Miniature and Low-Power Wireless Sensor Node Platform: State of the Art and Current Trends

Wireless sensor node is an autonomous and compact device that has capability to monitor a variety of real-world phenomena. It is designed composed of sensing device, embedded processor, communication module, and power equipment. Wireless sensor node is part of wireless sensor network where hundred or thousand sensor node can be deployed. Over the past decade Wireless Sensor Networks (WSNs) have emerged as one of the computing platforms of note within the electronics community. In prediction, there will be more than 127 million wireless sensor nodes deployed worldwide by 2014. We have surveyed 100 currently available wireless sensor network node platforms have been developed and produced not only by the research institutions, the universities but also some companies in last ten years. In this paper, we present a review of 27 different wireless sensor node platforms. We review these devices under a number of different parameters, and we highlight the key advantages of each node platform according to dimension and power consumption. We also discuss the characteristics and trend of development and deployment a wireless sensor node technology

Public key cryptography in resource-constrained WSN

In this paper we present a detailed review of the works on public key cryptography (PKC) in wireless sensor networks (WSNs). In the early days of sensor networks, public key cryptography was thought to be completely unfeasible considering its computational complexity and energy requirements. By this time, several works have proved that the lightweight versions of many well-known public key algorithms can be utilized in WSN environment. With the expense of a little energy, public key based schemes could in fact be the best choice for ensuring data security in high-security demanding WSN applications. Here, we talk about the notion of public key cryptography in WSN, its applicability, challenges in its implementation, and present a detailed study of the significant works on PKC in WSN

Wireless Multimedia Sensor Networks Applications and Security Challenges

The emergence of low-cost and mature technologies in wireless communication, visual sensor devices, and digital signal processing facilitate of wireless multimedia sensor networks (WMSNs). Like sensor networks which respond to sensory information such as humidity and temperature, WMSN interconnects autonomous devices for capturing and processing video and audio sensory information. WMSNs will enable new applications such as multimedia surveillance, traffic enforcement and control systems, advanced health care delivery, structural health monitoring, and industrial process control. Due to WMSNs have some novel features which stem the fact that some of the sensor node will have video cameras and higher computation capabilities. Consequently, the WMSNs bring new security of challenges as well as new opportunities. This paper presents WMSNs application and security challenges

Solar energy harvesting and software enhancements for autonomous wireless smart sensor networks

Civil infrastructure is the backbone of modern society, and maintaining said infrastructure is critical in maintaining healthy society. Wireless smart sensors (WSSs) provide a means to effectively monitor the performance of buildings and bridges to improve maintenance practices, minimize the costs of repair, and improve public safety through a process called structural health monitoring (SHM). WSSs, traditionally powered by batteries, are limited in the length of time they can operate autonomously. The frequent need to change batteries in the networks can drive up maintenance costs and diminish the advantage first realized with WSSs. Efforts have been made to minimize the power consumption of WSSs operating in SHM networks, but there have been a limited number of new power supply options, such as energy harvesting, used in full-scale SHM applications. This research develops a solar energy harvesting system to provide power to Imote2 WSS platform and increase the long-term autonomy of wireless smart sensor networks (WSSNs). The approach is validated on a cable stayed bridge in South Korea. Additionally, software enhancements are introduced to allow sensor data to be stored in non-volatile memory, potentially further enhancing the efficacy of WSSNs. This research has resulted in greater overall autonomy of WSSNs

A Survey of multimedia streaming in wireless sensor networks: progress, issues and design challenges

Advancements in Complementary Metal Oxide Semiconductor (CMOS) technology have enabled Wireless Sensor Networks (WSN) to gather, process and transport multimedia (MM) data as well and not just limited to handling ordinary scalar data anymore. This new generation of WSN type is called Wireless Multimedia Sensor Networks (WMSNs). Better and yet relatively cheaper sensors that are able to sense both scalar data and multimedia data with more advanced functionalities such as being able to handle rather intense computations easily have sprung up. In this paper, the applications, architectures, challenges and issues faced in the design of WMSNs are explored. Security and privacy issues, over all requirements, proposed and implemented solutions so far, some of the successful achievements and other related works in the field are also highlighted. Open research areas are pointed out and a few solution suggestions to the still persistent problems are made, which, to the best of my knowledge, so far have not been explored yet

ENERGY-EFFICIENT LIGHTWEIGHT ALGORITHMS FOR EMBEDDED SMART CAMERAS: DESIGN, IMPLEMENTATION AND PERFORMANCE ANALYSIS

An embedded smart camera is a stand-alone unit that not only captures images, but also includes a processor, memory and communication interface. Battery-powered, embedded smart cameras introduce many additional challenges since they have very limited resources, such as energy, processing power and memory. When camera sensors are added to an embedded system, the problem of limited resources becomes even more pronounced. Hence, computer vision algorithms running on these camera boards should be light-weight and efficient. This thesis is about designing and developing computer vision algorithms, which are aware and successfully overcome the limitations of embedded platforms (in terms of power consumption and memory usage). Particularly, we are interested in object detection and tracking methodologies and the impact of them on the performance and battery life of the CITRIC camera (embedded smart camera employed in this research). This thesis aims to prolong the life time of the Embedded Smart platform, without affecting the reliability of the system during surveillance tasks. Therefore, the reader is walked through the whole designing process, from the development and simulation, followed by the implementation and optimization, to the testing and performance analysis. The work presented in this thesis carries out not only software optimization, but also hardware-level operations during the stages of object detection and tracking. The performance of the algorithms introduced in this thesis are comparable to state-of-the-art object detection and tracking methods, such as Mixture of Gaussians, Eigen segmentation, color and coordinate tracking. Unlike the traditional methods, the newly-designed algorithms present notable reduction of the memory requirements, as well as the reduction of memory accesses per pixel. To accomplish the proposed goals, this work attempts to interconnect different levels of the embedded system architecture to make the platform more efficient in terms of energy and resource savings. Thus, the algorithms proposed are optimized at the API, middleware, and hardware levels to access the pixel information of the CMOS sensor directly. Only the required pixels are acquired in order to reduce the unnecessary communications overhead. Experimental results show that when exploiting the architecture capabilities of an embedded platform, 41.24% decrease in energy consumption, and 107.2% increase in battery-life can be accomplished. Compared to traditional object detection and tracking methods, the proposed work provides an additional 8 hours of continuous processing on 4 AA batteries, increasing the lifetime of the camera to 15.5 hours

Experimental evaluation of a video streaming system for Wireless Multimedia Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs) are recently emerging as an extension to traditional scalar wireless sensor networks, with the distinctive feature of supporting the acquisition and delivery of multimedia content such as audio, images and video. In this paper, a complete framework is proposed and developed for streaming video flows in WMSNs. Such framework is designed in a cross-layer fashion with three main building blocks: (i) a hybrid DPCM/DCT encoder; (ii) a congestion control mechanism and (iii) a selective priority automatic request mechanism at the MAC layer. The system has been implemented on the IntelMote2 platform operated by TinyOS and thoroughly evaluated through testbed experiments on multi-hop WMSNs. The source code of the whole system is publicly available to enable reproducible research. © 2011 IEEE