Inter-MARIO: A Fast and Seamless Mobility Protocol to Support Inter-Pan Handover in 6LoWPAN

Mobility management is one of the most important research issues in 6LoWPAN, which is a standardizing IP-based Wireless Sensor Networks(IP-WSN) protocol. Since the IP-WSN application domain is expanded to real-time applications such as healthcare and surveillance systems, a fast and seamless handover becomes an important criterion for mobility support in 6LoWPAN. Unfortunately, since existing mobility protocols for 6LoWPAN have not solved how to reduce handover delay, we propose a new fast and seamless mobility protocol to support inter-PAN handover in 6LoWPAN, named inter-MARIO. In our protocol, a partner node, which serves as an access point for a mobile node, preconfigures the future handover of the mobile node by sending mobile node's information to candidate neighbor PANs and providing neighbor PAN information like channel information to the mobile node. Also, the preconfigured information enables the foreign agent to send a surrogate binding update message to a home agent instead of the mobile node. By the preconfiguration and surrogate binding update, inter-MARIO decreases channel scan delay and binding message exchange delay, which are elements of handover delay. Additionally, we define a compression method for binding messages, which achieves more compression than existing methods, by reducing redundant fields. We compare signaling cost and binding message exchange delay with existing mobility protocols analytically and we evaluate handover delay by simulation. Analysis and simulation results indicate that our approach has promising fast, seamless, and lightweight properties.