A priority supported MAC protocol for emergency response wireless sensor networks

This paper presents P-PDB, a priority supported MAC protocol for emergency response wireless sensor networks. P-PDB is based on DCF protocol which is widely used in WLAN, Bluetooth, Zigbee and other randomly distributed networks. P-PDB introduces a parameter, contention window backoff probability, to regulate the node´s media accessing priority. An adaptive regulating strategy is also proposed. The nodes detecting the emergency are considered as high priority nodes which should obtain higher bandwidth. Every node estimates the achievable throughput according to the total node number, and adjusts the probability referring to the estimated collision probability and current throughput. Theoretical analysis and simulation results show that with this protocol the node of different priority can adaptively regulate its parameter to achieve the required throughput. Meanwhile, this protocol can maximize the media resource utilization.