The Research Of Cross-Layer Routing Algorithms In The Self-Organizing Networks

The self-organizing network is a communication network which utilizes private network devices or facilities to realize fast deployment under the circumstances of natural disaster, emergency rescue and other sudden events. The self-organizing network mainly covers four categories, which are trunking communication network, broad wireless access, mobile Ad Hoc network and wireless Mesh network. Among these, wireless Mesh network develops so fast without relying on existing infrastructure. This paper proposes respectively a network-wide flooding algorithm based on a combinatorial neighbor selection and a layer2 routing metric based on link state and realized the algorithm in Linux operating system aiming at the problem that exist in cross-layer routing protocol BATMAN-ADV which Open-Mesh open source group develops for wireless Mesh network.In order to exchange routing information, every node in the BATMAN-ADV protocol needs to send OGM broadcast messages periodicity. BATMAN-ADV sends OGM messages with the network-wide flooding algorithm.The algorithm brings large number of redundant rebroadcasts, serious contention and collision. Because of the above problem, this paper proposes CNSA, combinatorial neighbor selection algorithm for flooding control. In the CNSA, every node selects own rebroadcast nodes set standalone and restrict rebroadcast nodes set in the combinatorial neighbor selection set. The analysis result shows the proposed algorithm reduced rebroadcast overhead comparing with the MPR which the OLSR routing protocol use to reduce broadcast overhead in the layer3.BATMAN-ADV protocol uses distance vector routing metric to compute route. As distance vector routing metric has the problems of slow speed of convergence and routing loop, this paper proposes layer2 routing algorithm DBATMAN-ADV based on link state. In the DBATMAN-ADV algorithm, we use the strength of signal reception and the volume of traffic to measure link state. Since OGM carrys link state information of source node and its neighbour, every node will get the entire network topology. Every node independently computes route according to the entire network topology of self-maintaining, and no longer rely on relay nodes. The experiment result shows that DBATMAN-ADV algorithm improves routing convergence speed.To verify the proposed algorithm, a small Mesh network is established to test the function and performance of DBATMAN-ADV. Test indicates that the proposed DBATMAN-ADV protocol works well and has better performance than BATMAN-ADV.