A Study on Local Repair Routing Algorithm Based on Link-Duration for Urban VANET

There are a number of challenges that need to be addressed until a wide deployment of vehicular ad hoc networks (VANETs) becomes possible. In order to support Intelligent Transportation System (ITS) service, one of those critical issues consists of the design of scalable and stable routing algorithms that are robust to frequent path disruptions caused by vehicles´ mobility and buildings´ shadowing effect in urban environment. This paper argues the use of information on vehicles´ movement information (e.g., position, direction, velocity, acceleration, and digital mapping of nodes) to maintain stable routes by calculating possible link-durations and preventing link-breakage events prior to their occurrences. Vehicles broadcast hand-off packets if they realize that they are in a threshold zone to keep a link of data transmission unbroken. Prior to link-breakage events, the most stable link is set up by using the values of link-duration calculated beforehand. The scheme proposed in this paper guarantees a high level of stable communication in urban VANETs and reduces the overall traffic in highly mobile VANETs. The performance of the scheme was evaluated through commercial simulator QualNet 4.5, which supports various possible effects in the city condition. Simulation results indicate the benefits of the proposed routing strategy in terms of increasing the end-to-end throughput, reducing the number of link-breakage events, reducing the end-to-end delay.