Packet Rate Adaptation Protocol Based on Bloom Filter for Hidden Node Avoidance in Vehicular Ad-Hoc Networks

Most of the vehicular ad-hoc networks (VANETs) use the medium access control (MAC) layer of IEEE 802.11p, which is an extension of IEEE 802.11a standard. One of the critical issues with IEEE 802.11 networks is the hidden terminal problem. IEEE 802.11 networks use Request To Send (RTS) and Clear To Send (CTS) mechanism to alleviate the hidden terminal problem. The RTS/CTS mechanism, however, is inapplicable in broadcast communication. Since the safety data in VANET is transmitted over broadcast, the hidden terminal collision is still a critical problem. In this paper, we propose a hidden terminal collision mitigation protocol for broadcast communication of safety data, called Packet Rate Adaptation based on the Bloom filter (PRAB). The protocol derives the optimal packet generation rate as a function of the average number of hidden terminals. To estimate the number of hidden terminals, we introduce a notion of Bloom filter, which piggybacks the neighbor vehicles' information at a low overhead of packet size. We implemented the proposed protocol and evaluated with various vehicular networks. The simulation results exhibit that the proposed protocol provides 90% or higher packet reception probability even for high vehicle density networks, which correspond to 15% ~24% improvement over the previous protocols considered.