Mobile IoT: smart-HOP over RPL
Ref: CISTER-TR-140709 Publication Date: 16, Jul, 2014
Mobile IoT: smart-HOP over RPLRef: CISTER-TR-140709 Publication Date: 16, Jul, 2014
The 6loWPAN (the light version of IPv6) and RPL (routing protocol for low-power and lossy links) protocols have become de facto standards for the Internet of Things (IoT). In this paper, we show that the two native algorithms that handle changes in network topology --the Trickle and Neighbor Discovery algorithms-- behave in a reactive fashion and thus are not prepared for the dynamics inherent to nodes' mobility. Many emerging and upcoming IoT application scenarios are expected to impose real-time and reliable mobile data collection, which is not compatible with the long message latency and high packet loss exhibited by the native RPL/6loWPAN protocols. To solve this problem, we integrate a proactive hand-off mechanism (dubbed smart-HOP) within RPL, which is very simple, effective and backward compatible with the standard protocol. We show that this add-on halves the packet loss and reduces the hand-off delay dramatically to one tenth of a second, upon nodes' mobility, with a sub-percent overhead. The smart-HOP algorithm has been implemented and integrated in the Contiki 6LoWPAN/RPL stack (source-code available online) and validated through extensive simulation and experimentation.