Protocol Research And Node Implemention Of Wireless Mesh Network Based On Tdma And Network Coding

Wireless mesh network is widely used in military, commercial and civilian fields. Audio and video streaming in metropolitan area network access and emergency communications put forward higher requirements to wireless mesh network. Research on low latency wireless mesh network has great significance and value.This paper categorized overview delay characteristics of wireless mesh network based on TDMA scheduling algorithm and network coding in China and abroad. This paper analyze the node delay in wireless mesh network based on TDMA from system load and slot allocation position by queuing theory. On the basis this paper analyze the influence of transmission hops and flow distribution on end to end delay.Traditional slot allocation protocol does not consider the distribution of the slot position, based on the analysis of the influence of data frame size, this paper proposes minimum frame length uniformity dynamic slot allocation protocol DMFUSAP, which use main slots in two hops to calculate local minimum data frame length. Through the main slot rotation and shift the priority list, the slots of node evenly distributed. Simulation results show that 7-hop end to end delay of DMFUSAP decrease 54.9% than DP-TDMA and 46.5% than USAP.In consideration of the importance of routing and traffic distribution of wireless mesh network end to end delay, this paper takes the influence of the bandwidth of network coding node into account and proposes low delay coding aware routing protocol LDCAR. LDCAR estimate the link delay in routing initiation and select low delay link in real time. Simulation results show that the average end to end delay of LDCAR is decrease 42.3% than DCAR and 21.2% than QCAR at 25 session/min.Finally, on the basis of trade-offs on design specifications and design difficulty, this paper designs NIOS node system and can be flexibly configured on the network parameters based on actual network requirements. Test results show that when the data rate is 100 Kbps, one-hop latency is 1.89 ms and four-hop latency is 9.22ms; when data rate is 300 Kbps, one-hop latency is 9.31 ms and four-hop latency is 63.52 ms. The results show that the project is designed to meet the requirements.