Abstract

In wireless networks such as those based on IEEE 802.11, packet losses due to fading and interference are often misin-terpreted as indications of congestion, causing unnecessary decrease in the data sending rate due to congestion control at higher layer protocols. For delay-constrained applications such as video teleconferencing, packet losses may result in excessive artifacts or freeze in the decoded video. We pro-pose a simple and yet effective mechanism to detect and reduce channel-caused packet losses by adjusting the retry limit parameter of the IEEE 802.11 protocol. Since retry limit is left configurable in the IEEE 802.11 standard, and does not require cross-layer coordination, our scheme can be easily implemented and incrementally deployed. Experimen-tal results of applying the proposed scheme to a WebRTC-based realtime video communication prototype show signif-icant performance gain compared to the case where retry limit is configured statically.