WLAN Power Save by Header Compression and Packet Overhearing Reduction

Cellular, laptop, tablet and handheld devices support WLAN technology. In addition to the spectral efficiency and security issues, power consumption is a vital issue in making the usage of these devices widespread. Efforts are underway in improving power conservation in those devices and thus increasing the duration between recharging the battery. Power consumption is mainly due to the transmission of WLAN packets and the receiver listening and receiving packets. Internet packets contain several headers for routing required in a complex network. Those networks are mostly wired networks using TCP/IP protocol. The WLAN transmitter is encapsulating all the TCP/IP headers and adding its own WLAN header. In some cases, the combined headers length represents a significant portion of the total frame length. This paper focuses on reducing the combined headers length with different compression methods. Smaller headers imply smaller packets which take less time to transmit and therefore activate the power hungry WLAN transmitter for a shorter time. The receiver on time is also reduced using overhearing avoidance techniques. The performance of those new methods is evaluated using both simulation and analytical models. Both the simulation and the analytical WLAN power estimation were developed for this paper. The simulation and the analytical models concord and show that if those methods are combined, they can provide up to 30% power consumption reduction for high load and many active stations present on the same channel.