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					July 22, 2004                           doc.: IEEE 802.18-04-0030-02-0000




                IEEE 802.18 Radio Regulatory TAG


                Proposal for Part 15.244
        Cognitive Radio Operation in the TV Band




Submission                    Slide 1      John Notor, Cadence Design Systems, Inc.
 July 22, 2004                                               doc.: IEEE 802.18-04-0030-02-0000

Outline
• Introduction
• TV Band Incumbents
• Identifying Characteristics of Incumbents
• Elements of Cognitive Radio Operation
• Proposed Cognitive Radio Rules
• Analysis for Personal/Portable Devices
   – Operating Range of Personal/Portable Devices
   – Detection of DTV Signals
   – DFS Sensitivity vs DTV Service Contour Field Strength
   – Co-Channel Interference Range Margin
   – Terrain Blocking

• Analysis for Fixed Devices
• Wrap Up


Submission                                  Slide 2            John Notor, Cadence Design Systems, Inc.
    July 22, 2004                                           doc.: IEEE 802.18-04-0030-02-0000

Introduction

• On May 13, 2004, the FCC adopted ET Docket No. 04-186, “Unlicensed Operation
in the TV Broadcast Bands” in a Notice of Proposed Rulemaking (NPRM).
• As written, ET-04-186 proposes the following two classes of devices under a new
rules section, Part 15.244:
• Personal/Portable Devices
    –100 mW peak transmitter power, 400 mW peak EIRP (6 dBi antenna)
    –Transmission is permitted only when receiving a control signal indicating which TV
    channels are vacant from one of the following sources: a TV Broadcast station, an FM
    Broadcast station, or an unlicensed transmitter

• Fixed Access Devices
    –1 W peak transmitter power, 4 W peak EIRP (6 dBi antenna)
    –Must meet one of the following criteria
          –Include a GPS receiver and means of determining vacant TV channels in the area
          –Be installed by professionals to operate only on unused channels.

   Submission                                  Slide 3        John Notor, Cadence Design Systems, Inc.
    July 22, 2004                                     doc.: IEEE 802.18-04-0030-02-0000

Introduction

• Although ET 04-186 seeks comment on the possibility of using spectrum sensing,
and other cognitive radio techniques, to identify and avoid TV channels occupied by
an incumbent, and select channels for unlicensed operation, the Commission’s
proposed rules sections do not permit that approach.
• This presentation does the following:
    • Proposes a set of rules for an additional class of devices which permit
    cognitive radio technologies to be used in unlicensed devices operating in the
    TV band under Part 15.244.
    • Establishes that devices operating under these rules protect the operations of
    TV band incumbents based on widely available operational data and supporting
    analysis.




   Submission                             Slide 4       John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                     doc.: IEEE 802.18-04-0030-02-0000


TV Band Incumbents

• Full Service TV Broadcast Stations (CFR1 Title 47 Part 73).
     • Class A TV Broadcast Stations (CFR Title 47 Part 73 subpart J).
     • LPTV, TV Translator, TV Booster Stations, Auxiliary Operations, and Wireless
     Microphones (CFR Title 47 Part 74).
     • Private Land Mobile Radio Services (PLMRS) in 13 Metro Areas (CFR Title
     47 Part 90), including Public Safety communications systems.
     • Commercial Land Mobile Radio Services (CMRS) in 13 Metro Areas (CFR
     Title 47 Part 20).
     • Wireless Medical Telemetry Services (WMTS) (CFR Title 47 Part 95 subpart
     H).




  Submission                           Slide 5         John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                      doc.: IEEE 802.18-04-0030-02-0000


TV Band Incumbent Protection from Cognitive Devices
 • In order to insure that public safety operations are protected, Ch 14-20 are
   excluded from the proposed cognitive radio class of operation. If GPS were
   incorporated into these devices, the reasons for this exclusion could be
   overcome.
 • Wireless Medical Telemetry Services operate on Ch 37 within the TV band,
   which is excluded by the Commission’s proposed rules from Part 15.244
   device operations.
 • Wireless microphone operation as a Low Power Auxiliary Station under Part 74
   can protected by cognitive techniques, or by rule (assignment to specific
   channels in each service area, etc). This presentation does not address
   wireless microphones.
 • Wireless video assist devices are provided for as Low Power Auxiliary Devices
   in Part 74, but no equipment is presently authorized or licensed for operation.
   This class of equipment should be considered for termination.
 • The remaining incumbents are TV broadcast signals, which, because of their
   unique signatures (analog/NTSC, and digital/ATSC), are readily identifiable.
  Submission                            Slide 6         John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                                   doc.: IEEE 802.18-04-0030-02-0000


Analog TV (NTSC) Spectrum




 • Power primarily confined to Video and Audio carriers.
 • Distinctive double peaked spectrum makes identification by spectrum profiling relatively easy.
 • Relatively high narrowband power levels compared to DTV.



