Ultra-wideband (UWB, ultra wideband, ultra-wide band and ultraband) is a
radio technology
Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to ...
that can use a very low energy level for short-range, high-bandwidth communications over a large portion of the radio spectrum. UWB has traditional applications in non-cooperative
radar imaging
Radar is a system that uses radio waves to determine the distance (''ranging''), direction (geometry), direction (azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to det ...
. Most recent applications target sensor data collection, precise locating, and tracking.
UWB support started to appear in high-end
smartphones
A smartphone is a mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as mult ...
in 2019.
Characteristics
Ultra-wideband is a technology for transmitting information across a wide bandwidth (>500
MHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base u ...
). This allows for the transmission of a large amount of signal energy without interfering with conventional
narrowband
Narrowband signals are signals that occupy a narrow range of frequencies or that have a small fractional bandwidth. In the audio spectrum, ''narrowband sounds'' are sounds that occupy a narrow range of frequencies. In telephony, narrowband is ...
and
carrier wave
In telecommunications, a carrier wave, carrier signal, or just carrier, is a periodic waveform (usually sinusoidal) that conveys information through a process called ''modulation''. One or more of the wave's properties, such as amplitude or freq ...
transmission in the same frequency band. Regulatory limits in many countries allow for this efficient use of radio bandwidth, and enable high-data-rate
personal area network
A personal area network (PAN) is a computer network for interconnecting electronic devices within an individual person's workspace. A PAN provides data transmission among devices such as computers, smartphones, tablets and personal digital assi ...
(PAN) wireless connectivity, longer-range low-data-rate applications, and the transparent co-existence of radar and imaging systems with existing communications systems.
Ultra-wideband was formerly known as ''pulse radio'', but the FCC and the
International Telecommunication Union
The International Telecommunication Union (ITU)In the other common languages of the ITU:
*
* is a list of specialized agencies of the United Nations, specialized agency of the United Nations responsible for many matters related to information ...
Radiocommunication Sector (
ITU-R
The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications.
Its role is to manage the international radio-frequenc ...
) currently define UWB as an antenna transmission for which emitted signal bandwidth exceeds the lesser of 500 MHz or 20% of the arithmetic center frequency. Thus, pulse-based systems—where each transmitted pulse occupies the UWB bandwidth (or an aggregate of at least 500 MHz of a narrow-band carrier; for example,
orthogonal frequency-division multiplexing
In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission used in digital modulation for encoding digital (binary) data on multiple carrier frequencies. OFDM has developed into a popular scheme for ...
(OFDM))—can access the UWB spectrum under the rules.
Theory
A significant difference between conventional radio transmissions and UWB is that conventional systems transmit information by varying the power level, frequency, or phase (or a combination of these) of a sinusoidal wave. UWB transmissions transmit information by generating radio energy at specific time intervals and occupying a large bandwidth, thus enabling
pulse-position or time modulation. The information can also be modulated on UWB signals (pulses) by encoding the polarity of the pulse, its amplitude and/or by using orthogonal pulses. UWB pulses can be sent sporadically at relatively low pulse rates to support time or position modulation, but can also be sent at rates up to the inverse of the UWB pulse bandwidth. Pulse-UWB systems have been demonstrated at channel pulse rates in excess of 1.3 billion pulses per second using a continuous stream of UWB pulses (Continuous Pulse UWB or
C-UWB), while supporting forward error-correction encoded data rates in excess of 675 Mbit/s.
A UWB radio system can be used to determine the "time of flight" of the transmission at various frequencies. This helps overcome
multipath propagation
In radio communication, multipath is the propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths. Causes of multipath include atmospheric ducting, ionospheric reflection and refraction, and ...
, since some of the frequencies have a
line-of-sight trajectory, while other indirect paths have longer delays. With a cooperative symmetric two-way metering technique, distances can be measured to high resolution and accuracy.
