A Load-balancing Algorithm in Clustered VANET Networks

Abstract

Key Words:

VANET; IEEE802.11p; roadside units; load-balancing; Simulation NS-2 Summary: Vehicular ad-hoc Network (VANET) is a wireless network, which has the capability to increase the safety, efficiency and comfort of transportation systems. VANET can be used in safety applications, where low latency is of high importance, or for entertainment and Internet access. It is a part of the overall vision of Intelligent Transportation Systems (ITS).VANET networks have to overcome some issues and challenges related to their specific characteristics such as the very dynamic network topology related to the high velocity of vehicle and the unlimited VANET connections due to the road conditions. As the vehicle density is large, each RSU has to pass a large volume of data traffic from and to crossing vehicles. Therefore, a proper data traffic distribution between all potential paths of network means lower dropped packets caused by congested crowded areas. In this thesis, a load balancing algorithm between different roadside units using clustering technique is proposed. The purpose of clustering is improving the stability in the VANET networks and allowing a minimum number of vehicles to communicate with RSUs. The clustering is to group nodes into homogenous sets, where in each cluster; one cluster head (CH) is elected from cluster members. The purpose of this algorithm is to direct the data traffic to the appropriate roadside units with minimum load to avoid congestion and achieve the balance in data traffic among roadside units. In each cluster, a gateway vehicle is used to move data traffic from a heavily loaded RSU to a lightly loaded one. There are two different types of data traffic in the network. The real time data with high transmission priority and non-real time data traffic with low priority. Simulation results show the superiority of the algorithm in terms of network throughput, and number of dropped packets.