Harri Jokinen

Multi-slot packet radio air interface to TDMA systems-variable rate reservation access (VRRA)

This paper presents a new variable rate reservation access (VRRA) media access control (MAC) for packet radio systems. The VRRA algorithm is designed for TDMA based cellular networks, especially GSM. It utilizes alternatively one or multiple time slots per TDMA frame, depending on the requirements of the network operator and the user. The paper describes the VRRA MAC algorithm with simulation results. The simulation results are given for the GSM system operating in both single slot and multi-slot mode.

GSM/DCS air interface enhancements for high speed data applications

There has been a significant increase in demand for high speed data services over cellular networks, particularly by PCS in North America. The paper presents a proposal for enhancement of the GSM air interface to achieve the data rate expansion. The new proposal modifies the GSM air interface to allow multiple time-slot access of the TDMA frame by a single MS. Such a solution provides the platform for GSM to support a mixture of wide ranges of services with only moderate modifications of the air interface involved where the GSM modulation and basic TDMA frame structures are retained.<<ETX>>