MAX: Wide area human-centric search of the physical world

Abstract

We propose MAX, a system that facilitates human-centric search of the physical world. Instead of organizing objects a priori, it allows humans to search for and locate them as needed. Designed for the following objectives: (i) human-centric operation, (ii) privacy, and (iii) efficient searching of any tagged object, MAX provides location information in a form natural to humans, that is, with reference to identifiable landmarks (such as, "on the dining table") rather than precise coordinates. In the system, all physical objects from documents to clothing can be tagged, users then locate objects using an intuitive search interface. To make searching efficient, MAX adopts a hierarchical architecture consisting of tags (bound to objects), substations (bound to landmarks), and base-stations (bound to localities). Tags can be marked as either public or private, with private tags searchable only by the owner. MAX also provides for privacy of physical spaces. It requires minimal initial configuration, and is robust to reconfiguration of the physical space. We also present a methodology to design energy-optimal and delay-optimal query protocols for a variety of device choices, this optimizes system performance, and affords insight into the appropriate actions for various scenarios. We have implemented a simple prototype of MAX, demonstrating the feasibility of the system for human-centric search over several locations across a wide area. We contend that a MAX-like search system will enable sharing (e.g., books on a college campus) and trading (e.g., buying and selling used books) of physical resources, and will be the engine for a host of new applications. © 2008 ACM.