Efficient transport of voice-band signals on ATM networks

The asynchronous transfer mode (ATM) is now recognized as the preferred transfer mechanism for high speed services in digital networks. The long-term goal is to offer broadband integrated services digital networks (B-ISDN); so far, the main thrust has been on the development of high speed transport for data as well as video. It is unlikely that ATM can be implemented in all locations simultaneously. Therefore, there will be a need to interconnect the various local ATM networks or islands, located in different geographic regions and in different countries, using existing telephone networks. Unfortunately, most existing public switched telecommunications networks (PSTN) suffer from bandwidth limitations and are susceptible to bit errors. This could result in inefficient ATM implementations that may degrade the service quality. This paper presents architectures for connecting ATM islands that can be deployed in short intervals. The purpose is to optimize the bandwidth usage in the PSTN and retain the quality of voice-band services (i.e., speech and facsimile).