  Submission                                     Slide 7              John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                                    doc.: IEEE 802.18-04-0030-02-0000


Digital TV (ATSC) Spectrum




 • Power spread over center 5.38 MHz within a TV channnel.
 • Pilot tone is a distinctive feature when observed in a narrowband receiver.
 • Pilot tone power is 11.3 dB below average power measured in a 6 MHz bandwidth.

  Submission                                     Slide 8              John Notor, Cadence Design Systems, Inc.
      July 22, 2004                                                                        doc.: IEEE 802.18-04-0030-02-0000

Elements of Cognitive Radio Operation (1)
1.     Network Frequency Allocation (NFA):
     – Survey and monitor spectrum use patterns.
     – Avoid incumbents, operate network on an unused or lightly used channel.
2.      Link Power Control (LPC):
     – Keep network transmitter power low while maintaining good link quality.
     – LPC mitigates interference and promotes frequency reuse with networks located
       nearby.
3.      Incumbent Profile Detection (IPD):
     – Detect incumbent users based on specific spectrum signature (supports NFA)
          – Example: detecting the presence of a sound/video carriers in NTSC (analog TV)
            systems or a pilot tone in ATSC (DTV) systems.
4. Collision Detection And Avoidance (CDAA):
     – Transmitters wait until the channel is quiet before transmitting (“listen before talk”).
     – A receiving node acknowledges valid data by transmitting a response.
     – A transmitting node “detects” a collision if it does not receive an acknowledgement
       before a timeout occurs.
     – The protocol implements an appropriate backoff/retry timing mechanism for
       retransmission when a collision is detected.
     1. Notor, J., Radio Architectures for Unlicensed Reuse of Broadcast TV Channels, Communications Design Conference 2003.
     Submission                                                    Slide 9                    John Notor, Cadence Design Systems, Inc.
  July 22, 2004                                       doc.: IEEE 802.18-04-0030-02-0000

Proposed Cognitive Radio Rules
• These rules extend the FCC’s proposed rules for Part 15.244 devices to
  authorize cognitive radio techniques.
• Dynamic Frequency Selection (DFS) threshold: a TV channel shall be
  considered unoccupied when the electric field strength at the receiving antenna
  is less than the following averaged for 10 ms over the entire 6 MHz channel.
  – For Ch 5-6, E(dBu) < -7 dBuV/m/10 kHz
  – For Ch 7-13, E(dBu) < 1 dBuV/m/10 kHz
  – For Ch 21-51, excluding Ch 37 E(dBu) < 11 dBuV/m/10 kHz

• To operate on a channel whose ambient field strength is greater than the DFS
  threshold, the cognitive device must, using appropriate Incumbent Profile
  Detection techniques, verify that the channel is not being occupied by either an
  analog or a digital TV signal.
• The cognitive radio network shall give priority to operation on empty or lightly
  occupied channels.



 Submission                            Slide 10          John Notor, Cadence Design Systems, Inc.
  July 22, 2004                                            doc.: IEEE 802.18-04-0030-02-0000


Proposed Cognitive Radio Rules
• Transmit Power Control (TPC)
  – Link Power Control protocols must be included in the cognitive radio devices to
    minimize transmitter power while supporting reliable communications between any
    transmitter and any single receiver.
  – The LPC protocol operation shall cause the transmitter in any single node to single
    node link to begin reducing output power when the signal level at the receiver is
    greater than 20 dB above the receiver’s nominal sensitivity.
  – The TPC function shall keep the signal level at the receiver less than 30 dB above
    the receiver’s nominal sensitivity at least 50% of the time, including the impact of any
    regular broadcast operations (transmission from a controlling node to all other
    nodes).
• Listen Before Talk
  – The transmitters must operate in burst mode, with a maximum continuous burst
    length less than 1 second.
  – Cognitive radio devices must monitor the operational channel periodically to verify
    that the channel remains unoccupied by an analog or digital TV signal.



