Title: Memorised carrier sense multiple access with collision avoidance (MCSMA/CA) protocol for IEEE 802.11p

Authors: Jung-Shyr Wu; Yen-Chieh Cheng; Shiann-Tsong Sheu

Addresses: Department of Communication Engineering, National Central University, Taoyuan, 32054, Taiwan. ' Department of Communication Engineering, National Central University, Taoyuan, 32054, Taiwan. ' Department of Communication Engineering, National Central University, Taoyuan, 32054, Taiwan

Abstract: The wireless access in vehicular environment (WAVE) architecture has been standardised in the IEEE 802.11p specification in order to be widely deployed in roadway environments. The aim of the WAVE networks is to provide prompt emergency information as well as internet connectivity. However, the IEEE 802.11p contention-based medium access control (MAC) protocol would deteriorate transmission efficiency if the number of on-board units (OBUs) contending on an SCH is large. Moreover, synchronising all WAVE devices that perform channel switching may experience a period of above-average channel congestion immediately following a channel switch, possibly resulting in an unexpectedly high collision rate. As a solution, we propose an efficiency improvement scheme, namely memorized carrier sense multiple access with collision avoidance (MCSMA/CA) protocol, which improves the SCH throughput by means of a channel context switch mechanism. Numerical and simulation results demonstrate that the proposed scheme significantly promotes the standard transmission efficiency.

Keywords: channel access; context switch; IEEE 1609.3; IEEE 1609.4; IEEE 802.11p; wireless access; vehicular environment; vehicular communications; WAVE; multiple access; collision avoidance; emergency information; internet connectivity.

DOI: 10.1504/IJIPT.2012.047589

International Journal of Internet Protocol Technology, 2012 Vol.7 No.1, pp.52 - 61

Available online: 28 Jun 2012 *

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