Noname manuscript No. (will be inserted by the editor) A Distributed Spatial Index for Error-Prone Wireless Data Broadcast Baihua Zheng1, Wang-Chien Lee2, Ken C. K. Lee2, Dik Lun Lee3, Min Shao2 1 Singapore Management University, Singapore.
[email protected] 2 Pennsylvania State University, USA. {wlee,cklee,mshao}@cse.psu.edu 3 The Hong Kong University of Science and Technology, Hong Kong.
[email protected] Abstract Information is valuable to users when it is technologies can be classified into two basic approaches: available not only at the right time but also at the right on-demand access and periodic broadcast. On-demand place. To support efficient location-based data access access employs a pull-based approach where a mobile in wireless data broadcast systems, a distributed spa- client initiates a query to the server which in turn pro- tial index (called DSI ) is presented in this paper. DSI cesses the query and returns the result to the client over is highly efficient because it has a linear yet fully dis- a point-to-point channel. On-demand access is suitable tributed structure that naturally shares links in differ- for lightly loaded systems in which wireless channels and ent search paths. DSI is very resilient to the error-prone server processing capacity is not severely contended. wireless communication environment because interrupted search operations based on DSI can be resumed eas- On the other hand, periodic broadcast requires the ily. It supports search algorithms for classical location- server to proactively push data to the clients over a ded- based queries such as window queries and kNN queries icated broadcast channel.