scholarly journals IEEE 802.11-Enabled Wake-Up Radio: Use Cases and Applications

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 66 ◽  
Author(s):  
Elena Lopez-Aguilera ◽  
Ilker Demirkol ◽  
Eduard Garcia-Villegas ◽  
Josep Paradells
Keyword(s):  
Low Power ◽  
Ieee 802.11 ◽  
Energy Savings ◽  
Operation Mode ◽  
Data Communication ◽  
Use Cases ◽  
High Rate ◽  
Handheld Devices ◽  
Battery Lifetime ◽  
Wide Range

IEEE 802.11 is one of the most commonly used radio access technologies, being present in almost all handheld devices with networking capabilities. However, its energy-hungry communication modes are a challenge for the increased battery lifetime of such devices and are an obstacle for its use in battery-constrained devices such as the ones defined by many Internet of Things applications. Wake-up Radio (WuR) systems have appeared as a solution for increasing the energy efficiency of communication technologies by employing a secondary low-power radio interface, which is always in the active state and switches the primary transceiver (used for main data communication) from the energy-saving to the active operation mode. The high market penetration of IEEE 802.11 technology, together with the benefits that WuR systems can bring to this widespread technology, motivates this article’s focus on IEEE 802.11-based WuR solutions. More specifically, we elaborate on the feasibility of such IEEE 802.11-based WuR solutions, and introduce the latest standardization efforts in this IEEE 802.11-based WuR domain, IEEE 802.11ba, which is a forthcoming IEEE 802.11 amendment, discussing its main features and potential use cases. As a use case consisting of green Wi-Fi application, we provide a proof-of-concept smart plug system implemented by a WuR that is activated remotely using IEEE 802.11 devices, evaluate its monetary and energy savings, and compare it with commercially available smart plug solutions. Finally, we discuss novel applications beyond the wake-up functionality that IEEE 802.11-enabled WuR devices can offer using a secondary radio, as well as applications that have not yet been considered by IEEE 802.11ba. As a result, we argue that the IEEE 802.11-based WuR solution will support a wide range of devices and deployments, for both low-rate and low-power communications, as well as high-rate transmissions.

scholarly journals A Multi-Agent Reinforcement Learning Framework for Lithium-ion Battery Scheduling Problems

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1982
Author(s):  
Yu Sui ◽  
Shiming Song
Keyword(s):  
Reinforcement Learning ◽  
Scheduling Algorithm ◽  
Lithium Ion ◽  
Thermal Control ◽  
Use Cases ◽  
Limiting Factor ◽  
Scheduling Problems ◽  
Battery Lifetime ◽  
Learning Framework ◽  
Wide Range

This paper presents a reinforcement learning framework for solving battery scheduling problems in order to extend the lifetime of batteries used in electrical vehicles (EVs), cellular phones, and embedded systems. Battery pack lifetime has often been the limiting factor in many of today’s smart systems, from mobile devices and wireless sensor networks to EVs. Smart charge-discharge scheduling of battery packs is essential to obtain super linear gain of overall system lifetime, due to the recovery effect and nonlinearity in the battery characteristics. Additionally, smart scheduling has also been shown to be beneficial for optimizing the system’s thermal profile and minimizing chances of irreversible battery damage. The recent rapidly-growing community and development infrastructure have added deep reinforcement learning (DRL) to the available tools for designing battery management systems. Through leveraging the representation powers of deep neural networks and the flexibility and versatility of reinforcement learning, DRL offers a powerful solution to both roofline analysis and real-world deployment on complicated use cases. This work presents a DRL-based battery scheduling framework to solve battery scheduling problems, with high flexibility to fit various battery models and application scenarios. Through the discussion of this framework, comparisons have also been made between conventional heuristics-based methods and DRL. The experiments demonstrate that DRL-based scheduling framework achieves battery lifetime comparable to the best weighted-k round-robin (kRR) heuristic scheduling algorithm. In the meantime, the framework offers much greater flexibility in accommodating a wide range of battery models and use cases, including thermal control and imbalanced battery.