Applications
Real-time location
Ultra-wideband (UWB) technology is utilised for real-time locationing due to its precision and reliability. It plays a role in various industries such as logistics, healthcare, manufacturing, and transportation. UWB's centimeter-level accuracy is valuable in applications in which using traditional methods may be unsuitable, such as in indoor environments, where GPS precision may be hindered. Its low power consumption ensures minimal interference and allows for coexistence with existing infrastructure. UWB performs well in challenging environments with its immunity to multipath interference, providing consistent and accurate positioning. In logistics, UWB increases inventory tracking efficiency, reducing losses and optimizing operations. Healthcare makes use of UWB in asset tracking, patient flow optimization, and in improving care coordination. In manufacturing, UWB is used for streamlining inventory management and enhancing production efficiency through accurate tracking of materials and tools. UWB supports route planning, fleet management, and vehicle security in transportation systems.
UWB uses multiple techniques for location detection:
* Time of flight (ToF)
* Time difference of arrival (TDoA)
* Two-way ranging (TWR)
Mobile devices with UWB capability
Apple launched the first three phones with ultra-wideband capabilities in September 2019, namely, the
iPhone 11,
iPhone 11 Pro, and iPhone 11 Pro Max. Apple also launched Series 6 of Apple Watch in September 2020, which features UWB,
and their
AirTags featuring this technology were revealed at a press event on April 20, 2021.
The Samsung Galaxy Note 20 Ultra, Galaxy S21+, and Galaxy S21 Ultra also began supporting UWB, along with the Samsung Galaxy SmartTag+.
The
Xiaomi MIX 4 released in August 2021 supports UWB, and offers the capability of connecting to select
AIoT devices.
The
FiRa Consortium was founded in August 2019 to develop interoperable UWB ecosystems including mobile phones. Samsung, Xiaomi, and Oppo are currently members of the FiRa Consortium. In November 2020,
Android Open Source Project
Android is an operating system based on a modified version of the Linux kernel and other open-source software, designed primarily for touchscreen-based mobile devices such as smartphones and tablets. Android has historically been developed by ...
received first patches related to an upcoming UWB API; "feature-complete" UWB support (exclusively for the sole use case of ranging between supported devices) was released in version 13 of Android.
Industrial applications
* Automation and robotics: Its high data rate and low latency enable real-time communication and control between machines and systems. UWB-based communication protocols ensure reliable and secure data transmission, enabling precise coordination and synchronization of automated processes. This enhances manufacturing efficiency, reduces errors, and improves overall productivity. UWB can also be integrated into robotic systems to enable precise localization, object detection, and collision avoidance, further enhancing the safety and efficiency of industrial automation.
* Worker safety and proximity sensing: Worker safety is a concern in industrial settings. UWB technology provides effective proximity sensing and worker safety solutions. By equipping workers with UWB-enabled devices or badges, companies can monitor their location and movement in real-time. UWB-based systems can detect potential collisions between workers and machinery, issuing timely warnings to prevent accidents. Moreover, UWB technology allows for the creation of safety zones and controlled access areas, ensuring the safe interaction of workers with hazardous equipment or restricted zones. This helps enhance workplace safety, reduce accidents, and protect employees from potential hazards.
* Asset tracking and management: Efficient asset tracking and management are crucial for industrial operations. UWB enables precise and real-time tracking of assets within industrial facilities. By attaching UWB tags to equipment, tools, and inventory, companies can monitor their location, movement, and utilization. This enhances inventory management, reduces asset loss, minimizes downtime, and streamlines maintenance processes. UWB-based asset tracking systems provide accurate and reliable data, empowering businesses to optimize their resource allocation and improve overall operational efficiency.
Radar
Ultra-wideband gained widespread attention for its implementation in
synthetic aperture radar (SAR) technology. Due to its high resolution capacities using lower frequencies, UWB SAR was heavily researched for its object-penetration ability. Starting in the early 1990s, the
U.S. Army Research Laboratory (ARL) developed various stationary and mobile ground-, foliage-, and wall-penetrating radar platforms that served to detect and identify buried IEDs and hidden adversaries at a safe distance. Examples include the
railSAR, the
boomSAR, the
SIRE radar, and the
SAFIRE radar. ARL has also investigated the feasibility of whether UWB radar technology can incorporate Doppler processing to estimate the velocity of a moving target when the platform is stationary. While a 2013 report highlighted the issue with the use of UWB waveforms due to target range migration during the integration interval, more recent studies have suggested that UWB waveforms can demonstrate better performance compared to conventional Doppler processing as long as a correct
matched filter
In signal processing, the output of the matched filter is given by correlating a known delayed signal, or ''template'', with an unknown signal to detect the presence of the template in the unknown signal. This is equivalent to convolving the unkn ...
is used.
