Research On Routing Algorithm Of Wireless Ad Hoc Networks In Disaster Rescue Scenarios

In natural disasters and emergencies,the communication infrastructure in disaster areas is often severely damaged or the communication performance is seriously deteriorated,which greatly hinders rescue work.The wireless self-organizing network,which requires no infrastructure,and relies only on the dynamic self-organization and rapid establishment of wireless terminals,can provide great convenience for rescue.The wireless ad hoc network is a temporary,arbitrary topology network,and its routing protocol is the key to achieving and securing communications.The research of existing routing protocols mainly focuses on route discovery strategies.The research on on-demand routing is particularly prominent.In the research of the routing algorithm,if the design is targeted and refined according to different rescue scenarios,the network performance can be improved.This thesis analyzes the characteristics of typical disaster rescue scenarios and communication requirements in detail.Combined with existing wireless ad hoc network routing protocols,the research and improvement of routing protocols for disaster rescue scenarios with high-risk and node-energy constrained are carried out.In disaster scenarios such as high risk of nuclear leakage and wide rescue area,the number of rescue personnel allowed to enter is limited.In this thesis,MP_OLSR routing algorithm based on hop count is improved and optimized,and an expected transmission time is proposed.The multi-path OLSR routing algorithm performs route selection by calculating the ETX value and the bandwidth value of the inter-node link,in an effort to improve the link loss and bandwidth under-consumption of the MP_OLSR routing algorithm so as to guarantee the high bandwidth of the link.,high throughput and low latency,and even support multi-mode communication such as video.Simulation verification of NS2 shows that the improved OLSR routing algorithm proposed in this paper has obvious improvement and improvement in the end-to-end delay and throughput compared with the comparison routing algorithm.This thesis also studies disaster relief scenarios in remote mountain areas,where the energy of communication devices is limited.This thesis draws on the AODV routing algorithm and adopts route maintenance to reduce the network overhead.It designs an alternative route routing algorithm with idleness parameters.The idleness parameter is advertised through the Hello packet and stored in the neighbor table.In the route maintenance process,regardless of the location of the link break in the active route,the upstream node can try the local repair by selecting the largest idle neighbor stored in the neighbor table.The routing algorithm proposed in this paper reduces the control packet messages and their transmission overhead by introducing a controlled rerouting discovery mechanism.It also reduces the inherent congestion and delay.NS2 simulation results show that the improved routing algorithm in this paper has better performance than other algorithms in terms of normalized overhead and delay.