TV Repack & ATSC 3.0 SFNs and Future Proofing Antennas
Lou i s iana & M iss i s s ipp i Assoc ia t i ons o f B roadcas te r s
TV Eng inee r ing Con fe rence
Ch r i s t ine Zuba J une 2 , 2016
AGENDA
• The Process
• Proposal and budgeting
• Antenna considerations
• Transmission line considerations
• Inside RF
• 3.0 Future proofing
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INCENTIVE AUCT ION T IMEL INE
Event Current EstimateReverse Auction Initial Commitment Deadline March 29, 2016FCC Announces Initial Clearing Target Late April 2016FCC Sends Confidential Letters to Applicants April/May 2016FCC Holds Mock Auction(s) May 2016Reverse Auction Clock Rounds Begin May 2016Reverse Auction Clock Rounds End June/July 2016Forward Auction Begins June/July 2016
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HOW MANY STAT IONS D IRECTLY IMPACTED?
Spectrum Recovered
MHz
Highest Remaining TV Channel
Full Power
Stations
Class AStations
Total Stations Directly
Impacted*84 36 593 144 737
108 32 656 162 818114 31 695 164 859126 29 922 211 1133
Directly impacted stations are those currently assigned to spectrum that is to be cleared for wireless services
*Some will be participating in the auction thus reducing the number of directly impacted stations
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WHAT’S NEXT – STAT IONS ON THE MOVE
EventFile CP for Modified Facility 3 months after
reassignment PNPost-Auction Filing Windows (channel changes or expanded facilities)
• Window 1: Stations unable to meet technical parameters in reassignment PN
• Window 2: All other stations assigned to new channels
After staff processes initial applications
Construction Deadline Up to 39 mos. after reassignment PN
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REIMBURSEMENT PROCEDURE
Estimate of Reimbursement Costs– Must be submitted via LMS within three months of
Reassignment PN– Specific cost items:
• Transmitter• Antenna• Transmission Line• Tower Equipment and Rigging• Outside Professional Costs• Other Expenses
– For costs outside catalog, must submit supporting evidence and certify estimate made in good faith
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A TYP ICA L DTV TRANSMISS ION PLANT
• Basic transmission system blocks:• External RF Items:
• Mask Filter• RF Combiner• Transmission line• Antenna
ProgramMaterial
(Video, Audio,Data)
RFPOWERAMPLIFIER
RF
Control
Power Supplies
TRANSMITTER
Cooling
MASK FILTER COMBINER TRANSMISSION
LINE
Other transmitter(s)(if applicable)
ANTENNA
RFEXCITERLP
FILT
ER
• Transmitter, comprising:• Exciter• Amplifier• Power Supplies• Control• Cooling System
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WHAT’S IMPACTED BY REPACK?
ProgramMaterial
(Video, Audio,Data)
RFPOWERAMPLIFIER
RF
Control
Power Supplies
TRANSMITTER
Cooling
MASK FILTER COMBINER TRANSMISSION
LINE
Other transmitter(s)(if applicable)
ANTENNA
RFEXCITERLP
FILT
ERVery Likely
Very Likely
Likely100%Very
Likely
Possibly
• If moving from an affected channel to a new one:• The following items will need to be looked at
for retune or replacement:
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ANTENNA CONSIDERATIONS
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COVERAGE REPL ICAT ION
𝑃𝑟=𝑃 𝑡𝐺𝑡𝐺𝑟 𝜆2
(4𝜋 𝑅)2
1 MW ERP AT CH49 WILL BE ALLOCATED 687 KW ERP AT CH 25
• OET-69 “dipole factor”
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LOWER CHANNEL ANTENNA WITH SAME GA IN
Channel 51TFU-30JTH-R O4Ø10.75” Pipe27 Gain
(EPA) = 42.4 ft2
W = 3800 lbs.
ERP = 1 MWTPO = 37 kW
45.2 ft.
Channel 24TFU-30JTH-R O4Ø14” Pipe27 Gain
(EPA) = 68.7 ft2
W = 7000 lbs.
ERP = 588 kWTPO = 22 kW
58.3 ft.
