Localization using GPS Coordinates in IPv6 Addresses of Wireless Sensor Network Nodes

Abstract

Background/Objectives: This paper describes design considerations surrounding the implementation of a novel and standards-compliant scheme to incorporate GPS location information into the IPv6 address of Wireless Sensor Network (WSN) nodes. Methods/Statistical Analysis: A wide variety of localization protocols have been proposed which allow nodes to interpolate their location from their neighbors as an alternative to deploying more expensive WSN nodes with GPS receivers or other dedicated localization hardware. The scheme proposed here is similar to others in that it relies on ground-truth anchor nodes, and unique in that it uses the network address to convey this information. Findings: There are a number of interesting design considerations for location interpolation in a WSN that has a small number of sparsely distributed nodes with GPS ground-truth and a larger number of nodes that interpolate their location based on analysis of packets received with GPS coordinates and confidence intervals embedded in their addresses. Our calculations show that accurate GPS coordinates can be carried in the IPv6 address along with the transmission radius of the node, and this information is sufficient for a node to determine its location through triangulation. Additional flags can also be provided, such as an indicator of link quality, to refine this calculation and reduce the margin of error. The additional information can be different for each neighbor node, overcoming limitations on determining directionality in broadcast networks. Since the location information is carried in every packet header there is no overhead of a separate protocol and each node can do its calculations independently. Applications/Improvements: WSN nodes that report their geographic location in the address of every packet they send has obvious potential for refining information gathering in various types of deployments.