User Manual

Demand Assignment
System Overview GSI 002
605-0000-450
Draft Issue 1.3dr Date 8/02/00
Page 9 of 16
RF Combiner Shelf
Modem Shelf 1
Modem Shelf 2
Modem Shelf 3
Modem Shelf 4
CT Rack Expansion Rack
Alarm and Breaker Panel
Figure 3. Central Terminal Racks
2.3. Central Terminal Expansion Rack
The Central Terminal Expansion Rack connects to the Combiner Shelf in the DA Rack
and contains:
2.3.1. Modem Shelves
The Expansion Rack accommodates up to two modem shelves. Each Modem Shelf
terminates one RF Channel, supporting up to 15 radio links, and provides an E1
interface to the Access Concentrator. The Access Concentrator provides CAS, V5.1 or
V5.2 network interface with the Local Exchange. Each Modem Shelf also connects via
a V.24 (RS232) Network Management interface to the Sitespan network management
system.
2.3.2. Alarm and Breaker Panel
The Alarm and Breaker Panel Provides power for the modem shelves and conveys
alarms from the modem shelves to the CT station alarm scheme.