Ultra-wideband
Encyclopedia
Ultra-wideband is a radio technology that can be used at very low energy levels for short-range high-bandwidth communications by using a large portion of the radio spectrum. UWB has traditional applications in non-cooperative radar imaging. Most recent applications target sensor data collection, precision locating and tracking applications.
UWB communications transmit in a way that doesn't interfere largely with other more traditional narrowband
and continuous carrier wave
uses in the same frequency band. However first studies show that the rise of noise level by a number of UWB transmitters puts a burden on existing communications services. This may be hard to bear for traditional systems designs and may affect the stability of such existing systems.
(FCC) in United States are intended to provide an efficient use of scarce radio bandwidth while enabling both high data rate "personal area network
" (PAN) wireless connectivity and longer-range, low data rate applications as well as radar and imaging systems.
Ultra Wideband was traditionally accepted as pulse radio, but the FCC and ITU-R now define UWB in terms of a transmission from an antenna for which the emitted signal bandwidth exceeds the lesser of 500 MHz or 20% of the center frequency. Thus, pulse-based systems—wherein each transmitted pulse instantaneously occupies the UWB bandwidth, or an aggregation of at least 500 MHz worth of narrow band carriers, for example in orthogonal frequency-division multiplexing
(OFDM) fashion—can gain access to the UWB spectrum under the rules. Pulse repetition rates may be either low or very high. Pulse-based UWB radars and imaging systems tend to use low repetition rates, typically in the range of 1 to 100 megapulses per second. On the other hand, communications systems favor high repetition rates, typically in the range of 1 to 2 giga-pulses per second, thus enabling short-range gigabit-per-second communications systems. Each pulse in a pulse-based UWB system occupies the entire UWB bandwidth, thus reaping the benefits of relative immunity to multipath fading
(but not to intersymbol interference
), unlike carrier-based
systems that are subject to both deep fades and intersymbol interference.
"), supporting forward error correction encoded data rates in excess of 675 Mbit/s. Such a pulse-based UWB method using bursts of pulses is the basis of the IEEE 802.15.4a draft standard and working group, which has proposed UWB as an alternative PHY
layer.
One of the valuable aspects of UWB radio technology is the ability for a UWB radio system to determine "time of flight" of the direct path of the radio transmission between the transmitter and receiver at various frequencies. This helps to overcome multi path propagation, as at least some of the frequencies pass on radio line of sight. With a cooperative symmetric two-way metering technique distances can be measured to high resolution as well as to high accuracy by compensating for local clock drifts and stochastic inaccuracies.
Another valuable aspect of pulse-based UWB is that the pulses are very short in space (less than 60 cm for a 500 MHz wide pulse, less than 23 cm for a 1.3 GHz bandwidth pulse), so most signal reflections do not overlap the original pulse, and thus the traditional multipath fading of narrow band signals does not exist. However, there still is multipath propagation and inter-pulse interference for fast pulse systems which have to be mitigated by coding techniques.
(implemented on top of UWB).
, according to Federal Communications Commission
(FCC). A February 14, 2002 Report and Order by the FCC authorizes the unlicensed use of UWB in the range of 3.1 to 10.6 GHz. The FCC power spectral density emission limit for UWB emitters operating in the UWB band is -41.3 dBm/MHz. This is the same limit that applies to unintentional emitters in the UWB band, the so called Part 15 limit. However, the emission limit for UWB emitters can be significantly lower (as low as -75 dBm/MHz) in other segments of the spectrum.
Deliberations in the International Telecommunication Union
Radiocommunication Sector (ITU-R
) resulted in a Report and Recommendation on UWB in November 2005. National jurisdictions around the globe are expected to act on national regulations for UWB very soon. The UK regulator Ofcom
announced a similar decision on 9 August 2007.
More than four dozen devices have been certified under the FCC UWB rules, the vast majority of which are radar, imaging or locating systems.
