The PoSIM middleware for translucent and context-aware integrated management of heterogeneous positioning systems

The widespread availability of devices with multiple wireless interfaces and of heterogeneous positioning techniques open new market potentials for Location Based Services (LBSs), even if complicating their development. The paper claims the need for novel middlewares to manage dynamically retrieved client-side positioning systems in a synergic way and depending on context, i.e., LBS requirements, user preferences, device characteristics, and overall system state. To that purpose, we have designed and implemented PoSIM, a context-aware middleware for the synergic exploitation and control of heterogeneous positioning systems that facilitates the development and portability of LBSs. PoSIM is translucent, i.e., can provide LBS developers with differentiated visibility of data characteristics and control possibilities, thus dynamically adapting to application-specific deployment requirements and enabling cross-layer management decisions. The paper describes the translucent PoSIM architecture, some primary implementation insights, and how to practically use it to simplify LBS development via events, filters, and policies.