Issue No. 10 - October (2002 vol. 51)
<p><b>Abstract</b>—Database broadcast is an effective and scalable approach to disseminate information of high affinity to a large collection of mobile clients. A common problem of existing broadcast approaches is the lack of knowledge for a client to determine if all data items satisfying its query could be obtained from the broadcast. We therefore propose a <it>semantic-based broadcast</it> approach. A semantic descriptor is attached to each broadcast unit, called a <it>data chunk</it>. This semantic descriptor allows a client to determine if a query can be answered entirely based on broadcast items and, if needed, identify the <it>precise definition</it> of the remaining items in the form of a “supplementary” query. Data chunks can be of static or dynamic sizes and organized hierarchically. Their boundary can be determined on-the-fly, adaptive to the nature of client queries. We investigate different ways of organizing the data chunks over a broadcast channel to improve access performance. We introduce the <it>data affinity index</it> metric, which more accurately reflects client-perceived performance. A simulation model is built to evaluate our semantic-based broadcast schemes.</p>
Mobile databases, semantic-based broadcast, dynamic chunking, adaptive chunking, answerability.
H. V. Leong, K. C. Lee and A. Si, "Semantic Data Broadcast for a Mobile Environment Based on Dynamic and Adaptive Chunking," in IEEE Transactions on Computers, vol. 51, no. , pp. 1253-1268, 2002.