The vehicular ad hoc networks (VANETs) are an example of mobile networks, which utilizes dedicated short-range communication (DSRC) to establish a wireless connection between cars, and their primary purpose is to provide more security and comfort for passengers. These networks utilize wireless communications and vehicular technology to collect and disseminate traffic information, and it is required to be delivered to all vehicles on the network reliably and quickly. One of the major challenges raised in VANETs is that the communication path between the source and destination nodes is disconnected due to the dynamic nature of the nodes in this network, and the reconnection process of nodes through the new path reduces the performance of network. This paper presents a highway routing protocol to overcome some of the challenges of these networks including routing cost, delay, packet delivery rate, and overhead. The NS2 is used for simulation, and the performance of the proposed protocol is compared with the VMaSC-LTE and DBA-MAC protocols. The results of the simulation indicated that the proposed protocol outperforms the other two protocols in terms of delay, packet delivery rate, and routing overhead.

No abstract

VANETs are networks of connected intelligent vehicles that can communicate with each other, as well as with infrastructure and fixed roadside equipment. As a result of the lack of fixed infrastructure and open-access environment, security is crucial when sending packets. Secure routing protocols have been proposed for VANETs, but most are focused on authenticating nodes and creating a secure route, without considering confidentiality after the route is created. Using a chain of source keys validated by a one-way function, we have proposed a secure routing protocol called Secure Greedy Highway Routing Protocol (GHRP), which provides increased confidentiality over other protocols. As part of the proposed protocol, the source, destination, and intermediate nodes are authenticated using a hashing chain in the first stage, and in the second stage, one-way hashing has been used to increase data security. In order to resist routing attacks such as black hole attacks, the proposed protocol is based on the GHRP routing protocol. The proposed protocol is simulated using the NS2 simulator, and its performance is compared with that of the SAODV protocol. Based on the simulation results, the proposed protocol performs better than the mentioned protocol in terms of packet delivery rate, overhead, and average end-to-end delay.

No abstract

In mobile ad hoc networks, node mobility causes frequent link failures, thus invalidating the routes containing those links. This leads the frequent operation of route reconstruction that consumes lots of the network resources and the energy of nodes. Many efforts have been made to design reliable routing protocols that discover long lifetime routes. In these protocols by using reliability metrics for route selection, more reliable routes are discovered. In this paper, we review two mostly used network layer reliability metrics; "Route Expiration Time" and "Probabilistic Route Reliability" and propose a new one; "Probabilistic Route Reliability with Distance". Afterwards, the efficiency of these reliability metrics is evaluated by simulation experiments in different network conditions. The focus was concentrated on the number of route reconstructions as the performance metric. Simulation results show that by using all these three reliability metrics, number of route reconstructions is reduced and for the proposed one, the results are better than the others.