Implementation of an ATM network and PSTN/N-ISDN interworking gateway

Broadband networks based on asynchronous transfer mode (ATM) have already been in commercial operation in some countries. The ATM has the capability of integrating various types of services into a single network. However, the traditional narrowband services still accounts for the major portion of the total telecommunication services. So it is necessary to implement the interworking function between the ATM network and PSTN/N-ISDN. We present a narrowband-broadband network interworking gateway (NB-IWG), in which we exploited the dynamic composite cell mechanism to adapt the voice traffic into ATM cells and implemented the signalling interworking between the narrowband and broadband network