Research On Environment-and Service-Aware Routing Protocols For Flying Ad Hoc Networks

In the beyond-5G and 6G era,non-terrestrial networks,relying on unmanned flying platforms(UFPs),like unmanned aerial vehicles(UAVs),balloons,low/medium/high altitude platforms,and the low/medium/high earth orbit satellites,have stimulated substantial interests in numerous areas.To take advantage of UFPs,the concept of flying ad-hoc network(FANET)composed of multiple collaborative UFPs is advocated which is multi-hop,centerless and can be deployed flexible.FANET can be composed of homogeneous or heterogeneous flying vehicles,which can communicate with each other or interact with the surrounding environment to obtain some kind of valuable information.In FANET,information update and communication of flying vehicles is the most prominent feature.As the core of FANET,routing protocol undertakes the task of calculating appropriate routes between nodes to ensure efficient communication.However,FANET imposes grave challenges on the routing techniques due to stringent constraints of energy budget,high mobility,node density,dynamic alteration of topology,unconventional radio propagation model and sophisticated trajectory dynamics.In addition,with the increasing diversity and complexity of transmission services in FANET,users have higher requirements on transmission quality such as network bandwidth,rate and latency.Therefore,considering the characteristics of FANET network environment and diversified service types,two routing protocols are proposed in this paper.Firstly,we propose a betweeness centrality based dynamic source routing(BC-DSR)protocol for a FANET that moves in marching formation to execute a task.Considering both the temporal and spatial correlation of the movements of nodes in this scenario,we first propose a Gaussian-Markov process based mobility model based on the group mobility of UAVs,which is more appropriate for charactering the realistic marching formation scenario.We use the concept of betweeness centrality in graph theory to measure the importance of relay nodes as bridges and propose the calculation model of betweeness centrality.In this model,width-first algorithm is used to calculate the betweeness centrality of nodes.The calculated results are used to generate weights of links and construct weighted directed graphs.Finally,we calculate the optimal route according to the link weight of the weighted directed graph.Secondly,we propose a routing protocol that optimizes the quality of multi-service provisioning in FANET by modeling the link propagation latency and link duration between nodes.We present quantitative analysis of the link propagation latency and link stability,which supports the routing decision algorithm from the computing perspective.First of all,a mobility model is established by using the geocentric coordinate system,while the link propagation latency and link duration are calculated with the aid of the mobility model.The link propagation latency is a function of the communication distance between nodes.The relevant parameters in the link duration calculation model include the relative distance vector,relative velocity vector and acceleration vector between nodes.Then,the corresponding routing metrics are constructed for the three services considered,and the optimal routes are calculated based on these metrics.Simulation results show that the proposed routing protocol can reduce the network latency and packet loss rate while ensuring the quality of each service.