Linear Regression-Based Delay-Bounded Routing Protocols for Vehicular Ad Hoc Networks

Routing protocols for vehicular ad hoc networks (VANETs) have attracted a lot of attention recently. Most of the researches emphasize on minimizing the end-to-end delay without paying attention to reducing the usage of radio. This paper focuses on delay-bounded routing, whose goal is to deliver messages to the destination within user-defined delay and minimize the usage of radio. The messages can be delivered to the destination by the hybrid of data muling (carried by the vehicle) and forwarding (transmitted through radio). In the existing protocol, a vehicle may only switch the delivery strategy (muling or forwarding) at an intersection according to the available time of the next block. To improve previous works, our protocol uses linear regression to predict the available time and the travel distance and thus the vehicle can switch to a proper delivery strategy at a proper moment and can reduce the number of relays by radio. Our protocol contains two schemes: the greedy and centralized schemes. The greedy scheme uses only the local vehicle´s speed to predict the available time and decide when to switch the delivery strategy; while the centralized scheme uses the global statistical information to make the decision. Simulation results justify the efficiency of the proposed protocol.