 Submission                                Slide 11           John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                          doc.: IEEE 802.18-04-0030-02-0000

Analysis for Personal/Portable Devices

• The following analyses establishes the performance limits of cognitive radio
  operation for personal/portable devices:
   – Expected loss exponent (L.E.) for personal/portable operation.
   – Detection performance for DTV signals.
   – DFS sensitivity margin.
   – Co-channel interference range margin.
   – Terrain blocking footprint and issues.




  Submission                                  Slide 12      John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                                                     doc.: IEEE 802.18-04-0030-02-0000

Operating Range of Personal/Portable Devices
Table 1: Range data based on customer survey information (2)




      2. Table provided by Southern Communications and Electronics at the following web site:
      http://www.southernce.com/cgi-bin/SoftCart.exe/range.htm?L+scstore+josy3749+1088643303

  Submission                                                 Slide 13                    John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                                                       doc.: IEEE 802.18-04-0030-02-0000

Operating Range of Personal/Portable Devices
• A simple model(3) for path loss, L, assuming a single average loss exponent,
  LE, vs distance, and isotropic transmit and receive antennas.
  – Path loss vs d: L = Lo + 10*LE*log(d)
        – L is the difference between the transmitter PA output power, Pt, and the receiver
          input signal level, Pr
        – Lo = 20*log(4*pi*f/c)
        – Lo is the transmission loss at 1 m
        – f is the transmission center frequency in Hz
        – c is the velocity of light in free space, ~ 3*108 m/s
        – d is distance in m.
• So, for transmitter power, Pt, and received signal at the output of the receive
  antenna, Pr:
  – LE = (Pt – Pr – Lo)/[10*log(d)]

  3. Perez-Vega & Zamanillo, Path - Loss Model for Broadcasting Applications and Outdoor Communication Systems in the VHF and UHF Bands,
  IEEE Transactions on Broadcasting, Vol 48, No 2, June 2002.

  Submission                                                   Slide 14                    John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                            doc.: IEEE 802.18-04-0030-02-0000

Operating Range of Personal/Portable Devices
• VHF Loss Exponent estimates based on the operational characteristics of
  MURS radio handsets (151.820 MHz < fc < 154.600 MHz).
  – Sensitivity: 0.2 uV at limit of range, or -121 dBm
  – Antenna Gain: 0 dBi
  – Tx Power: 2 W (+33 dBm)
  – Pt – Pr = 33 – (-121) = 154 dB at the limit of range.
  – Lo = 16.1 dB at 153 MHz
  – Loss Exponent (LE) = (154 -16.1)/[10*log(d)], where d is the range in m.
• Table 2: Anecdotal range data based on Table 1 with loss exponent:
    Est. Range (m)    LE    Conditions
         6436         3.6   Outdoors, clear flat terrain
         3620         3.9   Suburban outdoor environments
         2011         4.2   Urban outdoor environments
          805         4.7   Inside shopping mall


  Submission                                  Slide 15        John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                                 doc.: IEEE 802.18-04-0030-02-0000

Operating Range of Personal/Portable Devices
• UHF Loss Exponent estimates based on the operational characteristics of FRS
  radio handsets (462.5625 MHz < fc < 467.7125 MHz).
  – Sensitivity: 0.2 uV at limit of range, or -121 dBm
  – Antenna Gain: 0 dBi
  – Tx Power: 500 mW (+27 dBm)
  – Pt – Pr = 27 – (-121) = 148 dB at the limit of range.
  – Lo = 25.8 dB at 465 MHz
  – Loss Exponent (LE) = (148 - 25.8)/[10*log(d)], where d is the range in m.
• Table 3: Anecdotal range data from various sources with loss exponent:
  Data Source      Est. Range (m)   LE    Conditions
  Manufacturers        3218         3.5   Over water
  McGuinn              2413         3.6   Hotel to hotel, 15th story room to lobby, Disney World
  Various              1609         3.8   Normal cluttered outdoor environment
  Notor                 984         4.1   Outdoors in Willow Glen Neighborhood, San Jose, CA
  Other                 402         4.7   Inside shopping mall

  Submission                                 Slide 16              John Notor, Cadence Design Systems, Inc.
  July 22, 2004                                             doc.: IEEE 802.18-04-0030-02-0000

Operating Range of Personal/Portable Devices

• VHF/UHF Loss Exponent (LE) range: 3.5 – 4.7
• Loss exponents by environment:
  – Outdoor Clear flat terrain: LE = ~ 3.5
  – Outdoor suburban/urban environment: LE = 3.8 – 4.2
  – Indoor to indoor, 15th floor hotel room to hotel lobby: LE = 3.6
  – Inside shopping mall: 4.7
• Operational experience based on loss exponent analysis tracks well between
  VHF and UHF portable radios.




