1. Stonestreet One

A royalty-free software Bluetooth stack available from TI is pre-integrated with TI's MSP430 and ARM® Cortex®-M3 and Cortex®-M4 MCUs. The stack is also available for MFi solutions and on other MCUs through TI's partner Stonestreet One (www.stonestreetone.com). Some of the profiles supported today include serial port profile (SPP), human. Stonestreet One has provided a hardware UART driver for TI’s Hands-Free Development Platform project. This API reference contains a description of the programming interfaces for the hardware UART driver. How to Use This Manual This document contains the following sections: Section 1 introduces the TMS320C54x hands-free development platform.

Ultra-WideBand

Ultra-wideband (also UWB, and ultra-wide-band, ultra-wide band,etc.) may be used to refer to anything with a very large bandwidth (e.g.: a type of samplingrate in the Speexspeech codec).This article discusses the meaning in radio communications.

Overview

Ultra-Wideband (UWB) is a technology for transmitting information spreadover a large bandwidth that should, in theory and under the rightcircumstances, be able to share spectrum with other users. A February 14,2002 Report and Order bythe Federal Communications Commission (FCC) [1]authorizes the unlicensed use of UWB in 3.1–10.6 GHz. This is intended toprovide an efficient use of scarce radio bandwidth while enabling both highdata rate personal-area network (PAN) wireless connectivity as well aslonger-range, low data rate applications as well as radar and imaging systems.More than four dozen devices have been certificated under the FCC UWB rules,the vast majority of which are radar, imaging or positioning systems. Deliberationsin the International Telecommunication UnionRadio communication Sector (ITU-R)have resulted in a Report and Recommendation on UWB in November of 2005.National jurisdictions around the globe are expected to act on nationalregulations for UWB very soon.

Ultra Wideband was traditionally accepted as impulse radio, but the FCC andITU-R now define UWB in terms of a transmission from an antenna for which theemitted signal bandwidth exceeds the lesser of 500 MHz or 20% bandwidth. Thus,pulse-based systems—wherein each transmitted pulse instantaneously occupies aUWB bandwidth, or an aggregation of at least 500 MHz worth of narrow bandcarriers, for example in orthogonal frequency-division multiplexing(OFDM) fashion—can gain access to the UWB spectrum under the rules. Pulserepetition rates may be either low or very high. Pulse-based radars and imagingsystems tend to use low repetion rates, typically in the range of 1 to 10 mega pulsesper second. On the other hand, communications systems favor high repetitionrates, typically in the range of 1 to 2 giga pulses per second, thus enablingshort-range gigabit-per-second communications systems. Each pulse in apulse-based UWB system occupies the entire UWB bandwidth, thus reaping thebenefits of relative immunity to multipath fading(but not to intersymbol interference), unlike carrier-basedsystems that are subject to both deep fades and intersymbol interference.

The FCC power spectral density emission limit is the same as forunintentional emitters in the UWB band, but is significantly lower in certainsegments of the spectrum.

A significant difference between traditional radio transmissions and UWBradio transmissions is that traditional transmissions transmit information byvarying the power/frequency/and or phase in distinct and controlled frequencieswhile UWB transmissions transmit information by generating radio energy atspecific times with a broad frequency range.

One ofthe valuable aspects of UWB radio technology is the ability for a UWB radiosystem to determine 'Time of Flight' of the direct path of the radiotransmission between the transmitter and receiver. With any radio transmissionthe signals reflect off of metallic objects and results in different radiosignal paths that then can arrive at the receiver later in time and interferewith radio transmission that went directly from the transmitter to thereceiver. With frequency based transmissions the sinusoidal waves add/subtractat the receiver antenna and make it difficult or impossible to distinguish thedirect transmission path from the reflected paths. This is called'multi-path fading' and 'multi-path interference'. However,with UWB transmissions the time encoding can be randomly dithered and thereceiver can then determine which is the direct path. With a bidirectionalsystem or a radar system this allows distances to be determined much moreaccurately.

Possible applications

Due to the extremely low emission levels, UWB systems tend to beshort-range. However, due to the short duration of the UWB pulses, extremelyhigh data rates are possible, and data rate can be readily traded for range bysimply scaling the number of pulses per data bit. Conventional OFDM technologycan also be used subject to the minimum bandwidth requirement of theregulations. High data rate UWB can enable wirelessmonitors,the efficient transfer of data from digital camcorders,wireless printingof 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.

UWBalso has the potential to enable 'see-through-the-wall' imagingtechnology and high-precision time-of-arrival-based localization approaches. ^[1]It is expected to exhibit excellent efficiency with a spatial capacityof approximately 1,000,000 bit/s/m².

See also

• Bluetooth
• Wireless USB
• WiMedia Alliance
• UWB Forum
• IEEE 802.15
• Wireless
• Network
• Bandwidth
• Fat Pipe
• Wideband
• IEEE 802.15.4a 'ZigBee'

External links

Standards andRegulations

• UWB Forum The UWB Forum is an open, non-profit industry association dedicated to collaboratively developing and administering specs from the physical layer up; enabling connectivity and interoperability for multiple industry-based protocols.
• WiMedia Alliance The WiMedia Alliance is an open, non-profit industry association dedicated to collaboratively developing and administering specs from the physical layer up; enabling connectivity and interoperability for multiple industry-based protocols sharing the MBOA-UWB spectrum.
• ITU-R Recommendations - SM series
• ITU-R Recommendations - P series
• FCC Title 47 of the Code of Federal Regulations
• FCC (GPO) Title 47, Section 15 of the Code of Federal Regulations
• FCC Electronic Document Management System (EDOCS)
• ETSI
• ISO
• IEC
• ISO/IEC JTC 001
• Ecma International
• Standard ECMA-368 High Rate Ultra Wideband PHY and MAC Standard
• Standard ECMA-369 MAC-PHY Interface for ECMA-368

Resources

• UWB Radio Technology Primer on UWB
• Ultra Wideband Systems Technologies and Applications
• UWBAntenna.com
• UWB Info and resources
• The Ultra-Wideband Radio Laboratory at the University of Southern California has many publications including 'Low Noise Amplifier Design for Ultra-Wideband Radio' by Jongrit Lerdworatawee, Won Namgoong, 2003
• FCC Docket file on UWB

Chip manufacturers

Semiconductor companies providing complete solutions for Certified WirelessUSB and Bluetooth 3.0, based upon the WiMedia ultra-wideband (UWB) technology,as well as proprietary solutions.(Errata: There is no Bluetooth spec. 3.0ready)

• Aether Wire & Location, Inc.
• Alereon Inc.
• Artimi Inc.
• FOCUS Enhancements
• Freescale Semiconductor
• Global Interface Technologies Inc.
• General Atomics
• Intel Corporation
• MultiSpectral Solutions
• Pulse~LINK
• Staccato Communications Inc.
• Texas Instruments
• Time Domain Corporation
• TZero Technologies
• WiQuest Communications, Inc.
• Wisair

Software providers

Stonestreet One

• Microsoft Microsoft Windows Drivers (including WHCI—wireless host controller interface)
• Stonestreet One Windows and Embedded drivers for UWB Hardware