
The PM 5000 has four BNC connectors that are used to synchronize multiple base
stations - two are used for Input Sync Signals (10 MHz and 1 PPS clocks) and two
are for Output Sync Signals (10 MHz and 1 PPS clocks). The PM 5000 internally gen
-
erates a 10 MHz clock and a PPS clock. If no clock sources are detected on its 10
MHz and Sync Input ports, the PM 5000 turns into SYNC MASTER mode, internally
generates 10 MHz and 1 PPS clocks, and outputs them to its Sync Output ports. On
the other hand, if external clocks are detected, the PM 5000 turns into SYNC SLAVE
mode, using the external clocks to synchronize itself, and outputs them to its Sync
Output ports. As the sync signal is always available on PM 5000’s Sync Output ports,
it is possible to daisy chain multiple PM 5000s together. Clock and Sync LED status
is shown in
Table 3-3.
To interconnect multiple Base Station Units:
1. Select one Base Station Unit as the main Sync Master.
2. Connect the Sync Out connector on the main Sync Master signal source to the
Sync In of the Slave Base station units. Additional units connect from Slave
Sync and Clock outputs.
3. Connect the Clock Out connector on the main Sync Master signal source to
the Clock In of the Slave Base station units
4. Repeat steps 2 and 3, for all additional slave Base Station units.
A short coax cable (RG6 or LMR) with BNC connectors must be used to interconnect
the base station radios. Note that two cables are needed for each base station con
-
nection. Although not required to co-locate multiple PM 5000 base stations, PM 5000
Table 3-3 Sync and Clock LEDs
LEDs Status
Ext. Clock LED Off: No External clock detected, Internal Clock selected.
On: Solid Green. External clock detected.
Sync LED Off: N/A
Solid Green: using internal source.
Blinking: using external source.
Solid Red: System Fault