Backpressure Scheduling And Opportunistic Routing Based On Network Coding In Wireless Multihop Networks

With the development of wireless communication technology,wireless multi-hop networks gradually provide services for the development of human economy and society and the convenience of daily life.However,uncertainty in the wireless environment lead to mang problems,such as unreliable links,limited throughput and so on,forcing people to constantly seek new solutions to improve the wireless network performance.The birth of network coding technology,brings an excellent idea for humans to optimize the performance of wireless networks.It can take advantage of the broadcast characteristics of wireless channels and give full play to the coding advantages.Until now,the research on the application of network coding in various aspects of wireless multi-hop networks is a hot topic,especially the application of network coding in scheduling and routing.Based on the existing research results,this thesis continues to explore the application of network coding in backpressure scheduling and opportunistic routing.Focusing on this research topic,this thesis mainly does the following work:Firstly,this thesis applies network coding to backpressure scheduling,and proposes a backpressure scheduling method based on network coding(BP-NC).The concept of coding probability and coding threshold is introduced into the actual wireless network with interference to judge the quality of the coding opportunity,and the network coding diagram is used to unify the actual interference mode and the ideal non-interference mode,so that the backpressure scheduling problem based on network coding is transformed into the maximum weight clique problem.In order to reduce the computational overhead caused by exhaustive search the maximum weight clique,an improved search algorithm is designed.The simulation results verify the effectiveness of the algorithm and show that the application network coding can further improve the network performance.Secondly,this thesis combines network coding with opportunistic routing,and puts forward an energy-aware opportunistic routing protocol based on network coding(EAOR-NC).In view of the increasingly serious problem of network energy consumption,consider to research the advantage of network coding in opportunity routing with energy consumption for measurement mechanism,then designs simulation by improving the original Bellman Ford algorithm,and compares the energy consumption with single shortest path routing(ShortPath – NoNC)and opportunity routing without network coding(EAOR – NoNC).In the end,it is found that the transmission energy of the packet is the lowest when considering the network coding.