 Submission                                  Slide 17         John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                           doc.: IEEE 802.18-04-0030-02-0000

Detection of DTV Signals

• DTV is the limiting case re: DFS/IPD for TV signals.
• Receiver Assumptions:
  – CNR: 6 dB is sufficient for detection of a narrowband signal like an ATSC pilot tone.
  – NF: 5 dB
  – Antenna Gain: 0 dBi
  – Predetection Bandwidth: 10 kHz
  – Post Detection Time Constant: 10 ms
  – Square Law Detector
• Sensitivity Calculation (CNR = 6 dB)
     S = -174 dBm/Hz + 10log(10 kHz) + 5 dB + 6 dB
     S = -123 dBm




  Submission                               Slide 18          John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                          doc.: IEEE 802.18-04-0030-02-0000

Detection of DTV Signals

• For a DFS detection threshold of -123 dBm/10 kHz applied to identifying a
  DTV signal by detecting the pilot tone, the equivalent clear channel DFS
  threshold for a DTV signal becomes:
  – DTV DFS = -123 dBm + 11.3 dB = -111.7 dBm ~ -112 dBm in a 6 MHz bandwidth
  – -112 dBm is below the thermal noise floor for a 6 MHz bandwidth, i.e. Np = -174
    dBm + 10log(6 MHz) = -106.2 dBm > -112 dBm, but the analysis remains valid,
    since the pilot tone can be detected in a 10 kHz bandwidth.
• Assuming a 0 dBi antenna and a 50 Ohm reference impedance, the equivalent
  DFS threshold in terms of electric field strength in a 6 MHz bandwidth is
  – E(dBu) = P(dBm) + 20log[f(MHz)] + 77.2
  – For Ch 6, E(dBu) = -112 + 20log[85] + 77.2 = 4 dBuV/m
  – For Ch 13, E(dBu) = 12 dBuV/m
  – For Ch 51, E(dBu) = 22 dBuV/m



  Submission                              Slide 19          John Notor, Cadence Design Systems, Inc.
      July 22, 2004                                                                     doc.: IEEE 802.18-04-0030-02-0000

DFS Sensitivity Margin - Personal/Portable Devices

• The sensitivity margin relative to the minimum in-service DTV field strength for a 30
  ft high receive antenna is:
  – For Ch 6, margin = 28 – 4 = 24 dB
  – For Ch 13, margin = 36 – 12 = 24 dB
  – For Ch 51, margin = 41 – 22 = 19 dB
• For a receiver outdoor antenna height of 2 m (nomadic personal/portable device),
  reduce the sensitivity margin by a 9 dB correction factor (4).
• Table 4 (p.19) shows sensitivity margin calculations for various stations in the FCC
  database, using the FCC calculator at: http://www.fcc.gov/mb/audio/bickel/curves.html.
• The DFS detector operating outdoors with an antenna height of 2 m can sense a
  TV channel outdoors at ranges > 21% farther than the service contour (Table 4) in
  unobstructed terrain.


    4. Mehrotra, A., Cellular Radio Performance Engineering, Artech House, 1994, p146

     Submission                                                     Slide 20              John Notor, Cadence Design Systems, Inc.
       July 22, 2004                                                                              doc.: IEEE 802.18-04-0030-02-0000


 Table 4: DFS Sensitivity Margin – Personal/Portable Devices
                                                                                       Service                                       DFS        DFS

                                                                                        Area       Contour     DFS (5)     DFS      Range      Range

                                        DTV        Band        HAAT         ERP         Limit       Range       Limit     Range     Margin     Margin

Station, Locale                          Ch       (MHz)          (m)        (kW)        (dBu)        (km)       (dBu)      (km)      (km)        (%)

WCFT-TV, Tuscaloosa, AL                   5        76-82       625.4         9.5          28        128.7        12       182.4       53.7      41.7%

KNSO, Merced, CA                          5        76-82       575.0        11.0          28        126.5        12       181.7       55.2      43.6%

KYES, Anchorage, AK                       6        82-88       277.0        45.0          28        120.5        13       180.5       60.0      49.8%

WEDY, New Haven, CT                       6        82-88        88.0         0.4          28         56.0        13        83.9       27.9      49.8%