REQUIRES LARGER HEAVIER ANTENNA
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LOWER CHANNEL ANTENNA - SAME WIND -LOAD
Channel 51TFU-30JTH-R O4Ø10.75” Pipe27 Gain
(EPA) = 42.4 ft2
W = 3800 lbs.
ERP = 1 MWTPO = 37 kW
45.2 ft.
Channel 24TFU-22JTH-R O4Ø10.75” Pipe20 Gain
(EPA) = 45.0 ft2
W = 3600 lbs.
ERP = 588 kWTPO = 29 kW
43.5 ft.
SAME SIZE AND WINDLOAD – LOWER GAIN
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ANTENNA PLANNING PROCESS
BroadcasterAntenna Supplier
Structural Engineer
Other Tower Tenants
Tower Owner
RF Engineering Consultant
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RF INFORMATION REQUIRED FOR ANTENNA PROPOSAL
• Channel• ERP• Polarization• Pattern to
match (if directional)
• F or G code
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TOWERS AND ANTENNAS
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• Basic Wind Speed• Antenna Elevation on Tower• Design Ice• Tower Height• Structure Class• Exposure Category• Topographic Category• Height of Crest Above Average Terrain• Seismic Spectral Response Acceleration
Site Criteria Needed for 222-G Antenna Proposal:
Much more Site Design Information is required from Broadcasters and/or Tower Engineers in 222-G
FUTURE PROOFING
• ATSC 3.0 Compatibility– Higher PAPR – need higher voltage
standoff in line and antenna– Wider bandwidth – be sure filters and
channel combiners are ready• Add V-POL to antenna ?• Single frequency Network ?
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4KUHDTV
Fundamentally change the way U.S. Broadcast TV is delivered.
Merging internet with broadcast with• More flexibility• More services• More robust delivery • More platforms
More bits to more places
More signal strength
MORE, MORE, MORE
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PAPR
• PAPR is “peak to average power ratio”
• “Crest factor” is voltage defined – therefore 3dB higher
• Common to measure at 0.01%
• ATSC 1.0 – 6 dB to 7 dB • ATSC 3.0 – 8.4 dB (7x)
10.0 dB (10 x) 11.0 dB (12 x) 13.0 dB (20 x)
?
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OCCUPIED BANDWIDTH
• ATSC 1.0 – 5.38 MHz• ATSC 3.0 – 5.832 MHz (ref ATSC S32-230r45, 4-6-
16)• FCC emission requirements unchanged
Ripple bandwidth
• Most six pole mask filters have adequate ripple bandwidth to pass 5.83 MHz
• Existing 6 pole filters OK • Tx needs 36 dB shoulders
• Thermal stability more important
Purpose is not to establish next generation planning factors
FCC ATSC A/53 minimum field strength 41 dBuReduce antenna height 30ft. to 6ft. 7 dBBuilding wall attenuation (10-28 dB) 15 dBSmaller inefficient receive antenna gain (-3 dBd) 9 dBMultipath (AWGN to Ricean / Rayleigh) (1-3 dB) 3 dBLocation correction F(95%,fade margin) 9 dB
Minimum required field strength for an indoor NG broadcast service to support a data rate based on 15 dB C/N
84 dBu
Based on• Outdoor• Fixed antenna at 30’• 6dB gain (10dB-4dB down
lead)• C/N 15 dB
[1] iBLAST DATA BROADCASTING FIELD TESTS“A Study to Understand and Quantify Reception of the ATSC Signal”, Andrew Miller, Steve Lacey, Jerry Glaser, Mike Stauffer, and Pete Ludé, 23 April, 2001[2] TV Technology: “DTV in the House, Part1”, Doug Lung, Sept 5, 2007[3] ITU-R BT.2033-1, “Planning criteria, including protection ratios, for second generation of digital terrestrial television broadcasting systems in the VHF/UHF bands”; “Effect of AWGN & Fading (Rayleigh & Rician) channels on BER performance of a WiMAX communication System, IJCSIS, Awon, Islam, Rahman and Islam[4] ITU-R P.1546-5 Method for point to area predictions for terrestrial services in the frequency range 30MHz to 3000 MHz.
