Research On Routing Algorithm Between Groups Based On Vehicle Grouping Under VANET Environment

Vehicular Ad-hoc Network, namely VANET, is the wireless communication network of connection between the vehicles, and between the vehicle and roadside equipment. It is able to establish a temporary ad hoc wireless mobile communications network without any auxiliary infrastructure. Besides, it is capable of collecting various information of the vehicle speed of vehicle or roadside equipment and road congestion, and realizing the dissemination and sharing of information through an ad hoc network, so as to improve road transport efficiency and ease severe traffic congestion, reduce traffic accidents, cut down energy and resource consumption.This paper analyzes the characteristics of vehicle travel under the circumstance of VANET, and puts forward the grouping of vehicles moving in the same direction within a certain distance. The vehicles traveling in the opposite direction work in group to communicate and exchange information on road congestion. The vehicles traveling in the same direction can often remain stable relative position, and sustain a long and stable communication, and when the driver gets a piece of useful information, this information will be of reference value to the adjacent vehicle. By achieving the effective exclusion of duplicate data transmission for certain purpose, and requesting the opposite vehicle of data with higher priority, it can greatly improve the effective data transfer rate.This paper also improves the routing algorithm of Delay Tolerant Networks(DTN) following grouping. The existing major routing algorithms of DNT have their own limitations. For example, Epidemic routing algorithm can only effectively display the characteristics of high data package delivery rate and little network delay when nodes have ample storage space, while Spray and Wait routing algorithm only applies to the occasion of relatively small node storage space. Thus, this paper puts forward that relay node should be assessed based on its storage space when it meets other nodes. If there is plenty of storage space, it is better to use Epidemic routing algorithms for the copy and transfer of the data, so as to reduce network latency and increase packet delivery ratio as much as possible. In case of lack of storage space, it is suggested to use Spray and Wait routing algorithm to reduce unnecessary data copies and save network resources. This paper also puts forward the measure of overall network communication capability to estimate the number of data packets copy and delay time, which can help discard the data packet exceeding predicated value, reduce unnecessary waste of network resources and hardware resources, and further improve the overall network communications capabilities.In the end, this paper conducts simulation and emulation with NS-2, and results show that, by grouping vehicles, the transmitting efficiency of effective data has been improved obviously compared with the situation where vehicles are not been grouped, and through the improvement of routing algorithm between groups, the delivery ratio of data package can be improved effectively under the premise that the waste of network resources is very low.