User Manual

Demand Assignment
System Overview GSI 004
605-0000-450
Draft Issue 1.3dr Date 8/02/00
Page 1 of 2 © Copyright Airspan Communications Corporation 1998
ACCESS CONCENTRATOR HARDWARE OVERVIEW
10. The Access Concentrator
The Access Concentrator (AC) is required when AS4000 is operating in “Demand
Assigned” mode to de-multiplex the traffic concentrated on the air-interface for
presentation to the network switching equipment. Also in system versions using
32kbit/s compression the decompression to 64kbit/s is performed within the AC.
Alarms and
Breakers
Access
Concentrator 1
Cable Interface
Access
Concentrator 1
Cards
Access
Concentrator 2
Cable Interface
Access
Concentrator 2
Cards
2.2M
600mm300mm
Figure 15. Access Concentrator Rack (covers removed)
The AC Unit consists of a Shelf and backplane for the various DA system cards, and a
Connector Panel that terminates all external and internal cable interfaces.
The configuration of the AC depends very much upon the customers’ installation. The
number of cards fitted will be at the discretion of the network operator, and managed
by Sitespan. There are thirteen Auxiliary slots which can take a XTU, CU or. A
fourteenth auxiliary slot is normally dedicated to the spare TU to facilitate relay change
over.