Browsing by Author "Chu, HC"

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A cell-based location-sensing method for wireless networks
(2003-06-01)
Chu, HC
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Jan, RH
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資訊工程學系
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Department of Computer Science
One of the most important applications for mobile commerce is location-based application and the core technology of location-based applications is the location-determination technology. In this paper, we present a location-sensing method, called cell-based location-sensing method and its positioning accuracy for the wireless networks with hexagonal structure and mesh structure. In addition, the accuracy of the method is optimized by tuning the transmitting power of base stations. In the optimal transmitting power, an accuracy of within 9.1667% (7.2182%) cell area for hexagonal structure (mesh structure) can be achieved by the cell-based location-sensing method. We believe that the results are useful for deploying wireless networks for location-based applications. Copyright (C) 2003 John Wiley Sons, Ltd.
A GPS-less self-positioning method for sensor networks
(2005)
Chu, HC
;
Jan, RH
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資訊工程學系
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Department of Computer Science
One challenging issue in sensor networks is to determine where a given sensor node(SN) is physical located. This problem is especially crucial for very small SNs. In this paper we present a GPS-less self-positioning method for sensor networks. In our method, a set of nodes, called as reference points (RPs), are deployed in the sensor network with overlapping regions of coverage. The RP periodically broadcasts beacon frames which contain localization data. The SN collects the beacon frames from RPs and processes the data in the frame, and then it can localize itself simply. The analysis of positioning accuracy are also given to show how well a SN can correctly localize itself.
Cell-based positioning method for wireless networks
(2002)
Chu, HC
;
Jan, RH
;
資訊工程學系
;
Department of Computer Science
One of the most important applications for mobile commerce is location-based application and the core technology of location-based applications is the location determination technology. In this paper, we present a positioning method, called as cell-based positioning method and its positioning accuracy measure for the wireless networks with hexagon structure and mesh structure. In addition, the positioning accuracy is optimized by tuning the base stations' transmission power In the optimal transmission power an accuracy of within 9.1% (7.2%) cell area for hexagonal structure, (mesh structure) can be achieved by cell-based positioning method. We believe that the results are useful to deploy wireless networks for location-based applications.
Improving the accuracy of cell-based positioning for wireless networks
(2004-12-20)
Jan, RH
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Chu, HC
;
Lee, YF
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資訊工程學系
;
Department of Computer Science
One fundamental issue for location-based services and applications is solving the location-sensing problem, i.e., determining where a given node is physically located in a network. In a previous paper, we have presented a location-sensing method, called the cell-based positioning method, and its positioning accuracy for the wireless networks with a hexagonal structure and mesh structure. Unfortunately, in real situations, a wireless network may not have a hexagonal or mesh structure. Thus, in this paper we consider networks with irregular structures and present an algorithm to determine the positioning accuracy of the cell-based method in such networks. In addition, we use the simulated annealing (SA) method to determine the locations and transmission ranges of base stations in order to achieve the best possible positioning accuracy. Simulation results show that the accuracy can be improved up to 30% by the SA method. The results are useful for deploying a wireless network for location-based applications. (C) 2004 Elsevier B.V. All rights reserved.