In this paper, a contention-based reservation MAC protocol is proposed for non-real-time burst traffic class in wireless ATM networks. The proposed protocol is characterized by the contention-based transmission of the reservation request and contention-free transmission of burst traffic. The design objective of the proposed protocol is to reduce contention delay during the contention phase of a connection. In order to reduce collision of reservation requests, the base station calculates the transmission probability based on the estimated load of reservation requests and the number of random access minislots, and broadcasts it over the frame header period of downlink channel. Wireless terminal, which has traffic burst, selects a random access minislot and transmits its reservation request with a received transmission probability. Based on the successfully received reservation, the scheduler allocates the uplink data slots to wireless terminal. Simulation results show that the proposed protocol can provide higher channel utilization, and furthermore, maintains constant delay performance in a heavy traffic environment.

This paper proposed a method of slot allocation in a multislot TDMA system when multiple service priorities are supported. The algorithm is tested both in Variable Rate Reservation Access (VRRA) and Advanced TDMA protocols. We exploit the multislot reservation capability to achieve the delay requirements of each priority level. The channel allocation algorithm assumed that all data terminals are capable of multislot reservation. In this case the delay variance can be controlled based on the packet length information and the accumulated delay of each data user. The performance of the system is evaluated using the cumulative delay distribution and mean overall delays for the different user types.