Research On Key Technologies Of Large-scale Hybrid Routing In Wireless Ad Hoc Networks

With the expansion of network scale and frequent movement of network nodes,the network topology of wireless ad hoc networks also changes frequently.So more efficient routing has become a research hotspot for large-scale networks.Common routing protocols include required routing protocols,active routing protocols and hybrid routing protocols.When the network scale increases dramatically,the performance of the network overhead of the active routing protocol deteriorates sharply and the routing delay of the on-demand routing protocol increases.The advantage of the hybrid routing protocol is that it combines the advantages of active and on-demand routing protocols and balances network performance.Therefore,the hybrid routing protocol is more suitable for large-scale networks.However,the hybrid routing protocol still has some shortcomings.For example,the routing area overlaps greatly,the network cost is large,the inter-domain repeated path finding and path finding delay become large.Based on the large-scale wireless ad hoc network in high-speed mobile scenarios,this paper improves the traditional intra-domain routing mechanism and intra-domain routing mechanism of the ZRP protocol.The main research content of this article has the following three points.Firstly,in view of the problems in the intra-domain routing mechanism,the election mechanism of the virtual central node and the optimized intra-domain routing message structure are designed.The virtual multi-center node selection mechanism is to select a node with a large traffic volume as the virtual center node based on the connectivity of neighbor nodes and the traffic volume,which solves the problem of large overlapping of routing areas in the domain.Routing messages in the domain include the message of establishing routing and the message of maintenance routing.Both of these routing messages carry the whole information of the local routing table,and there are cases where the routing messages are duplicated.Therefore,this article follows the format of the HELLO message and designs the intra-domain routing request message and the intra-domain routing reply message,thereby reducing the network overhead of intra-domain routing.Secondly,for the out-of-step problem of network layer routing and MAC layer resource,an inter-layer interaction mechanism is designed.The network layer initiates the resource scheduling process by sending corresponding primitive messages to the MAC layer,and the MAC layer replies the corresponding primitives to clarify the resource application results.Design the expired route cache mechanism to solve the problem of repeated path finding for the same service with two short intervals.Thirdly,this paper builds a routing cost and delay model based on a uniformly distributed network structure.By the MATLAB simulation platform to analysis performance,the best area radius is obtained.The performance of the optimized routing protocol is verified by the simulation code of the multi-center hybrid routing protocol written by the NS2 simulation platform.Finally,the network layer protocol architecture is designed based on the ARM＿LINUX platform to realize the function of multi-center hybrid routing protocol.