WASHINGTON and BALTIMORE --
The FCC has granted Sinclair’s WNUV-TV authority
to operate an experimental facility, BPEXDT-201301 16AFF. In a letter signed by
Barbara Kreisman, chief of the FCC’s Media Bureau Video Division, the commission granted the
station authority to “broadcast DVB-T2 signals on Ch. 40 in Baltimore, Md.,
subject to a number of conditions, including notification of healthcare
facilities in the area “that may potentially be affected by your operations;”
submission of “a report of the research, experimentation and results, showing
both positive and/or negative aspects of this experiment” at the conclusion of
the experiment; and, in conjunction with each application for renewal of the
authorization, a report pursuant to Sec. 74.113 of the FCC rules along with
“any other relevant information deemed appropriate by the license.” Sinclair is
also required to inform the commission should any unusual problems or
conditions arise during the authorization period at the time they occur.
The FCC released the experimental authorization application
from WNUV on Wednesday. It contains much more detail on the planned experiments.
While the FCC’s letter only mentions DVB-T2, the application says WNUV
anticipates that after testing DVB-T2, it will progress to testing DVB-Lite,
DVB-NGH, and a “non-standard variant derived from experimental outputs.”
WNUV said in its request, “Timing is driven by scarcity of test devices given
the ‘newness’ of NGH (for example). It is WNUV’s intent to participate in the
development of, and demonstrate, ‘the art of the possible,’ and to engage the
interest of many inter-related industries to help to define a future standard
that is harmonized with components of global standards. We hope that this
facility will be used as an extension of work ongoing throughout the broadcast
industry globally (ATSC 3.0, FoBTV and others).”
WNUV will provide a much needed platform for testing next-generation broadcast-technology
as it evolves. As such, it is likely to help shape the next-generation
broadcast standard. Information from the experimental operation will be shared
with NAB, ATSC, and the North American Broadcasters’ Association.
While the testing will start during overnight hours to verify compliance with
the FCC emission mask and to verify proper operation of both the transmitting
and receive equipment, including radio-frequency capture equipment and a
limited sample of receivers, the letter states that once these initial
overnight experiments are completed and “system optimization and calibration
requirements have been met, and initial field testing and data/information
gathering is verified, it is expected some daytime experimental activities will
WNUV’s programming will be carried on Sinclair’s WBFF in its entirety so
viewers will not lose The CW programming from WNUV during the testing either
over the air or via cable.
As I pointed out in my TV Technology
article, “OFDM: Getting
Down to Basics – Key Parameters
,” one of the major advantages of the newer
OFDM broadcast standards is they allow great flexibility in trading off data
rate for the extra robustness needed to reach portable and handheld devices and
even sets with indoor antennas. In its application, WNUV said it proposes
testing different coding rates using QPSK, 64 QAM and 256QAM.
I would expect the tests to show what type of antenna installation will be
required to receive less robust signals capable of supporting 4K UHDTV data
rates and what trade-offs in data rate will be necessary to provide reliable
reception on handheld devices in different environments.
One part of the experiment involves collecting RF captures. This will allow
evaluation of new receivers in the laboratory and provide a rich data set
showing real-world propagation channel characteristics that can be used to
optimize coding and other parameters in the next-generation broadcast system.
Reading the WNUV application, it is clear this experiment is much more than a
demonstration of OFDM and DVB-T2. WNUV proposes additional testing, including
use of MIMO (multiple input/multiple output) and MISO (multiple input/single
output) technology (see my TV Technology
columns linked below for details on how this works).
Making the transition to a new broadcast TV standard will not be simple. The
WNUV experimental operation will be critical in determining if the promise of
the new DVB standards, the new error-correction/coding schemes that approach
the Shannon limit, and new space/time transmission/coding techniques like MIMO
that increase robustness and data capacity are worth the pain of transitioning
to a new system. For TV broadcasting to survive, I hope it does.
WNUV summarized the key goal nicely in their application: “WNUV is seeking to
demonstrate to the industry and its leaders that there exists a path to more
effective distribution of current and future television content, to provide a
higher [quality of service] to our future viewers on multiple platforms, and therefore to make
best use of our spectrum as a television service.”
December. 27, 2012:
Broadcasters Plan Broadcast TV’s Future
can get an idea of what a next-generation broadcast system might involve by
looking at the work DVB has done with DVB-T2 and DVB-NGH. Those standards are
based on COFDM, and they allow different modulation and error-correction
techniques to trade off robustness and data rate, and support for multiple
Scientists Develop Single Antenna MIMO System
uses multiple antennas operating on the same frequency, but with different
data, to increase data rate without a corresponding increase in RF bandwidth.
This technology is used in 801.11n wireless networks and is also used on LTE
May 2, 2012
for Next-Generation Digital Broadcasting
At broadcast TV frequencies, particularly VHF, it is more difficult to obtain
the isolation required between the multiple receive antennas, but testing has
shown there is still some benefit to using multiple transmit antennas and a
single receive antenna—a MISO system.
March 30, 2012: “Huawei
Tests High-Speed LTE 4x4 LTE MIMO Network
On Tuesday, March 27, Huawei announced "the successful execution of the world’s
first LTE 4×4 MIMO field trial in the network of Deutsche Telekom."
March 6, 2012:
for Next-Generation Digital Broadcasting
I don’t see how next generation broadcasting can be made compatible with today’s
ATSC DTV tuners and achieve the desired spectrum efficiency and
interoperability with wireless broadband.
June 30, 2011:
MIMO Antenna Aids Multiband LTE
wireless communications using MIMO demands high isolation between antennas. An
increase in antenna isolation equates to an increase in available bandwidth.
The use of newly-allocated spectrum in the 700 MHz band presents unique
challenges to antenna designers who now must develop effective antennas that
work across spectrum ranging from 700 MHz (possibly even lower in the future)
to the upper ranges of the 2 GHz band.