NAIST-IS-MT1151206: Budi Rahmadya


A DTN/VANET Message Dissemination Technique Using Car Platoon

Budi Rahmadya (1151206)

Currently, trac jams and accidents are common problems on highways in big cities. In Japan, Intelligent Transport System (ITS) [1] has been used to alle- viate these problems. This technology uses wireless communication for sharing trac information among the roads and vehicles. Recently, usage of car naviga- tion system is widespread, and Vehicular Ad Hoc Networks (VANETs) that use multi-hop wireless communication among vehicles and devices on roadsides for sharing information are paid attention. There have already been many research publications for VANETs, that disseminate and share messages among vehicles.

Stable data transfer between two distant locations in a VANETs is inherently dicult due to the high speed and unpredictable mobility of vehicles. In some existing researches, a technique called a DTN (Disruption/Delay Tolerant Net- work) is employed to improve the delivery rate of messages in VANETs. In a DTN, no relaying node forwards a message if no suitable node is available for receiving the message. The node forwards the message later when such a node becomes available. In this way, a DTN can eciently deliver messages even in a case with frequent network partitions.

In this thesis, we enhance our previous work [31], that transfers messages from moving vehicles to a xed roadside location. We propose a new method that combines multi-hop communication with our previous DTN technique. In the proposed method, we assume that every vehicle is equipped with a naviga- tion system, and the current position and the future route of every vehicle is known. Vehicles periodically exchange route information, and forward messages to vehicles that will get closer to the message destination according to the future route information. The problem with this previous method is that each vehicle only exchanges messages between neighboring vehicles, and thus the eciency of message delivery was not high. In this thesis, we combine the idea of multi point relays (MPR) in OLSR protocol with the previous method, and make vehicles exchange messages between distant vehicles using multi-hop communication, and improve the message exchange eciency.

We are going to implement our proposed method using the trac simulator called SUMO [2] and evaluate the method by comparing the method with our previous method.