A Packet Scheduling Algorithm for Optimizing Downlink Throughput in Wireless LANs with the One-Sender-Multiple-Receiver Technique

In this paper, we study the packet scheduling problem in wireless LANs with the One-Sender-Multiple-Receiver (OSMR) transmission technique. OSMR allows the Access Point (AP) to send distinct packets to multiple nodes simultaneously, and has great potential in improving the network downlink throughput. We note that the AP needs a packet scheduling algorithm to make the decision of when a packet should be sent and whether it should sent together with other packets using OSMR. In this paper, we focus on the problem of maximizing downlink throughout when packet fragmentation is not allowed. Since the processor of the AP is not powerful and cannot execute complicated algorithms in real time, we propose a simple algorithm and prove that it has a performance ratio of 1/1+root 2. We evaluated our algorithm with packet traces collected from 802.11a networks, and the results show that our algorithm improves the network throughput significantly.