Energy Conservation in 802.11 WLAN for Mobile Video Calls

Battery powered mobile devices suffer from significant power consumption of the WiFi network interface during video calls. By utilizing the dynamic Power Save Mode (PSM), our study proposes an adaptive RTP packet transmission scheme for multimedia traffic. By merging the outbound packet delivery timing with inbound packet reception and estimating each delay component along the packet processing and transmission path, each client manages to meet the stringent end-to-end latency for packets while creating longer sleep intervals. As a benefit it involves no cross-layer communication overhead as the interface state transitions are completely transparent to the application. The experimental results show that 28.53% energy savings on the WiFi interface can be achieved while maintaining satisfactory application performance.