Digital TV Facts: The Latest

Digital TV viewers can expect improved over-the-air (OTA) reception from products that use LG’s new sixth-generation digital TV chipset, according to Choon Lee, who heads the DTV research lab at LG Electronics.

The enhanced technology has eliminated the multipath interference common in urban areas, Lee said. (That’s a big claim, and I sure hope we can believe him.) Improvements in synchronization and equalization should also make antenna positioning easier, according to the television manufacturer.

The ability of OTA viewers to easily obtain digital TV reception is one of the keys to a successful transition in 2009, when analog broadcasts will stop.

Will the $60 set-top converter boxes from LG or its Zenith subsidiary, scheduled to arrive next year, include the sixth-generation chip? The most recent answer to that question had been no—the box would instead use the fifth-gen LG chipset. But now I’m not so sure.

Here’s what their sixth-gen press release says:

Digital-to-analog converter boxes planned for introduction next year (for analog TVs to continue to receive free, over-the-air broadcasts after Feb. 17, 2009, when all U.S. broadcasting is digital) also will benefit from the low-cost, high-performance chipset.

Now, LG also notes that it will supply its chipset to other manufacturers. But nowhere do they explicitly say they will include the sixth-generation technology in their converter box. The company’s wording, I suspect, may be intentionally vague.

• Link: press release

The law that gave us the 2009 cutoff date for analog TV broadcasts has been challenged on procedural grounds almost since its (supposed) passage. (The procedure in question could hardly be more basic: The House and Senate failed to pass identical bills.) The Hill brings us up to date on the various federal lawsuits seeking to strike down the Deficit Reduction Act, which contains the DTV provisions.

Even if a judge throws out the law, I would still expect the current Congress to preserve the current Feb. 17, 2009, digital TV deadline by enacting new legislation. They just might sweeten the converter-box subsidy or make other tweaks, but I don’t see the date changing—unless, in the months immediately preceding the transition, consumers hit major snags. If digital TV’s over-the-air reception problems are behind it, and if the converter-box coupon program is run more competently than other projects of the Bush administration, the deadline will stick.

• Links: The Hill, Multichannel News

Mobile digital TV transmissions using A-VSB technology, demonstrated by Samsung at the Consumer Electronics Show, won mostly favorable press coverage last week. The proposed A-VSB standard shows real promise for delivering ATSC digital TV broadcasts—over the public airwaves—to mobile devices. Here’s a big question, though, about A-VSB:

What about HDTV?

While A-VSB really isn’t envisioned for HD broadcasts, a station using the technology might be in a position to shortchange its high-definition programming for home viewers. Doug Lung, in another indispensable “RF Report” post, quantifies the problem:

For broadcasters, the cost in terms of bandwidth for transmitting a signal like the one transmitted on Channel 22 by KVMY for the demonstration may be more than they can afford. The demonstration used quarter rate coding, which meant 3 Mbps were needed to transmit a 750 Kbps media stream. In addition to that, an additional 2.8 Mbps was used by the supplemental reference signal (SRS). This barely leaves enough room to transmit one HDTV program.

To support mobile TV, a station that multicasts could choose to degrade its HD broadcasts. Lung notes, however, that the Advanced Television Systems Committee

will be conducting tests of the proposed A-VSB standard, and acceptable reception may be possible with less error correction and less data devoted to the SRS.

HDTV enthusiasts are already on guard against cable and satellite firms, and broadcasters, too, who shortchange the HD signal. As for me, I welcome A-VSB. Free, on-the-go TV via your cell phone or laptop is a deal I simply wouldn’t want to pass up.

Earlier:
• Samsung to demo A-VSB mobile TV at CES
• Local channels on mobile TV: Test shows promise
• Mobile TV signals for free? Maybe, with A-VSB

• Link: TV Technology

A-VSB, an emerging technology that uses broadcast spectrum to deliver digital television to cellular phones and in-car TVs, will get its next test at the Consumer Electronics Show in Las Vegas:

[T]he invite-only demonstrations will be the first to use battery-operated handheld TVs, which Samsung will demonstrate in moving vehicles on Las Vegas streets and highways, [Samsung’s John] Godfrey said. The portable TVs, all prototypes, might also be demonstrated inside the convention center, the company said at press time.