There has been much concern over the interference of narrow band signals and UWB signals that share the same spectrum; traditionally the only radio technology that operated using pulses was spark-gap transmitter
s, which were banned due to excessive interference. However, UWB is much lower power. The subject was extensively covered in the proceedings that led to the adoption of the FCC rules in the US, and also in the meetings relating to UWB of the ITU-R that led to the ITU-R Report and Recommendations on UWB technology. In particular, many common pieces of equipment emit impulsive noise (notably hair dryers) and the argument was successfully made that the noise floor
would not be raised excessively by wider deployment of wideband transmitters of low power.
for a given bandwidth and signaling format. Channel capacity is the theoretical maximum possible number of bits per second of information that can be conveyed through one or more links in an area. According to the Shannon–Hartley theorem
, channel capacity of a properly encoded signal is proportional to the bandwidth of the channel and to the logarithm of signal-to-noise ratio
(SNR)—assuming the noise is additive white Gaussian noise. Thus channel capacity increases linearly by increasing bandwidth of the channel to the maximum value available, or equivalently in a fixed channel bandwidth by increasing the signal power exponentially. By virtue of the huge bandwidths inherent to UWB systems, huge channel capacities could be achieved in principle (given sufficient SNR) without invoking higher order modulations that need very high SNR to operate.
Ideally, the receiver signal detector should match with the transmitted signal in bandwidth, signal shape and time. Any mismatch results in loss of margin for the UWB radio link.
Channelization (sharing the channel with other links) is a complex problem subject to many practical variables. Typically two UWB links can share the same spectrum by using orthogonal time-hopping codes for pulse-position (time-modulated) systems, or orthogonal pulses and orthogonal codes for fast-pulse based systems.
Current forward error correction
technology, as demonstrated recently in some very high data rate UWB pulsed systems (like Low density parity check code) can — perhaps in combination with Reed–Solomon error correction
— provide channel performance very closely approaching the Shannon limit (See Shannon–Hartley theorem
). When stealth is required, some UWB formats (mainly pulse-based) can fairly easily be made to look like nothing more than a slight rise in background noise to any receiver that is unaware of the signal’s complex pattern.
Multipath
(distortion of a signal because it takes many different paths to the receiver with various phase shift and various polarisation shift) is an enemy of narrow-band radio. It equally affects UWB transmissions, but according to the Shannon-Hartley theorem and with reference to the variety of geometries applying to various frequencies, the capability for compensating is significantly enhanced. It causes fading where wave interference is destructive. Some UWB systems use "rake" receiver techniques to recover multi path generated copies of the original pulse to improve performance of the receiver. Other UWB systems use channel equalization techniques to achieve the same purpose. Narrow band receivers can use similar techniques, but are limited due to the poorer resolution capabilities of narrow band systems.
monitors
, the efficient transfer of data from digital camcorder
s, wireless printing
of digital pictures from a camera without the need for an intervening personal computer
, and the transfer of files
among cell phone
handsets and other handheld devices like personal digital audio and video players
.
UWB is used as a part of location systems and real time location systems. The precision capabilities combined with the very low power makes it ideal for certain radio frequency sensitive environments such as hospitals and healthcare. Another benefit of UWB is the short broadcast time which enables implementers of the technology to install orders of magnitude more transmitter tags in an environment relative to competitive technologies. U.S.-based Parco Merged Media Corporation was the first systems developer to deploy a commercial version of this system in a Washington, DC hospital.
UWB is also used in "see-through-the-wall" precision radar imaging technology, precision locating and tracking (using distance measurements between radios), and precision time-of-arrival-based localization approaches. It exhibits excellent efficiency with a spatial capacity
of approximately 1013 bit/s/m².
UWB has been a proposed technology for use in personal area network
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, high cost of initial implementations and performance significantly lower than initially expected are some of the reasons for the limited success of UWB in consumer products, which caused several UWB vendors to cease operations during 2008 and 2009.
