ITU Status

1
Project IEEE P802.15 Working Group for Wireless
Personal Area Networks (WPANs) Submission Title
State of International UWB Regulations in ITU
Date Submitted 15 September, 2004 Source
J. Foerster Company Intel Address JF3-212,
2111 NE 25th Ave., Hillsboro, OR,
97124 Voice503-264-6859, FAX [phone],
E-Mailjeffrey.r.foerster_at_intel.com Re
Informational Abstract This presentation
gives an update of the current ITU-R TG1/8
recommendations for UWB compatibility with
various wireless services. Purpose For
discussion by IEEE 802.15 TG3a. Notice This
document has been prepared to assist the IEEE
P802.15. It is offered as a basis for discussion
and is not binding on the contributing
individual(s) or organization(s). The material in
this document is subject to change in form and
content after further study. The contributor(s)
reserve(s) the right to add, amend or withdraw
material contained herein. Release The
contributor acknowledges and accepts that this
contribution becomes the property of IEEE and may
be made publicly available by P802.15.
2
State of International UWB Regulations in ITU

• Jeff Foerster
• Intel CorporationSeptember 16, 2004

3
Purpose of this presentation

• Provide the IEEE 802.15.3a body with some insight
  into the current state of the current ITU TG1/8
  recommendations
• Bring awareness to UWB community about
  challenging state of current recommendations
• Build upon nice summary of regulatory result
  presented in doc. IEEE 802.15-04/340r0 (authors
  T. Ikegami, T. Yasui, R. Kohno)
• Discuss possible areas the UWB industry could
  contribute to improve current recommendations
• Contribute technical analysis addressing some of
  the coexistence scenarios in the current
  recommendations
• Possible assumptions to revisit UWB device
  activity factors, usage scenarios, path loss
  models
• Describe benefits of UWB technology to companies
  and individual country regulators participating
  in TG1/8
• Attend TG1/8 meetings and/or individual country
  delegation meetings showing industry support for
  enabling worldwide spectrum harmonization for UWB
• Solicit feedback from task group to determine how
  best the IEEE can help support international
  harmonization of regulations which could have
  significant impact on 802.15.3a and .4a

4
General Problem Statement

• UWB as a generic underlay technology has the
  potential of causing harmful interference
• First, must admit there could be a problem in
  some coexistence scenarios
• Simple example ? UWB device 1 meter from a
  generic narrowband receiver
• Given above criteria and usage model (1 meter
  separation), allowed Tx power could be
  significantly lower than FCC Part 15 limits

5
General Problem Statement

• On positive side ? only a few wireless services
  would be anticipated to meet this particular
  usage scenario (i.e., cell phones, indoor WiMax
  systems, RLANs, Bluetooth)
• Note that indoor WiMax systems can operate at
  3.4-3.6 GHz where this usage scenario may be
  relevant
• Implications of simple example
• UWB emissions limits must be evaluated on a per
  service basis and not treated as a simple
  underlay technology, but rather a secondary or
  tertiary user of the shared spectrum
• Note that current ITU recommendations based upon
  protection criteria of current services,
  typically taking the form of an I/N ratio,
  contributed by individual ITU-R WP
• I/N lt -6 dB common, I/N lt -20 dB used for some
  fixed services
• Challenges to generalizing interference analysis
• Interference analysis dictated by underlying
  assumptions about interference criteria, usage
  models, device activity models, channel models,
  and other system parameters
• Some of these parameters require projecting
  future use, which is inherently difficult and
  subjective
• Simple example certainly has its limitations and
  does not address
• Single UWB devices near systems with high gain
  antennas
• Aggregation of interference from multiple UWB
  emitters (office and home environments)

6
Some Tentative ITU Recommendations
Based upon 1 foot separation (1 meter separation
limits would be 10 dB higher)

• Based upon dithered, average power results (not
  peak) at 10 meters.
• I/N lt -20 dB (criteria).
• Conclusions stated local restrictions could
  ensure sufficient protection distances (600 m) to
  allow -41 dBm/MHz Tx power.

7
Some Tentative ITU Recommendations
Based upon 30m separation distance from single
outdoor UWB device.
Based upon 1 dB degradation to SNR (criteria
still in discussion).
Other service not shown here Mobile Services
(Land, Maritime, Aeronautical, Amateur, Amateur
Satellite), Mobile Satellite (MSS, RNSS),
Broadcasting Services, other Science Services
(EESS, Meteorological Radar) Additional
information can be found in doc. IEEE
802.15-04/340r0 (authors T. Ikegami, T. Yasui, R.
Kohno).
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Comparison of FCC mask to current ITU
Recommendations

• Clearly, current ITU recommendations would make
  UWB unusable for high-rate communications systems
  (not all services accounted for below)

Propose ETSI sloped mask
RLAN
Fixed Services
Cellular
RAS
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Comments on current ITU Recommendations