[1][2]
[3]
[4]
S IGNAL STRENGTH APPROXIMATION
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Fixed HDNo service
Outdoor MobileIn / Out
Portable
Deep Indoor mobile HDIn /
Out Portable
In / Out Portable
In / Out PortableOutdoor
Mobile
Saturate from main antenna and add SFN sites
1. Increase beam tilt and add lots of power
2. Increase null fill3. Add a SFN
Fixed HD
41 dBu
41 dBu
Fixed Gateway
Fixed Gateway
BOOSTING THE S IGNAL STRENGTH
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Simply increase the null fill of your antenna later
In anticipation of ATSC 3.0 services, future proofing should be considered if purchasing an antenna now.
Field convertible null fill antenna
ADDING NULL F ILL & FUTURE PROOFING THE MAIN ST ICK
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z
θL
zo
𝐼 (𝑍 )
L
180 deg
Increase null fill
Lead to the development of custom illuminations with standard null fill that react positively to this theory
Equal amplitude
Linear phase
SUPERIMPOS ING AN OUT OF PHASE EXC ITAT ION
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Field convertible high null fill antenna using a future proof illumination
• Simple• Short conversion time• VSWR performance is
unaffected
10 dB increase
2 dB decrease in peak ERP
BOOST ING THE S IGNAL STRENGTH
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There is no “One Size Fits All” antenna solution for ATSC 3.0 SFN’s. A combination of panel, slot and broadband slot cavity antennas will be required
• Considerations• Azimuth pattern• Site sharing• Windload
constraints
WHAT TYPE OF A NTENNA TO USE AT SFN S ITES?
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Designing for service
Designing for coverage – old school thinking
Focus on consumers served Type of Service
InputsDeep indoor mobile HD
Fixed indoor Gateway HD
Indoor Nomadic - Portable
Outdoor mobile
Outdoor fixed HD Bootstrap
25 Mbps 25 Mbps 10 Mbps 5 Mbps 25 Mbps
FCC ATSC A/53 minimum field strength (dBu) 41 41 41 41 41 41 41Reduce antenna height factor 30 to 6 ft. (dB) 7 7 7 7 7 N/A 7Building wall attenuation (dB) 15 20 15 15 N/A N/A N/ASmaller inefficient receive antenna gain factor (dB) 9 9 6 6 9 N/A 9Dynamic multipath - AWGN to Ricean/Rayleigh (dB) 3 3 3 3 3 1 3Location correction F(95%,fade margin) 9 9 9 9 9 9 9
Required C/N (dB) 15 20 20 15 10 20 -6C/N Correction (dB) -15 -15 -15 -15 -15 -15 -15Total - Required signal strength at 30' (dBu) 84 94 86 81 64 56 48
S IGNAL STRENGTH REQUIREMENTS FOR TYPES OF SERV ICE
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Network planning assumptions / settings• CRC propagation model
• Communication Research Center – Canada• Much more realistic than Longley Rice• Uses clutter data
• Services / Bitrate / RSS needed at 30’ receive antenna height • Outdoor fixed HD / 25 Mbs / 56 dBu• Outdoor mobile / 5 Mbs / 64 dBu• Indoor nomadic-portable / 10 Mbs / 81 dBu• Fixed indoor gateway HD / 25 Mbs / 86 dBu• Deep indoor mobile HD / 25 Mbs / 94 dBu
• Network areas limited within the FCC 41 dBu contour or 103km from main antenna
• 47 CFR 73.626 – DTV distributed transmission systems• SFN Tower search
• All towers in the search are available• Towers located >10 km inside 103km circle• Restricted to tower heights > 60 m
• PROGIRA plan network planning tool
Adding Null Fill and a SFNPlanning the ATSC 3.0 Network
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WNUV – Baltimore Example
Assume• Replace antenna with a high null fill field
convertible antenna• Main antenna retains full ERP - 845 kW• Main antenna remains at full HAAT - 1200’• Strategically add SFN to coverage area using
existing towers.
