TDX-10 recorded announcement system using ADPCM coding technique

The interwork, hardware configuration, and design specification of a recorded announcement system are presented. The system, which is called the ready-made message announcement system (RMAS), has been developed for the TDX-10 electronic switching system. The main function of the system is to give the calling party an announcement message of why a call was not completed and what further action should be taken or to announce a message as a special service when a call was processed normally. RMAS consists of a software unit, an announcement primary-function software unit (APSU), and a hardware unit, called the announcement primary-function hardware unit (APHU), which is described