Passive Wi-Fi

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Passive Wi-Fi is a refinement of Wi-Fi technology that uses passive reflection to reduce energy consumption. [1]

Contents

Wi-Fi energy use

Wi-Fi use can account for up to 60 percent of a smartphone’s energy consumption. When not connected to a network, Wi-Fi consumes energy because the device constantly searches for a signal. [1]

Backscattering

The technique communicates via backscattering, reflecting incoming radio waves sent from a separate device. The technique is similar to contactless RFID chip cards although unlike such cards, the new technique does not require a special device to read the signal. [1]

The project effectively decoupled the analog and the digital radio signals. Power-intensive functions – like producing a signal at a specific frequency are assigned to a single device in the network that is plugged into the grid. Smartphones modify and reflect this signal to communicate to the router. Prototype passive devices transferred data as far as 100 feet through walls at 11 megabits per second. [1] The system used tens of microwatts of power, [2] 10−4 less energy than conventional Wi-fi devices, and one thousandth the energy of Bluetooth LE and Zigbee communications standards. [1]

Applications

Applications include smart home devices such as smoke detectors, temperature sensors and security cameras that will no longer require a power source. [3]

Related Research Articles

Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limited to 2.5 milliwatts, giving it a very short range of up to 10 metres (33 ft). It employs UHF radio waves in the ISM bands, from 2.402 GHz to 2.48 GHz. It is mainly used as an alternative to wire connections, to exchange files between nearby portable devices and connect cell phones and music players with wireless headphones.

<span class="mw-page-title-main">Wireless network</span> Network not fully connected by cables

A wireless network is a computer network that uses wireless data connections between network nodes.

<span class="mw-page-title-main">Wi-Fi</span> Wireless local area network

Wi-Fi is a family of wireless network protocols based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio waves. These are the most widely used computer networks in the world, used globally in home and small office networks to link desktop and laptop computers, tablet computers, smartphones, smart TVs, printers, and smart speakers together and to a wireless router to connect them to the Internet, and in wireless access points in public places like coffee shops, hotels, libraries, and airports to provide visitors with Internet connectivity for their mobile devices.

<span class="mw-page-title-main">Wireless</span> Transfer of information or power that does not require the use of physical wires

Wireless communication is the transfer of information (telecommunication) between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most common wireless technologies use radio waves. With radio waves, intended distances can be short, such as a few meters for Bluetooth or as far as millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of applications of radio wireless technology include GPS units, garage door openers, wireless computer mouse, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones. Somewhat less common methods of achieving wireless communications involve other electromagnetic phenomena, such as light and magnetic or electric fields, or the use of sound.

<span class="mw-page-title-main">Wireless access point</span> Device that allows wireless devices to connect to a wired network

In computer networking, a wireless access point (WAP), or more generally just access point (AP), is a networking hardware device that allows other Wi-Fi devices to connect to a wired network. As a standalone device, the AP may have a wired connection to a router, but, in a wireless router, it can also be an integral component of the router itself. An AP is differentiated from a hotspot which is a physical location where Wi-Fi access is available.

<span class="mw-page-title-main">Near-field communication</span> Radio communication established between devices by bringing them into proximity

Near-field communication (NFC) is a set of communication protocols that enables communication between two electronic devices over a distance of 4 cm (1.57 in) or less. NFC offers a low-speed connection through a simple setup that can be used to bootstrap more capable wireless connections. Like other "proximity card" technologies, NFC is based on inductive coupling between two so-called antennas present on NFC-enabled devices—for example a smartphone and a printer—communicating in one or both directions, using a frequency of 13.56 MHz in the globally available unlicensed radio frequency ISM band using the ISO/IEC 18000-3 air interface standard at data rates ranging from 106 to 424 kbit/s.

<span class="mw-page-title-main">Automatic meter reading</span> Transmitting consumption data from a utility meter to the utility provider

Automatic meter reading (AMR) is the technology of automatically collecting consumption, diagnostic, and status data from water meter or energy metering devices and transferring that data to a central database for billing, troubleshooting, and analyzing. This technology mainly saves utility providers the expense of periodic trips to each physical location to read a meter. Another advantage is that billing can be based on near real-time consumption rather than on estimates based on past or predicted consumption. This timely information coupled with analysis can help both utility providers and customers better control the use and production of electric energy, gas usage, or water consumption.

<span class="mw-page-title-main">Nordic Semiconductor</span>


Nordic Semiconductor is a Norwegian fabless technology company specializing in designing ultra-low-power wireless communication semiconductors and supporting software for engineers developing and manufacturing IoT products.

<span class="mw-page-title-main">Home network</span> Type of computer network

A home network or home area network (HAN) is a type of computer network that facilitates communication among devices within the close vicinity of a home. Devices capable of participating in this network, for example, smart devices such as network printers and handheld mobile computers, often gain enhanced emergent capabilities through their ability to interact. These additional capabilities can be used to increase the quality of life inside the home in a variety of ways, such as automation of repetitive tasks, increased personal productivity, enhanced home security, and easier access to entertainment.

