TDMA Scheduling Algorithm Satisfying Fairness For Wireless Sensor Network

With the rapid development of MEMS technology, machinery manufacturing technology,wireless communication technology and digital electronic circuit technology, the wirelesssensor has been paid more and more attention, and has been extensively studied. Wirelesssensor network has the very broad application space, whether in civilian or military has itsplay. In these application environment, each node periodically in the network to produce datarate may be different, even very different. If each node is still in accordance with the sameprobability of access channel, is bound to cause the nodes share the unfair channel.In order to solve the problem of uneven nodes for the channel, this paper proposed a novelscheduling algorithm for GTFA. GTFA algorithm is a TDMA time division multiplexingscheduling algorithm based on a graph coloring algorithm, so it combines advantages of thegraph coloring algorithm and TDMA algorithm. The main purpose of the graph coloringalgorithm is to partition the nodes in the network as independent set, node of eachindependent set is within the same color nodes, these nodes to avoid the data collision andtransmission interference. Then the TDMA algorithm can be divided into separate networktime slots, then the time slot assigned to independent sets of different, this ensures that nodescan work collaboratively and won’t produce the energy loss caused by the conflict.Because of the lack of global network topology and the routing master, methods to solvethe fairness to design a fully distributed is a huge challenge. In this paper, DVCA algorithmbased on graph coloring, use conflict model definition considering communicationinterference to communication on the non cluster head nodes to achieve conflict freescheduling. GTFA algorithm is divided into the network clustering, node coloring,independent set scheduling three steps. First network clustering clustering protocol forapplication of DWEHC, and then use the DVCA algorithm to cluster nodes were stained,divided into independent sets of different, according to the cluster node data flow statisticalinformation on independent sets of slot allocation. This scheduling considers the network structure and data flow distribution, strong ability to adapt to environmental changes. Thereare two points of innovation, the first one is to allocate time slots according to the networkdata information, the second is the time slot allocation phase is divided into two rounds, eachround according to the different emphases to set independently for scheduling, this ensuresthat the nodes in a network of large amount of data to obtain the channel bandwidth more.The simulation results show that, GTFA algorithm can improve the utilization rate ofwireless communication channel bandwidth, effectively solve the fairness problem of networkscene data flow maldistribution of channel assignment, optimization of each node in thenetwork energy consumption, prolong the network survival time.