User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
4 System Function
4-1
4 System Function
This chapter describes the main functions of cBTS3612, including transmission
networking, call procedure, signaling processing, baseband processing, RF
functions, and operation & maintenance function.
4.1 Transmission Networking
cBTS3612 supports star networking, chain networking and tree networking.
Different networking modes are realized through the flexible configuration of BCIMs.
Each BCIM provides 8 E1 interfaces and each cabinet can be configured with 2
BCIMs, so total 16 E1s can be configured.
I. Star networking
Star networking is the widely used, especially in the densely populated urban area.
Start networking is as shown in Figure 4-1.
In this mode, each BTS is directly connected with BSC with an E1 trunk line. The
networking is simple and maintenance is easy. Signals go through less links and the
line is more reliable. Future expansion is easier. However, this mode requires much
more transmission lines than any other mode.
BSC
BTS
BTS
BTS
E1
E1
E1
Figure 4-1
BTS star networking
II. Chain networking
Chain networking of the BTS is shown in Figure 4-2. It is applicable to sparsely
populated stripe areas, e.g. along the highways and railways.