Priority-based delay mitigation for event-monitoring IEEE 802.15.4 LR-WPANs

IEEE 802.15.4 slotted carrier-sense multiple access with collision avoidance (CSMA-CA) adopts periodic sleeping for energy efficiency support. However, such a periodic sleeping mechanism, especially with contention-based medium access, tends to cause additional sleep delay due to heavy contention. In this letter, we propose a priority-based scheme, comprising frame tailoring and priority toning, in order to relax such a problematic delay and guarantee time-bounded delivery of high priority packets in event-monitoring networks.