Implementation and analysis of IEEE 802.11 PSM in NS-2

Energy management in a wireless LAN is an important problem, as the viability of wireless devices depends very much on their battery life. In order to achieve energy efficiency of wireless devices, IEEE 802.11 protocol has designed an important scheme, Power Save Mode (PSM). This paper implements the PSM in NS-2 which is a popular discrete event simulator for analyzing the performance of network protocols. Firstly, the NS-2 patch of PSM is implemented in the WLAN with infrastructure mode. After validating the PSM implementation, we show that PSM can save wireless devices' energy while influencing bandwidth slightly. We analyze how the protocol parameters and network conditions affect the performance of PSM in terms of clients' energy consumption and energy efficiency metric. The experiment results show that the parameter configuration has a great impact on the performance of PSM. Especially, according to network conditions, a good configuration of protocol parameters is helpful to increase the energy efficiency of wireless clients.