tailieunhanh - Báo cáo hóa học: " Research Article On the Ability of the 802.11p MAC Method and STDMA to Support Real-Time Vehicle-to-Vehicle Communication"

vesearch Article On the Ability of the MAC Method and STDMA to Support Real-Time Vehicle-to-Vehicle Communication | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2009 Article ID 902414 13 pages doi 2009 902414 Research Article On the Ability of the MAC Method and STDMA to Support Real-Time Vehicle-to-Vehicle Communication Katrin Bilstrup 1 2 Elisabeth Uhlemann 1 3 Erik G. Strom 1 2 and Urban Bilstrup1 1 Centre for Research on Embedded Systems Halmstad University . Box 823 301 18 Halmstad Sweden 2 Department of Signals and Systems Chalmers University of Technology 412 96 Goteborg Sweden 3 Transport Information and Communication Volvo Technology Corporation 405 08 Goteborg Sweden Correspondence should be addressed to Katrin Bilstrup Received 1 May 2008 Revised 17 October 2008 Accepted 7 December 2008 Recommended by Onur Altintas Traffic safety applications using vehicle-to-vehicle V2V communication is an emerging and promising area within the intelligent transportation systems ITS sphere. Many of these new applications require real-time communication with high reliability meaning that packets must be successfully delivered before a certain deadline. Applications with early deadlines are expected to require direct V2V communications and the only standard currently supporting this is the upcoming IEEE included in the wireless access in vehicular environment WAVE stack. To meet a real-time deadline timely and predictable access to the channel is paramount. However the medium access method used in carrier sense multiple access with collision avoidance CSMA CA does not guarantee channel access before a finite deadline. In this paper we analyze the communication requirements introduced by traffic safety applications namely low delay reliable real-time communications. We show by simulation of a simple but realistic highway scenario that vehicles using CSMA CA can experience unacceptable channel access delays and therefore does not support real-time communications. In .