Context-Aware Hoarding of Multimedia Content in a Large-Scale Tour Guide Scenario - A Case Study on Scaling Issues of a Multimedia Tour Guide

This paper discusses scaling issues of a mobile multimedia tour guide. Making tourist-information available in a substantially large geographical area (e.g. a federal state in Austria) raises new questions, compared to providing similar information in a limited area (such as a museum). First, we have to assume a heterogeneous network infrastructure containing high and low bandwidth links and even total network loss. Video streaming is therefore not possible at any place. Secondly, the total amount of data grows linearly to the number of Points of Interest (POIs) which are augmented by the tour guide. Therefore, a preloading of all data onto a device with limited storage is not possible. A possible solution to these problems is hoarding, i.e. preloading an ”appropriate” subset of data. The crucial question is to find the proper subset in dependence of the actual context. The paper discusses the questions of (1) what kind of context information should be considered and (2) what kind of usage patterns can be assumed. Based on these considerations hoarding strategies are developed for the tour guide. The strategies are finally evaluated with real-world data from a federal state wide tourist-card system.