Teletraffic analysis of enhanced circuit switched data (ECSD) on GSM for mobile multimedia services

The Global System for Mobile Communications (GSM) has been a great success in providing both voice and low speed data services. The current evolution of GSM towards the third generation mobile communications system is attributed to its remarkable growth and also to the increasing demand for mobile data. The enhanced circuit switched data on GSM (ECSD) is one of the major evolutionary steps to serve real time high speed data services such as real time video and or file transfer. The ECSD enhances the bandwidth by combining several time slots and by utilizing efficient modulation and coding schemes. In this paper we present a Markov analysis of ECSD and compare its performance with the existing high speed circuit switched data on GSM (HSCSD), which also uses multi-slot allocation but with a conventional GSM physical air-interface. In this analysis we also consider the transmission errors on the radio interface. The results of the comparative analysis are presented in terms of grade of service, average throughput and average message transfer delay taking into account eventual transmission errors on the radio link.