Research Of Shadow Network System Based On WiMAX

Shadow network is a new concept, primitively appeared in reports. Its application background is mysterious, and there is not open application. Shadow network is to operate independently under government’s control and it can provide a low risk communication mode for activists or dissidents.Shadow network is similar to Ad Hoc network, which has these features:no center, self-organization, multiple-hop routing and so on. It is one kind of special wireless P2P (Point to Point) network. Each node in a network can be used as its neighbors’ router and to forward datum. Except PMP (Point to Multi-Point) mode, IEEE802.16d also supports Mesh mode, which has the theoretical foundation to set up P2P network. So this thesis proposes a shadow network scheme based on WiMAX (World Interoperability for Microware Access).Firstly, the thesis introduces the principle of WiMAX Mesh mode and analyzes the feasibility of shadow network based on WiMAX. Combining the characteristics of802.16, the thesis introduces the advantages of WiMAX shadow network.The thesis also analyzes and studies the networking scheme of shadow network. According to the different applications, the thesis proposes two kinds of networking scheme respectively.Then the thesis designs embedded terminal for shadow Internet based on the S3C2440processor. The terminal system uses Linux operating system as the software development platform. During the hardware design, the thesis chief completes the circuit designing of peripheral module for embedded terminal system; during the software design, the thesis establishes the cross development environment for embedded system, and transplants embedded Linux system and driver module.Finally, based on standard IEEE802.16-2004and NS2(Network Simulator version2) environment, the thesis develops a simulation platform for WiMAX Mesh mode. The whole platform consists of seven basic modules completing particular tasks. The organic integration of modules simulates the WiMAX Mesh mode. On the simulation platform, the thesis simulates coordinate distributed scheduling mechanism and analyzes the results.The test results of embedded terminal system for shadow Internet show that the system has achieved the disired goal. The simulation results show that the value of Exp has a significant impact on the prefomance of coordinate distributed scheduling mechanism in Mesh shadow network based on WiMAX.