Ultra-wideband pulse
Doppler radar
A Doppler radar is a specialized radar that uses the Doppler effect to produce velocity data about objects at a distance. It does this by bouncing a microwave signal off a desired target and analyzing how the object's motion has altered the fre ...
s have also been used to monitor vital signs of the human body, such as heart rate and respiration signals as well as human gait analysis and fall detection. It serves as a potential alternative to
continuous-wave radar systems since it involves less power consumption and a high-resolution range profile. However, its low signal-to-noise ratio has made it vulnerable to errors.
Ultra-wideband is also used in "see-through-the-wall" precision radar-imaging technology,
[Thales Group's through-the-wall imaging system](_blank)
/ref>[Michal Aftana]
Through-Wall Imaging with UWB Radar System
Dissertation Thesis, 2009 precision locating and tracking (using distance measurements between radios), and precision time-of-arrival-based localization approaches. UWB radar has been proposed as the active sensor component in an Automatic Target Recognition
Automatic target recognition (ATR) is the ability for an algorithm or device to recognize targets or other objects based on data obtained from sensors.
Target recognition was initially done by using an audible representation of the received signal ...
application, designed to detect humans or objects that have fallen onto subway tracks.
Data transfer
Ultra-wideband characteristics are well-suited to short-range applications, such as PC peripherals, wireless
Wireless communication (or just wireless, when the context allows) is the transfer of information (''telecommunication'') between two or more points without the use of an electrical conductor, optical fiber or other continuous guided transm ...
monitors, camcorder
A camcorder is a self-contained portable electronic device with video and recording as its primary function. It is typically equipped with an articulating screen mounted on the left side, a belt to facilitate holding on the right side, hot-sw ...
s, wireless printing
Printing is a process for mass reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The ...
, and file transfer
File transfer is the transmission of a computer file through a communication channel from one computer system to another. Typically, file transfer is mediated by a communications protocol. In the history of computing, numerous file transfer protoc ...
s to portable media player
A portable media player (PMP) or digital audio player (DAP) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. Normally they refer to small, Electric battery, batter ...
s. UWB was proposed for use in personal area network
A personal area network (PAN) is a computer network for interconnecting electronic devices within an individual person's workspace. A PAN provides data transmission among devices such as computers, smartphones, tablets and personal digital assi ...
s, and appeared in the IEEE 802.15.3a draft PAN standard. However, after several years of deadlock, the IEEE 802.15.3a task group was dissolved in 2006. The work was completed by the WiMedia Alliance and the USB Implementer Forum. Slow progress in UWB standards development, the cost of initial implementation, and performance significantly lower than initially expected are several reasons for the limited use of UWB in consumer products (which caused several UWB vendors to cease operations in 2008 and 2009).
Autonomous vehicles
UWB's precise positioning and ranging capabilities enable collision avoidance and centimeter-level localization accuracy, surpassing traditional GPS systems. Moreover, its high data rate and low latency facilitate seamless vehicle-to-vehicle communication, promoting real-time information exchange and coordinated actions. UWB also enables effective vehicle-to-infrastructure communication, integrating with infrastructure elements for optimized behavior based on precise timing and synchronized data. Additionally, UWB's versatility supports innovative applications such as high-resolution radar imaging for advanced driver assistance systems, secure key less entry via biometrics or device pairing, and occupant monitoring systems, potentially enhancing convenience, security, and passenger safety.
