Performance analysis of CSMA and IEEE 802.11 in Wireless Sensor Networks using GloMoSim and IEEE 802.11as a gimmick

Since its birth wireless communication became an indispensible part of the modern society. One major area that has a gigantic impact on the performance of wireless sensor networks (WSNs) is the Medium Access Control (MAC) layer. Many random access protocols exist in wireless sensor networks. Some of these protocols include Carrier Sense Multiple Access (CSMA), Multiple Access with Collision Avoidance (MACA), Multiple Access with Collision Avoidance for wireless (MACAW) and IEEE 802.11. All the protocols mentioned above except CSMA use Request To Send/Clear To Send (RTS/CTS) packets to avoid collisions (hidden terminal problem) which was a great problem for CSMA and that is the reason CSMA is almost obsolete for wireless communications. But after using RTS/CTS packets the protocols have to encounter some extra problems such as, energy consumption and end-to-end delay. The objective of this paper is to show the pros and cons of using RTS/CTS packets by comparing CSMA (does not use RTS/CTS) and IEEE 802.11 (uses RTS/CTS packets). We also portray that under some specific scenario the IEEE 802.11 is outperformed by CSMA which is also the novelty and contribution of this research work. This observation suggests that a lot of works have to be done to consider IEEE 802.11 an approximate perfect MAC layer protocol for WSNs. Index Terms CSMA, IEEE 802.11, MAC layer protocols, RTS/CTS.