New Access Technique in Vehicular Ad-Hoc Networks

Abstract

Vehicle Ad-Hoc Networks was developed to improve the safety and comfort while driving a car. In vehicleto-vehicle (V2V) communication, it is a challenging issue for single-radio devices to switch and operate between the seven DSRC channels allocated by the FCC and to support both safety and non-safety applications. Thereby, the IEEE 1609WG has contrived the IEEE 1609.4 Multi-channel Operation, a protocol that allows a device to switch channel operation over time so that it can efficiently utilize the multi-channel spectrum. However, this protocol showed some limitations, and this is showed through the low probability of successful transmission for safety messages and through the low throughput achieved for service messages. This paper proposes a new mechanism, Listening-based Immediate SCH Access (LISA), which enhances the channel utilization, i.e. improving the probability of successful safety packets transmission and increasing the throughput for service packets. Using LISA scheme, the probability of successful transmission has increased by 14% when the probability of transmission is equal to 80%, and the throughput has increased up to five times compared to the original protocol.