Mobile CoAP for IoT mobility management

For Web-based applications in Internet of Things (IoT) environment, the IETF CoRE Working Group developed the Constrained Application Protocol (CoAP). A limitation of CoAP is that it does not address a mobility management for CoAP sensor nodes, which may move between different IP domains of a wireless sensor network. In this paper, we propose the CoAP-based Mobility Management Protocol (CoMP), which can provide mobility management for mobile CoAP sensor nodes. CoMP keeps track of the current IP addresses of mobile sensor and enables sensing data to be reliably delivered to the Web clients, using both HTTP and CoAP. The idea is that CoMP employs a separate location management function to support CoAP service mobility, and two operating modes, CoMP holding and binding modes, are used for a reliable data transmission during handover. To do this, we have designed the architecture of CoMP. Furthermore, we have designed the detailed signaling flow, the message format and algorithm of CoMP for the mobility support. Finally, the numerical analysis and simulation results of the handover latency and packet loss show the benefits of the proposed protocol.