3MRP+: An improved multimetric geographical routing protocol for VANETs

The design of routing protocols in vehicular ad hoc networks (VANETs) is fundamental to achieve a high packets’ delivery ratio. Routing protocols whose operation considers the nodes’ positions use routing information updated according with the reception frequency of hello messages. The routing information can help to improve the routing to can include several metrics such as vehicle’s trajectory, vehicles’ density, percentage of packet losses, among others. There is a trade-o with the beaconing frequency: a high frequency provides a better accuracy in the selection of the next forwarding node to route a packet, but the overload increases due to a higher number of hello messages in the network. To decrease the overhead, the period of hello messages should be larger, although the eciency to choice the next forwarding node decreases. In this paper we have designed an ecient method to improve the accuracy of the nodes’ position used to select the next forwarding node. Our approach improves the operation of the routing protocol used in our performance evaluation. Simulations show the benets of our proposal, increasing the accuracy of the nodes’ selection and maintaining a same level of overhead, without the necessity to increase the beacon frequency.