Research And Implementation Of TDMA-based Slot Allocation Algorithm For Wireless Mesh Networks

The existing wireless Mesh network towards multiple wireless access technology convergence direction. The available radio resources in the wireless Mesh network is very limited. How to improve the radio resource utilization and increase the network capacity is the key issue to design the wireless Mesh network.In a highly competitive environment to maximize the channel utilization, efficient allocation of resources while ensuring the QoS. Especially in some resource reservation and QoS guarantee networks, such as public safety networks and tactical networks, TDMA-based MAC protocol reflects the greater advantage.In this paper, MAC layer TDMA slot allocation algorithm for wireless mesh network is studied, details are as follows:This paper firstly introduces the basic concepts of Mesh network, the structure and characteristics.And details the TDMA protocolswhich are used in MAC layer, including dynamic TDMA protocol FPRP and CA-TDMA, A combination of fixed and dynamic TDMA protocol ADAPT and P-TDMA.Then for the question about delay in TDMA wireless multi-hop Mesh network, Proposed low latency slot allocation algorithm DG-TDMA considering time slot reusein the current data flow.And around the wireless Mesh network MAC layer TDMA channel access method. Analyse the inadequate aspects of the M-USAP slot allocation algorithm.Proposed Wireless Mesh Network TDMA dynamic slot allocation algorithm SRHE-TDMA.Redesign the time frame structure,Proposed the hidden and exposed terminal situation between neighboring nodes through transitions and updatethe state of neighbor nodes,achieve conflict-free algorithm allocated slot, and the nodes within two hops can reuse the same time slot, improved MAC layer radio resource allocation efficiency.Finally do the performance simulationwith the two proposed algorithm.Simulation results show that compared with the minimum possible delay algorithm MPD, DG-TDMA algorithm in a large network load delay performance considerably, but the packet delivery ratio has improved significantly.SRHE-TDMA algorithm in the case of high node mobility and high load, due to network flexibility and high slot reuse, has better performance. Compared with the M-USAP algorithm, the overall throughput performance draw has been raised by 12%, delayed by an average has been decreased by20%.Based on the study based on TDMA radio resource allocation, it is necessary to validate and measure the algorithm SRHE-TDMA on the wireless node system.Then select the hardware for wireless node system and design the Mesh networking implementations.Including the MAC layer node mutual synchronization scheme, SRHE-TDMA dynamic slot allocation algorithm,optimize the node fair mechanism. Finally, based on the node system LM3S9B96 development board and CC1100 RF modulesestablished network successfully.The functional requirements of the MAC layer to meet the design.The network performance well after measurement, the maximum network throughput performance in chain topology can reach150.6kbps,and in star topologycan reach110.4kbps.