KMBC-TV, Kansas City, MO                  7      174-180       357.0        85.0          36        114.7        19       173.6       58.9      51.4%

KNTV, San Jose, CA                       12      204-210       376.6        103.1         36        118.2        20       174.7       56.5      47.8%

WDAF-TV,Kansas City, MO                  34      590-596       295.0       1000.0         41         96.2        30       125.1       28.9      30.0%

KLCS, Los Angeles, CA                    41      626-632       900.8        162.0         41        115.5        30       140.5       25.0      21.6%

WMSY-TV, Marion, VA                      42      638-644       448.0        100.0         41         89.8        30       112.9       23.1      25.7%

KWDK, Tacoma, WA                         42      638-644       695.0        144.0         41        107.0        31       129.7       22.7      21.2%

WTVX, Fort Pierce, FL                    50      686-692       438.3        704.0         41        106.0        31       132.2       26.2      24.7%

KOPX, Oklahoma City, OK                  50      686-692       483.0        200.0         41         97.8        31       120.1       22.3      22.8%

KDTV, San Francisco, CA                  51      692.698       701.0        476.3         41        118.5        31       144.1       25.6      21.6%
5. The DFS limit is calculated at a 2 m antenna height, assuming a 9 dB loss relative to signal strength at 30 ft (~9 m). So, for Ch 6, DFS Limit =4
dBuV/m + 9 dB =13 dBu. These calculations exclude terrain blockage effects.

      Submission                                                        Slide 21                      John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                           doc.: IEEE 802.18-04-0030-02-0000

Co-Channel Interference Range Margin
• Part 15.244 Device Tx Operating Parameters:
  – EIRP: 400 mW, or +26 dBm
  – E(dBu) = 104.8 + EIRP(dBm) – 20*log(d) = 131 dBu at d = 1 m.
  – Loss exponent (LE): 3.5 (lower limit of operational experience for portable devices).
• DTV Co-channel D/U: 23 dB at the edge of the service area.
• Maximum allowed co-channel interference field strength at the edge of the
  service contour (Full service DTV)
  – Ch 5-6: 28 – 23 = 5 dBu
  – Ch 7-13: 36 – 23 = 13 dBu
  – Ch 14-51: 41 – 23 = 18 dBu
• Interference Range (R), LE = 3.5, to DTV co-channel D/U = 23 dB limit
  – Ch 5-6: R = 10[(131 – 5) / 35] = 3.9 km
  – Ch 7-13: R = 10[(131 – 13) / 35] = 2.4 km
  – Ch 14-51: 10[(131 – 18) / 35] = 1.7 km

  Submission                                    Slide 22      John Notor, Cadence Design Systems, Inc.
    July 22, 2004                                      doc.: IEEE 802.18-04-0030-02-0000

Co-Channel Interference Range Margin

• FCC propagation calculations indicate that a unlicensed spectrum sensing
  device operating outdoors can sense a DTV signal 22-60 km outside the service
  contour of a DTV station, excluding terrain blocking effects.
• The optimistic range, LE = 3.5, of a Part 15.244 personal/portable transmitter,
  operating outdoors at a +26 dBm EIRP, to the field strength limit for an
  undesired co-channel signal within a service contour is 1.7 km to 3.9 km, also
  excluding terrain blocking effects.
• In nominal urban or suburban areas, where more obstructions exist, LE = ~ 4,
  and the range is more like 668 m to 1.4 km.
• So, DTV services areas are protected by a buffer zone (excluding terrain
  blockage effects) of greater than 18 km using spectrum sensing techniques.




   Submission                           Slide 23         John Notor, Cadence Design Systems, Inc.
  July 22, 2004                            doc.: IEEE 802.18-04-0030-02-0000

Co-Channel Interference Range Margin
                                                     Limit of DFS
                                                     Sensing Capability


                               DFS Range Margin:
  DTV Service Area
                               22-60 km




                         D/U Range Margin:
 Edge of                 20-56 km
 Service                                         Cognitive Radio Range to
 Contour                                         23 dB D/U Limit

                                       R     1.7 < R < 3.9 km
                                             (+26 dBm EIRP, LE = 3.5)




 Submission                 Slide 24         John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                                                           doc.: IEEE 802.18-04-0030-02-0000

Terrain Blocking
• Reduces the available signal level significantly in the blocked area relative to
  adjacent unblocked areas due to terrain features: mountains, buildings, interior
  walls. Example terrain blocking losses:
  – 40 dB over an 8 km stretch in Virginia for 50% of the cases, much fewer instances of
    40 dB change for smaller geographic segments (6)
  – 37 dB over a ~ 4 km stretch in Boulder, CO (7) (see p24)
  – 27 dB over an ~ 2.4 km stretch                     (8)   in Boulder, CO (see p.25)
  – 10 dB for building shadowing losses, and 10-20 dB for building penetration losses (9,10)
    (see p 26).

