QoS-Orientated Network Resource Allocation And Routing Optimization Mechanism In Vehicular Edge Network

With the development of Internet of Things,more and more devices can access the network.Among the various devices,the wireless access of vehicles can constitutes an edge network,which will provide real-time road information and significant traffic state.Thus,it has gradually got the public attention.However,due to the rapid movement of vehicles,the network topology is constantly changing,making it difficult to provide stable transmissions.Thus,how to provide reliable and effective network service quality in vehicular networks has become a new challenge.Broadly speaking,QoS(Quality of Service,QoS)features can be divided into two major aspects:one is service-based QoS,including service prioritization,differentiated services,user-aware QoS quality,etc.;the other is network performance-based QoS,ie,guarantee reasonability of indicators such as delay,bandwidth,and link reliability.Therefore,providing complete QoS guarantee for the network can from these two aspects.Corresponding to the vehicular edge network,when designing the QoS guarantee mechanism,it can be divided into two major steps:firstly,realizing service differentiation for a single vehicle,and providing different network resource services for different transmission services;secondly,providing network performance guarantee for information transmission between multiple vehicles.For overcoming the shortcomings in existing research,this paper studies the QoS guarantee mechanism in the vehicular edge network from the following two steps:(1)We propose a network resource allocation mechanism based on multi-priority bionic competition model to achieve service differentiation.Firstly,we deduce a context metric(CM)through fuzzy inference,which relates the urgency degree of a vehicle to its environment.The vehicle traffic is re-prioritized into four access categories(ACs)combined with the CM and transmission data types.Then we propose the multi-priority bionic competition model for data transmission,which considers the inter completion between the same priority ACs and the competition between different priority ACs.By adjusting the competitive parameters,we can control the transmission rate of different priority ACs and allocate proper network bandwidth.Finally,the simulation results show that our method improves the network throughput,reduces the mean delay and packet loss rate.(2)In order to guarantee the QoS performance of transmission,we propose a QoS-based Opportunistic Routing Mechanism(QORM).Firstly,we set up a QoS evaluation model(QEM).According to the different road connectivity condition,we calculate the three QoS indicators,that is link state(LS),transmission correct ration(TCR)and delay(D)respectively,which will accurately estimate the link quality of road segment.Then we propose the QoS-based opportunistic routing mechanism.This mechanism consists of two parts:first,setting up the candidate forwarding nodes sets of road segment according to the channel quality;and second,selecting optimal route path,which will choose next hop based on the results of QEM.The optimal next hop is the road segment with the best link quality,so as to develop the route performance.Finally,the results prove the accuracy of the QoS evaluation model and demonstrate that QORM outperforms the reference protocols.