(Why not demo it inside, too, at Samsung’s $875,000, 25,000-square-foot exhibit space? They will have sufficient room, I would say.)

A-VSB technology may even offer a path to more reliable reception for some U.S. home viewers whose over-the-air digital TV signals are plagued by interference. (Certain kinds of reception problems can be traced to inherent features 8-VSB, the modulation scheme used by the ATSC digital TV standard.)

HDTV lovers, ever vigilant, worry that bandwidth consumed by A-VSB will shortchange their high-definition signals. That could happen, especially on stations that offer multicasts concurrent with HD programming. Free, over-the-air mobile TV signals may, after all, come at a cost.

• Link: TWICE

Digital TV reception for over-the-air viewers in the U.S., a longtime worry, has made impressive strides, according to year-end articles from two DTV technology experts.

Inherent problems with the American digital television standard, while not widely known among the general public, raised early doubts within the TV industry about whether the cutover from analog to digital would end in disaster. As the 2009 cutover approaches, broadcasters may breathe a sigh of relief knowing that reception drop-out and multipath interference appear to have diminished significantly in the current generation of digital TV receivers for the ATSC standard.

Doug Lung:

“Fifth generation” demodulators have narrowed or eliminated the advantage DVB-T [Europe’s standard. –Ed.] had in multipath rejection. Mobile and portable reception is now possible….

The improvement in performance compared with older DTV tuners is amazing.

Pete Putman:

In short, the ATSC system has gone from a “works on paper, but not in the field” concept to a mainstream DTV transmission and reception standard over the past 10 years.

Earlier:
• Digital TV broadcasts ‘don’t work’
• As digital TV reception controversy dims, E-VSB gets another look
• Will digital TV reception problems doom broadcast TV?

• Links: TV Technology, Pro AV

Local digital TV channels might make their way to mobile phones over the broadcast spectrum, a road test of an emerging technology suggests. A variation on standard over-the-air transmission, A-VSB (Advanced-Vestigial Side-Band) is designed to compensate for a shortcoming in North America’s digital television standard:

Sinclair [Broadcast Group], which raised concerns in the late ’90s over the ATSC standard’s inability to support mobile or portable reception, is bullish on the technology.

Sinclair—an early, vocal critic of ordinary 8-VSB modulation—is on board? I’ll take that as a good sign. Tests in a car moving at up to 80 MPH, using Samsung equipment, were “pretty encouraging,” according to transmitter manufacturer Rohde & Schwarz.

Next question (premature, perhaps, but I’ll ask anyway): What kind of reception can we expect without a rooftop antenna?

Earlier:
• Mobile TV signals for free? Maybe, with A-VSB
• Handheld digital TV: U.S. market is still waiting
• Mobile TV coming to ’select’ US cities

• Link: Broadcasting & Cable

A technology columnist sounds the death knell for digital TV broadcasts:

And despite protests to the contrary, digital television—whether you care to purchase a high-definition set or not—will be an exclusive club for cable and satellite subscribers only. Over-the-air digital broadcasts simply don’t work. Not if we hold digital TV to the same expectations as flimsy analog signals.

Blame the persnickety nature of digital.

…Here in my office, only two of the five national networks (including PBS) come in reliably, and I’m just 30 miles away from a major city.

It is a bit of a rant. (By the way, the shutoff date for analog broadcasts is Feb. 18, 2009, and not “possibly 15 months from now,” as the Sun-Times has it). But the man’s complaint deserves to be heard: For some viewers, the end of analog TV will be, in effect, the end of free TV.

Since the author didn’t complain about having to install a rooftop antenna, I’ll bet he didn’t try. Really, though, if you didn’t have one in the ’60s, would you want one now? Not that anyone ever asked.

Earlier:
• As digital TV reception controversy dims, E-VSB gets another look
• Antenna aimed at digital-TV multipath reception problems
• Will digital TV reception problems doom broadcast TV?

• Link: Chicago Sun-Times

Reports of over-the-air reception problems once threatened to derail the digital TV standard chosen for the U.S. Today, as America prepares to say goodbye to analog television broadcasts in 2009, the reception controversy has been set aside.