      Note: For the data in Table 5, the indoor antenna was placed next to a window on the same side of
      the building where the outdoor signal strength was measured, which tends to produce more
      optimistic results than otherwise.
• Reduces the range margin at the edge of a service contour over that available in
  an unblocked situation.
  6. McHenry & Byrnes, Shared Spectrum Company Comments to FCC ET-02-380, p9
  7. Holoway, Sanders, & McKenna, NTIA Report 01-387, p24 and Figure 14
  8. Holoway, Sanders, & McKenna, NTIA Report 01-387, p24 and Figure 16
  9. McHenry & Byrnes, Shared Spectrum Company Comments to FCC ET-02-380, p.6
  10. Salehian, Khalil, Comparison Between the Field Strength of DTV Signals Inside and Outside of the
  Buildings, Communications Research Centre Canada.

  Submission                                                      Slide 25                     John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                                                     doc.: IEEE 802.18-04-0030-02-0000

Geographic Terrain Blocking
                                                                                    ~ 4 km


                                                                                                              1.3 V/m



                                                                                                             37 dB

                                                                                                              0.018 V/m




               Figure 14 reproduced from Holoway, Sanders, & McKenna, NTIA Report 01-387

  Submission                                                 Slide 26                      John Notor, Cadence Design Systems, Inc.
  July 22, 2004                                                                      doc.: IEEE 802.18-04-0030-02-0000
Geographic Terrain Blocking
                                                                        ~ 2.4 km




                                                                                                          1.2 V/m

                                                                                                         27 dB


                                                                                                           0.055 V/m




              Figure 16 reproduced from Holoway, Sanders, & McKenna, NTIA Report 01-387

 Submission                                                  Slide 27                     John Notor, Cadence Design Systems, Inc.
      July 22, 2004                                                                               doc.: IEEE 802.18-04-0030-02-0000

Terrain Blocking By Buildings
Table 5: Outdoor to Indoor Propagation Data (11)
  Site  Outdoor Outdoor                Indoor (dBm)       Floor # Outdoor 10 m Outdoor 10 m -                  Outdoor 2 m - Outdoor 10 m -
 Number 10 meters 2 meters                                        - Outdoor 2m Indoor Floor 2-4                Indoor Floor 1 Indoor Floor 1-4
         (dBm) (dBm)                                                  (dB)          (dB)                           (dB)            (dB)

     2         -54.6        -72             -62.2             2            17.4                 7.60                                7.60
     3          -71         -77              -70              2              6                 -1.00                                -1.00
     4         -35.3       -47.2             -51              1            11.9                                         3.80        15.70
                                            -34.6             2                                -0.70                                -0.70
     5          -47         -67             -60.4             1             20                                          -6.60       13.40
                                            -58.1             2                                11.10                                11.10
     6         -37.7       -53.2            -46.1             2            15.5                 8.40                                8.40
     7         -69.2       -74.3             -67              2             5.1                -2.20                                -2.20
     8         -44.9       -63.1            -61.9             1            18.2                                         -1.20       17.00
                                            -54.2             2                                 9.30                                 9.30
     9         -50.2       -60.5            -58.9             4            10.3                 8.70                                8.70
                                                          Average         13.44                 5.15                    -1.33       7.94
                                                            Min            5.10                -2.20                    -6.60       -2.20
Notes:
                                                            Max           20.00                11.10                    3.80        17.00
1. Sites 1-8 are 1-2 story single family brick homes.
                                                          Std Dev          5.63                 5.45                    5.20        6.65
2. Site 9 is a tall concrete apartment building.


