By Peter J. Brown

As broadcasters and direct-to-home (DTH) service providers prepare for the future, the migration from the established MPEG-2 encoding solution to a much more bandwidth- efficient solution seems almost inevitable. With demand for bandwidth-hungry, high-definition (HD) TV content growing in particular, many industry players and observers see the H.264 or MPEG-4 Part 10 standard as the most attractive solution.

The H.264/MPEG-4 standard, also known as Advanced Video Coding (AVC), holds an edge over Microsoft’s Windows Media Video 9 encoding platform, industry officials say. This Microsoft solution, better known as VC-1, has reached the critical step of Final Committee Draft status in the Society of Motion Picture and Television Engineers’ Video Compression Technology Committee, meaning that all the platform’s technical issues have been resolved. But since the terms of VC-1 licensing have yet to be announced, nobody really knows if the technology is going to be competitive, says David Price, vice president, business development at Harmonic Inc.’s Convergent Systems Division.

"Although AVC and VC-1 are virtually identical in terms of performance, it seems like the big money is behind AVC, with nine out of 10 of new operators opting for AVC," Price says. "It has become the focus of silicon, set-top box (STB) and encoder manufacturers alike." VC-1 has its roots in the more Internet Protocol (IP)-intensive personal computer environment, and for this reason, stands somewhat apart from the other two dominant broadcast-centric encoding platforms, MPEG-2 and MPEG-4 AVC, as a more IPTV-specific solution. "Although Microsoft has not got a winner with their VC-1 codec, they clearly have scored a home run with their IPTV middleware and ecosystem. The user experience brought about through their tremendous graphical user interface, taking advantage of the fundamental capabilities of an IP-based delivery system, will set the standard for how people view [and pay for] their video information," Price says.

The demand for VC-1 is more evident in Europe and Asia than in the United States, says Lisa Hobbs, senior director of marketing at Tandberg Television Inc. "Swisscom’s Bluewin is using it for an IPTV-based service and Malaysia’s MiTV project also just announced they will be deploying it for an IPTV network," says Hobbs. "It is true that we have seen a move toward AVC technology by satellite DTH [direct-to-home] broadcasters on a global basis, but VC-1 continues to play elsewhere."

While VC-1 has been selected by companies like Verizon V CAST, Crown Castle Mobile Media and BT Livetime to drive dynamic wireless video services, Microsoft continues to search for its first significant digital broadcasting service (DBS) or DTH customer. Still, VC-1 remains a force in an unpredictable multimedia marketplace, which appears eager to embrace such things as hybrid Digital Video Broadcasting for Handhelds (DVB-H)-based delivery solutions. Joe Powell, lead product manager for Windows Digital Media at Microsoft, says that, among other things, VC-1 can scale from wireless delivery to HD resolutions, all at very economic bit rates.

"Because Windows Media Video 9 advanced profile elementary streams can be delivered over conventional MPEG-2 transport streams, VC-1 is a great choice for satellite operators who are looking to the benefits that advanced codecs [coder-decoder] provide, yet do not want to significantly overhaul their infrastructure," says Powell. "Today, most of the digital cable, satellite and over-the-air services use MPEG-2 systems for packetization, multiplexing and synchronization of audio and video. Consequently, most of the STBs have the capability to process MPEG-2 transport streams. Microsoft makes it possible to use the Windows Media Audio and Video codecs with any media file container on any platform. Compared to MPEG-2, VC-1 can deliver the same quality for standard-definition (SD) and HD video in half to a third of the bit rate depending on the content."

Demand thus far suggests that both AVC and VC-1 will remain firmly on everyone’s radar screen for the foreseeable future.

"We are getting requirements for VC-1 as well as MPEG-4. That is why we designed the Universal Encoder platform to provide the flexibility in supporting one or the other," says Mario Rainville, associate vice president, product marketing at Princeton, N.J.-based Scopus Network Technologies. "As for the standards race, things are certainly getting more crisp from where they were a year ago, but I would not go as far as saying that the competitive nature of one standard or the other will fade out soon."

"MPEG-2 is still the standard video codec for professional applications," says NDSatcom spokesman Peter Neu "MPEG-4 AVC will follow for lower speed applications in the enterprise VSAT market in particular. While we see VC-1 more in the commercial market and end user business We expect MPEG-4 to take off in 2006."

Compression Vendors Keeping Up With Demand

Compatibility with ubiquitous, legacy MPEG-2 transport platforms will facilitate the introduction of AVC-driven HDTV, as well as instant access to the benefits that the format provides, according to Neil Brydon, director of product marketing at Sunnyvale, Calif.-based Modulus Video Inc. Not only is HD no longer confined to a few pioneering market areas and poised to become a mainstream global play, according to Brydon, but HD is becoming a must-have service offering.