Goal• Boost signal strength and provide
more services to more people• Provide deep indoor mobile HD in close to
highly populated areas• Provide indoor portable service in
targeted areas• Expand outdoor mobile services
41 dBu contour
103 km radius
BOOSTING THE S IGNAL STRENGTH
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Existing service after ATSC 3.0 switchover
WNUV – Baltimore Example
Existing Main
Antenna
ServiceRSS
(dBu)Population
ServedBootstrap 48 6,121,162Outdoor fixed HD 56 4,940,909Outdoor mobile 64 3,788,584Indoor nomadic-portable 81 1,905,382Fixed indoor gateway HD 86 1,429,098Deep indoor mobile HD 94 658,493
• Total population inside 41 dBu curve is 7.9M
• Services are inclusive
BENCHMARK
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Boost ing the s igna l s t rength WNUV – Baltimore ExampleEffect of increasing the null fill by simple field conversion
Existing antennaStandard null fill
Future high null fill
Lose 174k consumers using lower RSS services in outer coverage areas
Gain 441k consumers using data intensive services in near in coverage areas
Overlay
Existing Main
Antenna
Future High Null Fill
Converted
ServiceRSS
(dBu)Population
ServedPopulation
Served%
ChangePopulation
ChangeOutdoor fixed HD 56 4,940,909 4,847,172 -2% -93,737Outdoor mobile 64 3,788,584 3,716,684 -2% -71,900Indoor nomadic-portable 81 1,905,382 1,896,801 0% -8,581Fixed indoor gateway HD 86 1,429,098 1,527,028 7% 97,930Deep indoor mobile HD 94 658,493 1,001,992 52% 343,499
Replacing the Main Antenna with a Field Convertible High Null Fill Antenna
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Boost ing the s igna l s t rength WNUV – Baltimore Example
Effect of increasing the null fill by simple field conversion
Fixed outdoor HD
Outdoor mobile
Indoor nomadic-portable
Deep indoor mobile HD
Fixed indoor gateway HD
• Slight loss in consumers serviced by lower bit rates• Significant gain in consumers serviced with higher bit rates
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Boost ing the s igna l s t rength WNUV – Baltimore Example
Adding 50 kW ERP SFN sites with theoretical antenna patterns
1
2
3
4
Site 175m Tower50 kW ERP
Site 4100m Tower50 kW ERP
Site 275m Tower50 kW ERP
Site 375m Tower50 kW ERP
Each site begins omni directional then applies power reductions to meet FCC 41 limits
ADDING SFN S ITES TO THE EX IST ING MAIN ANTENNA
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Boost ing the s igna l s t rength WNUV – Baltimore Example
Effect of adding theoretical SFN sites to the main antenna with standard null fill elevation pattern
Gain 1.46M consumers throughout service offerings
Existing Main
Antenna
Standard Elevation Pattern
ServiceRSS
(dBu)Population
Served
+ SFN Population
Served%
ChangePopulation
ChangeOutdoor fixed HD 56 4,940,909 5,405,598 9% 464,689Outdoor mobile 64 3,788,584 4,189,184 11% 400,600Indoor nomadic-portable 81 1,905,382 2,157,756 13% 252,374Fixed indoor gateway HD 86 1,429,098 1,702,093 19% 272,995Deep indoor mobile HD 94 658,493 734,238 12% 75,745
CONVERT ING TO H IGH NULL F ILL AND ADDING SFN S ITES
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WNUV – Baltimore Example
• Significant gain in consumers serviced by lower bit rates• Slight gain in consumers serviced with higher bit rates
Effect of adding theoretical SFN sites to the main antenna with standard elevation pattern
Fixed outdoor HD
Outdoor mobile
Indoor nomadic-portable
Deep indoor mobile HD
Fixed indoor gateway HD
BOOSTING THE S IGNAL
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BOOSTING THE SIGNAL STRENGTH. WNUV – Baltimore Example
Effect of adding SFN sites and increasing the null fill of the main antenna
Gain 1.64M consumers throughout service offerings
Existing Main
Antenna
Future High Null Fill
Converted
ServiceRSS
(dBu)Population
Served
+ SFN Population
Served%
ChangePopulation
ChangeOutdoor fixed HD 56 4,940,909 5,283,509 7% 342,600Outdoor mobile 64 3,788,584 4,099,525 8% 310,941Indoor nomadic-portable 81 1,905,382 2,142,988 12% 237,606Fixed indoor gateway HD 86 1,429,098 1,760,761 23% 331,663Deep indoor mobile HD 94 658,493 1,077,222 64% 418,729