scholarly journals SUSTAINABLE LOW POWER SENSOR NETWORKS FOR DISASTER MANAGEMENT

2019 ◽  
Vol 1 (04) ◽  
pp. 247-255
Author(s):  
Khaled Kamel ◽  
Dr. Smys s
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Low Power ◽  
Life Time ◽  
Wireless Sensor ◽  
Wireless Devices ◽  
Battery Lifetime ◽  
Wide Range ◽  
Disaster Situation ◽  
Device Operation

The wireless sensor networks that framed using the tiny sensors that are very efficient in monitoring and conveying the information’s that are sensed are almost engaged in a wide range of applications with the from environment monitoring to health monitoring. The conventional wireless sensor in spite of its sensing capabilities requires lot of power to operate which in return reduces the life time of the sensors. This paves a way for the low power wireless sensor networks that brings downs the energy consumption, by setting limit on the modes of the device operation. The paper uses the low power wireless devices for the management of a manmade disaster situation such as the air pollution created by the vehicle movement in the cities. The system acts as an early warning for metro cities, with heavy vehicle flow, the industrial outcomes and the other causes that emits the poisonous gas polluting the environment. The proposed system with the low power wireless sensor networks is tested over a busy are to evince the system in terms of the battery lifetime of the system and its monitoring capability.

scholarly journals Low Power Cusped Field Thruster Developed for the Space-Borne Gravitational Wave Detection Mission in China

2021 ◽  
Vol 11 (14) ◽  
pp. 6549
Author(s):  
Hui Liu ◽  
Ming Zeng ◽  
Xiang Niu ◽  
Hongyan Huang ◽  
Daren Yu
Keyword(s):  
Low Power ◽  
Gravitational Wave ◽  
Attitude Control ◽  
High Efficiency ◽  
Experimental Investigations ◽  
Attitude Control System ◽  
Gravitational Wave Detection ◽  
Wave Detection ◽  
Wide Range ◽  
Institute Of Technology

The microthruster is the crucial device of the drag-free attitude control system, essential for the space-borne gravitational wave detection mission. The cusped field thruster (also called the High Efficiency Multistage Plasma Thruster) becomes one of the candidate thrusters for the mission due to its low complexity and potential long life over a wide range of thrust. However, the prescribed minimum of thrust and thrust noise are considerable obstacles to downscaling works on cusped field thrusters. This article reviews the development of the low power cusped field thruster at the Harbin Institute of Technology since 2012, including the design of prototypes, experimental investigations and simulation studies. Progress has been made on the downscaling of cusped field thrusters, and a new concept of microwave discharge cusped field thruster has been introduced.

scholarly journals Design of a high-stability heterogeneous clock system for small satellites in LEO

GPS Solutions ◽  
2021 ◽  
Vol 25 (3) ◽  
Author(s):  
Damon Van Buren ◽  
Penina Axelrad ◽  
Scott Palo
Keyword(s):  
Low Power ◽  
High Stability ◽  
Time Frame ◽  
System Stability ◽  
Small Satellite ◽  
Crystal Oscillator ◽  
Small Satellites ◽  
Clock System ◽  
Wide Range

AbstractWe describe our investigation into the performance of low-power heterogeneous timing systems for small satellites, using real GPS observables from the GRACE Follow-On mission. Small satellites have become capable platforms for a wide range of commercial, scientific and defense missions, but they are still unable to meet the needs of missions that require precise timing, on the order of a few nanoseconds. Improved low-power onboard clocks would make small satellites a viable option for even more missions, enabling radio aperture interferometry, improved radio occultation measurements, high altitude GPS navigation, and GPS augmentation missions, among others. One approach for providing improved small satellite timekeeping is to combine a heterogeneous group of oscillators, each of which provides the best stability over a different time frame. A hardware architecture that uses a single-crystal oscillator, one or more Chip Scale Atomic Clocks (CSACs) and the reference time from a GPS receiver is presented. The clocks each contribute stability over a subset of timeframes, resulting in excellent overall system stability for timeframes ranging from less than a second to several days. A Kalman filter is used to estimate the long-term errors of the CSACs based on the CSAC-GPS time difference, and the improved CSAC time is used to discipline the crystal oscillator, which provides the high-stability reference clock for the small satellite. Simulations using GRACE-FO observations show time error standard deviations for the system range from 2.3 ns down to 1.3 ns for the clock system, depending on how many CSACs are used. The results provide insight into the timing performance which could be achieved on small LEO spacecraft by a low power timing system.