The most recent evidence: Mark Aitken of Sinclair Broadcast Group told Broadcasting & Cable last month that converter boxes with fifth-generation digital TV chip technology will allow viewers to receive broadcasts reliably, if the box delivers a clean signal. Why is that remarkable? Because as recently as last summer, another Sinclair official charged that ATSC (the U.S. standard) “simply is not capable of meeting the needs of the average non–cable-connected viewer.”

The loudest complaints about ATSC reception shortcomings concern its modulation standard, called 8-VSB, used to decode the signal. In 2004, the Advanced Television Systems Committee approved a standard known as Enhanced VSB, or E-VSB, a technology designed to allow broadcasters’ digital TV signals to reach more households. Claudia Kienzle of TV Technology:

The primary purpose of E-VSB is to provide a robust signal that can be received in areas where a standard ATSC signal cannot. E-VSB could be used to simulcast a robust SD version of a primary HD program, allowing viewers located in fringe coverage areas to still view a program, albeit in standard definition, when they would otherwise receive no signal.

But despite the early buzz, E-VSB has gone nowhere, and Kienzle offers a look at why neither the manufacturers of TV sets or transmitters have adopted it.

In August, I asked Frank Eory of Freescale (the chipmaker, formerly part of Motorola) about Enhanced VSB’s prospects. Eory was principal author and editor of a report prepared for the ATSC in 2001 by an ad-hoc group that identified causes of failed digital TV reception.

“The simple truth,” Eory told me, “is that 8-VSB is a poor choice for a digital modulation standard, not only for DTV, but for any other digital wireless communication system. It is inferior to COFDM, which is used for broadcast DTV in most other countries, and also inferior to most digital cellular phone standards and wireless LAN standards that are in use around the world today.” Nonetheless, 8-VSB should not get all the blame for digital TV reception problems in the U.S., Eory said in an email exchange. Part of the problem is that “the FCC was given a nearly impossible task—to allocate an additional 6 MHz TV channel to every licensed TV broadcaster in the U.S., to be used for a ‘reliable’ DTV broadcast system, while simultaneously limiting interference to and co-existing with the existing analog TV broadcast channels.”

To design the nation’s digital TV system, then, compromises were made. The system that we now must live with allows little margin for error, and is designed to deliver digital television only to those viewers who currently get “good” analog TV reception. “Those who put up with snowy or ghosty analog TV pictures may or may not be able to receive DTV at all,” Eory explained.

Which brings us to E-VSB. Frank Eory:

“In the aftermath of the 8-VSB ad-hoc group’s report, the ATSC embarked on modifications to the 8-VSB standard, which led to something known as ‘Enhanced VSB.’ Unfortunately, the approved enhancements do little to improve urban reception, which is often interference-limited by multipath echoes. The enhancements can, however, extend the reach of DTV signals to viewers in outlying areas far from the TV transmitter. Some manufacturers are supporting E-VSB, but it does not seem to be gaining traction, since most people in the industry understand that it doesn’t address any of the fundamental reception problems. Quite simply, it adds cost to the receiver, with only a modest benefit for a small number of viewers. To make matters worse, E-VSB takes data away from the HDTV signal, potentially degrading HDTV picture quality.”

Broadcasters, having collectively spent billions on HD equipment, have recently opposed proposals that would allow cable companies to downconvert their high-definition signals for delivery to subscribers. By rejecting E-VSB (thus far), they have also shown reluctance to downgrade the images and sound on their own. The irony, of course, is that without Enhanced VSB, local stations will become even more dependent upon cable and satellite systems to deliver their programming to some viewers.

Earlier:
• Digital TV converter boxes due later this year
• Senate bill would allow cable to downconvert digital TV broadcasts
• Antenna aimed at digital-TV multipath reception problems
• Will new chips improve digital TV reception?
• LG set-top prototype uses 5th-generation chip

• Link: TV Technology

The converter boxes that will prolong the life of existing analog TV sets are slated for delivery later this year.

These set-top boxes—also known as digital TV adapters—will allow conventional TVs to continue receiving over-the-air broadcasts when the cutover to digital TV is completed in 2009.

Prototype converters from LG and Thomson, hooked up to ’80s-vintage analog TV sets, were on display at the National Association of Broadcasters (NAB) show earlier this week. The digital-to-analog converter box market could reach 20 to 40 million units by 2008, according to LG’s Zenith division.

