Practical Operations Concerns about HD Radio

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Practical Operations Concerns about HD Radio
FMeXtra Aaron Read (WEOS, Geneva)

• An engineering-lite look at the issues and
  concerns surrounding digital broadcast solutions
  like HD RadioTM and FMeXtraTM

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What is HD Radio?Hint the HD doesnt stand
for anything!

• Digital method of broadcasting created by
  iBiquity Digital Corp blessed by NRSC.
• IBOC uses existing AM FM spectrum.
• Hybrid system of analog digital.
• Backwards-compatible with todays radios.
• All-Digital possible in future (not FCC auth.
  yet)
• Allows for better-quality audio, data services,
  multicasting (FM only).

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HD Radio Hybrid Mode

• Analog radios just ignore digital sidebands
  (white noise)
• HD Radios tune to analog, detect digital, buffer
  for a few seconds, and blend from analog to
  digital audio.
• Requires PRECISE delay of analog to match
  digitals 7sec delay
• If digital signal is lost, blends back to analog.
• For multicast channels, radio will mute (most
  radios will eventually switch back to main
  channel analog)

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HD Radio Kibbles and bits

• AM HD 36kbps hybrid / 40-60 digital
• FM HD 96-120kbps hybrid / 300 digital
• Based on the HDC (AAC) codec audio quality is
  comparable.
• Its all just bits, so partitioning is possible.
  Using the bits for things other than audio also
  possible.

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Must my station install HD Radio?

• Unlike DTV (Feb.2009) there is no FCC mandate for
  HD Radio.
• Market-driven system listeners may effectively
  demand it.
• Competition with iPods, satradio, podcasts
• HD Radio is the only official digital broadcast
  solution to receive the NRSCs blessing.
• BUTtechnically there could be other IBOC
  solutions that are not HD Radio, but none exist
  as of now.

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HD Radios benefits FM AM

• Audio fidelity (not quality)
• AM sounds like FM, FM sounds like CD (20kHz audio
  B/W)
• Elimination of multipath interference
• Audio sound is consistent across your broadcast
  range.
• FM has multicasting extra radio stations in one
  signal.
• PSD (aka PAD) Artist / Title more
• Data Services Conditional Access, On-Demand
  Audio, iTunes Tagging (one-button purchasing),
  Downloads, Images/Videowhat else?

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HD Radios problems FM AM

• HDC algorithm is lossy Source material quality
  considerations / cascading algorithms.
• AM digital sidebands noisy band (nighttime,
  esp)
• Also true for FM, but not as problematic
• TIGHT tolerances Requires GOOD Engineering
• Initial costs are not cheap 75,000 - 250,000
• Ongoing licensing fees to iBiquity (a different
  paradigm)
• Getting in over your head what exactly you going
  to do with those extra channels/features?
• Is the ROI really there for you? vs.
• Is your stations mission/operation suddenly
  obsolete? (eek!)

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HD Radios problems AM

• Overall Not recommended!
• Severe adjacent-channel interference problems,
  audio fidelity is questionable, no multicast
  (data rate too low), Dir.Array questions
• Extremely low adoption by comm. broadcasters.
• Will HD Radio remain the NRSC standard for
  digital broadcasting on AM????

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HD Radios problems Lic. Fees

• iBiquity charges steep one-time licensing fees to
  buy activate an HD xmitter.
• Multicast channels have addl fees 1000/yr
  minimum or of revenue.
• Data services also have fees.
• Paradigm Shift in broadcaster thinking!

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HD Radios problems -10 vs. -20

• IBOC digital sidebands are -20dB (1/100th) to the
  analog signal.(analog1000 watts, digital10
  watts)
• Controversy that this is not enough ERP.
• Proposal Studies for -10dB (1/10th) ERP.
• Less efficient much bigger transmitters ()
• More interference concerns.
• NPR Labs study is a must-read.

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What about my FM antenna?

• Depends on implementation.
• Hi-level combining uses existing antenna
• Ensures equal coverage patterns
• Separate antennas has benefits (redundancy,
  overall simplification) but may have unequal
  coverage (very bad!) and requires addl tower
  space weight.

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Changing Perceptions

• IBOC breaks the norms of radio.
• Coverage only to 60dBu NO FRINGE!
• The FCCs warned us for years not to count on
  fringe!!
• Digital ON or OFFno gradual fade to static
• Old worries multipath interference, stereo hiss,
  not sounding loud enough.
• New worries cascading algorithms, bad
  processing, poor antenna placement / receiver
  quality, PAD/PSD done right/wrong.

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Upgrading your technical plant

• You may need all-new () gear!
• STLs HD data bursts, AES output
• Monitoring 7 sec delay, multicast channels,
  remotes, headphone processing
• Audio Storage MP3s Cascading algorithms
• Processing diff. for analog vs. HD
• Extra Arbitron PPMs (if youre in a PPM market)
• Extra webcasts of multicast channels?
• HD not as battle-tested, requires more regular
  and maintenance.

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Upgrading your schema

• Adding multicast channels is like adding new
  stations
• Extra studios? Processors? Monitoring? Access
  control? Audio gear? Computers?
• Extra staff??? Extra programming???
• Its like having to fill 72 hours every single
  day.
• Are you ready to handle this extra workload?

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HD Radio benefits

• Bragging rights! Getting late in the game for
  this, but you might still be able to claim first
  in your market.
• Fitting in with ethos at your college (some are
  really into digital media)
• Better teaching environment.
• Digital Platform Flexibility for new ideas
• iTunes tagging!

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Thinking outside the box

• Rent out your HD2/HD3 channel for profit.
• Rent someone elses HD2/HD3 channel for a better
  signal range.
• Offer to pay to install HD Radio cheap rent.
• Unusual formats on HD2/HD3
• 5 minute loop of headlines, weather, traffic
  sports plus one or two sponsors.
• Bring an underserved format to your market! NPR
  is a pioneer here XpoNential Radio (AAA) Radio
  Ahora (Spanish), Classical24, etc.

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Future Thinking HD Radio

• FCC doesnt mandate it, but your listeners might!
• Costs are high Long term planning needed!
• Probably longer than you will be at your college.
• IBOC and/or Multicasting may effectively require
  substantial upgrades in automation / studios /
  STL / processor / xmitter plant
• IBOC for AM suddenly that squeaky chair is
  quite audible!
• Very different processing vs. sound the same for
  analog-blend.
• Despite greater B/W (15kHz vs. 20kHz) no
  pre-emphasis.
• Professional Engineering Support is a MUST!

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Shameless Self-PromotionThe IBOC Handbook
Understanding HD RadioTM Technology

• Looking to really learn the engineering of IBOC /
  HD Radio? Read this book!
• First Only Overview of the Newly-Approved
  NRSC-5 (IBOC) Standard.
• Authored by David Maxson
• Illustrated by Aaron Read
• Available on Amazon.com

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Final Thoughts

• Questions and please no
• Rants, Screeds, Diatribes, Harangues, Raving,
  Tirades, Bullyragging, Vociferation, Bloviating,
  Railing, Objurgating, Badgering, Molestation,
  Nettling, Ruffling, Badgering, Pestering,
  Heckling or Persecution.
• Tell us your situation, well opine if
• HD Radio is right for you!
• Aaron Read can be reached via www.friedbagels.com/
  blog
• Need an engineer? www.sbe.org