TRANSMISSION QUALITY OF NORTH-AMERICAN CELLULAR, PERSONAL COMMUNICATIONS, AND PUBLIC SWITCHED TELEPHONE NETWORKS

Future long distance, and especially international calls, will involve an increasing number of multilink circuits of cellular, personal comm unications, mobile satellite, and public switched telephone network (P STN) type of connections incorporating a variety of speech coding devi ces. In particular, the rapid growth of cellular communications has hi ghlighted the need to characterize the quality of switched networks wh en cellular terminals are attached at their termination nodes. At the same time, the nonlinear nature of low-rate parametric speech coding h as rendered questionable analytical methods for estimating end-to-end voice quality of interconnected telecommunications networks. Instead, quantification of transmission performance appears to require direct s ubjective evaluation of the pertinent conditions of interest. In this paper the quality of interconnected North-American digital cellular an d future microcellular terminals with 16 kbit/s and 32 kbit/s DCME/PCM E-based switched and private telephone networks is quantified. From th ese assessments it can be concluded that cellular networks employing t he TIA IS-54 8-kbit/s VSELP algorithm may meet the end-to-end transmis sion planning criteria when interconnected with the switched network.