An exact analysis for CSMA/CA protocol in integrated voice/data wireless LANs

In this paper, we present an exact analysis for the performance of wireless LANs which support real-time and data communication using a carrier sense multiple access with collision avoidance (CSMA/CA) protocol. In the system, a user with a packet ready to transmit initially sends some pulse signals with random intervals within a collision avoidance period before transmitting the packet to verify a clear channel. The system consists of a finite number of users to share a common channel. Each user can be a source of both voice and data traffic. The time axis is slotted, and a time frame has an arbitrary large number of slots dependent on the chosen durations of the collision avoidance period and packet transmission period. A discrete-time Markov process is used to model the system operation. Numerical results are shown in terms of channel utilization and average packet delay for various packet generation rates. They indicate that the network performance can be improved by adequate choice of ratios between collision avoidance periods and transmission periods, and pulse transmission probability.