UWB communications transmit in a way that doesn't interfere largely with other more traditional narrowband
Narrowband
In radio, narrowband describes a channel in which the bandwidth of the message does not significantly exceed the channel's coherence bandwidth. It is a common misconception that narrowband refers to a channel which occupies only a "small" amount of space on the radio spectrum.The opposite of...
and continuous carrier wave
Carrier wave
In telecommunications, a carrier wave or carrier is a waveform that is modulated with an input signal for the purpose of conveying information. This carrier wave is usually a much higher frequency than the input signal...
uses in the same frequency band. However first studies show that the rise of noise level by a number of UWB transmitters puts a burden on existing communications services. This may be hard to bear for traditional systems designs and may affect the stability of such existing systems.
Overview
Ultra-Wideband (UWB) is a technology for transmitting information spread over a large bandwidth (>500 MHz) that should, in theory and under the right circumstances, be able to share spectrum with other users. Regulatory settings of Federal Communications CommissionFederal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...
(FCC) in United States are intended to provide an efficient use of scarce radio bandwidth while enabling both high data rate "personal area network
Personal area network
A personal area network is a computer network used for communication among computer devices, including telephones and personal digital assistants, in proximity to an individual's body. The devices may or may not belong to the person in question. The reach of a PAN is typically a few meters...
" (PAN) wireless connectivity and longer-range, low data rate applications as well as radar and imaging systems.
Ultra Wideband was traditionally accepted as pulse radio, but the FCC and ITU-R now define UWB in terms of a transmission from an antenna for which the emitted signal bandwidth exceeds the lesser of 500 MHz or 20% of the center frequency. Thus, pulse-based systems—wherein each transmitted pulse instantaneously occupies the UWB bandwidth, or an aggregation of at least 500 MHz worth of narrow band carriers, for example in orthogonal frequency-division multiplexing
Orthogonal frequency-division multiplexing
Orthogonal frequency-division multiplexing is a method of encoding digital data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital communication, whether wireless or over copper wires, used in applications such as digital television and audio...
(OFDM) fashion—can gain access to the UWB spectrum under the rules. Pulse repetition rates may be either low or very high. Pulse-based UWB radars and imaging systems tend to use low repetition rates, typically in the range of 1 to 100 megapulses per second. On the other hand, communications systems favor high repetition rates, typically in the range of 1 to 2 giga-pulses per second, thus enabling short-range gigabit-per-second communications systems. Each pulse in a pulse-based UWB system occupies the entire UWB bandwidth, thus reaping the benefits of relative immunity to multipath fading
Multipath interference
Multipath interference is a phenomenon in the physics of waves whereby a wave from a source travels to a detector via two or more paths and, under the right condition, the two components of the wave interfere...
(but not to intersymbol interference
Intersymbol interference
In telecommunication, intersymbol interference is a form of distortion of a signal in which one symbol interferes with subsequent symbols. This is an unwanted phenomenon as the previous symbols have similar effect as noise, thus making the communication less reliable...
), unlike carrier-based
Carrier wave
In telecommunications, a carrier wave or carrier is a waveform that is modulated with an input signal for the purpose of conveying information. This carrier wave is usually a much higher frequency than the input signal...
systems that are subject to both deep fades and intersymbol interference.
Concept
A significant difference between traditional radio transmissions and UWB radio transmissions is that traditional systems transmit information by varying the power level, frequency, and/or phase of a sinusoidal wave. UWB transmissions transmit information by generating radio energy at specific time instants and occupying large bandwidth thus enabling a pulse-position or time-modulation. The information can also be imparted (modulated) on UWB signals (pulses) by encoding the polarity of the pulse, the amplitude of the pulse, and/or by using orthogonal pulses. UWB pulses can be sent sporadically at relatively low pulse rates to support time/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 giga-pulses per second using a continuous stream of UWB pulses (Continuous Pulse UWB or "C-UWBC-UWB
C-UWB is an acronym for Continuous Pulse Ultra-wideband technology. C-UWB derives its UWB bandwidth by virtue of the short time duration of the individual pulses. Information can be imparted on UWB signals by encoding the polarity of the pulse, the amplitude of the pulse, and/or also by using...
"), supporting forward error correction encoded data rates in excess of 675 Mbit/s. Such a pulse-based UWB method using bursts of pulses is the basis of the IEEE 802.15.4a draft standard and working group, which has proposed UWB as an alternative PHY
PHY
PHY is an abbreviation for the physical layer of the OSI model.An instantiation of PHY connects a link layer device to a physical medium such as an optical fiber or copper cable. A PHY device typically includes a Physical Coding Sublayer and a Physical Medium Dependent layer. The PCS encodes and...
layer.
