期刊名称：International Journal of Engineering and Computer Science
印刷版ISSN：2319-7242
出版年度：2015
卷号：4
期号：1
页码：10005-10009
出版社：IJECS
摘要：The Medium Access Control (MAC) protocol is the main constituent which determines the system throughput using IEEE802.11 protocol in Wireless Networks. The MAC Layer system of the IEEE 802.11 protocol is also referenced as Distributed CoordinationFunction (DCF). In DCF mode, source nodes contend for the use of the channel in dispersed manner via the use of the Carrier SensingMultiple Access with Collision Avoidance (CSMA/CA) procedure. Using the CSMA/CA procedure, each source nodes sets up a Backoff timeaccording to a randomly selected interval from zero to the Contention Window (CW) size for an extra delay time before transmitting the datapackets. Binary Exponential Backoff (BEB) algorithm is used to randomize moments at which source nodes try to access the wirelessmedium. Additionally, in the Backoff mechanism, data packet collisions are not totally eliminated, and the system throughput is decreasedwhen the number of source nodes is large, and there is no fairness between source nodes. The BEB algorithm occupies number ofdisadvantages; one vital disadvantage is the problem of fairness. This research paper analyzes the behavior of the BEB algorithm used inIEEE 802.11 protocol. We have proposed a hybrid environment using IEEE802.11p protocol to enhance the fairness of the channel accessfor BEB algorithm. Hybrid approach adapts the way of increase or decrease of the contention window (CW) based on the number of theframe which is delivered successfully. NS-2 simulator is used to analyze the network's fairness of the channel access of the BEB algorithmin terms of throughput, end-to-end delay and packet dropping ratio. The result showed that comparing with IEEE 802.11 and BEBalgorithm, hybrid approach with IEEE 802.11p improves the fairness of the channel access and increases the network's throughputcapacity.
