An adaptive reservation protocol with a pre-emptive priority mechanism for wireless ATM LANs

This paper presents an adaptive reservation protocol called Centralized Adaptive Reservation (CAR) for supporting voice and data communications over a wireless ATM LAN. The protocol has two useful features, which may also be applied in other wireless LANs. First, with the aim of enhancing efficiency of access, the access probability of the voice terminals is varied dynamically based on the predicted number of contending voice terminals in the network. Second, a preemptive priority mechanisms is proposed to provide differentiated voice services and to enable efficient voice/data integration. A Markov model is presented to analyze the performance of these two features. A simulation model, which is validated by this analytical model, is used to evaluate the performance of the CAR protocol for a wireless ATM LAN. Our results show the effectiveness of CAR in providing pre-emptive priority services (e.g., for two different types/classes of voice terminals) and in integrating voice and data traffic while achieving high channel utilization.