Throughput Optimization for Multirate Multicasting Through Association Control in IEEE 802.11 WLAN

Abstract

Multicasting in wireless local area network is an efficient way to deliver message from a source user to a specified group of destination users simultaneously. In unirate multicasting, all users belonging to a particular group receive their services at the same basic rate. This may underutilize network resources as users requirements are generally heterogeneous in nature. To resolve this limitation, multirate multicasting is introduced, where different users belonging to a particular group may receive their services at different rates. Often dense deployment of access points (APs) is required for coverage and capacity improvement. Thus an station (STA) may come under the coverage range of several APs and hence there may exists many possible associations between the STAs and the APs. Hence finding an efficient association is very important as individual throughput of the STAs as well as the overall system throughput depend on it. We have developed an efficient algorithm to find an appropriate association for multirate multicasting. The objective is to maximize overall system throughput while respecting the user fairness. Through simulations, we have evaluated and compared the performance of our proposed algorithm with other well-known metrics such as received signal strength indicator, minimum hop-distance, in-range STA number and normalized cost. Results show that the proposed algorithm significantly improves the overall system throughput in comparison to these metrics.