E1 Surge Protector (Besp) - Huawei Airbridge cBTS3612-1900 User Manual

User Manual
Airbridge cBTS3612 CDMA Base Station

2.2.7 E1 Surge Protector (BESP)

I. Overview
BESP is placed in the upper part of BTS. It is a functional entity for BTS to
implement lightning protection with E1 trunk line. Two identical BESPs are installed
for each cabinet in consideration of limited space on top of the equipment and the
convenience of installation and dismounting. The 8 pairs of lightning protection units
are used to discharge the transient high voltage on the sheath and core of E1 trunk
line to PGND.
II. Structure and principle
Board structure is as shown in Figure 2-9.
BCIM
Figure 2-9 Structure of BESP
The board consists of three parts: DB25 connector, lightning protection unit and
DB37 connector.
When the BTS E1 trunk line is struck by the lightning, high voltage will arise first on
DB25. The high voltage will spread to the lightning protection units. The lightning
protection units have two protection levels: air discharge tube and voltage limit mesh.
BESP
8 E1s
Interface
DB37
2-19
Level-2
Level-1
protection
protection
PGND
Interface
Level-2
Level-1
protection
protection
DB25
PGND
Interface
DB25
Level-2
Level-1
protection
protection
PGND
System Description
2 Hardware Architecture
4 E1s
BSC
4 E1s
BSC