Next generation HDTV: A Demand-Driven Leap Ahead
By Peter J. Brown
The first generation High Definition Television (HDTV) was all about preparing HD-ready digital infrastructure, while second-generation HDTV is all about filling up the content pipe with programming that counts and pushing the HDTV network to do more for consumers, content producers and service providers. The satellite industry quickly is moving ahead and offering the second-generation HDTV solutions with everything from HDTV-optimized satellites to a new array of products aimed at handling much larger HDTV bitstreams.
SES Americom, for example, has already deployed the first of a pair of HD-optimized satellites that make up its HD-Prime neighborhood and, at press time, the next was scheduled for launch last month. SES Americom currently supports NBC and PBS broadcast HDTV as well as Discovery HD Theater, Showtime HD, Bravo HD and iN DEMAND (video-on-demand pay-per- view) on cable. Launched in early February with a C-band payload, Americom 10 (AMC 10) is operating at 135 degreesW. It replaced Satcom C 4. AMC 11 will soon appear at 131 degreesW, replacing Satcom C 3.
"We have built linearizers into the SSPAs [solid state power amplifiers] that improve the quality of the digital signal at the higher power levels. Our tests (both on-orbit and on the ground) indicate that we have minimized the bit errors at even the highest data rates, for example, those that would be appropriate for HD," says Carl Capista, vice president of media and entertainment services at SES Americom.
In addition, the SSPAs’ output on AMC 10 and AMC 11 are 20 percent greater in comparison to the Traveling Wave Tube Amplifiers (TWTAs) output on C 3 and C 4, according to Capista. The satellites’ reflectors are shaped to provide a consistent coverage pattern so that an HD signal is delivered equally in Maine, Texas and Florida, for example.
"We have people transitioning from analog to SD [Standard Definition], and this has freed up capacity for HD," adds Capista. "All the basic cable programmers have plans afoot for HD in 2005 as more cable systems are offering HD as part of their basic service lineups."
Second-generation HDTV is happening on the ground as well, and it is happening much faster than anticipated because the original model of using the full ATSC (Advanced Television Systems Committee) load of 19.4 Mbs is on the verge of becoming outdated.
"Do I agree? Absolutely," says Gil Maxwell, senior vice president and COO at Maine Public Broadcasting Corp. "Today, it is the full 19.4 Mbs, but as soon as someone figures out how to make money using some of the bits in the stream, the quality argument will quickly disappear."
According to Maxwell, the Snell and Wilcox concept of ‘Mole Technology’ might be seen as a first-generation solution. This involved sending the encode instructions with the video as metadata so that when decoding took place, one could use the same algorithms to recompress the signal, thus maintaining the best possible quality. In contrast, an example of a second-generation HDTV device is the new multistandard HD compression pre-processor from Snell and Wilcox known as the CPP1000 Prefix-HD, which can reduce bandwidth requirements for satellite broadcasters by eliminating unwanted signal artifacts, among other things.
"With the software today, you can inspect the stream to see what encode tools were used and then make the best decision absent any metadata as to where to get the other bits to throw away," says Maxwell. "Once you have all the extra you can squeeze out, you then start tossing information until you reach the limit you set. Our limit is 12 Mbs. When there is a lot of motion, you can start to see the results of the additional reduction."
Significant Regional Differences
According to Warren Hobson, director of corporate strategy at Tandberg Television, there is no reason why the European trend will not mirror the more evolved HDTV roll-out in North America. "The affordability of displays remains an issue, but we already can see the volume of HDTV set production growing quickly and driving down prices as a result," says Hobson. "The competitive dynamics in North America, where service providers are using HDTV very effectively to win subscribers, are becoming more apparent."
Hobson sees a subtle link between a new wave of advanced new set-top boxes (STBs) and the widespread migration to the new advanced encoding and DVB-S2 modulation solutions. He does not rule out the possibility that cable service providers and DBS operators alike might end up with a mixed base of legacy and advanced STBs.
"The fairly high bandwidth requirements of HDTV on delivery channels can burn into multiplex capacity quickly," says Hobson. "Hence the interest in vastly enhanced compression, along with the DVB-S2 advanced modulation solutions, which will start appearing late this year and in 2005."
