A QoS Routing Algorithm Based on Software-Defined Vehiclar Ad-Hoc Network

A Vehicular Ad-Hoc Network(VANET) is a Mobile Ad-Hoc Network(MANET) composed of mobile vehicular nodes.It does not rely on infrastructure to either establish a communication link orrealize communication. Owingto the high mobility of vehicles and limited wireless-communication resources, it is difficult for VANETs to guarantee Quality of Service(QoS).To solve this problem, this paper introduces a Software-Defined Network(SDN).In particular, amulti-constrained QoS routing algorithm suitable for Doftware-Defined Vehicular Ad-Hoc Network(SDN-VANET) is proposedthatharnessesthe advantages of SDN control and forwarding separation to ensurevehicle QoS.First, the SDN controller schedules a vehicle's service based on deadline constraints.Second, this paper proposesan Adaptive Hybrid Shuffled Frog-Leaping Algorithm(AH-SFLA).The SDN controller calculates the appropriate value of the data on the transmission link according to the QoS index and the global topology information and uses this as a benchmark to search for an optimized path.At the same time, alternative link mechanisms and QoS resource consumption thresholds are set to implement routing maintenance in order toreduce the probability of network failures.Finally, mininet-wifi and SUMO are combined to build an SDN-VANET environment, and the AH-SFLA routing algorithm is compared with the performances ofIGA and IICSFLA.The experimental results show that compared with IGA and IICSFL, AH-SFLA can improve the average end-to-end delay index by 57.74% and 46.6%, reduce the packet-loss rate by 29.9% and 18.6%, and increase the cost of standardized routing by 36.93% and 27.2%, respectively, effectively guaranteeingQoS in VANET.