%0 Journal Article
%T Performance Analysis of the IEEE 802.11s PSM
%A Mirza Nazrul Alam
%A Riku J£¿ntti
%A Jarkko Kneckt
%A Johanna Nieminen
%J Journal of Computer Networks and Communications
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/438654
%X With the introduction of IEEE 802.11 power save mode (PSM), a lot of work has been done to enhance the energy saving ability of the wireless nodes. The ultimate goal of the research is to make the networking equipment carbon neutral and prolong the lifetime of the energy limited device for various applications; in some cases it is a trade-off between energy efficiency and delay. However, few studies have been made until now in the area of IEEE 802.11s based link specific power mode. The essence of this method is the ability of a node to maintain different power modes with its different peer nodes at the same time. A new peer service period (PSP) mechanism is also proposed in IEEE 802.11s amendment for transmitting to a receiver operating in PSM. In this paper the performance of the link specific power mode is studied for a single- and a multilink network in terms of energy, delay throughput, and sleep duration. It is found that at small load the energy saving could be as high as eighty percent when compared with the active mode operation. A stochastic model, based on discrete time discrete state Markov chain, is developed for one peer link operation to study the system behavior closely during PSM operation. 1. Introduction From the last decade, the deployment of mobile wireless devices has been rising by leaps and bounds in varieties of applications, such as in data access purpose, in wireless automation and control, making Voice over Internet Protocol (VoIP) calls, and in other QoS sensitive applications. However, these mobile devices are battery powered and have limited amount of operational time. As the batteries are limited resource of energy, devising an efficient energy saving protocol is now a critical issue for battery-constrained wireless devices. Generally, a significant amount of energy of a wireless node is dissipated in wireless radios. During normal operation a radio typically undergoes the following three states: transmitting, receiving, and idle state. The transmitting state consumes the highest amount of energy since the major portion of the energy is dissipated in power amplifier. In the idle state the radio obtains transmission opportunities (TXOPs) and is capable to start receiving the transmissions. The idle state consumes a little bit less energy than receiving state but in the long run this state contributes a significant portion of the total energy consumption. Therefore in PSM, the node avoids unnecessary operation in idle state and when a node neither receives nor transmits it switches to the sleep state. The sleep state
%U http://www.hindawi.com/journals/jcnc/2012/438654/