Design And Implementation Of Multi-hop Wireless Network Message Switching Protocol

With the development of network technology, accessing to broadband through wireless technology has become an important way to acquire information. Meanwhile, because of the drastic increasing of the number of accessed users, the variety of web service and the increasing demand for transmission quality, how to ensure the safe and reliable transmission in wireless link, to improve the utilization rate of existing wireless cyber source and to optimize the transmission performance of the wireless network have become the most important research topics of wireless communication research in nowadays. Network Coding is a new message-switching technology which fused coding in the routing. It points out that, the network can reach its maximal information flow if every node in the network can encode received data in a linear or nonlinear way. Traditional network coding has the advantages such as increasing the network throughput, balancing the network load, improving the utilization rate of the broadband and saving the energy consumption of nodes.This paper first discussed the transmission characteristics of wireless multi-hop networks and the fundamental theories and key technologies of network coding. Then a message switching plan of Multi-Hop Wireless Network based on Network Coding was proposed. Begin with the most basic single relay network, this paper introduced the scheme of this process in details, and then extended to two-relay-network and three-relay-network. Finally, the feasibility of this scheme in any N relay network was proved in theory, and the conclusion was derived that the message switching plan based on Network Coding can save more transmission time and energy consumption of sending than the traditional plan based on store-and-forward. It can save 25% transmission time and 50% energy consumption of sending at most.Afterwards, this paper designed a set of protocol based on the message switching plan of Network Coding. It discussed the function of each layer in this protocol stack and the emphases and difficulties in the process of design and implementation. Finally, this protocol was implemented using C language, and simulation of wireless nodes application was designed on Windows platform. The simulation of message switching process based on Network Coding is implemented in Multi-Hop Wireless Network. Thesimulation results also validated the inference that Network Coding can save the energy consumption of sending which was mentioned above. Finally, this paper summarized the progress made in the design and implementation of message switching protocol which based on Network Coding, and also pointed out existing problems and research direction in the future.