Management
The following loops are available on units with a line interface (MS/RS, E3,
E2 and E1).
Line Loop
Loops an incoming line signal back to its origin. The loop
is done in the plug-in unit, close to the line interface, see
Figure 82 on page 108. An AIS is sent to the TDM bus.
A Line Loop in combination with a BERT in an adjacent
NE is used to test the transmission link between the two
NEs.
In the MMU2 E/F STM-1 the traffic signal that shall be
transmitted is looped back just after base-band interface.
Local Loop
Loops a line signal received from the TDM bus back to
its origin, see Figure 82 on page 108. An AIS is sent
to the line interface.
A Local Loop in combination with a BERT in another NE
can be used to test a connection as far as possible in
the looped NE.
In the MMU2 E/F a Local Loop at the far end loops back
the STM-1 traffic at base-band level.
The following loop is only supported on the MMU.
Rx Loop
This loop is similar to the Connection Loop but the loop
is done in the plug-in unit close to the TDM bus, where a
group of E1s in the traffic connection is looped back to its
origin, Figure 82 on page 108.
An Rx Loop can be used on the far-end MMU to verify
the communication over the radio path, see Figure 83
on page 108.
In the MMU2 E/F the RX Loop applies to the wayside
E1 traffic.
107
12/221 02-CSH 109 32/1-V1 Uen A 2008-03-14
To Next Page
Loading...
