An Efficient Channel Access Scheme for Vehicular Ad Hoc Networks

Table 1

Comparison of existing schemes.

Scheme	Applied on VANET	EDF	Adjustment of CW	Fast topology	Throughput calculated/not calculated	Backoffs calculated/not calculated
Alasmary and Zhuang Scheme [10]	Yes	No	Adjust CW sizes according to the three fixed CW ranges based on their speed and not based on the time they leave the range of the RSU	Yes	Average compared to proposed scheme	Average compared to proposed scheme
Wang et al. [12]	Yes	No	No	No	Not calculated	Not calculated
Choi et al. [13]	Yes	No	No	Yes	Not calculated	Not calculated
Suthaputehakun and Ganz [14]	Yes	No	It defines min and max CW size	No	Not calculated	Not calculated
Bohm and Jonsson [15]	Yes	No	No	No	Not calculated	Not calculated
Balon and Guo [16]	Yes	No	Local reception rate of the nodes	No	Not calculated	Not calculated
Rawat et al. [17]	Yes	No	It adapts the CW size considering the packet collision rate	No	Not calculated	Not calculated
Bouassida and Shawky [18]	Yes	Yes	No	No	Not calculated	Not calculated
Balador et al. [19]	Yes	No	Based on the network traffic density	No	Not calculated	Not calculated
Reinders et al. [20]	Yes	No	It adjusts the CW size based on traffic density	No	Not calculated	Not calculated
Raut and Jeyakumar [21]	Yes	No	By sliding window with dynamic persistence factor (PF)	No	Not calculated	Not calculated
EL Korbi and Azouz Saidane Scheme [11]	No	Markov chain-based model	No	No	Not calculated	Not calculated
Dang et al. [22]	Yes	No	No	No	Scheme is evaluated for improving throughput	Not calculated
Proposed Scheme	Yes	Priority based scheme	This scheme assigns priority to vehicles based on their deadline in which they leave the range of RSU; the priorities are determined on real-time basis by changing CW size according to the deadlines in which the vehicles are going to leave the RSU range	Yes	Good as compared to EL Korbi and Azouz Saidane Scheme [11]	Good as compared to EL Korbi and Azouz Saidane Scheme [11]