Transmission Timing Control to Avoid Collisions Among Both Aperiodic and Periodic Packets in Wireless Sensor Networks

Currently, many kinds of wireless sensor networks need to communicate aperiodically generated packets like event detection as well as periodically generated ones for environmental, vital monitoring, and so on. Thus, collisions should be avoided among both aperiodic and periodic packets. In this paper, we propose a method to schedule transmission timings of aperiodic and periodic packets at the application layer from the source nodes. This has advantages of no modification to the MAC layer standardized by IEEE 802.11, 802.15.4, etc. and low cost of sensor nodes, compared with existing approaches based on the MAC layer modifications. To the best of our knowledge, this is the first proposal that controls transmission timings of both aperiodically and periodically generated packets at the application layer. Performance evaluation verifies that the proposed method improves packet loss rate compared with existing application layer approaches that control transmission timings of only periodic packets.