CONVERT ING TO H IGH NULL F ILL AND ADDING SFN S ITES
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WNUV – Baltimore Example
• Significant gain in consumers serviced by both lower and high bit rates
Effect of adding SFN sites and increasing the null fill of the main antenna
BOOSTING THE S IGNAL STRENGTH
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Replacing SFN sites with antenna designs that closely replicate the theoretical patterns
WNUV – Baltimore Example
Site 175m Tower42 kW ERP
Site 4100m Tower50 kW ERP
Site 275m Tower37 kW ERP
Site 375m Tower38 kW ERP
Combination of panel and slot antenna designs
BOOSTING THE S IGNAL STRENGTH
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WNUV – Baltimore Example
Effect of changing SFN sites to real antenna designs and increasing the null fill of the main antenna
Gain 1.58M consumers throughout service offeringsNote : Theoretical antennas gain = 1.64M
Existing Main
Antenna
Future High Null Fill
Converted
ServiceRSS
(dBu)Population
Served
+ Real Ant. SFN
Population Served
% Change
Population Change
Outdoor fixed HD 56 4,940,909 5,276,767 7% 335,858Outdoor mobile 64 3,788,584 4,095,082 8% 306,498Indoor nomadic-portable 81 1,905,382 2,123,632 11% 218,250Fixed indoor gateway HD 86 1,429,098 1,742,929 22% 313,831Deep indoor mobile HD 94 658,493 1,065,715 62% 407,222
BOOSTING THE S IGNAL STRENGTH
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WNUV – Baltimore Example SummaryPopulation gained over using “as is”
existing main antenna for ATSC 3.0 services
Add high null fill to existing
antenna
Add theoretical SFN to existing main antenna with standard
null fill
Add theoretical SFN to main antenna with
converted high null fill
Replace theoretical SFN with real antennas and
converting main antenna to high
null fill
4% decrease
BOOSTING THE S IGNAL STRENGTH
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There is no “One Size Fits All” antenna solution for ATSC 3.0 SFN’s. A combination of panel, slot and broadband slot cavity antennas will be
required
• Considerations• Azimuth pattern• Site sharing• Windload
constraints
WHAT TYPE OF ANTENNA TO USE AT THE SFN SITES?
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• Slot Antennas:• Much smaller size• Less windload• Higher reliability
• Less connections• Less parts
1966 RCA adDisadvantage – Slotted coaxial antennas have a limited channel range
WHAT TYPE OF ANTENNA TO USE AT THE SFN SITES?
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• Slotted coaxial antennas• Versatility - Azimuth patterns can be tailored to meet any
coverage requirement• Pipe size• # of slots around• Orientation of slots• Power division between slots• Addition of fins and directors
SLOT TED COAXIAL ANTENNAS
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• Full UHF band operation• Excellent choice for co-located shared SFN
sites• Very good pattern flexibility
• Number of panels around• Location• Orientation• Amplitude and phase division• Element beam width
BROADBAND PANEL ANTENNAS
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Pylon Antenna Panel Antenna
+ =
TFU-WB
Panel Bandwidth Performance in a Pylon Package
Broadcasting ATSC 3.0 from Black Mountain
• Broadband – Channels 14-51• Low windload • New w/g slot cavity technology• Economical alternative to
panels
Disadvantage• Some loss in pattern flexibility
• Single cavity limited to directional and cardioid variations
BROADBAND SLOT CAVITY ANTENNAS
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• ATSC 3.0 services will require a new definition of received signal strengths
• Through the use of advanced SFN planning tools and innovative antenna design, these required signal strengths can be achieved
• There is no “One Size Fits All” antenna solution for ATSC 3.0 SFN’s. A combination of panel, slot and broadband slot cavity antennas will be required
CONCLUS ION
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