scholarly journals Prototype Design and Experimental Evaluation of Autonomous Collaborative Communication System for Emerging Maritime Use Cases

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3871
Author(s):  
Jiri Pokorny ◽  
Khanh Ma ◽  
Salwa Saafi ◽  
Jakub Frolka ◽  
Jose Villa ◽  
...  
Keyword(s):  
Communication System ◽  
Autonomous Vehicles ◽  
High Speed ◽  
High Capacity ◽  
Workplace Safety ◽  
Unmanned Vehicles ◽  
Use Cases ◽  
Automated Systems ◽  
Collaborative Communication ◽  
Wide Range

Automated systems have been seamlessly integrated into several industries as part of their industrial automation processes. Employing automated systems, such as autonomous vehicles, allows industries to increase productivity, benefit from a wide range of technologies and capabilities, and improve workplace safety. So far, most of the existing systems consider utilizing one type of autonomous vehicle. In this work, we propose a collaboration of different types of unmanned vehicles in maritime offshore scenarios. Providing high capacity, extended coverage, and better quality of services, autonomous collaborative systems can enable emerging maritime use cases, such as remote monitoring and navigation assistance. Motivated by these potential benefits, we propose the deployment of an Unmanned Surface Vehicle (USV) and an Unmanned Aerial Vehicle (UAV) in an autonomous collaborative communication system. Specifically, we design high-speed, directional communication links between a terrestrial control station and the two unmanned vehicles. Using measurement and simulation results, we evaluate the performance of the designed links in different communication scenarios and we show the benefits of employing multiple autonomous vehicles in the proposed communication system.

Sustaining Research-Based Practices in Reading

1999 ◽  
Vol 20 (5) ◽  
pp. 263-287 ◽  
Author(s):  
Janette K. Klingner ◽  
Sharon Vaughn ◽  
Marie Tejero Hughes ◽  
Maria Elena Arguelles
Keyword(s):  
Instructional Practices ◽  
High Rate ◽  
Strategic Reading ◽  
School Year ◽  
Wide Range ◽  
Sustained Use ◽  
Development Experience ◽  
Collaborative Strategic Reading ◽  
Research Based Practices ◽  
Over Time

This study examined the extent to which the reading instructional practices learned by a cohort of teachers who participated in an intensive, yearlong professional development experience during the 1994-1995 school year have been sustained and modified over time. Teachers learned three multileveled practices—partner reading, collaborative strategic reading, and making words—that promote gains in reading for students from a wide range of achievement levels. Teachers were observed and interviewed 3 years later to determine the extent to which they continued to implement the practices, the ways in which they modified them, and factors that influenced their sustained use of the practices. With the exception of one teacher, all the teachers sustained one or more of the three practices at a high rate.

INTRA-APPLICATION ENERGY REDUCTION FOR MICROPROCESSOR LOW-POWER DESIGN

2009 ◽  
Vol 18 (01) ◽  
pp. 181-198 ◽  
Author(s):  
XIAO XIN XIA ◽  
TENG TIOW TAY
Keyword(s):  
Energy Consumption ◽  
Low Power ◽  
Sampling Method ◽  
Energy Savings ◽  
Low Power Design ◽  
Energy Reduction ◽  
Software Optimization ◽  
Application Identification ◽  
Instructions Per Cycle ◽  
Important Design

Energy consumption is one of the most important design constraints for modern microprocessors, and designers have proposed many energy-saving techniques. Looking beyond the traditional hardware low-power designs, software optimization is becoming a significant strategy for the microprocessor to lower its energy consumption. This paper describes an intra-application identification and reconfiguration mechanism for microprocessor energy reduction. Our mechanism employs a statistical sampling method during training runs to identify code sections among application that have appropriate IPC (Instructions per Cycle) values and could make contributions to program runtime energy reduction, and then profiles them to dynamically scale the voltage and frequency of the microprocessor at appropriate points during execution. In our simulation, our approach achieves energy savings by an average of 39% with minor performance degradation, compared to a processor running at a fixed voltage and speed.

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