Location-aware caching for spatial queries in dynamic environments

Spatial query processing is important to the emerging mobile network applications such as ad hoc networks and mobile sensor networks. The conventional caching techniques are ineffective in dealing with spatial queries in dynamic environments due to the following reasons: first, the cache contents are described based on queries instead of data locations, which lead to the inefficiency in describing the data content distribution in the network; in addition, the results of earlier queries may be invalidated immediately after query resolution due to the mobility of data objects; moreover, the data volumes and number of clients may be quite large that deteriorate the performance of conventional caching approaches. In this paper, we address these issues using position-locus map, a caching scheme that reflects the distribution of mobile data objects based on the analysis of locations of interest and earlier queries. We show that spatial queries may be answered efficiently with the position-locus map, with reduced search cost and system overhead