Research And Simulation Of COPE Network Coding

With the development of information technology, the number of Internet usersand the requirements of transmitting quality are increasing continuously. Using thelimited resources of network efficiently and improving the capability of networkcommunication have been a focal research in wireless communications. Networkcoding allows and encourages the intermediate nodes to transfer information after it isencoded, which can largely improve the capability of network communication. COPEproposed by Katti, et al. is the first practical network coding model in wirelessenvironment. Multi-channel multi-interface technology can utilize the bandwidthefficiently. Based on the above two points, the paper researched network coding andmulti-channel multi-interface.The main work is listed as follows:1. Proposed a COPE scheme based on flow coding-aware after analyzing thedefect of COPE scheme: the coding process confines to two-hop routing and waits forcoding opportunity passively. And the scheme is simulated on NS2simulationplatform. The improved scheme uses guessing mechanisms, and finds the potentialcoding node in the route discovery process. Then it selects the best path to transmitdata according to the hops and the code chance. The node judges weather to code thepackets by the packets’ route information, increasing the coding opportunities.Simulation results show that the improved scheme can effectively improve thenetwork performance.2. Proposed a COPE scheme based on decoding buffer management afteranalyzing the simulation results of the COPE scheme in1and the COPE‘s usage ofbuffer queue. And the scheme is simulated on NS2simulation platform. Theimproved scheme stores the listened packets which can be used to decode, increasingthe effective utilization of the decoding buffer queue. The results show that theimproved scheme can improve throughput.3. Proposed a COPE scheme based on multi-channel multi-interface afteranalyzing the defect of COPE scheme in1and2: the scheme is only suitable for the single-channel single-interface environments, and it doesn’t take full advantage ofspectrum resources. The scheme listens all the data packets which transmitted on thechannels, and codes the data packets in the interface queue, improving the bandwidthefficiency of network. And the scheme is simulated on NS2simulation platform.Thesimulation results show that with the increasing of the number of the channel andinterface, the improved scheme can increase the network performance.4. Carried out the expansion of multi-channel multi-interface in order to achievethe simulation, as the mobile node model under NS2supports single channel andsingle interface.Then designed an interface switching strategy and channel schedulingalgorithm.This paper studied network coding and multi-channel multi-interface technologyunder wireless network environment, and proposed and simulated the improvements.The simulation results from NS2simulator have proved that the technology of thispaper is effective.