There are two sides to the coin of next-gen TV standard ATSC 3.0 where diginets are concerned. If scores of stations opt to sell their spectrum in the incentive auction and abandon their diginet affiliations, stations that choose to keep their spectrum will have the additional capacity to accommodate at least some of them. However, the new standard will also give stations the ability to transmit IP data services on their excess spectrum. If those prove more lucrative, the diginets may be out of luck. This is the final part of a four-part special report on multicasting. Read the other stories here.
Diginets feeling threatened by the squeeze of TV spectrum that would follow a successful FCC incentive auction and repack have reason to be hopeful — or maybe not.
ATSC 3.0, the next-generation digital television transmission standard under development, will make it possible to transmit a far greater number of channels in a 6 MHz slice of spectrum than the current standard, ATSC A/53 (also called ATSC 1.0).
Today’s standard gives television broadcasters 19.4 megabits per second to deliver an ATSC 1.0 transport stream. ATSC 3.0 will make it possible to deliver in the range of 26-28 mbps as an encapsulated IP data stream. (However, the bit rate is theoretical until the standard is actually deployed and tested.)
What that all means is if scores of TV stations opt to sell their spectrum in the incentive auction and abandon their diginet affiliations, stations that choose to hang on to their spectrum will have the additional capacity to accommodate at least some of them.
However, ATSC 3.0 will also allow stations to offer data services on their excess spectrum. If they prove more lucrative, the diginets may yet be out of luck. Broadcasters will go where the money is.
The FCC wants to hold the incentive auction in the first part of 2016, but given the complexity of the effort the schedule could slip. After the FCC buys spectrum from broadcasters, it intends to turn around and sell it to wireless carriers and make a profit for the U.S. treasury. Preparing the recovered spectrum for sale will involve a reorganization — or repacking — of the TV band.
The ATSC 3.0 standard leverages orthogonal frequency-division multiplexing (OFDM) and high efficiency video coding (HEVC) H.265 video encoding rather than 8VSB and MPEG-2 as does ATSC 1.0. OFDM makes the pipe from the transmitter to the receiver fatter, while HEVC puts video on a starvation diet.
For example, where a broadcaster today might devote 12 mbps to transmit a single HD channel via ATSC 1.0’s MPEG-2 encoding, HEVC will make it possible to broadcast the same HD channel at 3-4 mbps, says Jay Adrick, a consultant to GatesAir who is participating in the standard development.
Similarly, an ATSC A/53 3 mbps standard-definition channel could be compressed down to the kilobyte range, he says. On the other end of the resolution continuum, HEVC will compress 4K Ultra HD to about 12 mbps.
Coupled with OFDM’s fatter pipe, that means broadcasters conceivably could carry at least six HD channels in one single 6 MHz channel, many times more SD channels.
So, in a post-auction world, it should be possible for stations to continue broadcasting a rich multicast channel lineup in addition to a primary channel, and perhaps even share a 6 MHz assignment with another station in town.
However, the same next-gen TV standard that makes carrying all of these subchannels possible will enable stations and station groups to pursue new business models that could change what it means to be a television broadcaster
But the new standard will bring with it new competition for the broadcasters’ bits.
In addition to more TV, the new standard gives broadcasters the ability to transmit IP data packets for a variety of data-distribution services. Broadcasters might provide the services themselves or lease capacity to third parties.
That’s a truly transformational development for the broadcast industry, says Mark Aitken, SVP of technology at the Sinclair Broadcast Group and a leading ATSC 3.0 proponent, adding the services should have the same quality of service and effectiveness as those offered by wireless carriers.
While not every broadcaster will choose to get into the wireless data delivery business, those that do “will find extreme value in the bit distribution business for a whole variety of new services,” he says.
The very law that set in motion the disruptive TV spectrum auction and repack also authorized flexible use of broadcast spectrum. The Middle Class Tax Relief and Job Creation Act of 2012 gives the FCC permission to grant a waiver of broadcast service rules to TV broadcasters in lieu of their receiving reimbursement from the $1.75 billion Broadcaster Relocation Fund to pay the expenses resulting from moving to a new channel assignment.
The flexible-use waiver is available only as long as broadcasters provide “at least one broadcast television program stream on such spectrum at no charge to the public,” the act says.
Data delivery vs. multicasting is not an either-or-decision. ATSC 3.0 is being created with the ability to broadcast mobile, SD, HD and Ultra HD television as well as data at the same time. It uses layered division multiplexing, LDM, to enable multiple waveforms to be transmitted at once, Adrick says.
Although ATSC 3.0 makes that possible, the new standard’s ability to carry IP packets as deftly as a wireless service will demand broadcasters think carefully about how they choose to allocate their bit-carrying capacity. One day in the not-too-distant future they may find themselves contemplating whether it is more profitable to carry reruns of Gilligan’s Island or transmit wireless data.
Says Aitken: “It is very easy to imagine a future where television is part of our business, but there is a plethora of other business interests that will leverage our bit distribution capacity because we can do it better, we can do it more efficiently, we can do it at a lower cost point, and we can do it on a basis that will be a rival to the other wireless carrier industry.”
This is the final part of a four-part special report on multicasting running this week. Read the other stories here.