一种公平的路边基站下行业务调度算法

Fair traffic scheduling algorithm for the roadside unit

针对车辆网络中现有路边基站下行业务调度算法公平性差的问题,提出了一种公平的基于网络流的路边基站下行业务调度算法.首先,建立包含车辆节点和时隙节点的二部图,如果在给定时隙内车辆节点位于路边基站的通信覆盖范围内,则在该车辆节点与对应的时隙节点之间添加边;然后,在二部图的基础上添加虚拟的源节点和目的节点,建立网络流图;最后,通过计算网络流图的最小花费最大流,得到了一种公平的路边基站下行业务调度策略.仿真结果表明,在保证最大化车辆业务请求的情况下,与现有算法相比,这种算法提高了车辆之间业务请求的公平性,在offline情况下公平性提高了约116.4%,在online情况下公平性提高了约25.9%.

To improve the fairness performance of the downlink traffic scheduling algorithm, a network flow based downlink traffic scheduling algorithm is proposed for the roadside unit （RSU） in vehicular networks. In the proposed algorithm, a bipartite graph is constructed firstly, where the node set is composed by the vehicle set and the timeslot set. At any given timeslot if a vehicle can communicate with the RSU, then an edge between the given timeslot and that vehicle is added into the edge set. Next, a flow network graph is constructed based on the bipartite graph by adding a virtual source node and a virtual sink node. By applying the conventional minimum cost maximum flow algorithms, a minimum cost maximum flow can be computed, which is converted to the fair traffic scheduling strategy. Simulation results show that, when the total vehicle requirements are maximized, compared with the existing algorithms, the fairness performance of the proposed algorithm is improved by 116.4% in the offline case, and by 25.9% in the online case.