Raisecom Technology Co., Ltd
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5. Function and application
5.1. Network element type
OPCOM3100-155 is suitable for network end access. It can provide STM-1, E1
and Ethernet access and can be configured as TM, ADM and REG.
1
．
Terminal multiplexer (TM)
The main function of terminal multiplexer (TM) is multiplexing low speed E1
or Ethernet signal to high speed STM-1 SDH signal and demultiplexing
high speed STM-1 SDH signal to low speed E1 or Ethernet signal.
STM-1 optical
signal
E1 electrical signal/Ethernet
signal
Figure 5-1 TM network element type
2
．
Add/Drop multiplexer (ADM)
Add/Drop multiplexer (ADM) is the most common network element type in
SDH network, it has both synchronous multiplexing function and digital cross
connection function, and can add/drop the tributary signal flexibly. For example
the access E1 signal can be multiplexed to both east STM-1 signal and west
STM-1 signal.
S T M - 1 o p t i c a l
s i g n a l
E 1 e l e c t r i c a l s i g n a l / E t h e r n e t s i g n a l
S T M - 1 o p t i c a l
s i g n a l
Figure 5-2 ADM network element type