Fortunately, the industry is much more experienced than it was during the introduction of MPEG-2. Major operators like DirecTV, BSkyB, Euro1080 and others are announcing their intent to implement AVC to conserve bandwidth, and Modulus already has shipped HD AVC encoders and decoders to three customers for early trial. "DTH players need it to compete with cable," Brydon says. "HD is greedy for bandwidth, however, and to deliver HD the operators need to use the most efficient delivery technology. AVC is recognized as the right technology, but clearly the solution needs end-to-end capability in the form of both the encoders and STBs. The STBs have been on the right path and now the large U.S. DTH operators are using their market strength to stimulate, expedite and ensure the availability of the requisite AVC STBs."

HD has finally turned a corner thanks to a combination of affordable display technology, content supply and the fact that the new AVC compression technology enables efficient delivery, according to Brydon. "Interest is coming from affluent markets around the globe. Europe is an interesting case study, the numbers of proposed services is small, but growing from zero base means that the growth in absolute terms is huge," says Brydon. "The largest market opportunity is in the North American DTH market, dominated by a few giant operators that have already announced their intent to broadly implement new services based on HD AVC."

Tandberg Television is focusing its efforts on advanced video coding technology, as well as performance upgrades to its existing MPEG-2 encoders, says Hobbs. "MPEG-2 will not go away anytime soon," she says. "DirecTV announced it would be deploying our AVC HD encoder for its new HD channels launching this year. BSkyB in Europe announced the same thing, but at the same time, we also announced a couple of weeks ago an MPEG-2 deployment for digital simulcast to Sunflower Broadband for use in cable."

Tandberg offers ICE — the Intelligent Compression Engine — a card that fits into the company’s E5710 or E5780 MPEG-2 encoders to create either VC-1, AVC SD or HD encoders. The EN5980/EN5990, which are the HD versions of the encoders, became available for shipment at the end of 2004. They also use an ICE card, albeit with HD rather than SD software, according to Hobbs. "We have shipped the EN5990 to DirecTV and BSkyB. We are still waiting for commercially available versions of the HD STBs, but the encoders are ready to go," says Hobbs.

Price says that the market is watching and waiting for the missing HD-AVC/SD-MPEG-2 STBs appear. "The new System-on-Chip (SOC) silicon is only just starting to be sampled, so it will not be until next year that next generation HD STBs become available. Once that happens, HD can really take off with AVC," he says.

Harmonic is focused on bringing AVC, MPEG-2 and VC-1 video encoding platforms (with multiple profiles) to the market with all the capabilities now required of an IP-delivered ecosystem. The company already has sold its MV450 MPEG-2 encoder to customers such as Fox and Sinclair Broadcast Group and will be introducing a next-generation AVC HD encoder before the end of the year, Price says. Because telecommunications companies and cable service providers can provide a true on-demand unicast experience, satellite operators will have to develop a hybrid service of some sort in conjunction with a terrestrial-based solution for unicast content in order to remain competitive, according to Price. "This means teaming with DTT [digital terrestrial television) operators, broadband operators or next generation 802.16 WiMax services," says Price.

According to Hobbs, advanced coding is still considered to be an emerging technology, with only a handful of companies capable of shipping equipment today and even fewer users in the marketplace actually having commercially deployed services. "This is the wave of the future and large scale deployments will likely only choose to go in this direction for bandwidth savings in the future. But there is still a tremendous amount of MPEG-2 equipment deployed, so I believe transcoding technologies will also be critical — the ability to go from MPEG-2 to advanced coding or vice versa without coming all the way back to baseband and starting over," says Hobbs. "There has been a lot of talk in the marketplace about this in the last six months and I believe the first generation of these boxes will be out in the next year."

LG Electronics is focusing on transcoding solutions for DBS and over-the-air terrestrial signals, says Richard Lewis, senior vice president, technology and research, at LG Electronics USA Inc. "We have a strong demand throughout the United States for DirecTV transcoders, especially for the lodging industry, and a strong demand in the Western states for terrestrial transcoding. We have a number of requests for transcoding other signals and we expect to produce products to meet these needs in the future."

Applications And Opportunities Exist Beyond TV Distribution

Scopus is developing a new generation of encoding platform — the Universal Encoder (UE-9000) — and integrating advanced DVB-S2 modulation/demodulation techniques into its satellite receivers to reduce bandwidth utilization, says Rainville. The AVC real time encoders are much more complex than today’s MPEG-2 solutions, he says.

