Research On Routing Protocol And Vertical Handover Algorithm In Emergency Communication Network

Natural disasters and public emergencies will cause the failure of traditional communication methods,and communication congestion or even interruption around disasterprone areas.How to start the emergency communication mechanism,construct an emergency communication network quickly and efficiently,and improve the transmission efficiency of the network has become an urgent problem to be solved.Emergency communication has the characteristics of time and place uncertainty,unpredictability of communication needs,business urgency,rapid network construction,node mobility,heterogeneity of communication technology,etc.How to solve the key problems in emergency communication to ensure smooth communication in emergency situations are of great significance for promptly reporting the disaster to the rear and speeding up rescue activities.After the emergency,the public network facilities may be damaged and the communication is interrupted.The use of mobile ad hoc network(MANET)can quickly complete the establishment of the basic communication network.Through efficient data routing between nodes,local regional communication coverage can be established;in addition,the emergency communication network has heterogeneous characteristics.Considering the mobility of the node and the need to deliver field data to the outside world in real time,when the mobile node begins to gradually leave the current access network and enter the coverage of another heterogeneous communication network,in order to ensure that the communication session is not interrupted and has high communication quality,it is necessary to solve the problem of vertical handover of high-speed mobile nodes in heterogeneous networks.Therefore,the problem of vertical switching of MANET routing protocols and heterogeneous networks is a problem that needs to be solved in emergency communications.The traditional MANET routing protocol will result in higher latency and packet loss rate,and the overall network throughput is also limited,which cannot meet the emergency MANET’s needs for real-time and network congestion avoidance.Existing vertical handover research results do not take into account the heterogeneous characteristics of emergency communication networks.Most of them are based on single network signal quality.It is easy to switch to a single high-quality network in a centralized manner,causing network resources to be exhausted,increasing the node access failure rate,and causing a ping-pong effect.This paper analyzes the reasons why the traditional ant colony routing algorithm is no longer applicable in this application scenario in response to the rapid dynamic change of network topology and sudden network congestion in emergency communications,and proposes a routing algorithm MLSA suitable for emergency communication networks,using ant colony algorithm framework combined with reinforcement learning process for system modeling,limits the network link performance statistical analysis process to higher priority areas,and scores different routing decision processes by detecting the status information of local neighbor nodes.And make policy adjustments based on network feedback,thereby improving overall network performance,conducive to alleviating network congestion,and increasing the realtime and stability of data transmission.Experiments show that,in the environment of higher node mobility,MLSA has obvious performance advantages over the classic on-demand routing protocols AODV and DSR in response to network congestion in emergency communications.By considering the multi-attribute decision vertical switching requirements in heterogeneous networks of emergency communications,aiming at the hot network congestion caused by the local optimization strategy in the existing algorithms,in order to avoid the exhaustion of high-quality base station resources and maintain the network environment where the nodes are located.For long-term gain,this paper proposes a multi-attribute decision vertical switching algorithm CM-VHO based on Markov process.The algorithm comprehensively considers the benefits / expenses generated by different network parameters on the system,blurs the input indicators,maps the input of continuous space to a limited discrete output space,and assigns a corresponding proportion of weights.By weighted summation of the state transition matrix,the switching action is selected according to the maximization of network revenue,which improves the network resource utilization.Experiments show that,in a multi-network heterogeneous emergency communication environment,CM-VHO has obvious performance advantages over the classic multi-attribute vertical handover algorithm TOPSIS due to the consideration of node mobility and the comprehensive evaluation of the long-term benefits brought by vertical handover.