-
Proceedings of the Sixth IASTED International Conference on Communications, Internet, and Information Technology, July 2-4, 2007, Banff, Alberta, Canada; 01/2007
-
[show abstract]
[hide abstract]
ABSTRACT: For wireless sensor networks, localization is crucial due to the dynamic nature of deployment. In relative localization, nodes use the distance measurements to estimate their positions relative to some coordinate system. In absolute localization, a few nodes (called anchors) need to know their absolute positions, and all the other nodes are absolutely localized in the coordinate system of the anchors. Relative and absolute localization methods differ in both the performance and the cost. We present a new approach to relative localization that we refer to as: simple hybrid absolute-relative positioning (SHARP). In SHARP, a relative localization method (M1) is used to relatively localize N<sub>r</sub> reference nodes. Then, an absolute localization method (M2) uses these N<sub>r</sub> nodes as anchors to localize the rest of the nodes. Choosing N<sub>r</sub>, M1, and M2 gives a wide range of performance-cost tuning. We have done extensive simulation using the multidimensional scaling (MDS) method as M1 and the ad-hoc positioning system (APS) method as M2. While previous research shows that MDS gives better localization results than APS, our simulation shows that SHARP outperforms MDS if both the localization error and the cost are considered.
Distributed Computing Systems Workshops, 2005. 25th IEEE International Conference on; 07/2005
-
[show abstract]
[hide abstract]
ABSTRACT: Summary form only given. Knowing the positions of nodes in sensor networks are essential for many applications. We propose a new method, MDS-MAP(R), that determines the relative positions of nodes based on local distance information. Given a communication path between a starting node and a remote node, the nodes on the path first compute their local relative maps based on local distance estimates in a distributed fashion, using the MDS-MAP method. Then, the relative maps of adjacent nodes along the path are aligned based on their common nodes and their optimal linear transformation parameters are computed. Finally, the relative position of the remote node in the coordinate system of the starting node is determined by applying the sequence of linear transformations. The method can easily be extended from the single-path peer-to-peer communication situation to other types of communications such as multicasting or broadcasting. The accuracy of relative position estimation is affected by several factors, including the network connectivity, the errors of local distance measures, the length of the path, and the number of common nodes of two adjacent relative maps. Through simulation, we analyze the effect of these factors on the position estimation errors. We show that the new method performs well on both regular and irregular networks when there are enough connectivity and the distance measurement errors are small.
Parallel and Distributed Processing Symposium, 2004. Proceedings. 18th International; 05/2004
-
[show abstract]
[hide abstract]
ABSTRACT: Recent advances in MEMS (micro-electromechanical systems), processor, radio, and memory technologies have dramatically enabled development of wireless sensor networks. A sensor network is a large network of small sensor nodes, capable of sensing, communication, and computation. It can be deployed to sense some physical phenomenon for a wide variety of applications. During recent years, research in wireless sensor networks has become more and more active. Network protocols developed for sensor networks are of great importance to meet specific design goals of sensor networks. We present a survey of recent work addressing network protocols, including routing and information dissemination algorithms, for wireless sensor networks. We evaluate them in terms of design goals, assumptions, operation models, energy models, and performance metrics.
Information Technology: Research and Education, 2003. Proceedings. ITRE2003. International Conference on; 09/2003
-
[show abstract]
[hide abstract]
ABSTRACT: Wireless sensor networks have become possible because of the on-going improvements in smart sensor technology. One important issue in wireless sensor networks is to achieve energy-efficient operation in order to extend network lifetime. For many applications, placement of sensing nodes can be pre-determined. In this paper, we propose several power-efficient routing algorithms for a sensor network with 2D grid topology, demonstrating that optimal routings are operation-specific and energy consumption can be minimized by optimally selecting data paths and base station location.
Information Technology: Research and Education, 2003. Proceedings. ITRE2003. International Conference on; 09/2003
