Mutual Aid Among Sensors: An Emergency Function for Sensor Networks

A large number of wireless sensor nodes in a certain area results in high contention. Inevitably, the transmissions of any possible critical data packets may fail due to collisions. In this letter, we introduce an aspect of human intelligence in wireless sensor networks, influenced by cooperative networking, which enhances the timely delivery of critical data. Mutual aid among sensors is an emergency out-of-the-box medium access control function for IEEE 802.15.4-2020. Specifically, the network coordinator detects critical data packets and sets an emergency flag to its next beacon to inform the nodes that they may overhear data packets. When a node overhears a critical data packet from a neighboring node, it switches to sleep mode and stays idle until the end of the superframe. Thus, interference is mitigated locally and temporarily. Simulation results, using the CC2650 radio parameters in OMNeT++, show that interference is reduced significantly, in favor of the timely delivery of critical data packets.