Along with a new SD/HD statistical multiplex solution, Tandberg is rolling out an integrated E5784 and E5788 HD DSNG encoder with QPSK/8PSK (Quadrature Phase Shift Modulation/Eight Phase Shift Modulation) satellite modulation, all integrated into a single 2RU (two rack unit) package.
"Nobody is going to await the arrival of the new technology," says Hobson. "HDTV event coverage, such as the upcoming Summer Olympics, with HDTV contribution links back to the United States from Europe will create a flood of HDTV content, adding considerable momentum to HDTV display sales, particularly in the United Kingdom."
Long Cycle To Achieve Mass Penetration
HDTV is still a luxury item, and early adopters are still playing an important role despite rising HDTV sales, according to Carlo Basile, president, Americas at Israel-based Scopus Network Technologies Inc. "The sales curve here is a hockey stick. It is just the same as we saw with the 15 year color TV roll-out starting in the 1950s," says Basile. "The HDTV infrastructure is there, but it is still maturing from the standpoint of the customer accessing integrated capabilities and benefiting from greater bandwidth efficiencies. There is substantial room for future growth."
NBC Olympics is installing Scopus E-1100 SD and E-1800 HD encoders at the International Broadcast Center in Athens, Greece, to beam two HD channels and up to 25 SD channels back to its viewers. NBC has Scopus IRD-2800 integrated receiver decoders (IRDs) at its facilities in the United States. A pair of digital satellite newsgathering (DSNG) trucks will be equipped with these Scopus encoders as well. Scopus also offers the Intelligent Video Gateway (IVG), an HD/SD video router capable of performing transcoding, rate shaping and grooming, all in a single 1RU (one rack unit) device.
"The satellite industry can use a very powerful grooming platform. Given that bandwidth requirements for HD content are five or six times higher than the bandwidth requirements for the delivery of SD content, the IVG with its 4 Gbs routing/grooming capacity is ideal for any headend," says Basile. "Satellite operators also benefit from the digital-to- digital processing–bit rate adaptation and rate shaping–capabilities in digital turnaround scenarios."
The Scopus’ Intelligent Video Networking (IVN) concept, which includes the IVG, focuses on IP-based headends where all the different components–encoders, receivers, video processing units–are interconnected through an IP network. "With our IVN and IP-based architectures, the complex and expensive matrices of traditional ASI [Asynchronous Serial Interface] based headends are eliminated," says Basile. "An IP headend has another attractive feature. It facilitates the implementation of redundancy, a much-needed ingredient in mission-critical satellite distribution."
Bitstream Basics: More Services Or Higher Quality?
There is an ongoing effort in the terrestrial broadcast, Direct-to-Home/Direct Broadcast Satellite (DTH/DBS) and cable industries to establish a set of operating guidelines that deals with what HDTV should look like, and what is really acceptable to the consumer. Is everybody reading off the same page? Not quite.
"As HDTV is starting to establish itself as a compelling value proposition rather than as a luxury item, there is a growing realization that a certain line can be crossed wherever compression occurs, and the service provider risks underwhelming consumers," says Bryan Willson, senior engineer of video products at Radyne Comstream. "In order to succeed, broadcasters need enough bits to make it all work."
Cable often starves its SD services at under 2 Mbs, and "they are getting away with it," he says. "At the end of the day, they have to make a decision about what is more important, more services or higher quality."
While encoding is going to experience big changes in the future, the question is when this migration to Advanced Video Coding or Windows Media 9 will actually take place. In the meantime, the focus is on satellite performance given fixed power configurations, new modulation schemes with new forward error correction techniques, and the pending launch of several Ka-band satellites, which will result in a lot more available capacity.
"The quantum leap that we will see with the adoption of DVB-S2, for example, is going to happen faster than most people realize especially when it comes to contribution links including DSNG in HDTV where we can provide both ends of the pipe," says Willson. "However, the DVB-S2 contribution model is still limited by what is happening downstream. This makes high-quality picture generation from the start so important given the likelihood that the images will go through a succession of compression."
HDTV content distribution for live events to theaters or digital cinemas is seen as a high growth opportunity in many regions. The 2003 Super Bowl and The 2002 World Cup were two recent special events where Tiernan encoders were used. And last summer, JVC and Radyne Comstream formed a partnership to address this live event market using the JVC DM- D4600U decoder and the Tiernan THE15A HD MPEG-2 encoder. Beaming high-quality HD imagery at rates of 70 Mbs is well within the range of the THE15A, which can operate at rates over 100 Mbs.
