Wake-up Radio Systems Research Articles

Bandwidth-Based Wake-Up Radio Solution through IEEE 802.11 Technology.

IEEE 802.11 consists of one of the most used wireless access technologies, which can be found in almost all consumer electronics devices available. Recently, Wake-up Radio (WuR) systems have emerged as a solution for energy-efficient communications. WuR mechanisms rely on using a secondary low-power radio interface that is always in the active operation mode and is in charge of switching the primary interface, used for main data exchange, from the power-saving state to the active mode. In this paper, we present a WuR solution based on IEEE 802.11 technology employing transmissions of legacy frames by an IEEE 802.11 standard-compliant transmitter during a Transmission Opportunity (TXOP) period. Unlike other proposals available in the literature, the WuR system presented in this paper exploits the PHY characteristics of modern IEEE 802.11 radios, where different signal bandwidths can be used on a per-packet basis. The proposal is validated through the Matlab software tool, and extensive simulation results are presented in a wide variety of scenario configurations. Moreover, insights are provided on the feasibility of the WuR proposal for its implementation in real hardware. Our approach allows the transmission of complex Wake-up Radio signals (i.e., including address field and other binary data) from legacy Wi-Fi devices (from IEEE 802.11n-2009 on), avoiding hardware or even firmware modifications intended to alter standard MAC/PHY behavior, and achieving a bit rate of up to 33 kbps.

An Energy-Efficient Duty-Cycled Wake-Up Radio Protocol for Avoiding Eavesdrop in Wireless Sensor Networks

Wake-Up Radio System (WuR)) is frequently regarded due to the fact the best opportunity to supplant MAC (Media get right of entry to manipulate) conventions with the commonplace cyclic cycle of chipping away at wireless sensor networks (WSN). The Double Radio Protocol (DoRa) is some other MAC conference for the WuR in-band framework with addressability. No matter the reality that the DoRa conference improves the electricity skills of the WSN, irrespective of everything it testimonies a assembly difficulty whilst the WuR framework is wanted all the time. The WuR squanders a number of vitality while it hears arousing request from superb hubs, but it isn't predicted or described in fantastic employments. On this paintings, a cyclic flexible DoRa (DC-DoRa) cycle is proposed to take care of the difficulty of listening to. The principle idea of the interest is to empower the WuR embody earlier than guidance the hub and cripple WuR after the hub has sent the statistics. Nitty gritty recreations are completed beneath OMNeT ++ utilising actual information parameters to expose the huge energy reserve price range performed with the useful resource of the two conventions and the digital disposal of over-tuning in with DCDoRa. Reality be cautioned, everyday electricity utilization is a couple of instances lower with the DoRa convention contrasted with general MAC conventions. Notwithstanding the reality that the communicate can constitute as much as 93% of WuR's capacity usage with the DoRa convention, it's miles dwindled to truely 1% with the DC-DoRa convention.

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

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.

An Alternative to IEEE 802.11ba: Wake-Up Radio With Legacy IEEE 802.11 Transmitters

Current standardization process for Wake-up Radio (WuR) within the IEEE 802.11 Working Group, known as the IEEE 802.11ba, has brought interest to the IEEE 802.11-related technologies for the implementation of WuR systems. This paper proposes a new WuR system, where the Wake-up Transmitter (WuTx) is based on the legacy IEEE 802.11 Orthogonal Frequency Division Modulation (OFDM) Physical Layer (PHY) specification. Using the IEEE 802.11, OFDM PHY makes it possible for an IEEE 802.11a/g/n/ac transmitter to operate as WuTx for this WuR system. The WuTx generates a Wake-up Signal (WuS) coded with an amplitude-based digital modulation, achieving a bit rate of 250 kbps. This modulation, which we call Peak-Flat modulation, can be received using low-power receivers. A simulated proof of concept of the WuTx based on the IEEE 802.11g is presented and evaluated using MATLAB WLAN Toolbox. A method to generate the Peak-Flat modulated WuS from an IEEE 802.11a/g standard-compliant transmitter, using only software-level access, is explained. In addition, two possible low-power Wake-up Receiver (WuRx) architectures capable of decoding the presented modulation are proposed. The design of those receivers is generic enough to be used as a reference to compare the performance of the Peak-Flat Modulation with the other state-of-the-art approaches. The evaluation results conclude that the Peak-Flat modulation has similar performance compared to the other IEEE 802.11 WuR solutions on the reference receivers. Moreover, this solution provides a notorious advantage: legacy OFDM-based IEEE 802.11 transmitters can generate the Peak-Flat modulated WuS.

