Structure And Principle - Huawei Airbridge BTS3612A-1900 Technical Manual

Technical Manual
Airbridge BTS3612A CDMA Base Station
lightning protection with E1/T1 trunk line. The 8 pairs of lightning protection units of the
BESP are used to discharge transient high voltage on the sheath and core of E1/T1
trunk line to the PGND.

2.7.2 Structure and Principle

I. Structure
The structure of BESP is shown in Figure 2-7.
BCIM
Figure 2-7 Structure of BESP
The board consists of three parts: DB25 connector, lightning protection unit and DB37
connector.
Lightning protection unit
E1/T1 lightning protection unit has two inbound lines connected with DB25, two
outbound lines connected with DB37, and one PGND. Here PGNDs of all lightning
protection units can be interconnected.
DB37 connector
The DB37 is a male connector, connected with eight E1/T1 cables.
DB25 connector
BESP
8 E1s/T1s
Interface
DB37
Chapter 2 Baseband Subsystem
Level-2
Level-1
protection
protection
PGND
Level-2
Level-1
protection
protection
PGND
Level-2
Level-1
protection
protection
PGND
2-15
System Principle
4 E1s/T1s
Interface
BSC
DB25
4 E1s/T1s
Interface
BSC
DB25