User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
5 System Configuration
5-5
Table 5-1
Configuration of BCPMs
BTS configuration
Number of type-A BCPM
Number of type-B BCPM
O1
1
Not recommended
O2
2
Not recommended
S111
2
1
S222
4
2
S333
6
3
S444
8
4
The above configurations are for cdma2000 1X system. For 3-sector configuration,
type-B BCPMs are recommended. For IS95 configuration, the quantity should be
reduced by half.
In normal cases, no redundancy is required. If one board fails, system will
automatically shield the faulty board. In this case, the system capacity decreases,
but the service is maintained.
III. BRDM
There are two types of BRDM boards, namely multi-mode BRDM and single-mode
BRDM. The multi-mode BRDM is used to connect the BTRM in the cabinet, while
the single-mode BRDM is used to cascade the SoftSite (ODU3601C).
Providing 6 pairs of ports for leading out optical fibers, the multi-mode BRDM can be
connected with 6 BTRMs. For full configuration of 36 BTRMs, 6 BRDMs are needed.
In the case BTRMs are less than 6, only 1 BRDM should be configured. For 6-12
BTRMs, 2 BRDMs are needed. The BRDM should be configured from slot No.12
and No.13.
When more than 12 BTRMs are configu red, BRDMs are needed in slots No.8, No.9,
No.20 and No.21 to increase the number of optical fiber interfaces, as shown in
Figure 5-3. The configuration principle is that one more BRDM shall be configured
when 6 BTRMs are added.
The single-mode BRDM provides 3 pairs of ports, leading out optical fibers. It can
cascade 3 SoftSites (ODU3601C) in star networking.
IV. BCKM
Normally, one BCKM is enough. For redundancy purpose 2 BCKMs can be used
(working in active/standby mode). BCKM receives GPS signal from outside and
provides 10MHz clock connection tester externally. In addition, it provides some
other interfaces.
