Enhancing Intra Safety Area Queuing (ISAQ) for Channel-Aware based BSM Verification Scheme in VANETS

Abstract

One of the main goals of vehicular ad hoc networks (VANETs) is to increase road safety and traffic efficiency, by using information which is shared among vehicles in a wide range of Intelligent Transportation Systems (ITS) applications such as crash warning, sudden-brake warning, and lane-change warning. Safety messages are transmitted from each vehicle at a fixed rate such as ten messages per second. In dense roads with many lanes or with many vehicles close to each other, there could be many safety messages received by a vehicle. Each safety message must be verified by a time consuming cryptographic operation before its information can be reliably utilized. This leads to a problem since the rate that messages are received can be much higher than the verification rate. This problem could be serious with densely occupied roads and when ITS applications require a high transmission rate of safety messages. To solve this problem, some solutions have been proposed so that the safety messages are verified in which messages from closer vehicles are given higher priority and farthest vehicle‘s messages are given lower priority. The solutions to achieve this can be categorized into two approaches. Vehicle status based and channel-aware based prioritization approaches. The former approaches completely rely on mobility information within BSM (i.e. speed, direction, acceleration, headings, etc), that will leads the schemes to be vulnerable to different security threats like broadcast tampering and denial of service (DoS). On the other hand, the latter used the received signal strength of BSM to classify the messages into five fixed safety areas, so that the security issues in the former approach covered. However, still, the messages within each safety area need to be prioritized to satisfy the demands of ITS application which recommend that nearby vehicle‘s BSM need to get verification time before far vehicles even within their corresponding safety areas. In this paper, we proposed Enhancing Intra Safety Area Queuing (ISAQ) for a Channel-aware based BSM verification scheme. We design safety messages prioritization scheme by using the hybrid of the two existing approaches. To classify the messages into different safety areas, we used the received power of the message. And to rank the messages within their safety area, we used the combination of transmitter-receiver distance and messages arrival time at the vehicle‘s buffer. From the simulation result, we observed that our modified safety message prioritization scheme for verification is more secured during BSM classification and efficient during BSM ranking than existing schemes.