Design and realization of DSC equipment

In domestic communication networks, there exist analog and digital telecommunication systems at the same time. Signalling transformation equipment is needed for the interface of these two kind of systems. Digital line signalling conversion equipment (DSC) is used for the transformation between digital 2600 Hz line signalling carried by voice channels and digital type ABCD line signalling carried by TS16 in PCM. That is, the digitalized single frequency 2600 Hz line signalling carried by voice channels is on one side of the 2048 kbits/s digital trunk, and digital type ABCD line signalling carried by timeslot 16 is on the other side of the PCM trunk interface. The DSC interface equipment transforms the two sides associated signalling. DSC equipment may be built independently for PCM terminal equipment or TDM/FDM 60 channels TMUX, and installed in SPC rooms or other suitable places. It may be put together with PCM terminal equipment or TDM/FDM 60 channels TMUX. The DSC equipment consists of the following parts: digital trunk interface, filter and detector for signalling, microprocessor, alarm and display. The block diagram of the DSC equipment is shown. The authors adopt a series of MITEL chips to realize the trunk interface, system control and digital switch.<>