Ericsson RBS 2106 Hardware Reference Manual page 96

Radio Base Station
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PCM Overvoltage Module
This module contains overvoltage protection for the PCM lines. If the PCM
lines are terminated in equipment outside the RBS equipment room, these
lines must be protected by overvoltage protectors (OVP) in the DF. Failure to
do so might damage the DXU-21, if a voltage transient is transported along
the cable. The RBS 2206 is designed for 100/120 Ÿ EDODQFHG WZLVWHG SDLU
cable. If 75 Ÿ XQEDODQFHG FRD[LDO FDEOH LV WR EH FRQQHFWHG WKH PRGXOH PXVW
contain a balun card that converts 75 Ÿ XQEDODQFHG WR  Ÿ EDODQFHG
line.
LAPD concentration and LAPD multiplexing are used to make the
transmission resource more efficient.
Optional Transmission Equipment
The cabinet can be connected to optional transmission equipment that is
mounted externally. The optional transmission equipment used is:
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The connectors used for this are:
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9 Alarms
The RBS 2206 can be connected to a maximum of 16 external alarms. A DF is
used for external alarm connection. Each alarm connection is provided with
over-voltage protection. (One OVP module protects two alarm connections.)
The alarm device can set the alarm by either an open or closed circuit. The
alarm device connected to the screw terminals should be isolated relay
contacts. A closed contact (logic zero) is required to be below 2 kŸ DQG DQ
open contact (logic one) above 100 kŸ 7KH FXUUHQW WKURXJK D FORVHG  Ÿ
contact is 1.2 mA. The voltage between terminals with an open contact is 24 V
22 (24)
T1 1.5 Mbit/s, 100 Ω balanced PCM line.
E1 2 Mbit/s, 75 Ω unbalanced (balun used), or 120 Ω balanced line.
Transmission adapter (not connected to DF)
DXX (installed in the OXU)
Mini-link
Mini DXC (installed in the OXU)
TMR 9202
PCM cables
+24 V DC cables
Blank panels for connectors to the OXU
RBS 2206
EN/LZT 720 0225 R3A