The Research On Simulation Technology Of Ad Hoc Network Testbed

MANET is a new type of mobile wireless communication network,which has gained much attention in the field of military communications with its flexibility and practicability.MANET is different from the mobile wireless communication network and traditional routing protocols are not adapted to it for its features of no center,self-organization and free movement.Therefore,it is required that we should research and develop particular routing protocols to support it.During the research of MANET routing protocols,software simulation and field test are generally adopted to verify the designed routing protocols.Software simulation is commonly used to carry out a preliminary verification on principle and performance of routing protocols,while field test is used for the test during the developing process and the final validation before formal deployment.It requires repeated testing in the development process of MANET routing protocols.Although the result of field test is accurate and reliable,its cost is higher and the operation is relatively complicate.In addition,the field test is easy to be affected by the external factors,which is bad for us to solve the problem of routing protocols.For the case,this paper proposes a method of building ad hoc network testbed based on wired network and a ad hoc network testbed closed to the real environment has been designed and implemented based on VxWorks by the research of simulation technology about ad hoc network.Using this method,the standard TCP/IP protocol stack is modified and extended,which adds emulated wireless link layer in the middle of network layer and data link layer.MANET is simulated by detailed design of header of emulated wireless link layer and setting up simulated model for the function of emulated wireless link layer,which aims to simulate the characteristics of-dynamic network topology,low transmission rate,limited transmission distance and weak anti-interference ability.In the same time,according to the protocol stack architecture of Vx Works,the emulated wireless link layer is applied to the virtual communication simulator as a key module and adds functional components to simulate the.real wireless communication node.Finally,the ad hoc network testbed is established in the laboratory,xwhich combines virtual communication simulators with the management and control platform and the data collection and analysis platform.The testbed not only overcomes disadvantages of high cost and complex operation,but solves the problem of repeatability of scenarios in field test,reduces the test time and improves the efficiency of the development.In addition,it can configure different scenarios by the management and control platform and collect experimental data in real time for its display and summary by the data collection and analysis platform,so as to facilitate the network researchers to test and verify protocols.