(11) Ibid, adapted from the original CRC Canada report, including the addition of the last three columns of analysis.
    Submission                                                          Slide 28                       John Notor, Cadence Design Systems, Inc.
  July 22, 2004                                           doc.: IEEE 802.18-04-0030-02-0000

Terrain Blocking Mitigation
• Limit transmit power of personal/portable devices.
   – At +26 dBm EIRP, the optimistic range of personal/portable devices to the co-
     channel D/U threshold is 2.4 to 3.9 km in clear, flat terrain (LE = 3.5).
   – In environments where terrain is irregular, LE ~ 4 and the range is more like 668 m
     to 1.4 km (see slide 30).
   – Using TPC reduces the interference range by reducing network aggregate
     transmitter power, decreasing the likelihood of interference.
   – Burst mode operation reduces the impact of transmissions to DTV operation relative
     to the assumption of continuous operation built into the D/U regulatory limits.
• Require all devices to include DFS/IPD capability, not just access points, and
  a DFS/IPD spectrum survey sharing mechanism across the network.
   – If all devices include DFS/IPD capability and include an information sharing
     mechanism, the spectrum sensing footprint is increased, reducing the probability
     that an occupied channel will go undetected.
   – Avoids the possibility of a shadowed master control device accidentally trying to set
     up the network co-channel with a TV broadcast incumbent.



 Submission                               Slide 29           John Notor, Cadence Design Systems, Inc.
   July 22, 2004                                                doc.: IEEE 802.18-04-0030-02-0000

Co-Channel Interference in Blocked Terrain

                   DTV Service Area




                                                    Terrain Shadow
                      Lb
                                                Personal/portable device range to
                                                23 dB D/U in uneven terrain, LE ~ 4,
                                                668 < R < 1.4 km at +26 dBm EIRP
Edge of
Service
Contour

                           Shadow Depth (dB)         Lb (km)
                                  27                      2.4
                                  37                      4.0
                                  40                      8.0

  Submission                                   Slide 30           John Notor, Cadence Design Systems, Inc.
    July 22, 2004                                       doc.: IEEE 802.18-04-0030-02-0000

 Analysis for Fixed Devices

• The following analyses establishes the performance limits of cognitive radio
  operation for fixed devices:
  – DFS sensitivity margin.
  – Co-channel interference range margin.
  – Terrain blocking footprint and issues.




   Submission                                Slide 31     John Notor, Cadence Design Systems, Inc.
      July 22, 2004                                      doc.: IEEE 802.18-04-0030-02-0000

DFS Sensitivity Margin – Fixed Devices

• The sensitivity margin relative to the minimum in-service DTV field strength for a 30
  ft high receive antenna is:
  – For Ch 6, margin = 28 – 4 = 24 dB
  – For Ch 13, margin = 36 – 12 = 24 dB
  – For Ch 51, margin = 41 – 22 = 19 dB
• Table 6 (p.32) shows sensitivity margin calculations for various stations in the FCC
  database, using the FCC calculator at: http://www.fcc.gov/mb/audio/bickel/curves.html.
• The DFS detector operating outdoors with an antenna height of 30 ft (~9 m) can
  sense a TV channel outdoors at ranges > 46% farther than the service contour
  (Table 6) in unobstructed terrain.




     Submission                            Slide 32         John Notor, Cadence Design Systems, Inc.
         July 22, 2004                                                                           doc.: IEEE 802.18-04-0030-02-0000

   Table 6: DFS Sensitivity Margin – Fixed Devices

                                                                                   Service                                        DFS      DFS
                                                                                     Area      Contour     DFS     DFS(12, 13)   Range    Range
                                      DTV        Band        HAAT        ERP         Limit     Range       Limit    Range        Margin   Margin
Station, Locale                        Ch       (MHz)         (m)        (kW)        (dBu)       (km)      (dBu)      (km)       (km)       (%)
WCFT-TV, Tuscaloosa, AL                 5        76-82       625.4        9.5         28        128.7       3        224.1        95.4    74.1%
KNSO, Merced, CA                        5        76-82       575.0       11.0         28        126.5       3        226.0        99.5    78.7%
KYES, Anchorage, AK                     6        82-88       277.0       45.0         28        120.5       4        246.4       125.9    104.5%
WEDY, New Haven, CT                     6        82-88       88.0         0.4         28        56.0        4         104         48.0    85.7%
KMBC-TV, Kansas City, MO                7      174-180       357.0       85.0         36        114.7       10       233.8       119.1    103.8%
KNTV, San Jose, CA                     12      204-210       376.6      103.1         36        118.2       11       233.8       115.6    97.8%
WDAF-TV,Kansas City, MO                34      590-596       295.0      1000.0        41        96.2        21       164.3        68.1    70.8%
KLCS, Los Angeles, CA                  41      626-632       900.8      162.0         41        115.5       21       171.9        56.4    48.8%
WMSY-TV, Marion, VA                    42      638-644       448.0      100.0         41        89.8        21       136.5        46.7    52.0%
KWDK, Tacoma, WA                       42      638-644       695.0      144.0         41        107.0       22       156.7        49.7    46.4%
WTVX, Fort Pierce, FL                  50      686-692       438.3      704.0         41        106.0       22        166         60.0    56.6%
KOPX, Oklahoma City, OK                50      686-692       483.0      200.0         41        97.8        22       146.3        48.5    49.6%
KDTV, San Francisco, CA                51      692-698       701.0      476.3         41        118.5       22       177.3        58.8    49.6%

