Prediction-Based Reliable Data Forwarding Method in VANET

Abstract

Vehicular Ad hoc Network (VANET) is one of technologies to realize various ITS services for safe driving and efficient traffic control. However, data delivery in VANETs is complicated due to high mobility and unreliable wireless transmission. In this paper, we develop a novel forwarding scheme to deliver packets in a reliable and timely manner. The proposed forwarding scheme uses traffic statistics to predict the encounter of two vehicles, and optimize its forwarding decision by taking into consideration the probability of successful transmission between them at the encounter place. We evaluate our scheme through simulations and show that our proposed scheme provides reliable data delivery in VANETs. Routing protocols [2,3] in VANET have been studied extensively, especially based on mobile ad hoc networks (MANET). Generally, mobile ad hoc routing protocols aim to achieve reliable packet delivery and low delivery delay, with minimal communication overhead and network resource.MANET routing protocols can be largely classified into two categories: proactive routing and reactive on-demand routing [5] . The proactive routing protocol calculates a route from one node to all other nodes in advance. Representative proactive protocols include Destination-Sequenced Distance-Vector (DSDV) and Optimized Link State Routing (OLSR).In contrast, the reactive routing protocol discovers a route only when it is explicitly requested. Dynamic Source Routing (DSR), and Ad hoc On Demand Distance Vector (AODV) are most widely used.Although many routing protocols that have been developed in MANET, most of them do not work well in VANET. It has been shown that many previous routing protocols for MANETs perform poorly in VANETs [6,7] . One of the main problems is that the previous routing protocols fail to achieve This paper is organized as follows. Section 2 summarizes related work. Section 3 provides the system model. Section 4 explains our data forwarding scheme, and Section 5 evaluates its performance. Finally, Section 6 concludes this paper. Ⅱ. Related WorkIn VANETs, many data forwarding schemes use the carry-and-forward approach, where a vehicle carries message until it can transmit the message to the destination or to a relay node. Traffic information (e.g., traffic density and average vehicle speed per road segment) is commonly used to guide the forwarding operation.Greedy Perimeter Stateless Routing (GPSR) has been proposed to actively utilize wireless communications for forwarding [8] . In this protocol, a vehicle can transmit its packet to a neighboring vehicle that are geographically closer to the destination. In the meantime, if the vehicle with the packet is the closest to the destination among those in its neighbors, while it cannot directly transmit the packet to the destination yet, GPSR switches to its mode such that the packet can be forwarded following the right-hand rule (rather than the 130 shortest distance). GPSR outperforms DSR in many aspects [9] in terms of packet delivery ratio and overhead. Greedy Per...