"We are getting requirements for VC-1 as well as AVC. That is why we designed the Universal Encoder platform to provide the flexibility in supporting one or the other. As for the standards race, things are certainly getting more crisp from where they were a year ago, but I would not go as far as saying that the competitive nature of one standard or the other will fade out soon," says Rainville.

In the satellite and broadcast space, Scopus has been very active in deploying its solution for the end-to-end digital delivery of syndicated programming with the IRD-2900 satellite receiver serving as the centerpiece, Rainville says.

For distribution and contribution, the selection of a new codec has an impact on both the origination and the reception. In distribution, the total system cost is more sensitive to the receiver/decoder usually deployed in large quantities, so it is important to offer professional receivers that can be configured for a specific application. "More powerful and cost optimized devices would help reduce the overall cost of the real time encoder," Rainville says. "Advanced codecs provide a better compression ratio and lead to greater bandwidth savings, but the cost of such is reflected in the complexity of the implementation."

Envivio UK Ltd. provides MPEG-4 products for IPTV, enterprise, mobile and broadcast services such as Japan-based Mobile Broadcasting Corp.’s MobaHO! platform. The satellite- based digital multimedia broadcasting service uses Envivio Inc.’s AVC 4Caster real-time encoder. "The large bandwidth requirements of HD explains why many vendors have bypassed SD to concentrate on the considerable opportunity available for HD," says Ian Trow, Envivio’s vice president for marketing. "2006 is going to be the year for HD, when widespread availability of consumer STBs and broadcasters launch premium services suited to HD. There are early adopters, like DirecTV, who are leading the way for the market to follow. We are just at the beginning of a large shift towards HD, particularly in North America. Europe is showing signs of readiness with Sky’s announcement of an HD service launch."

Applications beyond television distribution represent one of the largest opportunities for vendors of new compression systems, Trow says. "Business TV, distance education, surveillance and remote monitoring are examples of markets that can draw on the improvements in compression technology and the synergy of new systems with IP network infrastructure. Beyond STB and Professional IRD [integrated receiver and decoder] availability, the need for video-oriented server provision including flexible middleware solutions that can be scaled from enterprise applications up to large scale IPTV deployments are key requirements."

Quality of Service and multicast are two keys areas requiring attention to support widespread adoption of the new compression systems, Trow says. "Infrastructure providers are embracing the new compression technologies by upgrading network capability, to guarantee provision for video related services. BT’s deployment of an Multiprotocol Label Switching (MPLS)-based network in the United Kingdom is a good example of the shift towards standard infrastructure as opposed to dedicated broadcast links," he says.

Video Gateways And Servers Matter, Too

When it comes to delivering video content via IP over farflung networks, video compression or encoding solutions represent just one part of the equation. Video gateways complement encoders by preserving the quality of compressed video during end-to-end transmissions. All the efficiencies gained during the compression process are of little value if the IP video or content arrives at its destination in anything less than the highest possible broadcast quality.

According to Dan Album, spokesman for Path 1 Network Technologies Inc., gateways such as Path 1’s Vx8000 video gateway are used in numerous satellite-related deployments, primarily by broadcasters who move video over terrestrial IP networks (such as among their various studios) and then send post-production video content to their satellite uplink facilities for worldwide distribution. CBS and Fox Broadcasting, for example, used Path 1’s equipment as both the primary and backup technologies for their respective 2004 and 2005 Super Bowl broadcasts in HD, according to Album. "In many ways, long-haul video transport is the most critical link in the video distribution chain. Video sent over IP networks is subject to many errors — delays in the packet stream, lost packets, packets arriving out of sequence, image jitter, etc. Path 1’s gateways corrects these transport errors and ensures that whether you are sending video across the street or across the world, it will maintain broadcast quality when it arrives at the uplink facility," he says.

"Compression removes information and bits, so any problems or hiccups during transmission are amplified accordingly. Macroblocking, dropped frames, etc. are more likely to be enhanced (in a negative way) if the transport is not perfect. This is especially problematic in cases where video needs to move over long distances, Album adds. "Gateways are the best way to maximize the investment in these expensive encoders — particularly the HD-AVC encoders."

SD and HDTV delivery aside, Alcatel Alenia Space announced in early 2005 that it had installed DVB-RCS gateways provided by Quebec-based Xiplink Networking, a subsidiary of Xiphos Technologies Inc., in the Middle East and will soon install them in Northern Africa Among other things, the Xiplink Hub Optimized Gateway compresses HyperText Transport Protocol (HTTP) data more efficiently and automatically, says Alcatel Alenia Space spokesman Laurent Zimmerman. "Satellite user customers get a better web browsing experience," he says. "A Performance Enhancing Proxy (PEP) at the hub isolates the service from any weak behavior of the Internet or any servers behind or, more precisely, from servers that do not support TCP-sat options such as extended window or selective acknowledgements. In brief, it helps the satellite access provider to commit on service delivery relatively independently of the internet network or service providers."

