Optimisation of packet access mechanisms for advanced time division multiple access (ATDMA)

The authors describe the development of candidate medium access control mechanisms for the RACE R2084 advanced time division multiple access system (ATDMA) which will accommodate variable bit rate services. Within the ATDMA project attention has been directed towards packet access mechanisms and the development and optimisation of these mechanisms has been largely based on computer simulation. The authors illustrate, in particular, the power of the simulation tool in the extraction of statistical information which may be used to optimise system performance. Such information is not readily derived from analytical techniques and it is essential to combine analytical and simulation tools for full performance tuning. The two packet access mechanisms considered for ATDMA are both developments of PRMA and are known as block reservation multiple access (BRMA) and PRMA++. The essential difference between these mechanisms is that in BRMA all slots on the uplink may be used for resource reservation, whereas in PRMA++ the slots on the uplink are separated into reservation slots (R slots) and traffic information slots (I slots)