CoAP and database integration for sleeping and non-routable nodes

The idea of the Internet of Things, which emerged in recent years, became one of the main fields of interest in industrial and academic research. The Constrained Application Protocol (CoAP) is one of the technologies aspiring to a standard in the IoT world. CoAP was designed to provide a low-overhead, machine-to-machine communication for constrained devices in a way similar to HTTP. In this paper we propose a solution, which enables non-routable and legacy sensor networks to utilize the CoAP protocol and integrate with a centralized database. The CoAP protocol is used in an “inversed” fashion, where a node acts as a client, that is actively publishing the data rather than serving it on demand. Even though this model seems contrary to the “Web of Things” idea, we find it useful for certain network types, in which nodes may not be directly accessible, for example networks containing nodes with long sleep periods or networks not based on the IEEE 802.15.4 and 6LoWPAN standards. The presented solution was initially implemented for the needs of the project RADCARE¹. In this implementation the CoAP protocol and a database were used for gathering human life parameters sensed by a dedicated radar system.