Xiplink focuses on a hub-only solution aimed at optimizing interactions at the Transmission Control Protocol (TCP) and HTTP layers in DVB-RCS environments, and this enables users to shape network traffic to match network bandwidth without displacing Quality of Service parameters. The Xiplink Hub Optimized Gateway offers a forward channel of 45 Mbps and a return channel of up to 20 Mbps. Optional client browser tuning can further enhance performance. "The Xiplink Hub Optimized Gateway is a solution for improving the efficiency and performance of broadband IP access systems. Installed at the hub, the system optimizes the TCP flow while allowing the independent enforcement of QoS and service level agreements," says Charlie Younghusband, Xiplink’s product manager. "The HTTP compression alone provides a reduction of approximately 15 percent in bandwidth utilization, permitting more users on less bandwidth."

While Xiplink is not unique in this respect, Alcatel selected Xiplink because of a requirement by some customers that mandated PEP transparency to IP addressing. "The hub only solution is not more difficult to implement than PEP with clients on remote sites. In any case, you have to integrate and tune the PEP product to the dynamic behavior of the hub and satellite terminal in terms of available memory and resource allocation," says Zimmerman.

"Satellite streaming is basically used in a multicast streaming environment. Multicasting is more difficult to do and more expensive to set-up. Multicasting is mainly geared towards Intranets. Among the benefits, it allows multiple viewers of one video stream which saves cost on bandwidth and a video stream can bypass the Internet and be placed directly in an Intranet," says Derrick Freeman, video streaming and compression specialist at GeniusDV. "However, most networks are not multicast-enabled and the Internet is geared for unicasting, rather than multicasting. And there is need for IP/DVB PC cards — a card to view any satellite streaming is a hindrance for larger audiences especially — and for satellite receivers as well."

As Zimmerman mentioned, servers can present problems. Envivio has developed a server designed specifically to support the streaming of AVC in IPTV, enterprise and broadcast deployments via its ability to handle MPEG-4 systems content, which is known as Binary Format for Scenes (BIFS).

"The BIFS capabilities within MPEG-4 allow the delivery of complex interactive multimedia scenarios. The key advantage of BIFS is that individual objects within a multimedia scene are encoded and transmitted separately," says Trow. "A server that can process BIFS has two key benefits: increased workflow since complex scenes comprising of multiple objects can keep the objects as separate entities right up to the STB, and the inclusion of mixed graphic and pictures in a scene. Among other things, this dedicated server approach also allows middleware to be based around standard network infrastructure, greatly reducing the cost of system implementation," adds Trow.

"Along with the enhancing video compression technology, strong management capabilities of the available network bandwidth capacity, as well as the flexibility of the satellite network topology for video contribution and distribution is key. This will enable service providers to offer attractive services with competitive commercial conditions to their customers," says Neu.

Conclusion: Juggling Costs And Bandwidth Resources

While delivering highly compressed digital video as IP may be the ultimate destination for the global television sector, the timetable is open to question. Issues such as overall network security and reliability and where exactly television is heading in terms of its future menu need to be resolved before the conventional broadcast world gives way to a fully enabled interactive, pulled content or on-demand model.

"The technological and business shifts required for that are too significant to be able to do it in the short or medium term. Eventually though, it would appear to be the best option for the consumer and we have now developed the technology to enable it," says Aditya Kishore, director, media & entertainment strategies at Boston-based Yankee Group. "From here on it is more a question of technology evolution to support the scale and bandwidth required, and the development of new business models to support it economically — new advertising formats, audience measurement solutions, metrics, etc.

"The problem is that there is a very significant investment that has already been made in existing equipment. So it is a question of managing the transition in a cost-effective manner. On the one hand, for cable, IPTV, and DBS service providers, there is a need to manage limited bandwidth resources with the growth of HD, VOD and increasing broadband connection speeds. On the other hand is the cost of replacing equipment," adds Kishore.

Long term goals aside, a migration to advanced compression schemes like MPEG-4 AVC appeals to everyone. However, like anything else, is a matter of resources and budgets. Coming up with a cost-effective transition strategy and then implementing it in a measured manner is what counts.

"All of the bits and pieces are there. We see the market looking for more turnkey and outsourced solutions. Customers are looking to work with service providers who will provide a comprehensive solution, including compression and satellite equipment as well as space segment. The video owners simply want to hand off their video signal and know that it will arrive at the other end," says Semperbon.

Peter Brown is Via Satellites’s Senior Multimedia & Homeland Security Editor.