UWB products/chips
Regulation
In the U.S., ''ultra-wideband'' refers to radio technology with a bandwidth
Bandwidth commonly refers to:
* Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range
* Bandwidth (computing), the rate of data transfer, bit rate or thr ...
exceeding the lesser of 500 MHz or 20% of the arithmetic center frequency
In electrical engineering and telecommunications, the center frequency of a filter or channel is a measure of a central frequency between the upper and lower cutoff frequencies. It is usually defined as either the arithmetic mean or the geometr ...
, according to the U.S. Federal Communications Commission
The Federal Communications Commission (FCC) is an independent agency of the United States government that regulates communications by radio, television, wire, internet, wi-fi, satellite, and cable across the United States. The FCC maintains j ...
(FCC). A February 14, 2002 FCC Report and Order authorized the unlicensed use of UWB in the frequency range from 3.1 to 10.6 GHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose formal expression in ter ...
. The FCC power spectral density
In signal processing, the power spectrum S_(f) of a continuous time signal x(t) describes the distribution of power into frequency components f composing that signal. According to Fourier analysis, any physical signal can be decomposed into ...
(PSD) emission limit for UWB transmitters is −41.3 dBm/MHz. This limit also applies to unintentional emitters in the UWB band (the "Part 15" limit). However, the emission limit for UWB emitters may be significantly lower (as low as −75 dBm/MHz) in other segments of the spectrum.
Deliberations in the International Telecommunication Union
The International Telecommunication Union (ITU)In the other common languages of the ITU:
*
* is a list of specialized agencies of the United Nations, specialized agency of the United Nations responsible for many matters related to information ...
Radiocommunication Sector (ITU-R
The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications.
Its role is to manage the international radio-frequenc ...
) resulted in a Report and Recommendation on UWB in November 2005. UK regulator Ofcom
The Office of Communications, commonly known as Ofcom, is the government-approved regulatory and competition authority for the broadcasting, internet, telecommunications and mail, postal industries of the United Kingdom.
Ofcom has wide-rang ...
announced a similar decision on 9 August 2007.
There has been concern over interference between narrowband and UWB signals that share the same spectrum. Earlier, the only radio technology that used pulses was spark-gap transmitter
A spark-gap transmitter is an obsolete type of transmitter, radio transmitter which generates radio waves by means of an electric spark."Radio Transmitters, Early" in Spark-gap transmitters were the first type of radio transmitter, and were the m ...
s, which international treaties banned because they interfere with medium-wave receivers. However, UWB uses much lower levels of power. The subject was extensively covered in the proceedings that led to the adoption of the FCC rules in the US, and in the meetings of the ITU-R leading to its Report and Recommendations on UWB technology. Commonly-used electrical appliances emit impulsive noise (for example, hair dryers), and proponents successfully argued that the noise floor
In signal theory, the noise floor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system, where noise is defined as any signal other than the one being monitored.
In radio com ...
would not be raised excessively by wider deployment of low power wideband transmitters.
Coexistence with other standards
In February 2002, the Federal Communications Commission (FCC) released an amendment (Part 15) that specifies the rules of UWB transmission and reception. According to this release, any signal with fractional bandwidth greater than 20% or having a bandwidth greater than 500 MHz is considered as an UWB signal. The FCC ruling also defines access to 7.5 GHz of unlicensed spectrum between 3.1 and 10.6 GHz that is made available for communication and measurement systems.
Narrowband signals that exist in the UWB range, such as IEEE 802.11a transmissions, may exhibit high PSD levels compared to UWB signals as seen by a UWB receiver. As a result, one would expect a degradation of UWB bit error rate performance.
Technology groups
See also
References
External links
* IEEE 802.15.4a Includes a C-UWB physical layer, may be obtained fro
Standard ECMA-368 High Rate Ultra Wideband PHY and MAC Standard
Standard ECMA-369 MAC-PHY Interface for ECMA-368
ITU-R Recommendations – SM series
See: RECOMMENDATION ITU R SM.1757 Impact of devices using ultra-wideband technology on systems operating within radiocommunication services.
SubPart F: Ultra-wideband
– WCSP Group – University of South Florida (USF)
The Ultra-Wideband Radio Laboratory at the University of Southern California
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Data transmission
Radio communications
Radio technology