Fast mobility support in low-power wireless networks: smart-HOP over RPL/6LoWPAN
Ref: CISTER-TR-130703 Publication Date: 11, Jul, 2013
Fast mobility support in low-power wireless networks: smart-HOP over RPL/6LoWPANRef: CISTER-TR-130703 Publication Date: 11, Jul, 2013
With the emergence of low-power wireless hardware new ways of communication were needed. In order to standardize the communication between these low powered devices the Internet Engineering Task Force (IETF) released the 6LoWPAN standard that acts as an additional layer for making the IPv6 link layer suitable for the lower-power and lossy networks. In the same way, IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) has been proposed by the IETF Routing Over Low power and Lossy networks (ROLL) Working Group as a standard routing protocol for IPv6 routing in low-power wireless sensor networks. The research performed in this thesis uses these technologies to implement a mobility process. Mobility management is a fundamental yet challenging area in low-power wireless networks. There are applications that require mobile nodes to exchange data with a fixed infrastructure with quality-of-service guarantees. A prime example of these applications is the monitoring of patients in real-time. In these scenarios, broadcasting data to all access points (APs) within range may not be a valid option due to the energy consumption, data storage and complexity requirements. An alternative and efficient option is to allow mobile nodes to perform hand-offs. Hand-off mechanisms have been well studied in cellular and ad-hoc networks. However, low-power wireless networks pose a new set of challenges. On one hand, simpler radios and constrained resources ask for simpler hand-off schemes. On the other hand, the shorter coverage and higher variability of low-power links require a careful tuning of the hand-off parameters. In this work, we tackle the problem of integrating smart-HOP within a standard protocol, specifically RPL. The simulation results in Cooja indicate that the proposed scheme minimizes the hand-off delay and the total network overhead. The standard RPL protocol is simply unable to provide a reliable mobility support similar to other COTS technologies. Instead, they support joining and leaving of nodes, with very low responsiveness in the existence of physical mobility.
Master Thesis, Instituto Superior de Engenharia do Porto.