Neighbor Discovery In Heterogeneous Distributed Transmission

Gradually the mobile terminal evolves for the direction of multi-mode, multi-interface, multi-channel, the heterogeneous network which is overplayed and combined by many different kinds of access networks becomes the trends of the wireless communication. It is the urgent problem for heterogeneous networks to implement inter-connection, resource-sharing, spectrum efficiency increasing and present a ubiquitous network environment with full orientation service. Although several independent links can be gotten which show strong complementarily by using multiple modes, the advantage of multi-interface has not been reflected for mobile intelligent terminals in current networks. It just used channel path with the'best'link quality, while discarding the cooperative transmission derived by parallel channel and the surrounding nodes. If heterogeneous distributed networks can be integrated by multi-interface multi-channel nodes, not only the wireless resource allocation can be optimized, but reachability and connectivity can be increased among the nodes in one networks. The necessity and premise for heterogeneous distributed networks is to get the neighbor information in multi-interface mode. Therefore the following aspects are included in the paper:1, In order to solve the problem of different access technologies in underlying layer of distributed networks, a multi-modes integration protocols for heterogeneous networks is introduced between the MAC layer and IP layer in this paper, and the function and mechanisms of this protocol entity is represented. The reachability of nodes in heterogeneous networks is analyzed and simulated based on the mentioned protocol. Simulation results show that compared to the homogeneous wireless networks, the heterogeneous ones composed by multi-modes terminals can enhance the reachability and expansibility of self-organization, as well as implement the communication among heterogeneous terminals2, In this paper, a neighbor discovery mechanism is proposed for heterogeneous distributed transmission. All nodes in this networks collect information notification aiming at looking for surround neighbors by sending neighbor collection message through all its interface, or listens on its interfaces to receive the neighbor collection message. At the stage of multi-hop neighbor discovery, the neighbor information from all interfaces in last stage should be integrated and broadcasted from each interface in the node. In this inter-exchange way the nodes can collect the neighbor information. After the information conformity for records of neighbor topology database, a complete networks topology graph is presented for all nodes, under this circumstance there is at least one path between two heterogeneous terminals. In networks simulation, all nodes can find its multiple neighbor relationship corresponding to its own interfaces channels.