Dynamic priority back-up algorithm based on IEEE802.11 DCF

The Distributed Coordination Function (DCF) in the IEEE 802.11 protocol is a random access scheme based on the carrier sense multiple access with collision avoidance (CSMA/CA). In recent years, there have been numerous research on the performance analysis and model of DCF under the assumption that the transmission queue is always nonempty (i.e. saturation state). In this paper, we propose a dynamic priority back-up algorithm (DPBA) for IEEE802.11 DCF, the basic idea of DPBA is each node should collect statistical data of other node´s transmission while sensing the channel, and maintaining a sending data table for all node in network. When the node has data to transmit, it will calculate the dynamic priority and connection window according to the number of successful sending, the number of successful sending and the statistical data in sending table. Simulation results show that DPBA can properly assign channel among nodes in proportion to their dynamic priority as well as enhance the network saturation throughput.