Reference Manual

Channel Distribution Function

Shared terrestrial

signalling channel

TRX

01_0299B

Figure 146 Sharing terrestrial signalling channel

Messages are sent forward to their destinations without adding, deleting

or changing information.

Messages addressed to MO CF are sent to MO CF. All other messages

are sent to the TRXs.

The function terminates when MO CF has lost its data link connection.

At termination, MO CF is disconnected from the shared terrestrial

signalling channel. The signalling link to/from the TRXs is undisturbed

at the disconnection.

It also terminates when the channel distribution function becomes re-

conﬁgured in such a way that signalling to any TRX is no longer

performed on a shared terrestrial signalling channel. This is the normal

way to terminate this function.

56.3.4 Multidrop

For an RBS conﬁgured for multidrop, the function is initiated during

restart of the CMRU.

For an RBS not conﬁgured for multidrop, the function is initiated when

the parameter Network Topology is set by the OMT to indicate

multidrop (cascade).

The multidrop connected RBSs are connected so that each RBS uses its

port A towards the BSC and port B towards the next RBS. The latter

RBS is connected in the same way with port A towards the previous

RBS (and indirectly the BSC) and port B towards the next RBS etc.

Only RBSs supporting multidrop can be included in the multidrop

connection chain. The ﬁgure illustrates the case with three RBSs.

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EN/LZT 720 0008 P2A

2001-11-28

Preliminary