One of the valuable aspects of UWB radio technology is the ability for a UWB radio system to determine "time of flight" of the direct path of the radio transmission between the transmitter and receiver at various frequencies. This helps to overcome multi path propagation, as at least some of the frequencies pass on radio line of sight. With a cooperative symmetric two-way metering technique distances can be measured to high resolution as well as to high accuracy by compensating for local clock drifts and stochastic inaccuracies.
Another valuable aspect of pulse-based UWB is that the pulses are very short in space (less than 60 cm for a 500 MHz wide pulse, less than 23 cm for a 1.3 GHz bandwidth pulse), so most signal reflections do not overlap the original pulse, and thus the traditional multipath fading of narrow band signals does not exist. However, there still is multipath propagation and inter-pulse interference for fast pulse systems which have to be mitigated by coding techniques.
Uses
The UWB characteristics are very well suited to short-distance applications. A representative case is for PC Peripherals; see Wireless USBWireless USB
Wireless USB is a short-range, high-bandwidth wireless radio communication protocol created by the . Wireless USB is sometimes abbreviated as "WUSB", although the USB Implementers Forum discourages this practice and instead prefers to call the technology "Certified Wireless USB" to distinguish it...
(implemented on top of UWB).
Regulation
Ultra-Wideband (UWB) may be used to refer to any radio technology having bandwidth exceeding the lesser of 500 MHz or 20% of the arithmetic center frequencyCenter 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...
, according to Federal Communications Commission
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...
(FCC). A February 14, 2002 Report and Order by the FCC authorizes the unlicensed use of UWB in the range of 3.1 to 10.6 GHz. The FCC power spectral density emission limit for UWB emitters operating in the UWB band is -41.3 dBm/MHz. This is the same limit that applies to unintentional emitters in the UWB band, the so called Part 15 limit. However, the emission limit for UWB emitters can be significantly lower (as low as -75 dBm/MHz) in other segments of the spectrum.
Deliberations in the International Telecommunication Union
International Telecommunication Union
The International Telecommunication Union is the specialized agency of the United Nations which is responsible for information and communication technologies...
Radiocommunication Sector (ITU-R
ITU-R
The ITU Radiocommunication Sector is one of the three sectors of the International Telecommunication Union and is responsible for radio communication....
) resulted in a Report and Recommendation on UWB in November 2005. National jurisdictions around the globe are expected to act on national regulations for UWB very soon. The UK regulator Ofcom
Ofcom
Ofcom is the government-approved regulatory authority for the broadcasting and telecommunications industries in the United Kingdom. Ofcom was initially established by the Office of Communications Act 2002. It received its full authority from the Communications Act 2003...
announced a similar decision on 9 August 2007.
More than four dozen devices have been certified under the FCC UWB rules, the vast majority of which are radar, imaging or locating systems.
There has been much concern over the interference of narrow band signals and UWB signals that share the same spectrum; traditionally the only radio technology that operated using pulses was spark-gap transmitter
Spark-gap transmitter
A spark-gap transmitter is a device for generating radio frequency electromagnetic waves using a spark gap.These devices served as the transmitters for most wireless telegraphy systems for the first three decades of radio and the first demonstrations of practical radio were carried out using them...
s, which were banned due to excessive interference. However, UWB is much lower power. The subject was extensively covered in the proceedings that led to the adoption of the FCC rules in the US, and also in the meetings relating to UWB of the ITU-R that led to the ITU-R Report and Recommendations on UWB technology. In particular, many common pieces of equipment emit impulsive noise (notably hair dryers) and the argument was successfully made that the noise floor
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 the noise is defined as any signal other than the one being monitored....
would not be raised excessively by wider deployment of wideband transmitters of low power.
