A Dynamic Power Tuning for the Constrained Application Protocol of Internet of Things

Constrained application protocol (CoAP) has been designed for M2M and IoT applications. The resource directory (RD) in CoAP requires periodical updates by other nodes. However, a regular update process causes extra signaling overhead and drains the node's battery, which consequently reduces the battery lifetime of all nodes. Thus, there is a need to adjust the update interval to prolong the lifetime of the entire network. Although this problem has been investigated in the literature, it is still in its infancy as existing works do not consider the dynamic periodic adjustments of the update messages. To fill in this gap, this paper devise a new adaptive tuning approach between CoAP clients and their CoAP-RD to adjust the frequency of updates based on the battery level of the transmitting node. We evaluated our protocol using simulation experiments. The simulation results confirm that the adaptive tuning approach outperforms its traditional counterpart by 10 to 15% with respect to the overall network lifetime.