Composable ad hoc location-based services for heterogeneous mobile clients

This paper introduces a comprehensive architecture that supports adapting a client deviceʹs functionality to new services it discovers as it moves into a new environment. Users wish to invoke services - such as controlling the lights, printing locally, gaining access to application-specific proxies, or reconfiguring the location of DNS servers - from their mobile devices. But a priori standardization of interfaces and methods for service invocation is infeasible. Thus, the challenge is to develop a new service architecture that supports heterogeneity in client devices and controlled objects while making minimal assumptions about standard interfaces and control protocols. Four capabilities are needed for a comprehensive solution to this problem: (1) allowing device mobility, (2) augmenting controllable objects to make them network-accessible, (3) building an underlying discovery architecture, and (4) mapping between exported object interfaces and client device controls. We motivate the need for these capabilities by using an example scenario to derive the design requirements for our mobile services architecture. We then present a prototype implementation of elements of the architecture and some example services using it, including controls to audio/visual equipment, extensible mapping, server autoconfiguration, location tracking, and local printer access.