Theoretical discussion
One performance measure of a radio in applications like communication, locating, tracking, and radar, is the channel capacityChannel capacity
In electrical engineering, computer science and information theory, channel capacity is the tightest upper bound on the amount of information that can be reliably transmitted over a communications channel...
for a given bandwidth and signaling format. Channel capacity is the theoretical maximum possible number of bits per second of information that can be conveyed through one or more links in an area. According to the Shannon–Hartley theorem
Shannon–Hartley theorem
In information theory, the Shannon–Hartley theorem tells the maximum rate at which information can be transmitted over a communications channel of a specified bandwidth in the presence of noise. It is an application of the noisy channel coding theorem to the archetypal case of a continuous-time...
, channel capacity of a properly encoded signal is proportional to the bandwidth of the channel and to the logarithm of signal-to-noise ratio
Signal-to-noise ratio
Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. It is defined as the ratio of signal power to the noise power. A ratio higher than 1:1 indicates more signal than noise...
(SNR)—assuming the noise is additive white Gaussian noise. Thus channel capacity increases linearly by increasing bandwidth of the channel to the maximum value available, or equivalently in a fixed channel bandwidth by increasing the signal power exponentially. By virtue of the huge bandwidths inherent to UWB systems, huge channel capacities could be achieved in principle (given sufficient SNR) without invoking higher order modulations that need very high SNR to operate.
Ideally, the receiver signal detector should match with the transmitted signal in bandwidth, signal shape and time. Any mismatch results in loss of margin for the UWB radio link.
Channelization (sharing the channel with other links) is a complex problem subject to many practical variables. Typically two UWB links can share the same spectrum by using orthogonal time-hopping codes for pulse-position (time-modulated) systems, or orthogonal pulses and orthogonal codes for fast-pulse based systems.
Current forward error correction
Forward error correction
In telecommunication, information theory, and coding theory, forward error correction or channel coding is a technique used for controlling errors in data transmission over unreliable or noisy communication channels....
technology, as demonstrated recently in some very high data rate UWB pulsed systems (like Low density parity check code) can — perhaps in combination with Reed–Solomon error correction
Reed–Solomon error correction
In coding theory, Reed–Solomon codes are non-binary cyclic error-correcting codes invented by Irving S. Reed and Gustave Solomon. They described a systematic way of building codes that could detect and correct multiple random symbol errors...
— provide channel performance very closely approaching the Shannon limit (See Shannon–Hartley theorem
Shannon–Hartley theorem
In information theory, the Shannon–Hartley theorem tells the maximum rate at which information can be transmitted over a communications channel of a specified bandwidth in the presence of noise. It is an application of the noisy channel coding theorem to the archetypal case of a continuous-time...
). When stealth is required, some UWB formats (mainly pulse-based) can fairly easily be made to look like nothing more than a slight rise in background noise to any receiver that is unaware of the signal’s complex pattern.
Multipath
Multipath interference
Multipath interference is a phenomenon in the physics of waves whereby a wave from a source travels to a detector via two or more paths and, under the right condition, the two components of the wave interfere...
(distortion of a signal because it takes many different paths to the receiver with various phase shift and various polarisation shift) is an enemy of narrow-band radio. It equally affects UWB transmissions, but according to the Shannon-Hartley theorem and with reference to the variety of geometries applying to various frequencies, the capability for compensating is significantly enhanced. It causes fading where wave interference is destructive. Some UWB systems use "rake" receiver techniques to recover multi path generated copies of the original pulse to improve performance of the receiver. Other UWB systems use channel equalization techniques to achieve the same purpose. Narrow band receivers can use similar techniques, but are limited due to the poorer resolution capabilities of narrow band systems.
Multiple antenna technologies
- Distributed MIMO: To increase the transmission range, this scheme exploits distributed antennas among different nodes.
- Multiple antenna: Multiple antenna schemes such as MIMO have been used to increase the system throughput and the reception reliability. Since UWB has almost impulse-like channel response, the combination with multiple antenna techniques is preferable as well. Coupling MIMO spatial multiplexing with UWB's already high throughput gives the possibility of short-range networks with multi-gigabit rates.