• Current recommendations makes UWB unusable for
  high-rate communications
• However, there are a number of technical areas
  worth revisiting
• Most interference criteria based up meeting an
  I/N limit (interference-to-thermal noise ratio,
  -6 dB and -20 dB typical, depending on service)
• This criteria can be very conservativein some
  cases, criteria results in limits well below OOB
  and unintentional radiation limits for other
  devices
• Activity factors need to reflect realistic
  expected UWB device operation
• Intel and others have submitted modifications to
  these factors in the ITU and encourage others to
  support the new data and/or contribute their own
  data
• Usage models need to reflect realistic expected
  UWB device operation
• Time sharing of spectrum in high density
  environment should be considered (many devices
  associated with same piconet and time-sharing
  coordinated by MAC)
• Outdoor use expected to be rare (mainly
  peer-to-peer synchronizing of data)countries can
  limit outdoor infrastructure (as is done in US)
• In many cases, path loss models based upon free
  space propagation, which may be unrealistic
• Accurate path loss modeling is critical, and
  should not be chosen lightly
• Lots of discussion on path loss models in Annex
  2 Methodologies for interference analyses of
  systems using UWB technology with systems
  operating under Radiocommunication Services show
  NLOS path loss with exponent gt2
• Some analysis use free space path loss even when
  indoor-to-outdoor propagation is encountered

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Comments on current ITU Recommendations

• Other areas worth contributing to in ITU
  recommendations
• Mitigation techniques could be used by both UWB
  devices and some of the narrowband services
• Power control could be implemented by a UWB
  device to lower potential interference
• Countries could limit outdoor use of UWB devices
  initially
• Some services, like RAS and EESS, could increase
  protection area via localized regulations/laws
• Static or dynamic notching techniques could be
  applied by a UWB device
• Why do the current recommendations differ so much
  from FCC mask?
• Current ITU protection criteria is very different
  from that used by FCC (FCC has stated that
  comparing interference to thermal noise is not
  sufficient criteria)
• This is a difficult parameter and can be
  subjective, depending on service
• Different services exist in different frequency
  bands which were not considered by FCC during
  proceedings
• WiMax systems are allocated 3.4-3.6 GHz in much
  of the world, recent NPRM could allow WiMax
  systems at 3.6 GHz in the USthis service did not
  exist during FCC proceedings
• Some countries are considering allocation of
  spectrum in the 3-4 GHz band for future cellular
  (B3G) systems
• Some services in US operating in unlicensed
  spectrum, while same services are given primary
  use of the same spectrum (RLANs in the 5 GHz
  bands)
• FCC lets market decide in the US how best to deal
  with potential interference in these bands
• Primary and secondary user designation outside of
  US dictates that sharing must be regulated more
  explicitly
• Based upon current analysis and ITU process, it
  looks unlikely that FCC mask (or even ETSI mask)
  will be recommended by the ITU-R TG1/8
• Based upon above discussion, there are good
  reasons to have a different mask

11
Fixed Service Analysis Revisited

• Recall Fixed services occupy most of the
  spectrum in 3.1-8.5 GHz
• Obviously, this analysis has implications on most
  of the in-band spectrum currently allocated in
  the US
• A number of scenarios studied
• (1) Single indoor UWB device impact on indoor FS
  terminal at 1 meter separation distance
• (2) Single outdoor UWB device impact on outdoor
  FWA and P-P system
• (3) Multiple UWB devices in a multi-story office
  building near a FWA and P-P system
• (4) Multiple UWB devices in a residential area
  near a FWA and P-P system

12
Fixed Service Analysis Revisited

• Comments on Case (1) Single indoor UWB device
  impact on indoor FS terminal at 1 meter
  separation distance
• Current recommended PSD -70 dBm/MHz
• Suggest PSD used for frequencies up to 5 GHz
• However, main spectrum targeted for indoor FWA
  equipment (WiMax) would occupy only 3.4-3.6 GHz
• Based upon current criteria of I/N lt -6 dB,
  analysis supporting recommendation looks sound
• Potential mitigation techniques using adaptive
  detection and avoidance strategies could enable
  use of the spectrum on an opportunistic basis and
  prevent the need for a permanent notch
• Comments on Case (2) Single outdoor UWB device
  impact on outdoor FWA and P-P system
• Current recommendation (extrapolation from
  graphsnot explicit in doc.)
• FWA at 3.5 GHz -53 dBm/MHz
• PP at 4 GHz -60 dBm/MHz ( -53 dBm/MHz at 7.7
  GHz, -50 dBm/MHz at 10.5 GHz)
• Based upon current criteria of I/N lt -20 dB
• Does not take into account limited outdoor UWB
  device activity

13
Fixed Service Analysis Revisited

• Comments on case (3)
• Intel has contributed to text in Annex 3 showing
  the aggregating interference is significantly
  lower when considering realistic WPAN association
  models
• Currently, results have not been incorporated in
  recommendations

