Dynamic CoAP Mode Control in Real Time Wireless IoT Networks

IEEE 802.15.4 is one of the preferred mechanisms to provide modulation and media access control in wireless Internet of Things networks. With the goal of preserving battery life, IEEE 802.15.4 is characterized by low power consumption that results in low signal-to-noise ratios responsible of low transmission rates and high bit error rates. In these low rate lossy networks, and from the application layer perspective, the constrained application protocol provides lightweight session management and control with two modes of operation: 1) a reliable mode where retransmissions guarantee packet delivery at a cost of increased latency, power consumption, and throughput and 2) an unreliable mode that provides packet loss-prone delivery of packets with lower battery use. In this paper, we present a dynamic mode selection mechanism that extends battery life while minimizing latency as well as transmission rates and improving overall quality of service.