Applications
Due to the extremely low emission levels currently allowed by regulatory agencies, UWB systems tend to be short-range and indoors applications. However, due to the short duration of the UWB pulses, it is easier to engineer extremely high data rates, and data rate can be readily traded for range by simply aggregating pulse energy per data bit using either simple integration or by coding techniques. Conventional OFDM technology can also be used subject to the minimum bandwidth requirement of the regulations. High data rate UWB can enable wirelessWireless
Wireless telecommunications is the transfer of information between two or more points that are not physically connected. Distances can be short, such as a few meters for television remote control, or as far as thousands or even millions of kilometers for deep-space radio communications...
monitors
Video monitor
A video monitor also called a broadcast monitor, broadcast reference monitor or just reference monitor, is a display device similar to a television set, used to monitor the output of a video-generating device, such as playout from a video server, IRD, video camera, VCR, or DVD player. It may or...
, the efficient transfer of data from digital camcorder
Camcorder
A camcorder is an electronic device that combines a video camera and a video recorder into one unit. Equipment manufacturers do not seem to have strict guidelines for the term usage...
s, wireless printing
Printing
Printing is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....
of digital pictures from a camera without the need for an intervening personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
, and the transfer of files
Computer file
A computer file is a block of arbitrary information, or resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished...
among cell phone
Mobile phone
A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...
handsets and other handheld devices like personal digital audio and video players
Portable media player
A portable media player or digital audio player, is a consumer electronics device that is capable of storing and playing digital media such as audio, images, video, documents, etc. the data is typically stored on a hard drive, microdrive, or flash memory. In contrast, analog portable audio...
.
UWB is used as a part of location systems and real time location systems. The precision capabilities combined with the very low power makes it ideal for certain radio frequency sensitive environments such as hospitals and healthcare. Another benefit of UWB is the short broadcast time which enables implementers of the technology to install orders of magnitude more transmitter tags in an environment relative to competitive technologies. U.S.-based Parco Merged Media Corporation was the first systems developer to deploy a commercial version of this system in a Washington, DC hospital.
UWB is also used in "see-through-the-wall" precision radar imaging technology, precision locating and tracking (using distance measurements between radios), and precision time-of-arrival-based localization approaches. It exhibits excellent efficiency with a spatial capacity
Spatial capacity
Spatial capacity is an indicator of "data intensity" in a transmission medium. It is usually used in conjunction with wireless transport mechanisms. This is analogous to the way that lumens per square meter determine illumination intensity....
of approximately 1013 bit/s/m².
UWB has been a proposed technology for use in personal area network
Personal area network
A personal area network is a computer network used for communication among computer devices, including telephones and personal digital assistants, in proximity to an individual's body. The devices may or may not belong to the person in question. The reach of a PAN is typically a few meters...
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, high cost of initial implementations and performance significantly lower than initially expected are some of the reasons for the limited success of UWB in consumer products, which caused several UWB vendors to cease operations during 2008 and 2009.
See also
External links
- IEEE 802.15.4a Includes a C-UWBC-UWBC-UWB is an acronym for Continuous Pulse Ultra-wideband technology. C-UWB derives its UWB bandwidth by virtue of the short time duration of the individual pulses. Information can be imparted on UWB signals by encoding the polarity of the pulse, the amplitude of the pulse, and/or also by using...
physical layer, may be obtained from http://www.ieee.org - Standard ECMA-368 High Rate Ultra Wideband PHY and MAC Standard
- Standard ECMA-369 MAC-PHY Interface for ECMA-368
- Standard ISO/IEC 26907:2007
- Standard ISO/IEC 26908:2007
- ITU-R Recommendations - SM series See: RECOMMENDATION ITU R SM.1757 Impact of devices using ultra-wideband technology on systems operating within radiocommunication services.
- FCC (GPO) Title 47, Section 15 of the Code of Federal Regulations SubPart F: Ultra-wideband
- Use of MIMO techniques for UWB
- Numerous useful links and resources regarding Ultra-Wideband and UWB testbeds – WCSP Group – University of South Florida (USF)
- The Ultra-Wideband Radio Laboratory at the University of Southern California
- DGPS + UWB