12. The FCC calculator won't accept E field levels less than 10 dBu, so for channels 5 and 6, ERP was increased by a factor of 4, and 10 dBu was
   used as the DFS Limit for the calculation of range,.
13. DFS Range assumes a 30 ft receiver antenna height for the fixed antenna.




        Submission                                                      Slide 33                     John Notor, Cadence Design Systems, Inc.
    July 22, 2004                                                     doc.: IEEE 802.18-04-0030-02-0000

 Interference Range Margin – Fixed Devices
• Table 7 shows the interference range margin for 23 dB D/U, assuming 30 m base
  station antenna height and 9 m client antenna height.
• Unlicensed device range to D/U limit were calculated using the NTIA Irregular
  Terrain Model in area prediction mode, using the reverse calculation, 50% of the
  locations, 50% of the time.
• The D/U range margin is 15.6 – 93.3 km (see p34).

Table 7: Interference Range Margin

                                                                       Range to         DFS             D/U

      TV                               D/U                 Required    D/U limit       Range           Range

    Channel     Center Freq   E@1m    E limit               Loss         ITM           Margin          Margin

                    (MHz)     (dBu)   (dBu)                  (dB)        (km)           (km)            (km)

      6              85       140.8     5                   135.8        32.4            48             15.6

      12            207       140.8     13                  127.8        22.3           115.6           93.3

      51            695       140.8     18                  122.8        17.1           58.8            41.7


   Submission                                   Slide 34                 John Notor, Cadence Design Systems, Inc.
  July 22, 2004                                doc.: IEEE 802.18-04-0030-02-0000

Co-Channel Interference Range Margin
                                                         Limit of DFS
                                                         Sensing Capability

                                       DFS Margin:
  DTV Service Area                     48–116 km




                         D/U Range Margin:
                         15.6–93.3 km
 Edge of
 Service                                             Cognitive Radio Range to
 Contour                                             23 dB D/U Limit


                                           R
                                                    17.1 < R < 32.4 km
                                                    (+36 dBm EIRP)



 Submission                 Slide 35             John Notor, Cadence Design Systems, Inc.
  July 22, 2004                                         doc.: IEEE 802.18-04-0030-02-0000

Wrap Up

• Based on the proposed rules, the operational data, and the analysis presented
  herein, cognitive devices using spectrum sensing techniques can reliably
  operate in the TV band without causing interference to TV broadcast channels.
• The cognitive radio mode of operation is proposed as an addition to the rules
  for Part 15.244 devices already proposed by the FCC in the TV Band NPRM.
• The application of cognitive radio technology to TV band unlicensed operation
  is an important step in realizing the full potential for a wide range of centralized
  and distributed networks utilizing otherwise unoccupied spectrum.




 Submission                             Slide 36          John Notor, Cadence Design Systems, Inc.
  July 22, 2004                                           doc.: IEEE 802.18-04-0030-02-0000

Acknowledgements
 • The following organizations and individuals were immensely helpful in
   preparing this presentation:
    – The Berkeley Wireless Research Center, especially
        – Professor Robert W. Brodersen
        – Gary Kelson
        – Danijela Cabric’
    – The Communications Research Centre Canada, especially
        – Gerald Chouinard
        – David Rogers
        – Khalil Salehian
    – Intel Corporation, especially
        – Jeffrey Schiffer
        – Alan E. Waltho




 Submission                               Slide 37          John Notor, Cadence Design Systems, Inc.
  July 22, 2004                                         doc.: IEEE 802.18-04-0030-02-0000

Acknowledgements
      – Shared Spectrum Corporation, especially
              – Mark McHenry
              – William Byrnes
      – Professor Adam Wolisz, Technische Universitat Berlin
      – Michael Lynch, Nortel
      – Denis Kuwahara, Boeing




 Submission                             Slide 38          John Notor, Cadence Design Systems, Inc.

				
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