P-P aggregated interference from WPAN typical
deployment in comparison with the generic
hot-spot potential worst case.
20-25 dB difference
Trial of the revised Hot Spot scenario used for
the calculation of the aggregate power in this
UWB application
Simulations provided by Fabrice Labourasse,
Mikhail Lyakh, Oleg Semenov.
14
Fixed Service Analysis Revisited

• Comments on case (4) Multiple UWB devices in a
  residential area near a FWA and P-P system
• Assumptions
• Interference criteria I/N lt -20 dB
• Path loss model Free space
• 33 assumed LOS (included outdoor devices
  indoor through window propagation)
• 100 and 21 peak activity factors (for each
  device)
• Discussion includes potentially adding a 5 dB
  safeguard margin
• I/N lt -20 dB is already very conservative
• 5 dB safeguard margin does not seem necessary on
  top of conservative I/N lt -20 dB

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Fixed Service Analysis Revisited

• Comments on case (4) Impact of channel model and
  activity factor
• Note Using free space propagation, interference
  ? 8 as size area ? 8 (clearly not realistic)

Evaluation of interference to 4GHz P-P FS
receiver with different propagation models for
10000 indoor devs/km2, 5 activity factor
35 dB difference
Interference model for high density urban
environment
Rx int. level meeting I/N-20dB
Analysis and simulations not yet submitted to
TG1/8 planned contribution for November meeting.
Simulations provided by Fabrice Labourasse,
Mikhail Lyakh, Oleg Semenov.
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Take-aways

• Current ITU-R TG1/8 recommendations would make
  UWB unusable for high-rate communications
• There are a number of technical areas which merit
  revisiting in the analysis
• Activity factors
• Usage models
• Path loss models
• Balancing the aggregation of a number of
  conservative assumptions
• Balancing OOB emissions requirements for other
  services compared to in-band recommendations for
  UWB
• There may be other areas worth revisiting which
  are specific to a particular service (expected
  minimum separation distance, antenna responses,
  etc.)
• Some services may require emissions below FCC
  mask
• Indoor WiMax systems in 3.4-3.6 GHz !
• RAS ?
• RLAN in 5 GHz bands ?
• Many other services in ITU-R TG1/8 recommendation
  show a need for emissions below FCC maskresults
  after revisiting analysis based upon revisiting
  above areas are TBD

17
Working Documents and Timelines

• Current open working documents in the ITU-R TG1/8
• Compatibility Report
• Compatibility Recommendation
• Characteristics Recommendation
• Methodology Recommendation
• Regulatory Framework Recommendation
• ITU-R TG1/8 meetings

ITU-R Recommendations
Individual Country Proceedings / Authorizations
Current date to finalize Recommendations
(2 Interim Meetings)
9/29- 10/5
5/18- 5/27
11/4 11/10
2004 2005 2006 2007 2008
18
Implications and Call to Action

• Many countries are looking to the ITU-R TG1/8 to
  providing recommendations for specific country
  regulations
• It currently looks unlikely the FCC mask will be
  recommended, and for valid reasons
• ITU-R TG1/8 recommendations will have significant
  impact on the IEEE 802.15.3a standard, if we want
  this standard to meet international requirements
• We need to change the perception of UWB
  technology as a generic overlay technology
• UWB technology should be considered as a
  secondary or tertiary user of the available
  spectrum which is capable of re-using spectrum in
  a very localized area using a low transmit power
  spectral density (PSD)
• The low PSD enables the sharing and reuse of
  spectrum with services not expected to be in
  close proximity as long as the aggregation of
  multiple devices in realistic deployments does
  not cause harm
• UWB technology is not just below the noise
  floor of every device
• Some services which are expected to operate in
  very close proximity can cause harmful
  interference
• Aggregation of interference needs careful study,
  using realistic assumptions, to ensure all
  services are protected
• The UWB industry needs to work with users of the
  shared spectrum to come up with a mutually agreed
  upon sharing plan
• We will not succeed in creating a harmonized,
  useful set of regulations without engaging with
  and working with users of the spectrum we would
  like to share

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Implications and Call to Action

• Companies wishing to see UWB viable outside the
  US must engage with both local regulatory bodies
  and ITU-R task groups and working parties
• Both regulators and other companies (especially
  ones who may not have direct interest in UWB)
  must understand why UWB is necessary to support
  some applications
• The only way to achieve very high peak
  throughputs (future Gbps) at low cost and low
  power consumption at short range is to have
  available spectrum which is gt desired peak
  throughput
• Other technologies can achieve high throughputs,
  but not at the cost and complexity potentially
  achievable by UWB based systems
• Greater UWB industry support is needed to show
  the high level of interest and desire for this
  technology
• What can the IEEE do to help improve the current
  state of the ITU-R TG1/8 recommendations?
• What can your company do to help improve the
  current state of the ITU-R TG1/8 recommendations?