Wireless visual sensor network (VSN) can be said to be a special class of wireless sensor network (WSN) with smart-cameras. Due to its visual sensing capability, it has become an effective tool for applications such a...Wireless visual sensor network (VSN) can be said to be a special class of wireless sensor network (WSN) with smart-cameras. Due to its visual sensing capability, it has become an effective tool for applications such as large area surveillance, environmental monitoring and objects tracking. Different from a conventional WSN, VSN typically includes relatively expensive camera sensors, enhanced flash memory and a powerful CPU. While energy consumption is dominated primarily by data transmission and reception, VSN consumes extra power onimage sensing, processing and storing operations. The well-known energy-hole problem of WSNs has a drastic impact on the lifetime of VSN, because of the additional energy consumption of a VSN. Most prior research on VSN energy issues are primarily focusedon a single device or a given specific scenario. In this paper, we propose a novel optimal two-tier deployment strategy for a large scale VSN. Our two-tier VSN architecture includes tier-1 sensing network with visual sensor nodes (VNs) and tier-2 network having only relay nodes (RNs). While sensing network mainly performs image data collection, relay network only for wards image data packets to the central sink node. We use uniform random distribution of VNs to minimize the cost of VSN and RNs are deployed following two dimensional Gaussian distribution so as to avoid energy-hole problem. Algorithms are also introduced that optimizes deployment parameters and are shown to enhance the lifetime of the VSN in a cost effective manner.展开更多
Traditional simulators have deficiencies of scalability, thus they are not so efficient in running simulations with large-scale networks. In this paper, we present a new simulator, namely EasiSim, specifically for eva...Traditional simulators have deficiencies of scalability, thus they are not so efficient in running simulations with large-scale networks. In this paper, we present a new simulator, namely EasiSim, specifically for evalu-ating sensor net-works on a large scale. EasiSim is featured by organizing its core components, including nodes, topology and scenario, in a hierarchically structured approach. The hierarchically structured organiza-tion enables nodes to process all the concurrent events in one batch, hence reducing the running time by an order of magnitude. Moreover, we propose a visualization scheme based on a Client/Server model which separates the graphical user interface (GUI) from the simulation engine, and therefore the scalability of the simulator will not be decreased by complex GUI. Extensive simulations show that EasiSim outperforms ns-2 in terms of real running time and memory usage.展开更多
The objective of this contribution is to present expositive review content on currently available experimental tools/services/concepts used for most emerging field Wireless Sensor Network that has capability to change...The objective of this contribution is to present expositive review content on currently available experimental tools/services/concepts used for most emerging field Wireless Sensor Network that has capability to change many of the Information Communication aspects in the upcoming era. Currently due to high cost of large number of sensor nodes most researches in wireless sensor networks area is performed by using these experimental tools in various universities, institutes, and research centers before implementing real one. Also the statistics gathered from these experimental tools can be realistic and convenient. These experimental tools provide the better option for studying the behavior of WSNs before and after implementing the physical one. In this contribution 63 simulators/simulation frameworks, 14 emulators, 19 data visualization tools, 46 testbeds, 26 debugging tools/services/concepts, 10 code-updation/reprogramming tools and 8 network monitors has been presented that are used worldwide for WSN researches.展开更多
针对现有农田监测系统在网关与服务器远程通信、视频信号传输、设备供电等方面存在的问题和缺陷,开发出一套基于无线传感网络的农田远程监测系统。系统以传感器节点、视频监控设备、无线网桥、ZigBee网关、远程服务器为硬件平台,以Visua...针对现有农田监测系统在网关与服务器远程通信、视频信号传输、设备供电等方面存在的问题和缺陷,开发出一套基于无线传感网络的农田远程监测系统。系统以传感器节点、视频监控设备、无线网桥、ZigBee网关、远程服务器为硬件平台,以Visual Studio 2012为软件开发环境,结合SQL Server2005数据库技术,实现远程服务器对大田现场的实时数据查询、历史数据查询、数据报表、视频查看、异常状态报警、辅助决策等功能,并提供PC和手机端的两种访问方式。实践表明:该系统实现了对监控区域环境数据、作物生长信息的有效监测,满足现代农业对农田监测的要求。展开更多
文摘Wireless visual sensor network (VSN) can be said to be a special class of wireless sensor network (WSN) with smart-cameras. Due to its visual sensing capability, it has become an effective tool for applications such as large area surveillance, environmental monitoring and objects tracking. Different from a conventional WSN, VSN typically includes relatively expensive camera sensors, enhanced flash memory and a powerful CPU. While energy consumption is dominated primarily by data transmission and reception, VSN consumes extra power onimage sensing, processing and storing operations. The well-known energy-hole problem of WSNs has a drastic impact on the lifetime of VSN, because of the additional energy consumption of a VSN. Most prior research on VSN energy issues are primarily focusedon a single device or a given specific scenario. In this paper, we propose a novel optimal two-tier deployment strategy for a large scale VSN. Our two-tier VSN architecture includes tier-1 sensing network with visual sensor nodes (VNs) and tier-2 network having only relay nodes (RNs). While sensing network mainly performs image data collection, relay network only for wards image data packets to the central sink node. We use uniform random distribution of VNs to minimize the cost of VSN and RNs are deployed following two dimensional Gaussian distribution so as to avoid energy-hole problem. Algorithms are also introduced that optimizes deployment parameters and are shown to enhance the lifetime of the VSN in a cost effective manner.
文摘Traditional simulators have deficiencies of scalability, thus they are not so efficient in running simulations with large-scale networks. In this paper, we present a new simulator, namely EasiSim, specifically for evalu-ating sensor net-works on a large scale. EasiSim is featured by organizing its core components, including nodes, topology and scenario, in a hierarchically structured approach. The hierarchically structured organiza-tion enables nodes to process all the concurrent events in one batch, hence reducing the running time by an order of magnitude. Moreover, we propose a visualization scheme based on a Client/Server model which separates the graphical user interface (GUI) from the simulation engine, and therefore the scalability of the simulator will not be decreased by complex GUI. Extensive simulations show that EasiSim outperforms ns-2 in terms of real running time and memory usage.
文摘The objective of this contribution is to present expositive review content on currently available experimental tools/services/concepts used for most emerging field Wireless Sensor Network that has capability to change many of the Information Communication aspects in the upcoming era. Currently due to high cost of large number of sensor nodes most researches in wireless sensor networks area is performed by using these experimental tools in various universities, institutes, and research centers before implementing real one. Also the statistics gathered from these experimental tools can be realistic and convenient. These experimental tools provide the better option for studying the behavior of WSNs before and after implementing the physical one. In this contribution 63 simulators/simulation frameworks, 14 emulators, 19 data visualization tools, 46 testbeds, 26 debugging tools/services/concepts, 10 code-updation/reprogramming tools and 8 network monitors has been presented that are used worldwide for WSN researches.
文摘针对现有农田监测系统在网关与服务器远程通信、视频信号传输、设备供电等方面存在的问题和缺陷,开发出一套基于无线传感网络的农田远程监测系统。系统以传感器节点、视频监控设备、无线网桥、ZigBee网关、远程服务器为硬件平台,以Visual Studio 2012为软件开发环境,结合SQL Server2005数据库技术,实现远程服务器对大田现场的实时数据查询、历史数据查询、数据报表、视频查看、异常状态报警、辅助决策等功能,并提供PC和手机端的两种访问方式。实践表明:该系统实现了对监控区域环境数据、作物生长信息的有效监测,满足现代农业对农田监测的要求。
