A Simple Approximate Analysis of Floating Content for Context-Aware Applications

Abstract

Context-awareness is a peculiar characteristic of an ever expanding set of applications that make use of a combination of restricted spatio-temporal locality and mobile communications, to deliver a variety of services to the end user. It is expected that by 2014 more than 1:5 billion people would be using applications based on local search(search restricted on the basis of spatio-temporal locality), and that mobile location based services will drive revenues of more than $15 billion worldwide [1]. A common feature of such context-aware applications is the fact that their communication requirements significantly differ from ordinary applications. For most of them, the scope of generated content itself is local. This locally relevant content may be of little concern to the rest of the world, therefore moving this content from the user device to store it in a well-accessible centralized location and/or making this information available beyond its scope represents a clear waste of resources (connectivity, storage). Due to these specific requirements, opportunistic communication can play a special role when coupled with context-awareness. The benefit of opportunistic communications is that it naturally incorporates context as spatial proximity is closely associated with connectivity.

Recently an opportunistic communication paradigm, known as floating content (FC) [2], conceived to support server-less distributed content sharing was proposed. It aims at ensuring the availability of data within a certain geographic area called anchor zone (AZ). Within the AZ, any time a user who is unaware of the content enters the transmission range of another user possessing it, the content is shared opportunistically. Nodes delete content once they go out of AZ. In recent literature([1], [2]), authors derived an asymptotic condition called criticality condition under which content floats asymptotically.