Research On Neighbors-Scheduling-Based Multiple Access Protocol In Distributed Networks

In ad hoc networks, hidden terminals and exposed terminals present widely. Hidden terminals cause a mass of collisions between packets and control messages when network load is heavy. Retransmission of data wastes lots of bandwidth resource. Exposed terminals cause that neighbors in ad hoc networks won't send data concurrently although their data won't be collided at the receivers. So, hidden terminals shall be reduced as many as possible to reduce data collisions so that bandwidth resource can be utilized more efficiently.In this paper, I will study media access control (MAC) protocols for single channel and propose a new MAC protocol named NSBMA ( Neighbors-Scheduling-Based Multiple Access) based on the studies, in which each node modifies state values of sending and receiving for every time-segment (T-seg) according to neighbors' time-scheduling and reserves T-segs based on state values. Nodes determine whether a T-seg can be utilized to send by the receiving state value or receive data by the sending state value. Thus, neighbors can choose the same T-segs to send data which makes NSBMA be able to resolve exposed terminals problems. Simulation results show that NSBMA gains significant increase in throughput compared to MACA and TRAMA.WSN is one special application of ad hoc networks. There are many sensor nodes in WSN who are powered by batteries. Charge and replace batteries are impossible in many application situations. WSN requests MAC to reduce end-to-end delay and energy consumption. We obtain TMNSBMA by adopting the temporary receiving T-segs to reduce end-to-end delay, and minimal listening time to save energy. Simulation results showed NSBMA can decrease energy consumption without increasing latency than ECR-MAC and RMAC.