ULTRA WIDE BAND A EUROPEAN PERSPECTIVE Presented by: John Mettrop, UK CAA Dale Stacey, Eurocontrol

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ULTRA WIDE BAND A EUROPEAN PERSPECTIVEPresent
ed by John Mettrop, UK CAA
Dale Stacey, Eurocontrol
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INTRODUCTION

• INTRODUCTION
• What is UWB ?
• History, how did it start
• Projected market
• The Scenario
• Major Stakeholders
• External View
• Proposed limits (3 masks)
• Advantage of European Mask
• Methodology
• Aviation S/I limits
• Aviation band overlay
• Conclusions
• Unfinished work

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What is Ultra Wide Band ?

• Ultra Wide Band (UWB) Services are not currently
  covered under the service definitions of the ITU
  radio regulations
• UWB technology uses sharp impulses to pass
  information, of very low power. (By fourier
  analysis sharp pulses in time domain broad
  spread out bandwidth in frequency domain
• The broad definition that seems to be accepted by
  the radio community is Ultra Wideband is when
  the absolute bandwidth of the signal being
  conveyed is equal or greater than 20 of the
  central carrier frequency OR a signal whose
  absolute bandwidth is 500 MHz or more. (taken
  from ECC report 64, and TG1/8 definitions)

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History, how did it start !

• The opportunist mass marketeers in the US spotted
  a loophole in the FCC regulations pertaining to
  maximum RF emission limits permitted from an
  electronic box.( FCC part 15 limits -41.3 dBm/MHz
  flat limit corresponds to a 500µV field strength
  measured at 3 metres from dirty device.)
• Equipment suppliers saw this as a window of
  opportunity
• Lobbied the US government trade and industry
  sector to support developing this opportunity,
  and won !
• FCC announced a standard mask in favour of the
  UWB community in april 02 (Ignored some of the
  concerns of Aviation, (ie NTIA studies))

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Projected Market

• It is estimated (by FCC and ECC) that there will
  be three different applications coming under the
  heading of UWB
• Wall imaging and medical imaging equipment
• Through wall imaging and surveillance
• Communication and measuring equipment (98 of
  units)

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THE SCENARIO

• Aggregate units/km2 - NO ONE KNOWS !
• Guesses are for upto 10,000 per square kilometre
• an activity factor of 5 max (this is supplied by
  the manufacturers)
• outdoor factor of 20
• Studies are based on this !

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Major stakeholders in UWB

• FCC (initiators)
• ITU TG 1-8 formed Compatibility between
  ultra-wideband devices (UWB) and
  radiocommunications services , specifically to
  study UWB, first meeting 21-24 january 03
• In Europe TG 3 was set up in the ECC
  specifically to answer the questions of UWB and
  provide a balanced view
• Also of recent seen a growth in the pro UWB
  community in Europe comprising the major
  communication equipment manufacturers keen to
  jump on this opportunity (significantly
  influencial in TG3)
• TG3 is also balanced by the large user radio
  community interests in Europe (Producing a more
  balanced and pragmatic view to study)

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EXTERNAL VIEW
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PROPOSED LIMITS

• 3 MAIN OPTIONS.
• Original US proposed flat limit of -41.3 dBm/MHz
• FCC Emission mask (of 22nd april 02)
• Proposal by ECC for a slope mask
• Nb there are some minor submasks of these not
  discussed here

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The advantage to Aviation of the ECC slope mask

• Aviations requirements have generally been
  incorporated
• It presents the limits most favourable to the
  Aviation community
• It enables the UWB to develop technology that is
  less likely to cause problems to Aviation

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METHODOLOGY FOR ARRIVING AT UNWANTED UWB LIMITS

• Sequence-
• Determine minimum (usually ICAO defined) wanted
  receive signal levels into Aviation system
  receiver
• Establish S/I (or I/N) criteria (again usually
  from ICAO documentation or ITU recs)
• Calculate the maximum unwanted (aggregate)
  interference signal power permissible at an
  equivalent isotropic antenna input
• Establish the minimum distance criteria between
  UWB device and Aviation system receiver
• Calculate back using fspl, the maximum output
  EIRP/MHz of UWB signal power (for single and
  multiple entry scenarios)

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AVIATION S/I LIMITS (STEP 2)(intra system from
ICAO Annex 10)
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MAXIMUM ACCEPTABLE UWB PSD FOR KNOWN MINIMUM
SEPARATION DISTANCE (extract from ECC report 64),
(STEP 3,4,5)
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Unfinished work and further questions

• Modelling radar antennas and refining
  compatibility criteria between UWB and radar.
• Some confirmation of the noise like properties of
  UWB
• Some practical validation of system interference
  limits
• Some missing values in the Aviation portfolio (ie
  Radars)
• Gaining Aviation support to favour the European
  ECC report 64 approach over the FCC proposals
• What if the predicted maximum deployment of 500
  units/km2 with activity factor 5 and outdoor
  deployment factor20 is wrong !
• How can we be assured aggregate unit on
  utilisation will be less than 5 activity per
  device? And 80 of units will be indoor.

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CONCLUSION

• The Aviation community is strongly encouraged -
• to stand behind the work of ECC TG3. Aviations
  requirements have been considered and
  incorporated into the output study document ECC
  report 64 this position and European proposals
  provide the best means to protect Aviations
  spectrum interests from the harmful effects of
  UWB.
• Oppose the flat limits of -41.3 dBm and the
  alternative FCC mask proposed in april 2002 on
  account that these proposals blatantly disregard
  Aviations requirement to interference free
  spectrum !
• Note that the values provided so far are largely
  theoretical and some practical validation is
  required of the inter system S/I values and
  validation of the properties of UWB to be truly
  noise like.
• To note that there are still some open ended
  issues with compatibility between UWB and radar
  systems, this will require more development work
  on the radar antenna models, maybe involving a
  statistical approach
• Note that for the time being the above steps will
  alleviate the threat of UWB to Aviation systems,
  however, this doesnt guarantee the scenario
  cannot change and UWB could become a threat to
  Aviation again !