TV Band Repacking II: ‘A Complex Engineering Problem’
WASHINGTON: There are many known unknowns
outlined in the proposal to auction more TV spectrum off for wireless services.
The Federal Communications Commission released its full proposal this week after
having approved it unanimously on Friday. The Notice of Proposed Rulemaking seeks
comments on the auction structure, clearing the spectrum, repacking TV stations
and the associated costs, among other items.
The auction itself will comprise a three-part procedure. Broadcasters will name
their selling price in an initial reverse auction. The commission will repack the
spectrum within required parameters. The cleared spectrum will be offered to wireless
providers in a forward auction.
TV station licensees may participate in the reverse auction in one of four ways—by
going off the air, moving from a UHF to a VHF assignment, sharing a channel, or
voluntarily accepting additional interference. The commission is proposing either
a single-round sealed bid procedure, or a timed, multiple-round, dynamic auction
in which sellers indicate their “willingness to accept iteratively lower payments
in exchange for relinquishing rights.” Those who opt out during the process would
not be able to re-enter. It describes the second option as “preferable” because
participants wouldn’t have to determine their final sell price up front. Only full-power
and Class A licensees will be eligible to participate.
Once the reverse auction is complete, the commission will have to repack all
remaining broadcasters in whatever TV channels are left over. The 2010 National
Broadband Plan envisioned clearing a contiguous band between Chs. 31 and 51 (572-698 MHz), but
because broadcasters are not compelled to part ways with spectrum, the post-auction
configuration cannot be anticipated.
“We must solve a complex engineering problem by determining how stations that retain
their current spectrum usage rights are assigned channels,” the NPRM states.
The Spectrum Act portion of the bill extending unemployment benefits, passed in
February, provided the FCC with the authority to conduct a spectrum incentive auction
under specific conditions. E.g., it dictates that commission can’t force a licensee
to move from a UHF to a VHF assignment; VHF being notoriously poor for digital broadcast
signal reception. It also directs the FCC to make “all reasonable effort” to preserve
a TV station’s coverage area as it’s now calculated. The auction NPRM seeks comment
on how to do so.
It also proposes scoring bids in the reverse auction by incorporating factors such
as coverage area, and the impact on repacking. Bids from stations that would make
the repacking more difficult because they would block more potential channel re-assignments,
would receive a lower score, for example, “making them more likely to have their
bids accepted, and, equivalently, less likely to be assigned a channel in their
pre-auction band,” the NPRM states.
The scoring procedure might also consider the scarcity of VHF spectrum in a given
“It may be helpful to think of the repacking of stations
with different service areas and bid values into the broadcast television spectrum
as being analogous to the process of packing boxes into a trunk when these boxes
have different sizes and values,” the NPRM states.
The commission is proposing two repacking formulas—an “integer programming algorithm,”
or a simpler “sequential algorithm.”
The integer algorithm would use computer optimization software to find the most
efficient way to clear the relinquished TV spectrum while satisfying Congressional
directives. The software would “minimize the sum of reverse auction bids accepted
and the relocation costs of stations that are assigned to new channels,” the NPRM
says, adding that “due to the complexity of the problem, an ‘ideal’ or provably
optimal repacking solution using an integer programming model may not be feasible
in a timely manner.” Rather, an “approximate” repacking solution may be applied.
The sequential algorithm approach would start with stations that don’t participate
in the auction. They would be the first to receive a new channel assignment. For
participating stations, “the determination would be based on the scored bids from highest to lowest,
as long as the station can feasibly be assigned a channel,” the document says.
The commission seeks feedback on both options, as well as whether to anticipate
the repacking will leave some areas with no broadcast TV service at all.
“Should we seek to address any such risk as an auction design matter or through
other steps outside of the incentive auction?,” the NPRM asks.
FLEXIBLE INTERFERENCE OPTION
The commission proposes three options for fulfilling the Congressional directive
of making “all reasonable effort” to preserve signal coverage. One is a flexible
option by which Station A goes off the air, eliminating interference with Station
B, which is then subjected to interference from another repacked station, Station
C. The FCC proposes allowing an interference-area swap as long as the total population
coverage area decreases by no more than 0.5 percent.
“We believe that interpreting the statute as referring to total, rather than specific, population served
would satisfy the statutory mandate,” the NPRM says.
However, option No. 2 interprets the statute as preserving service for the same
specific viewers for eligible stations. Under this approach, no channel reassignment
could reduce another TV station’s population service area as of Feb. 22, 2012, by
more than 0.5 percent.
