A Virtual Grouping Scheme for Improving the Performance of IEEE 802.11 Distributed Coordination Function

S.-M. Kim and Y.-J. Cho (Korea)


Backoff Algorithm, DCF, Virtual Group, and Wireless LAN


Performance of the IEEE 802.11 Distributed Coordination Function (DCF) drops dramatically in terms of throughput, delay, and jitter as the number of active stations becomes large. In this paper, we propose a simple and effective scheme, called Distributed Coordination Function with Virtual Group (DCF/VG), for improving the performance of the IEEE 802.11 DCF mechanism. In this scheme, each station independently decides a virtual group cycle using the information observed by the carrier sensing mechanism. The virtual group cycle consists of one or more virtual groups and a virtual group includes an idle period and a busy period. Each station chooses one virtual group and operates only in the chosen group of the virtual group cycle and does not operate during the other groups. In other words, each station decreases its backoff counter and tries to transmit its packet during the period of the chosen virtual group like in the IEEE 802.11 DCF. Performance of the proposed scheme is investigated by simulation. Our results show that the proposed scheme is very effective and has high throughput and low delay and jitter under a wide range of contention levels

Important Links:

Go Back