Bypassing vocoders in CDMA mobile-to-mobile calls

In present-day CDMA networks, interconnection of mobile switching centers (MSCs) results in a mobile-to-mobile call typically being processed by the vocoder twice, once for mobile-to-land transmission and again for the land-to-mobile portion of the call. Bypassing vocoders in CDMA mobile-to-mobile calls will improve the voice quality and increase the subscriber serving capacity of the base station controller (BSC) and MSC, providing an evolutionary step towards the open and flexible architecture for next generation wireless networks. To bypass vocoders in CDMA mobile-to-mobile calls, this paper proposes interconnecting BSCs via an ATM network using AAL2, complementing the effort to interconnect wireless network components with ATM networks to provide a high-speed backbone. The use of AAL2 is recommended because of the bandwidth efficiency it can achieve with the given transmission of low-rate, short, and variable length packets in a delay-sensitive application. This paper discusses the setup procedure of a mobile-to-mobile call that bypasses the vocoder. We simulated the delivery of mobile-to-mobile calls over AAL2 to study the impact of GCRA traffic policing and cell spacer traffic shaping on the ATM network based inter-BSC connection