Use of Proxy Mobile IPv6 for Mobility Management in CoAP-Based Internet-of-Things Networks

Recently, the constrained application protocol (CoAP) has been standardized for remote control of various sensor devices in Internet of Things networks. In CoAP, to support the handover of mobile devices, service discovery should be performed again. So, the handover delay may be increased significantly. To address this limitation of CoAP, in this letter, we propose the two mobility management schemes based on the proxy mobile IPv6 (PMIPv6): CoAP-PMIP and CoAP-DPMIP. In CoAP-PMIP, local mobility anchor (LMA) and mobile access gateways (MAGs) are used to provide network-based mobility support for sensor devices. Each device has to register its IPv6 address with LMA, and all messages are transmitted through LMA. In CoAP-DPMIP, the role of LMA is distributed to each MAG. By using distributed MAGs, this scheme can provide optimized transmission path and also reduce the handover delay. From ns-3 simulations, we can see that the CoAP-DPMIP scheme provides better performance than the CoAP and CoAP-PMIP schemes, in terms of total delay associated with binding update, data transmission, and handover.