An Analysis of Data Dissemination on VANET by using Content Delivery Network (CDN) technique

Abstract

Data dissemination on VANET (Vehicular Ad Hoc Network) has been receiving attention where useful information, such as traffic information and accident warning, can be shared among vehicles. In this paper, we propose to use CDN (Content Delivery Network) technique for disseminating information to destination nodes via a set of replica nodes, or CDN nodes, by repeatedly transmitting the content originating from the source node to the replica nodes. Our proposed CDN technique is deployed on VANET running OLSR (Optimized Link State Routing) Protocol. The CDN nodes are selected from MPR (Multi-Point Relay) nodes in OLSR, since these nodes can optimally cover all subscriber nodes. In order to avoid the interference problem in the broadcasting environment, the number of MPR nodes to be selected as CDN nodes is reduced. This results in decrement of CDN nodes in use are limited. The network under our consideration is divided into two parts. The first part covers from the source nodes to the CDN nodes while the second part covers from the all CDN nodes to the destination nodes. In the first part, the OLSR on VANET is employed while in the second part, the broadcasting technique is applied where packets are repeatedly broadcast. In this work, the performance of our proposed CDN technique is evaluated by simulation using NS3 (Network Simulator 3). According to the simulation results, our proposed CDN on VANET improves drastically the overall successful transmission rate as compared to the typical OLSR on VANET. Finally, we also propose a mathematical performance analysis for forwarding packets from the source to a set of destination nodes, by considering the successful transmission rate at the destination nodes as our evaluation metric. The result is provided in a closed-form expression.