For customers with mobile HD/SD requirements, Radyne Comstream offers a flyaway earth station known as the Modular Integrated Broadcast Systems (MIBS), which is designed for HDTV services where rapid deployment is a vital concern.
Ready To Go "Voom"Ing
Rainbow 1, owned and operated by a unit of Cablevision Systems Corp. known as Rainbow DBS, is now operating at 61.5 degreesW. This satellite is a Lockheed Martin A2100AX equipped with 24 MHz Ku-band transponders and 22 individually programmable spotbeams, among other things, which can allow for geographic-specific programming as well all continental U.S. coverage, according to Steve Pontillo, senior vice president and general manager at Rainbow Network Communications, another unit of Cablevision.
"This will give Rainbow DBS the ability to bring unique programming to a diverse group of subscribers," says Pontillo. "Since most of the advanced technology lies within the uplink and the subscriber HD STBs, it gives Voom a clear advantage over the competition now and in the future."
Globecomm Systems was involved in designing the uplink. NDS is providing its VideoGuard conditional access technology, along with an HD electronic programming guide, and NDS digital video recorder content protection and storage technology. The Motorola STB has slots to allow for a card-based migration to MPEG-4, although Voom is not saying exactly when an upgrade from MPEG-2 will take place.
"We are currently researching the viability of incorporating DVB-S2 with the release of MPEG-4 compression as well," says Pontillo. "The current modulation being used is 8PSK."
For its HDNews offering, Voom is using a combination of both satellite and fiber to backhaul content. All content is transmitted in 1080i.
Democratizing HD In Europe
Belgium-based HD programming provider Euro1080, a pan-European HDTV service provider, already deployed some 3,000 HD demo STBs without conditional access. In addition, interested customers ordered 30,000 Zinwell Quali-TV STBs with conditional access all across Europe, according to Euro1080 spokesperson Vicky De Beule. The plan is for the Euro1080 HD programming stream to be totally encrypted in January 2005 using Irdeto Plsys-based conditional access cards from Irdeto Access.
Euro1080 offers two HD channels including a Main channel, which airs 24-hours-a-day in four-hour blocks, and the Event channel, which beams HD special event content to digital cinemas. A half transponder is used on Astra 1H for the Main channel, while the Event channel is on Sirius 2. Euro1080 currently beams HD content primarily in English, but starting in January 2005, German and French will be added with Italian and Spanish coming shortly thereafter.
"Because all the equipment used for production is 1080 x 1920, the same Alfacam mobile HD production vehicles used for live HD transmissions can also used for SD production in a simulcast," says De Beule. "This enables us to greatly reduce our production costs."
"We created the Event channel so everybody can enjoy the wonderful HD images. Because equipment for home theaters and HD displays in general is still very expensive–an HD plasma costs approximately 6000 euros[U.S. $7,250]–we know that just a few can afford it," adds De Beule. "This is why we created the Event channel; to democratize HD."
HDTV Is A Win-Win
Japan is the overall HDTV leader. Based on HDTV units shipped data from the Japan Electronics and Information Technology Industries Association, we count a total of 2 million- plus HDTV viewing households, slightly ahead of the United States, which has an estimated 1.5 million. In mid-April Tokyo-based Space Communications Corp. was preparing to launch Superbird 2A, a Boeing 601 Ku-/Ka-band hybrid, which is designed to deliver HDTV, among other things. Consumers in the United Kingdom, Sweden, South Korea and Australia are also enjoying HDTV.
There are several HDTV wild cards in the United States. The FCC is floating the idea of possibly accelerating the Digital TV transition, while at the same time, the Satellite Home Viewer Improvement Reauthorization Act taking shape in Congress has local-into-local service via DBS going through various twists and turns.
For the most part, HDTV is a win-win for the satellite industry, which already enjoys a considerable lead over any alternative terrestrial services when it comes to HDTV programming distribution in particular.
Peter J. Brown is Via Satellite’s Senior Multimedia & Homeland Security Editor. He also volunteers as a satellite technology and communications advisor to the Maine Emergency Management Agency.