The commission concedes that although the second option would be less disruptive
to viewers, “it might increase the cost of clearing spectrum” by reducing repacking
The third method for preserving signal coverage involves establishing a separate
interference standard for stations that did not interfere with one another as of
Feb. 22, 2012, and leaving the rest in place. Under that scenario, the FCC proposes
to raise the de minimis interference standard
from 0.5 to 2 percent for the post-Feb. 22 interfering stations.
ALLOTMENT OPTIMIZATION MODEL
Just how the commission determined that it could reclaim 20 TV channels—40 percent
of the broadcast spectrum—has been a point of contention since it proposed doing
so in the 2010 National Broadband Plan. The commission said it used an Allotment Optimization Model,
which was never revealed to the public despite repeated requests from members of Congress
In this week’s NPRM, the commission said the AOM was an “alpha version based on
several simplifying assumptions about broadcast interference; it did not incorporate
the methodology… which the Spectrum Act requires be used in the repacking.” Consequently,
the Notice says, that AOM may have “limited or no applicability in this proceeding.”
The commission is proposing to divide the reclaimed spectrum into 5 MHz
blocks, in which the uplink band would start at Ch. 51 and extend downward to Ch.
37, with downlink from Ch. 36 downward toward the repacked TV band. A 6 MHz guard band would be left in between the
newly designated wireless spectrum and the TV band for use by unlicensed devices.
The NPRM anticipates that unlicensed devices will be operable in the repacked TV
band. It also proposes to set aside Ch. 37 for unlicensed devices, as well as opening
the two channels now reserved for wireless microphones.
Radio Astronomy Services and wireless medical telemetry operations now occupy Ch.
37, which the commission is proposing to move. Clearing Chs. 37-51 also begs the question of what to do with fixed broadcast
auxiliary stations, low-power auxiliary stations and unlicensed wireless microphones.
The NPRM does not address Private Land Mobile Radio Service and Commercial Mobile
Radio Service licensees that operate on a co-primary basis with TV stations in 11
Metropolitan areas on Chs. 14-20—the T-band. They will be addressed in a forthcoming
notice, the commission said.
It seeks feedback on “reasonable deadlines” for stations transitioning to new channel
assignments or going dark, and on how to structure the reimbursement program—actual
cost payments or advance payments based on estimates.
The NPRM acknowledges that the TV spectrum auction must raise enough money to
cover not only the $1.75 billion Congress authorized for relocating TV stations
and retuning cable headends, but for other operations as well. The Spectrum Act sets aside $2 billion for building out a first-responder
wireless broadband network on TV spectrum known as the “D Block,” relinquished in the 2009 digital transition. Up to $300 million is designated for relocating Ch. 37 licensees.
Congress anticipated raising $15 billion after the set-asides and calculated the
sum into off-setting $30 billion spent for extending unemployment benefits.
If the auction fails to raise enough money to cover the set-asides, there will be
no license reassignments and no repacking.
TO BROADCAST OR NOT
The NPRM encourages broadcaster participation and reiterates what the commission has long made clear—that it considers
broadcasting a less than optimal use of the spectrum, particularly since a majority
of households subscribe to pay TV service. The commission cites Nielsen numbers
that put over-the-air reliance at 10 percent. Nielsen’s OTA numbers, however, don’t
reflect cord-cutting. Even though pay TV platforms lost 1.5 million subscribers
between 2010 and 2011, Nielsen does not show a correlative gain in OTA households.
The commission gives broadcasting credit for ratings—96 of the top 100 shows during
the 2011-12 season were on broadcast networks. And it noted the technological advances
made by stations since June 2009, when broadcasters made the switch to digital broadcasting
and relinquished 108 MHz of spectrum for wireless services. Many continue to upgrade
facilities with digital, file-based workflows, high-definition equipment and multiplatform
While the commission’s NPRM emphasized that 29 percent of the commercial TV stations
in the country do not multicast, it also cited SNL Kagan numbers indicating that
the number of multicast programming signals jumped by 81 percent last year to 4,552.
It said that “only a fraction” offer mobile DTV channels—120, according to the Open
Mobile Video Coalition.
The FCC’s 205-page NPRM includes many more details that likely will be analyzed
by industry engineers and attorneys in the weeks ahead. The documents are posted
on the FCC’s website.
The docket No. is 12-268. John Eggerton of B&C
provides more details about the auction procedure with “FCC
Outlines Broadcast Incentive Auction Proposal.” Please contact TV Technology
with your comments, analysis and observations regarding the NRPM.
~ Deborah D. McAdams