NCaAC: Network Coding-Aware Admission Control for Prioritized Data Dissemination in Vehicular Ad Hoc Networks

Vehicular Ad hoc NETworks (VANETs) are becoming an important part of people’s daily life, as they support a wild range of applications and have great potential in critical fields such as accident warning, traffic control and management, infotainment, and value-added services. However, the harsh and stringent transmission environment in VANETs poses a great challenge to the efficient and effective data dissemination for VANETs, which is the essential in supporting and providing the desired applications. To resolve this issue, Instantly Decodable Network Coding (IDNC) technology is applied to stand up to the tough transmission conditions and to advance the performance. This paper proposes a novel admission control method that works well with any IDNC-assisted data dissemination algorithm, to achieve fast and reliable data dissemination in VANETs. Firstly, the proposed admission control strategy classifies the safety-related applications as high priority and the user-related applications as low priority. It then conducts different admission policies on these two prioritized applications’ data. An artfully designed network coding-aware admission policy is proposed to regulate the flow of low-priority data requests and to prevent the network from congestion, through comparing the vectorized distances between the data requests and the encoding packets. Moreover, the carefully planned admission strategy is benefit for maximizing the network coding opportunities by inclining to admit requests which can contribute more to the encoding clique, thus further enhancing the system performance. Simulation results approve that the proposed admission control method achieves clear advantages in terms of delay, deadline miss ratio, and download success ratio.