Broadcasters are guardedly optimistic about the technology. Mark Aitken, director of advanced technology for Sinclair Broadcast Group, says the fifth-generation DTV chips from LG and other manufacturers will receive over-the-air signals reliably, provided the box delivers a clean signal to the chip. He’s more concerned about the quality of the radio-frequency components that may find their way into low-cost boxes.

“The federal government would be remiss in its duty if it agrees to allow a $40 subsidy to be applied to a product that didn’t meet some sort of minimum requirements,” says Aitken.

(Gee, they have been remiss in their duties, now that you mention it…)

Converter boxes won’t hit the $50 target price initially, I gather. Single-chip tuners and sales volume should ultimately drive down the cost.

• Link: Broadcasting & Cable

The prototype set-top converter box LG demonstrated on Capitol Hill last week did in fact include the 5th-generation LG chip, according to TV Technology.

Four electronics companies showed lawmakers their digital-to-analog converters, and all provided basically good reception with an indoor antenna, in a location where multipath interference would be expected. If the final versions of these products arrive on the market working just as well as the prototypes, and eventually sell at reasonable prices, fewer households will be left behind by the digital TV transition.

• Link: TV Technology

A new line of attack against digital TV reception problems is reported by chipmaker Micronas, which announced a new product family today. Their DRX-H line makes over-the-air reception more robust, they say, even in situations regarded as notoriously difficult.

We’ve written here recently about the “multipath” reception problems that can occur particularly in metropolitan environments where the signal path between you and the broadcast tower is obstructed. Signals get reflected off buildings or terrain, with the echoes sometimes reaching or exceeding the desired signal level. In certain urban settings, especially, these so-called 0dB echoes can be a big problem.

Instead of filtering out the echoes, Micronas’s primeD technology combines multiple echoes to create a single, stronger signal, which the company says results in enhanced overall reception quality. The results are supported by lab and field tests conducted by independent test facilities, according to a press release.

Problems with digital TV reception in the U.S. have been studied and debated for years. Much of the criticism focuses on alleged deficiencies in 8-VSB, the radio frequency modulation format used under the ATSC standard for DTV broadcasts in the U.S.

“We are approaching theoretical limits of the 8-VSB demodulation standard thanks to our unique implementation,” said Rich Citta, Chief Scientist of Micronas Semiconductors. Citta is described as a key architect of the current Advanced Television Systems Committee DTV standard.

What consumers would like to know, of course, is when the chip will show up in digital TVs, set-top boxes and related products.

• Source: Micronas press release

Because of deficiencies in the U.S. digital TV broadcasting standard, viewers will lose access to over-the-air TV when analog broadcasts end, according to a Sinclair Broadcast Group official.

For years, Sinclair has objected to the digital format chosen by the FCC. Their latest objection comes in a pull-no-punches editorial by Nat Ostroff, Sinclair’s vice president of new technology, for a trade publication. Ostroff charges that the transmission standard, known as ATSC 8-VSB,

simply is not capable of meeting the needs of the average non–cable-connected viewer.

That transmission system, by the very admission of the FCC Office of Engineering and Technology, is only a rooftop receiving-antenna system and always will be. All efforts to date to make the digital system work as well as the analog system of today in terms of simple antenna reception have failed.

He criticizes the National Association of Broadcasters for supporting a firm 2009 deadline for ending analog TV broadcasts and mocks the idea that a “‘magic’ set-top converter box” will allow viewers to receive digital TV broadcasts on their old analog sets. “Such a box does not yet exist,” he writes.

An earlier FCC report found that in the top ten TV markets, 50 percent of locations in urban centers would have difficulty receiving 8-VSB digital TV. While the competing COFDM standard, used in Europe, was found to work better in urban areas, the U.S. standard was given an advantage in “fringe” areas further from a broadcast transmitter.

Sinclair, which owns 61 TV stations, is no stranger to controversy. A boycott against the broadcaster was organized last year after it ordered its stations to show a film attacking Sen. John Kerry in the final days before the 2004 presidential election. Earlier that year Sinclair pulled a Nightline broadcast, devoted to reading the names of U.S. soldiers killed in Iraq, from its ABC affiliates.

• Source: Broadcasting & Cable editorial in AVS Forum
• Also: 8-VSB vs. COFDM from TV Technology