Supporting r4nge queries in a wireless environment with nonuniform broadcast

摘要

In a wireless computing environment, a server disseminates information by periodically broadcasting data on ‘air', while clients ‘catch' their desired data on the fly. To determine the data to be broadcast, the server constructs a broadcast program. While a nonuniform broadcast program has been demonstrated to be effective in reducing the average access times for single-record retrievals, existing nonuniform broadcast programs perform poorly for range queries. In this paper, we propose a new algorithm to generate nonuniform broadcast programs that can facilitate range queries. Our algorithm supports selective tuning using the flexible indexing scheme. We conducted an extensive simulation study, and our results show that the proposed algorithm can generate programs that lead to significant improvement (in terms of both access time and tuning time) for range queries without sacrificing much on the performance of single object retrievals.