Geolocation Technologies Suitable to Meet Regulatory Requirements for TV White Spaces

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Geolocation Technologies Suitable to Meet
Regulatory Requirements for TV White Spaces
Authors
Abstract This tutorial is to be presented during
the IEEE 802 Plenary session on July 2011 in San
Francisco. It gives an introduction to the
accuracy requirements for geolocation in TV White
Space and an overview of geolocation techniques
that can be used for this purpose.
Notice This Document has been prepared to assist
the IEEE P802.22. 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. ReleaseThe
contributor acknowledges and accepts that this
contribution becomes the property of IEEE and may
be made publicly available by P802.22.
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Geolocation technologies suitable to meet
Regulatory Requirements for TV White Spaces

• FCC 10-174 Second Memorandum Opinion and Order
• 23 September 2010

15.711 (b) Geo-location and database access
requirements. (Page 65) (1) The geographic
coordinates of a fixed TVBD shall be determined
to an accuracy of /- 50 meters by either an
incorporated geo-location capability or a
professional installer. In the case of
professional installation, the party who
registers the fixed TVBD in the database will be
responsible for assuring the accuracy of the
entered coordinates. The geographic coordinates
of a fixed TVBD shall be determined at the time
of installation and first activation from a
power-off condition, and this information may be
stored internally in the TVBD. (2) A Mode II
personal/portable device shall incorporate a
geo-location capability to determine its
geographic coordinates to an accuracy of /- 50
meters. A Mode II device must also re-establish
its position each time it is activated from a
power-off condition and use its geo-location
capability to check its location at least once
every 60 seconds while in operation, except while
in sleep mode, i.e., in a mode in which the
device is inactive but is not powered-down. (3)
(4) All geographic coordinates shall be
referenced to the North American Datum of 1983
(NAD 83).
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Geolocation accuracy requirements for E911
FCC MOO 97-402, Revision of the Commission
Rules To Ensure Compatibility with Enhanced 911
Emergency Calling Systems
FCC 11-107, Third Report and Order, Second
Further Notice of Proposed Rulemaking and Notice
of Proposed Rulemaking

• Network-based geolocation technology(Triangulatin
  g the callers wireless signal in relation to
  nearby cell sites)
• 100 m accuracy 67 of the 911 calls (probability
  that the location would be within 100 m radius of
  the CPE actual location).
• 300 m accuracy 95 of the 911 calls.
• Handset-based geolocation technology(GPS or
  similar technology installed in the callers
  handset)
• 50 m accuracy 67 of the 911 calls.
• 100 m accuracy 95 of the 911 calls.

FCC E911 phase 2 accuracy requirements by Sept
11, 2012.
To be sunset in 2019.
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Geolocation accuracy vs fine ranging accuracy

• For a given geolocation error, the ranging error
  has to be smaller because geolocation methods/
  techniques can be subject to location geometry
  degradation.

Trilateration
Triangulation

• Assuming that the geometry degradation
  amplification is 2X (on average), the required
  ranging accuracy is /- 25 meters.
• In addition, the network device electronics
  propagation delays (residual delay) accuracy is
  assumend to be /- 30 ns. This results in /- 10
  meters ranging error
• In 802.22, this residual delay needs to be
  measured by the manufacturer with an accuracy
  ofat least /-30 ns (IEEE Std 802.22-2011,
  subclause 7.7.7.3.4.10.)
• Thus the required fine ranging accuracy needs to
  be /- 15 meters

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Coarse ranging use and limitations

• Ranging is used in communication systems to
• Adjust the frequency of the CPE transmitted
  signal
• Adjust the timing of the CPE transmitted signal
• Adjust the signal transmission power for proper
  reception
• Signal the modulation and FEC to be used for
  operation
• Ranging can also be used for a rough estimate of
  the signal flight time. However, the accuracy is
  limited, at best, to the signal sampling period

T1 time of transmission
T2 time of reception
Base Station
CPE Customer Premise Equipment
T4 time of reception
T3 time of transmission
Signal flight time 1/2 ((T4 - T1) - (T3 - T2))
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Satellite-based geo-positioning

• Global Positioning System (GPS)
• provides location and time information
• needs unobstructed line-of-sight (outdoor)
• need time to lock to at least 3 satellites
• Differential Global Positioning System (DGPS)
• is an enhancement to GPS that uses a network of
  fixed, ground-based reference stations to
  broadcast the difference between the positions
  indicated by GPS and the known fixed positions.
• Assisted Global Positioning System (AGPS)
• can improve the startup performance, or
  time-to-first-fix (TTFF) of a GPS positioning
  system. Uses terrestrial network resources to
  locate and utilize the satellites faster and
  improve performance in poor signal conditions.
  It is used extensively with GPS-capable cellular
  phones (E911). It can allow for some indoor
  operation.
• Russian GLONASS system
• European Galileo system

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Terrestrially-based geo-positioning

• Time-based
• Time of Arrival (TOA) terminal is at
  intersection of three circles centered at three
  BSs gt trilateration (need synchronous
  networks)(outdoor)
• Time Difference of Arrival (TDOA) terminal is at
  intersection of three hyperbola for which foci
  are at the three BSs gt trilateration(need
  synchronized BSs)(outdoor)
• Larger signal bandwidth (e.g., UWB) results in
  higher resolution ranging (indoor)

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Terrestrially-based geo-positioning

• Angle-based
• Angle of Arrival (AOA) smart and/or directional
  antennas used at two BSs gt triangulation
  (outdoor)
• Radio Map
• RSS Radio Map Off-line pre-calibration, on-line
  matching of RSS at BSs to identify location of
  terminal (urban indoor)
• Fingerprinting using local multipath signature
  (urban indoor)

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Terrestrially-based geo-positioning

• Other network-based positioning techniques
• Cell ID BS and sector with which the terminal is
  communicating
• Observed Time Difference of Arrival (OTDOA) (for
  UMTS networks)
• Uplink Time Difference of Arrival (U-TDOA)
  relies on multi-laterations
• Non network-based positioning technique
• Round Trip Time (RTT) total round-trip time from
  a BS to a CPE and back to the BS to determine the
  BS-CPE distance. Triangulation on multiple RTTs
  will allow geo-positioning (outdoor indoor).

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References

1. Guolin Sun, Jie Chen, Wei Guo, and K.J.Ray Liu,
   Signal Processing Techniques in Network-Aided
   Positioning, IEEE Signal Processing Magazine,
   July 2005
2. Hui Liu, Houshang Darabi, Pat Banerjee and Jing
   Liu, Survey of Wireless Indoor Positioning
   Techniques and Systems, IEEE Transactions on
   Systems, Man, and Cybernetics Part C
   Applications and Reviews, Vol. 37, No. 6,
   November 2007, pages 1067-1080
3. A. Roxin, J. Gaber, M. Wack, A. Nait-Sidi-Moh,
   IEEE Globecom Workshops Washington, DC (2007)