A Data Forwarding Strategy In Delay Tolerant Networks Under Post-disaster Relief Environment

Delay Tolerant Network, since to its specific environment, the mobile nodes arefrequently limited to lack of steady end to end among nodes and the node path to thecommunication range, resulting that each node communicates intermittently a type ofnetwork. It can be widely used in many fields, such as interstellar communications,vehicle networks, wildlife tracking, environmental monitoring, and disaster relief andso on.In post-disaster environments, people suffer a lot. And it is extremely difficulg toobtain information and regain personal properties. In order to carry out disaster reliefwork in a timely manner, the need for information collected during the search andrescue to adopt preferred data transmission strategies in a timely manner to collecteach data transmission to the disaster relief command center. Therefore, how to find abetter data in disaster relief forwarding policy environment is a key issue inpost-disaster relief work.In this paper, arming at a particular scene disaster relief environment, thedisaster relief work in the collection of disaster information is analyzed. Observed inpost-disaster relief work, disaster relief workers have difference, they range in a smallarea in a random walk model search and rescue work. Rescue workers need a timelymanner to collect information forwarded to the central node to start disaster reliefwork. When rescue workers the opportunity to meet with other people, you need toconsider whether to forward the information collected to each other. By analyzing thetype of search and rescue personnel and their mobile features, this paper presents akind of post-disaster relief environments delay tolerant network model. In this model,the search and rescue personnel considered as random mobile nodes to meet randommovement model, tents or emergency rescue vehicles considered staticcommunication nodes, and information can be sent directly to the affected disasterrelief command center. On this basis, a further contacts between nodes based on dataforwarding latency tolerance policy is proposed. The main idea of forwarding the datais first recorded in the history of the delay information of the contact node,forwarding the data stored in its own reference table. Then when a node encountersother mobile nodes when moving, when to exchange their data forwarding referencetable information, and then update their data forwarding reference tables. Data access node according to the current state of the network forwarding the reference table tocalculate the delay time of each path in the network, and all valid draw shortesttransmission path delay, to analyze whether a message within the time range oftolerance, if the condition is data forwarding, otherwise the node continues to moveuntil it encounters a suitable forwarding node.Simulation results show that the data forwarding scheme under disaster reliefenvironments presented in this paper can be handled in a timely manner underconditions tolerable delay. Compared with Spray, MaxProp and the Prophet, thetransmission efficiency and the throughput of the network news is improved.