Location Based Services (LBS)

Introduction

The main  areas that contribute to Location Based Services are Context-Aware Computing, Ubiquitous (Pervasive) Computing, Location Aware Computing and Mobile Computing in general.

One of the hardest problems here is Location Privacy.   It is also a very important one, for Location Based Services (LBS) to become "successful" (and, by that, I mean useful and useable).

The second challenge is one of suitable abstractions.  Location is just one kind of context.  The general idea is not just location-aware computing, but context-aware computing.   Only when the computer (no pretense here that it is a single entity, distributed computing is assumed by default) becomes aware of the users' context (context includes identity, role, activity, location, orientation, ambient conditions...etc), it will be able to reach the ideal of "do what I mean" as opposed to "do what I say".

My recent work described here has the goal of developing a framework for context-aware mobile computing in general.  The ideas have not yet been implemented, but I have proposed means of protecting privacy by two means: (1) by arranging to disclose just the right "level" (the notion of level here includes granularity and relevance level) of context (location) information and (2) by combining this with access control policies.  I have also included distance-like concepts in this model.

Read further for more details on this work.

Realms  and States: A Framework for Context-Aware Mobile Computing
Published in the Proceedings of the 1st ACM Workshop on m-Commerce, held in conjunction with the 7th ACM/IEEE Conference on Mobile Computing and Communication (MOBICOM 2001), July 2001, Rome.

ABSTRACT

Location awareness is an important part of context-aware mobile computing. We present the idea of logical location contexts which provides enhanced privacy and supports specialized notions of distance, and offers a paradigm that unifies  location with other types of context.  This is developed in the form of a framework consisting of realms, which are collections of spatial states, with realm-maps providing mappings between realms. The lowest realm relies on raw (physical) location.   Multiple arbitrary realms are allowed to co-exist.

Many applications do not necessarily need access to raw location.  With our model, such applications access only states in specified realms of interest, thus supporting location privacy.   Policies guard such access at the granularity of realms and states. Provision for specialized realm-specific and state-specific notions of distance enables spatial awareness and reasoning. The framework is presented formally.  The ensuing architecture has good properties with respect to privacy, manageability, distribution of computation and scalability.

Link to uncorrected paper in ACM Digital Library (with an error in Fig.2)
The error is fixed in the version available here:
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