http://www.tvtechnology.com/news/0002/-qa-mark-aitken-on-one-media-atsc-30-sfn-trials/278233
Q&A: Mark Aitken on ONE Media ATSC 3.0 SFN Trials
Sinclair favors SFN for full coverage
March 22, 2016
By Deborah D. McAdams
BALTIMORE-A consortium of broadcast technology developers reported doing field
tests of ATSC 3.0 concepts over a single frequency network on the East Coast on
Monday this week. (See "ONE Media Conducts ATSC 3.0 'Concept' SFN Trials.") One
Media, Sinclair Broadcast Group, Teamcast, Acrodyne, Comark and LG contributed
technology and elbow grease to the effort.
Sinclair has been at the forefront of supporting the deployment of ATSC 3.0, an
advanced broadcast TV transmission standard said to support features such as
interactivity, personalized content delivery and mobile reception, among
others. Mark Aitken, vice president of advanced technology for Sinclair, is the
company's ATSC 3.0 evangelist. He fielded questions from TV Technology about
the 3.0 SFN tests, which took place with transmitters in Sinclair's home turf
of Baltimore, and neighboring Washington, D.C.
TV Technology: What is the chief benefit of using a single frequency network
versus the traditional big stick, big power method?
Aitken: An SFN allows a broadcaster to provide a higher signal level where he
or she wishes to do so. It also allows for a more uniform signal level to be
spread across an area to provide for service. This is not to be confused with
coverage, which is the out-lived and of-little-relevance term used today.
As well, when fully understood, it is possible to define a QoS (quality of
service) for specific reception modes-fixed, portable, mobile, indoor, etc.
Also, higher signal saturation allows the delivery of more bits, and with
geographically disperse transmission sites, leveraging tools within the ATSC
3.0 standard makes it is possible to provide hyper-local services within the
contours of the individual sites. SFNs are supplemental, but open new business
opportunities.
TV Technology: In what way will single frequency networks impact a
broadcaster's post-incentive auction coverage area?
Aitken: Positively!? Kidding, actually it is the service area that is
positively impacted. If we are to be good stewards of our resources, we will
work with the Federal Communications Commission to allow minor coverage
modifications that would allow shared siting (co-siting) of SFN facilities,
providing better uniform services as a result of minimizing interference that
results from multiple sites.
TV Technology: What is the duration of the STA, and what further does this
coalition hope to achieve under this STA?
Aitken: STAs are typically six months in duration, with reauthorizations
allowed.
TV Technology: The ONE Media press release said this was "the first of hundreds
of SFNs Sinclair Broadcast Group and other broadcasters will roll out in
adoption of the next-gen technology." Whom else, and why?
Aitken: Speaking for SBG, we see opportunities in NextGen services: Ease of
reception, including inside the home? Who would not want that? What new
businesses can be driven with an 'all-IP' wireless pipeline? CDNs?
Prepositioning 'most-consumed' entertainment?
Mobile rules the roost. We should be part of it, either independently or in
conjunction with other service providers.
TV Technology: Why specifically is Sinclair adopting SFNs?
Aitken: 1) More consistency of an easy to receive OTA service. 2) Larger
potential audience reach. 3) Higher signal saturation allows the delivery of
more bits. (Bits/Hz is Shannon limit defined and vary as a function of
signal-to-noise ratio).
TV Technology: The tests were conducted on Ch. 43, which may no longer be part
of the TV band after the auction. What are the implications for SFNs in lower
frequencies, particularly in the high and low VHF bands?
Aitken: UHF will survive post-auction, so the specific UHF channel is somewhat
irrelevant. Also, SFNs provide the same impact on all frequencies, but physics
dictate the usefulness within constraints of power. Additionally, high-VHF may
be a great place to provide for hybrid vehicular mobile services.
TV Technology: The field-tested SFN used two transmitters-an Acrodyne 60 kW
IOT in Baltimore and a GatesAir solid-state Maxiva ULXT-12 in D.C. What was the
EIRP of each transmitter?
Aitken: Baltimore = 800 kW EIRP. Washington = 120 kW EIRP
TV Technology: Why only two transmitters? Does this technically constitute an
SFN?
Aitken: Yes. Got to start somewhere; more to follow. We are working towards an
understanding of matching SFN emulation model (theoretical) with real-world
results. We are partnering on developing a state-of-the-art synchronization and
distribution method. We are developing an understanding of the impact of all
issues that impact the broadcast transmission topologies that are possible
(i.e., optimization of service).
TV Technology: Did this test use the full ATSC 3.0 transmission format, or some
flavor of it?
Aitken: A fully compliant ATSC operating mode (similar to Korea's Mode 4
parameters, modified for transmitter spacing (impact-to-GI and other
timing-related parameters). This is truly a first; a start to the required
learning.
TV Technology: What is meant by "specific coverage" field tests?
Aitken: First, confirmation of synchronization and ability of receivers to
receive. More to come.
TV Technology: What part of the ATSC 3.0 STL standard will this trial attempt
to define and finalize?
Aitken: There is not yet a standard, we will continue to co-development.
Nowhere near final...
TV Technology: Were both audio and video transmitted in sync?
Aitken: Nope, not required. Soon to follow.
TV Technology: LGE as in LG Electronics, correct? This group has previously
worked with Samsung
Aitken: Yes, LGE...we have worked with all parties, and have flourishing
relationships with them and many others.
TV Technology: Is there a specific requirement beyond ATSC 3.0 reception for
this receiver type?
Aitken: ATSC 3.0 compliance at this time.
TV Technology: Were any of the receivers for this test mobile-enabled?
Aitken: Mobile capable? Yes, but not yet tested...we just turned it on!
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