Paper Info
Title
A Proxy-Based Approach to Continuous Location-Based Spatial Queries in Mobile Environments
Abstract
Caching valid regions of spatial queries at mobile clients is effective in reducing the number of queries submitted by mobile clients and query load on the server. However, mobile clients suffer from longer waiting time for the server to compute valid regions. We propose in this paper a proxy-based approach to continuous nearest-neighbor (NN) and window queries. The proxy creates estimated valid regions (EVRs) for mobile clients by exploiting spatial and temporal locality of spatial queries. For NN queries, we devise two new algorithms to accelerate EVR growth, leading the proxy to build effective EVRs even when the cache size is small. On the other hand, we propose to represent the EVRs of window queries in the form of vectors, called estimated window vectors (EWVs), to achieve larger estimated valid regions. This novel representation and the associated creation algorithm result in more effective EVRs of window queries. In addition, due to the distinct characteristics, we use separate index structures, namely EVR-tree and grid index, for NN queries and window queries, respectively. To further increase efficiency, we develop algorithms to exploit the results of NN queries to aid grid index growth, benefiting EWV creation of window queries. Similarly, the grid index is utilized to support NN query answering and EVR updating. We conduct several experiments for performance evaluation. The experimental results show that the proposed approach significantly outperforms the existing proxy-based approaches.
Year
DOI
Venue
2013
10.1109/TKDE.2011.203
IEEE Trans. Knowl. Data Eng.
Keywords
Field
DocType
ewv,nearest neighbor query,mobile environments,valid region caching,estimated valid regions,cache storage,estimated window vectors,tree data structures,index structures,grid index,mobile clients,evr growth,valid region,spatial locality,grid index growth,nn query,window queries,spatial query processing,spatial query,proxy-based approach,window vector,temporal locality,effective evrs,nn query answering,continuous location-based spatial queries,location-based service,continuous nearest-neighbor queries,evr-tree,mobile client,window query,mobile computing,query processing,mobile communication,computer architecture,location based service,artificial neural networks,servers,indexes
Mobile computing,Data mining,Locality of reference,Computer science,Tree (data structure),Server,Location-based service,Spatial query,Grid,Mobile telephony
Journal
Volume
Issue
ISSN
25
2
1041-4347
Citations 
PageRank 
References 
8
0.47
20
Authors
2
Name
Order
Citations
PageRank
Jiun-Long Huang159247.09
Chen-Che Huang2434.82