Abstract
In Wireless Local Area Networks (WLAN), portable devices such as notebooks, tabs, and smart phones are powered by batteries with limited energy. With the great increase of using such portable devices, energy efficiency becomes one of the most important issues in wireless networks that are based on IEEE 802.11b standard. Although, IEEE 802.11b standard enables devices with limited batteries' capacity to send and receive more data, it is not suitable for high load networks. In high load networks, Access Point (AP) cannot immediately deliver buffered packets to portable devices which leads to batteries' drain as devices have to stay in active state for long time. Towards solving this great issue, an energy efficient downlink scheduling algorithm for WLAN is presented in this paper. The proposed scheduler aims to reduce the probability of medium contention and waiting time during the reception of buffered data packets from the AP without affecting the quality of service performance. The presented scheduler proposes a time slotted scheme to enhance the Power Saving Mode of IEEE 802.11b standard. The proposed approach is validated analytically and experimentally. Qualnet network simulator is used for this purpose. Promising results are obtained compared to legacy IEEE 802.11 protocol, and the Shortest Job First scheduler protocol in terms of energy saving, and throughput.