A Simple Guide to Low-Power Wireless Technologies: Balancing the Tradeoffs for the Internet of Things and Medical Applications

In recent years, low-power radio has expanded to encompass a broad range of wireless technologies, architectures, standards, and applications. The Internet of Things (IoT) and implantable electronics have multiplied the use cases for standard commercial architectures, such as ZigBee, Bluetooth, and near-field communication (NFC), while also opening the door for more exploratory radio architectures like duty-cycled wake-up radio systems, ultranarrow-band radios, and ultrawideband (UWB) impulse radios (IRs), to name just a few.

Impact of in-band interference on a wake-up radio system in wireless sensor networks

The energy efficiency of Wireless Sensor Networks (WSNs) is considerably improved with Wake-up Radio (WuR) systems. However, their resilience to interference is often neglected in the literature. This might be an issue due to the proliferation of wireless devices and the growing field of internet of things. In this paper, we evaluate the impact of in-band interference from wireless devices on a WuR system. The approach proves that WuR systems are still performing well when coexisting with external wireless networks, even if the energy-efficiency is slightly reduced.

Ultra Low Power Wake-Up Radios: A Hardware and Networking Survey

In wireless environments, transmission and reception costs dominate system power consumption, motivating research effort on new technologies capable of reducing the footprint of the radio, paving the way for the Internet of Things. The most important challenge is to reduce power consumption when receivers are idle, the so called idle-listening cost. One approach proposes switching off the main receiver, then introduces new wake-up circuitry capable of detecting an incoming transmission, optionally discriminating the packet destination using addressing, then switching on the main radio only when required. This wake-up receiver technology represents the ultimate frontier in low power radio communication. In this paper, we present a comprehensive literature review of the research progress in wake-up radio (WuR) hardware and relevant networking software. First, we present an overview of the WuR system architecture, including challenges to hardware design and a comparison of solutions presented throughout the last decade. Next, we present various medium access control and routing protocols as well as diverse ways to exploit WuRs, both as an extension of pre-existing systems and as a new concept to manage low-power networking.

On-Demand Sensor Node Wake-Up Using Solar Panels and Visible Light Communication.

To significantly reduce, or eliminate completely, the energy waste caused by the standby (idle) mode of wireless sensor nodes, we propose a novel on-demand wake-up system, which allows the nodes to be put into sleep mode unless their activation is truly necessary. Although there have been many studies proposing RF-based wake-up radio systems, in this work, we develop the first visible light communication (VLC)-based wake-up system. The developed system can extend the existing VLC systems and can be exploited to derive new application areas such as VLC tags. The system uses an off-the-shell indoor solar panel as receptor device of the wake-up signal as well as for energy harvesting purposes, through which it is able to harvest enough energy for its autonomous work. The design, implementation details and the experimental evaluation results are presented, which include flickering characterization and wake-up range evaluations. The results show that the developed system achieve reasonable wake-up distances for indoor environments, mainly where the use of VLC systems are considered.

