US 4,730,302 AGranted

Monitoring means for digital signal multiplex equipment

AssigneeSiemens Aktiengesellschaft

InventorsFranz Fuerlinger, Albrecht Grabner, Werner Pokorny, Walter Steiner, Wilhelm Volejnik

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Abstract

In a switching location for TDM multiplexing of a combination of a plurality of channels for digital signals to form a common channel in one transmission direction and for demultiplexing a common transmission channel into a plurality of channels in the opposite transmission direction, the signals of the individual communications channels are combined to form pulse messages each of which is preceeded by a frame identifier word monitored by a monitoring memory with respect to its bit sequence and with respect to its periodicity. Double monitoring devices and one's density monitoring devices are provided for the input signals arriving via the individual communications channels. Potentially, code converter monitoring devices for the input and output signals are provided. A stepping bit monitoring device is provided for the input signals arriving via the individual communications channels. A level monitoring device is provided for the input signals arriving via the common communications channel. A frame clock monitoring device is provided for the common incoming transmission channel. A synchronism of the receiving device is monitored for the demultiplexer. Bit error monitoring is provided for the input signal of the demultiplexer. Frequency monitoring devices and level monitoring devices are provided for the output signals for the individual communications channels departing the apparatus.

Monitoring apparatus for a switching system apparatus in which a plurality of transmission signals are time-division multiplexed to form a common multiplexed transmission signal, and a common time-division multiplexed received signal is demultiplexed into a plurality of received signals, each of the pulsed messages including a frame identifier word, said apparatus comprising:

a multiplexer and a plurality of incoming transmission channels connected to said multiplexer;
a demultiplexer and a plurality of outgoing receiving channels connected to said demultiplexer;
a common outgoing transmission output connected to said multiplexer and a common incoming receiving input connected to said demultiplexer;
a plurality of first level monitoring devices each connected to a respective incoming transmission channel for monitoring the signal level of the respective channel;
a plurality of regeneration circuits each connected in a respective incoming transmission channel as a respective one's density monitor;
a plurality of first code converters each connected in a respective incoming transmission channel for converting signals of a first code into signals of a second code;
a stuffing bit rate monitor connected to said multiplexer and operable to insert stuffing bits;
a plurality of second code converters each connected in a respective outgoing receiving channel for converting signals of the second code into signals of the first code;
frame identifier word recognition means including clock recovery means connectable to said common outgoing transmission channel and to said common incoming receiving channel;
a second level monitoring device connected to said clock recovery means for monitoring the level of signals received on said common incoming receiving channel;
a frame clock monitor connected to said demultiplexer;
a synchronism monitor connected to said demultiplexer;
a bit error monitor connected to said demultiplexer;
a plurality of frequency monitors each connected to a respective outgoing receiving channel;
and
a plurality of third level monitors each connected to a respective outgoing receiving channel.

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Abstract

Claims4