The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The DARPA Near Zero Power RF and Sensor Operations (N-ZERO) program seeks to overcome the power limitations of persistent sensing by developing wireless, event-driven sensing capabilities that allow physical, electromagnetic and other sensors to remain dormant — effectively asleep yet aware — until an event of interest awakens them. State-of-the-art sensors use active electronics to monitor the environment...
A multi layered approach is proposed to provide energy and spectrum efficient designs of Cognitive Radio Based Wireless Sensor Networks (CR-WSN) at the smart grid utility. CR-WSNs consume higher power and involve complex design procedure. Since smart grid wireless applications being used currently are meant to save power, we model the CR-WSN based home area networks by keeping minimum power consumption...
This paper proposes a compact DC-DC buck converter with low output power and very low quiescent current dissipation for use in an ultra-capacitor based wireless sensor networks (WSNs) nodes. This converter is controlled by a self-oscillation topology in order to achieve less silicon area and lower quiescent dissipation than the conventional designs. The work is implemented in the standard 0.35um CMOS...
Recently, we start to see Wireless Sensor Network (WSN) solutions on the market, which are mostly based on 802.15.4 standard or Zigbee equivalent. Most of these solutions integrate an 8-bit to 32-bit low power microcontroller, one or multiple sensors and run on batteries. However, business is not yet there massively. Does it mean we need additional innovation to boost market adoption? The aim of this...
This work addresses system aspects of implantable medical sensor devices. Different concepts for power supply and communication are compared and discussed. State of the art systems mainly rely on one common frequency for both wireless data and energy transmission. This publication highlights the specific pros and cons of different frequency ranges. The proposed Split Frequencies Concept (SFC) uses...
Bell's Law predicts continual reductions in the size of computing systems. We investigate the status of the next paradigm shift that will usher in ubiquitous computing - sub-mm3 sensor nodes. However, this form factor remains beyond the capabilities of modern integrated circuit design techniques due to battery size. This paper describes new ultra-low power circuit techniques applied to digital processors,...
Based on a wireless sensor network with fixed network structure applied to grain storage monitoring system, the thesis designs an effective awakening strategy in the case of the non-synchronous network nodes. It enhances one-time-wake-up-rate of nodes with low power consumption, which overcomes the disadvantage of the universal awakening strategy. Experiment results show that one-time-wake-up-rate...
In the recent years, Wireless Body Sensor Networks (WBSNs) attracted much attention in the research community. The key to success for WBSNs is the utilization of highly efficient transceivers and the application of intelligent policies to handle the limited (energy) resources. Simulations are a frequently used tool to evaluate different policies and analyze the performance of wireless networks in...
This paper presents a compact wireless sensor node for 3D motion sensing, which can be used in wearable computing research. The sensor node is based on a commercial orientation sensor module and a wireless communication module. To extend the lifetime of this motion sensor node in many wearable computing applications, a power management unit is designed and implemented, which consists of a micro controller...
When deploying a sensor network into a harsh environment the need for high levels of fault tolerance and maximising the usage of available resources become extremely important. This has been achieved by implementing a highly fault tolerant system based on our Gumsense boards. These combine an ARM-based Linux system with an MSP430 for sensing and power-control. It also allows for dynamic schedule modifications...
This paper describes critical circuit building blocks for emerging sensing applications, particularly those where volume, and therefore power consumption constraints are orders of magnitude below current state of the art. Developments in ultra-low power microprocessors and memories are described, along with sub-nW timekeeping circuits, pW voltage references, and efficient DC-DC voltage conversion...
Recent advances in integrated circuit technology scaling, analog circuitry, and wireless communication have created the possibility for complex low noise, low power wireless instrumentation to be deployed in previously impossible scenarios, particularly in the realm of wireless sensing for biology research and biomedical applications. The generation of portable, autonomous devices made possible by...
This paper describes an ultra-low-power RF transceiver implemented as part of a system-on-chip. The transceiver operates in the 868/915 MHz frequency band using binary FSK modulation at a 45 kbit/s data rate. It achieves -89 dBm receiver sensitivity and -6 dBm transmitter output power while consuming 1.6 mA and 1.8 mA, respectively, from a 1.2 to 1.5 V supply. It is fabricated in 0.13 mum CMOS occupying...
This paper presents RF microsystems constituted by low-power devices for use in wireless sensors networks. As it is expected, the major emphasis is given to the fabrication of RF transceivers for integration in these microsystems. Features like low-power and low-voltage operations are discussed, at the same time are presented RF transceivers for the frequencies of 433 MHz, 2.4 GHz and 5.7 GHz, in...
While the gravimetric energy density is continuously growing up by the battery manufacturers, the embedded systems designers have to consider a lot of issues to fulfill the power consumption requirements. Wireless sensor nodes (WSN) are typically equipped with a battery, sensors and communication devices. The use of WSN and their design benefits from the development of the communication protocols...
In energy constrained wireless sensor networks, it is very important to conserve energy and prolong active network lifetime while ensuring proper operations of the network. To extend the lifetime of a sensor network, one common approach is to dynamically schedule sensors?? work/sleep cycles (or duty cycles). In our work we have considered cluster based heterogeneous wireless sensor network, by deploying...
A wireless sensor network (WSN) consists of a large number of sensor nodes which are deployed over an area to perform local computations based on information gathered from the surroundings. Each node in the network is equipped with a battery, but it is almost very difficult to change or recharge batteries; hence, maximizing the lifetime of the network through minimizing the energy is an important...
More than a decade of research in the field of thermal, motion, and vibrational energy scavenging has yielded increasing power output and smaller embodiments. Power management circuits for rectification and DC-DC conversion are becoming able to efficiently convert the power from these energy scavengers. This paper summarizes recent energy scavenging results and their power management circuits.
Wireless sensor node (WSN) lifetime is correlated with the battery current usage profile. State of the art in wireless sensor nodes current consumption shows that available models have not been extensively tested and experimentally validated. This work aims to seek answers to the following questions: is it accurate the node lifetime prediction obtained with available models? Moreover, is the radio...
Body sensor network (BSN) is a wireless network of implantable and/or wearable smart sensors. They can be deployed in medical applications, such as patients monitoring inside or outside hospital environment, as well as in high performance professional sports and other non human related applications. The size of a sensor node and its power consumption are major challenges in the design of implantable...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.