An Energy-Efficient Duty-Cycled Wake-Up Radio Protocol for Avoiding Overhearing in Wireless Sensor Networks

Wake-up radio (WuR) system is often presented as the best candidate for replacing traditional duty cycled Medium Access Control (MAC) protocols in Wireless Sensor Networks (WSNs). The Double Radio (DoRa) protocol is a new MAC protocol for in-band WuR system with addressing capabilities. While the DoRa protocol improves the WSNs energy efficiency, it still suffers from an overhearing problem when the WuR system is very often requested. The WuR wastes a noticeable amount of energy when overhearing to wake-up demand intended to other nodes, but it is neither measured nor solved in other works. In this paper, an adaptive duty-cycled DoRa (DC-DoRa) is then proposed to solve the overhearing problem. The primary concept of the work is to enable the WuR functionality before the node is addressed and to disable the WuR after the node sent data. Extensive simulations under OMNeT++ using real input parameters are then performed to show the significant energy-savings through the two protocols and the nearly suppression of overhearing with DC-DoRa. In fact, the mean power consumption is three-order below using the DoRa protocol compared to traditional MAC protocols. While overhearing can represent up to 93% of the WuR energy consumption with the DoRa protocol, it is reduced to only 1% with the DC-DoRa protocol.

IEEE 802.11‐enabled wake‐up radio system: design and performance evaluation

Today, the vast majority of personal communication devices, such as laptops, smartphones, and logically wireless fidelity (Wi-Fi) access points feature IEEE 802.11 chipsets. In turn, wake-up radio (WuR) systems are used to reduce the significant energy waste that wireless devices cause during their idle communication mode. A novel WuR system is introduced that enables any IEEE 802.11-enabled device to be used as a WuR transmitter without requiring any hardware modification. The corresponding developed WuR receiver achieves a remarkably low power consumption of 10.8 μW and operates in the Wi-Fi 2.4 GHz band. By means of thorough physical tests, it is shown that the proposed IEEE 802.11-based WuR system enables important energy savings.

Performance Evaluation and Comparative Analysis of SubCarrier Modulation Wake-up Radio Systems for Energy-Efficient Wireless Sensor Networks

Energy-efficient communication is one of the main concerns of wireless sensor networks nowadays. A commonly employed approach for achieving energy efficiency has been the use of duty-cycled operation of the radio, where the node's transceiver is turned off and on regularly, listening to the radio channel for possible incoming communication during its on-state. Nonetheless, such a paradigm performs poorly for scenarios of low or bursty traffic because of unnecessary activations of the radio transceiver. As an alternative technology, Wake-up Radio (WuR) systems present a promising energy-efficient network operation, where target devices are only activated in an on-demand fashion by means of a special radio signal and a WuR receiver. In this paper, we analyze a novel wake-up radio approach that integrates both data communication and wake-up functionalities into one platform, providing a reconfigurable radio operation. Through physical experiments, we characterize the delay, current consumption and overall operational range performance of this approach under different transmit power levels. We also present an actual single-hop WuR application scenario, as well as demonstrate the first true multi-hop capabilities of a WuR platform and simulate its performance in a multi-hop scenario. Finally, by thorough qualitative comparisons to the most relevant WuR proposals in the literature, we state that the proposed WuR system stands out as a strong candidate for any application requiring energy-efficient wireless sensor node communications.

Design, development, and performance evaluation of a low-cost, low-power wake-up radio system for wireless sensor networks

Energy-efficient operation is a challenge for wireless sensor networks (WSNs). A common method employed for this purpose is duty-cycled operation, which extends battery lifetime yet incurs several types of energy wastes and challenges. A promising alternative to duty-cycled operation is the use of wake-up radio (WuR), where the main microcontroller unit (MCU) and transceiver, that is, the two most energy-consuming elements, are kept in energy-saving mode until a special signal from another node is received by an attached, secondary, ultra-low power receiver. Next, this so-called wake-up receiver generates an interrupt to activate the receiver node's MCU and, consequently, the main radio. This article presents a complete wake-up radio design that targets simplicity in design for the monetary cost and flexibility concerns, along with a good operation range and very low power consumption. Both the transmitter (WuTx) and the receiver (WuRx) designs are presented with the accompanying physical experiments for several design alternatives. Detailed analysis of the end system is provided in terms of both operational distance (more than 10 m) and current consumption (less than 1 μA). As a reference, a commercial WuR system is analyzed and compared to the presented system by expressing the trade-offs and advantages of both systems.