<span class="mw-page-title-main">ANT (network)</span>

ANT is a proprietary multicast wireless sensor network technology designed and marketed by ANT Wireless. It provides personal area networks (PANs), primarily for activity trackers. ANT was introduced by Dynastream Innovations in 2003, followed by the low-power standard ANT+ in 2004, before Dynastream was bought by Garmin in 2006.

<span class="mw-page-title-main">Indoor positioning system</span>

An indoor positioning system (IPS) is a network of devices used to locate people or objects where GPS and other satellite technologies lack precision or fail entirely, such as inside multistory buildings, airports, alleys, parking garages, and underground locations.

<span class="mw-page-title-main">Airplane mode</span> Device setting to suspend radio-frequency signal transmission

Airplane mode is a setting available on smartphones and other portable devices. When activated, this mode suspends the device's radio-frequency (RF) signal transmission technologies, effectively disabling all analog voice, and digital data services, when implemented correctly by the electronic device software author. When cellular phones became prevalent in the 1990s, some communication headsets of aircraft pilots would register an audible click when a cellular phone on the aircraft would transceive a signal. This clicking on the headsets became overwhelmingly distracting to airframe control, with more and more phone calls from airplane passengers as time went on. This led to the banning of electronic device use on airplanes and ushered in the era of airplane mode. This airplane travel condition diverged cellular network device development from hardware to software and the smart phone was created.

There are several uses of the 2.4 GHz band. Interference may occur between devices operating at 2.4 GHz. This article details the different users of the 2.4 GHz band, how they cause interference to other users and how they are prone to interference from other users.

Bluetooth Low Energy is a wireless personal area network technology designed and marketed by the Bluetooth Special Interest Group aimed at novel applications in the healthcare, fitness, beacons, security, and home entertainment industries. It is independent of classic Bluetooth and has no compatibility, but Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) and LE can coexist. The original specification was developed by Nokia in 2006 under the name Wibree, which was integrated into Bluetooth 4.0 in December 2009 as Bluetooth Low Energy.

Asset tracking refers to the method of tracking physical assets, either by scanning barcode labels attached to the assets or by using tags using GPS, BLE, LoRa, or RFID which broadcast their location. These technologies can also be used for indoor tracking of persons wearing a tag.

<span class="mw-page-title-main">Silicon Labs</span> Global technology company

Silicon Laboratories, Inc. is a fabless global technology company that designs and manufactures semiconductors, other silicon devices and software, which it sells to electronics design engineers and manufacturers in Internet of Things (IoT) infrastructure worldwide.

<span class="mw-page-title-main">RF module</span>

An RF module is a (usually) small electronic device used to transmit and/or receive radio signals between two devices. In an embedded system it is often desirable to communicate with another device wirelessly. This wireless communication may be accomplished through optical communication or through radio-frequency (RF) communication. For many applications, the medium of choice is RF since it does not require line of sight. RF communications incorporate a transmitter and a receiver. They are of various types and ranges. Some can transmit up to 500 feet. RF modules are typically fabricated using RF CMOS technology.

Ambient backscatter, also known as RF backscatter, uses existing radio frequency signals, such as radio, television and mobile telephony, to transmit data without a battery or power grid connection. Each such device uses an antenna to pick up an existing signal and convert it into tens to hundreds of microwatts of electricity. It uses that power to modify and reflect the signal with encoded data. Antennas on other devices, in turn, detect that signal and can respond accordingly.

Smartphone ad hoc networks are wireless ad hoc networks that use smartphones. Once embedded with ad hoc networking technology, a group of smartphones in close proximity can together create an ad hoc network. Smart phone ad hoc networks use the existing hardware in commercially available smartphones to create peer-to-peer networks without relying on cellular carrier networks, wireless access points, or traditional network infrastructure. Wi-Fi SPANs use the mechanism behind Wi-Fi ad-hoc mode, which allows phones to talk directly among each other, through a transparent neighbor and route discovery mechanism. SPANs differ from traditional hub and spoke networks, such as Wi-Fi Direct, in that they support multi-hop routing and relays and there is no notion of a group leader, so peers can join and leave at will without destroying the network.

Bluetooth beacons are hardware transmitters — a class of Bluetooth Low Energy (LE) devices that broadcast their identifier to nearby portable electronic devices. The technology enables smartphones, tablets and other devices to perform actions when in close proximity to a beacon.

References

  1. 1 2 3 4 5 Puiu, Tibi (2016-02-25). "Passive Wi-Fi uses 10,000 less energy and can power devices". ZME Science. Retrieved 2016-02-25.
  2. Anderson, John (2016-02-24). "Passive Wi-Fi more energy efficient than conventional Wi-Fi, ZigBee and Bluetooth LE". www.gizmag.com. Retrieved 2016-02-25.
  3. "Power from the Air". MIT Technology Review. 2016-02-25. Retrieved 2016-02-25.[ dead link ]