User Manual

Demand Assignment
System Overview GSI 002
605-0000-450
Draft Issue 1.3dr Date 8/02/00
Page 7 of 16
2. The Central Terminal
The Central Terminal (CT) is the AS4000 Base Station. This is deployed in omni or
sectored cell configurations supporting variable numbers of Subscriber Terminals (ST)
per cell. The CT is a multi-service platform hosting single and dual line telephony,
multi-line telephony, digital data leased lines and ISDN basic rate interfaces. The CT
can operate in two modes, depending on the type of service and traffic levels supported.
Fixed Assignment is used when STs must have a dedicated radio link. Demand
Assignment is utilised when STs can share the available radio resources, and sustain an
“engineered” grade of service.
The CT provides the traffic interface to the network switching via the Access
Concentrator for Demand Assigned systems. The CT also provides an interface to the
AS8100 management systems.
Antenna Feeder
To Access
Concentrator
Airspan DA
Central Terminal Racks
Antenna
DA
Rack
Expansion
Rack
Network Interfaces
(4x 2Mbit/s)
Figure 2. DA Central Terminal with 4 DA Modem Shelves