A multi-hop broadcast routing algorithm based on real-time traffic estimation for VANETs

In this paper, we propose an efficient multi-hop broadcast routing algorithm based on Real-time Traffic Estimation in vehicular ad-hoc networks (VANETs) including a novel relay node selection scheme and an efficient adaptive rebroadcast wait delay strategy. Firstly, we take the overall traffic information into consideration to select the relay node, which is different with the traditional scheme only considering the distance information. In order to obtain more accurate traffic information in the target road segment, we employ the real-time traffic estimates algorithm to predict the information. Furthermore, we also reduce the rebroadcast waiting just select only one rebroadcast node by considering many influence factors such as the traffic density and the vehicle information. Therefore, a weighted utility function (WUF) is formulated to comprehensively consider the effect of these factors. Furthermore, the value of WUF can also be utilized to determine the waiting time of the rebroadcast node to achieve the adaptive wait scheme. Finally, the timeout retransmission strategy is employed to improve the reliability of broadcast message transmission at the source node. Theoretical and simulation results demonstrate the effectiveness of the proposed algorithm in terms of the packet delay, data redundancy, effective permeability and network robustness, when compared with classical M-Flood and Slotted algorithms.