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May, 2001 TIME DOMAIN ® UWB Technology Michal Freedhoff, Ph.D. Director of Regulatory Policy Michal.freedhoff@timedomain.com
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May, 2001 TIME DOMAIN ® What Is Ultra-Wideband? A wireless technology that uses ultra-low power (microwatts) to deliver megabits across multiple gigahertz It can fuse high performance communications with precision location and high resolution radar sensing
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May, 2001 TIME DOMAIN ® What Is Ultra-Wideband? Definition At Part 15 powers (a few tens of microwatts total - across several GHz), cannot be reliably measured below 10 dB down points UWB signals at higher center frequencies will have larger bandwidths fu-flfu-fl fu+flfu+fl 2 0.25 Where: f u = upper 10 dB down point f l = lower 10 dB down point
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May, 2001 TIME DOMAIN ® Time Modulated Ultra-Wideband Not a sinewave, but millions of pulses per second Time coded to make noise-like Channelization Anti-jam Smooths spectrum Pulse position modulation 500 ps Time Randomized Time Coding Amplitude ps “0”“1” Power Spectral Density (dB) -80 -40 0 Frequency (GHz) 12345 Random noise signal
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May, 2001 TIME DOMAIN ® Time Domain UWB – Three Technologies in One Enables vast improvements Wireless communications Precision tracking Radar sensing PulsON, A Chip Based Solution
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May, 2001 TIME DOMAIN ® Save and Protect Lives Victims of crimes and disaster Police, fire, rescue personnel Workplace, environmental and highway safety Military and civilian security Independent Living/Better Health Care Aged and disabled independence Diagnosis and treatment Lower costs “Digital Divide” relief Lower cost indoor broadband Complement and Extend Reach of GPS Aviation safety Worldwide Race - Breakthrough Technology Jobs/Economic Development Global Technology Leadership Relieve “spectrum drought” Unique Benefits of UWB
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May, 2001 TIME DOMAIN ® POTS CATV MMDS Satellite Optical DSL Cable Modem FTTH Broadband To The Home... The Challenge: “Broadband Thru The Home” What is UWB’s Role in the Future of Broadband Wireless
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May, 2001 TIME DOMAIN ® TM-UWB Enables… In-Building 3-D Precision Location & Tracking (indoors +/- 3 cm) Proposed TimeTag TM Design for Precision Tracking People Tracking – DOC SBIR to track firefighters – DOD to track soldiers in urban training scenarios Asset Tracking – Partnership with GE and grant from NIST to track medical equipment in hospitals
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May, 2001 TIME DOMAIN ® Radar Prototype Waiver from FCC to sell a limited number of Radarvision devices Through wall motion sensing for law enforcement, and earthquake rescue
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May, 2001 TIME DOMAIN ® Unlicensed Spectrum 123456 Power Frequency (GHz) Part 15 2.4 GHz UNII Bands Although UWB technology operates at the same or lower power levels currently allowed for numerous applications under the FCC’s Part 15 rules, a change of the rules is needed to accommodate this new form of wireless technology Not to scale
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May, 2001 TIME DOMAIN ® US Regulatory Status of UWB Presently billions of digital devices that emit UWB-like signals (laptops, PDAs, etc.) Operate in the US under unlicensed “Part 15” rules Basic requirement of Part 15: Thou shalt not create harmful interference
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May, 2001 TIME DOMAIN ® What is Harmful Interference? The FCC must decide what constitutes harmful interference. This is a critical spectrum management issue. US Statutory definition of harmful interference (FCC) “Interference which endangers the functioning of a radionavigation service or other safety services or seriously degrades, obstructs or repeatedly interrupts a radio communications service operating in accordance with these [international] Radio Regulations.” 47 CFR 2.1 US NTIA definition NTIA ITS website adds that harmful interference “must cause serious detrimental effects such as circuit outages and message losses as opposed to interference that is merely a nuisance or annoyance that can be overcome by appropriate measures.”
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May, 2001 TIME DOMAIN ® Rule Change: “Noise is Noise” Regardless of What Causes It Radio-wave power (noise) causes interference Interference has nothing to do with whether the noise source is an “intentional” or “unintentional” emitter Appropriate measure is power level, not “intent” UWB power limits set by FCC should be: Equivalent to power limits for both “unintentional” and “spurious” emissions (-71dBW/MHz, the Part 15 power level) Lower than out-of-band power limits allowed for licensed services e.g., PCS and MSS are allowed to emit slightly more energy in restricted bands than all Part 15 devices UWB power limits are no different than levels emitted by existing Part 15 devices. Therefore, UWB should be treated like other Part 15 devices: Intentional vs. unintentional distinction is unnecessary
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May, 2001 TIME DOMAIN ® GPS Coexistence Testing Johns Hopkins Applied Physics Laboratory Sponsored by Time Domain Analyzed data taken by Applied Research Laboratory, University of Texas (ARL:UT) Comprehensive testing produced 20 GB of data including conducted and radiated testing of multiple receiver types and UWB modes as well as other digital devices operating at Part 15 power Developed 12 measures of GPS receiver performance related to number of satellites, position accuracy, and reacquisition time
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May, 2001 TIME DOMAIN ® An Example Graph from JHUAPL Report Asymptotic curve with noticeable effects starting at 3 meters
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May, 2001 TIME DOMAIN ® JHUAPL Analytic Results TM-UWB emissions are white noise-like signals that can be modeled as average power Multiple TM-UWB emissions add as average power TM-UWB emissions resemble emissions from devices operating at Part 15 power levels– un- keyed walkie-talkie Developed theoretical model that accurately predicted both ARL:UT and other experimental data DoD Joint Spectrum Center recently showed that NTIA and UT/JHU data largely say the same thing. TDC performed similar analysis
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May, 2001 TIME DOMAIN ® Aggregate Issue Why isn’t the night sky as bright as the day? Can’t be an aggregate issue on the large scale if the average propagation path is less than free space Except over very short ranges, free space paths don’t exist At the power levels that the FCC may authorize, applications must be short range applications
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May, 2001 TIME DOMAIN ® Conclusions The benefits of UWB are unique, and in many cases cannot be realized using other technologies UWB can be introduced at Part 15 power levels without causing harmful interference
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