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May, 2001 TIME DOMAIN ® UWB Technology Michal Freedhoff, Ph.D. Director of Regulatory Policy

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Presentation on theme: "May, 2001 TIME DOMAIN ® UWB Technology Michal Freedhoff, Ph.D. Director of Regulatory Policy"— Presentation transcript:

1 May, 2001 TIME DOMAIN ® UWB Technology Michal Freedhoff, Ph.D. Director of Regulatory Policy

2 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

3 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

4 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) Frequency (GHz) Random noise signal

5 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

6 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

7 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

8 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

9 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

10 May, 2001 TIME DOMAIN ® Unlicensed Spectrum Power Frequency (GHz) Part 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

11 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

12 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.”

13 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

14 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

15 May, 2001 TIME DOMAIN ® An Example Graph from JHUAPL Report Asymptotic curve with noticeable effects starting at 3 meters

16 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

17 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

18 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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