QUALITY-OF-SERVICE PROVISIONING SYSTEM FOR MULTIMEDIA TRANSMISSION IN IEEE 802.11 WIRELESS LANS

摘要

In this paper, we propose a polling with non-preemptive priority based access control scheme for the IEEE 802.11 protocol. Under such a scheme, modifying the DCF access method in the contention period supports multiple levels of priorities such that user mobility can be supported in wireless LANs. The proposed transmit-permission policy and adaptive bandwidth allocation scheme derive sufficient conditions such that all the time-bounded traffic sources satisfy their time constraints to provide various QoS (quality-of-service) guarantees in the contention free period while maintaining efficient bandwidth utilization at the same tune. In addition, our proposed scheme is provably optimal for voice traffic, minimizing the average waiting tune for voice over IP packets. In addition to theoretical analysis, simulations are conducted to evaluate the performance of the proposed scheme. As it turns out, our design indeed provides a good performance in the IEEE 802.11 wireless LANs environment.