Central Concerns and Questions
We are interested in developing mechanisms for users to retrieve location-dependent data from wireless broadcast channels efficiently (i.e., with less energy consumption and shorter access latency).
Emerging Ideas and Initiatives
The data broadcast on air is only available to users when it is broadcast. In another words, wireless broadcast system does not support random access like traditional database environments. Existing indexing structures designed for traditional database environments allow random access and backtracking to speed up the search. As a result, existing indexes cannot guarantee the efficiency of the search for wireless systems. In other words, wireless channel is error-prone, and the dissemination approaches have to take the frequent packet loss into consideration, and should be able to support immediate resume once packet loss happens.
Selected Publications
[1] Xiao Zhang, Wang-Chien Lee, Prasenjit Mitra, and Baihua Zheng.Processing TNN Query in Multi-Channel Access Environment, Proc. the 11th International Conference on Extending Database Technology (EDBT'08), March 25-30 2008: 438-449.
[2] Baihua ZHENG, Wang-chien Lee, Dik Lun Lee. On Searching Continuous Nearest Neighbors in Wireless Data Broadcast Systems, IEEE Transactions on Mobile Computing (TMC), 6(7): 748-761, July, 2007.
[3] Baihua Zheng, Jianliang Xu, Wang-chien Lee, and Dik Lun Lee. Grid-Partition Index: A Hybrid Approach to Nearest-Neighbor Queries in Wireless Location-Based Services . International Journal on Very Large Data Bases (VLDBJ), 15(1):21-39, January, 2006.
[4] Wang-chien Lee and Baihua Zheng. DSI: A Fully Distributed Spatial Index for Wireless Data Broadcast. Proc. the 25th International Conference on Distributed Computing Systems (ICDCS'05), June 6-9, 2005: 349-353.
[5] Baihua Zheng and Dik Lun Lee. Information Dissemination via Wireless Broadcast. Communications of the ACM , 48(5): 105-110, May, 2005.
[6] Baihua Zheng, Wang-chien Lee, and Dik Lun Lee.Spatial Queries in Wireless Broadcast Systems. Wireless Network, 10(6): 723-736, December, 2004.
Projects, Presentations and Posters
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