Infrastructure-assisted efficient broadcasting in hybrid vehicular networks

Transmission power adaptation has been widely employed to improve on the network performance. However designing an adaptation technique that could lower the number of collisions and delay under unreliable connectivity and fast topological changes due to high speed vehicles is a challenging task. In this paper we proposed an efficient broadcasting scheme using transmission power adjustment. There are two main contributions. Firstly, a multi-tiered architecture is described for hybrid vehicular networking. Offloading control message exchange among vehicles from vehicle-to-vehicle (V2V) to vehicle-to-infrastructure (V2I) can potentially results in better overall performance. Secondly, a centralized transmission power adaptation technique is proposed. By taking in to account the current topology state, contextual information of vehicle movement is derived in terms of estimated link expiration time. Each vehicle is then assigned a transmission power which ensures connectivity with long lasting links only. A simulation based performance evaluation study shows that the proposed power adaptation technique results in significantly lower packet collision rate and delay while maintaining a shorter average transmission range.