Going Digital -- A Time of Flux
Over the past six years we have been writing about the transition from the analog world to the digital one and about the lack of connection between isolated islands of technology in the home. So it's surprising we didn't understand just how complex it would be to choose and install wiring and systems to support networked media and communications—video, audio, data and telephone services—in a way that worked well now and had flexibility and "staying power" for the future. Our recent experience of equipping our Florida condo for networked digital media showed us the difficulty of "doing the right thing" at a time when so much is changing simultaneously and solutions are in a state of flux.
In this and the next two articles, we summarize what we took away from our recent experiences. This first section talks about the three worlds of audio/video, the PC and home networking and describes the dozen or so variables now changing simultaneously in them.
The second article "Media and Broadband In Our Condo: Some Answers, More Questions" highlights the process we went through in deciding what we wanted to achieve and what we were able to get working during the past few months.
The third section "Digital Interconnects and PCs for Television" reflects on two key questions that remain unresolved—based on our experience and what we have heard about vendor plans for the future: the "right" interconnect for the highest-quality television, and the role of PCs for television.
Parallel Evolving Worlds
The A/V and PC worlds have been evolving in parallel:
- The audio/video (A/V) world has been analog, standard definition and self-contained in a home entertainment center. All equipment is assumed to be in close proximity. If there are several A/V sources (AM/FM tuner, CD or DVD player, VCR, cable or satellite box), an A/V receiver selects which source is heard on the loudspeakers and seen on the TV screen. Equipment is connected together with interconnecting cables that are mostly analog, short and run "point to point" from the output of one device to the input of another.
- The PC world has been mostly been about data, graphics, web browsing and email, and mostly self-contained in a home work center. All equipment (PC, monitor, keyboard, mouse, printer, scanner, perhaps digital camera and digital camcorder) is in close proximity. Interconnecting cables (serial, parallel, USB) are digital, short and "point to point" from the output of one device to the input of another.
- Home networking has mostly been about moving data between a broadband modem and several PCs. There is usually no network connection between the TV world and the PC world.
These are all changing rapidly:
- Television broadcasting and television sets are both going from analog to digital, and from standard definition to high definition;
- DVD players (which have always been digital) are going from standard definition to high definition; new DVD formats are required to handle high definition (and there are two warring formats);
- Personal video recorder (PVR) functionality is appearing in many forms—in stand-alone devices like TiVo, as features of advanced satellite and cable set-top boxes, and in PCs;
- On-demand music and video are appearing in many forms, both for the TV and for the PC;
- Downloading music and video over the Internet is growing rapidly, moving from illicit peer-to-peer file sharing to legitimate services such as iTunes and MovieLink;
- PCs—running software such as Windows Media Center Edition—are increasingly used to record and play audio and video content;
- Video screens—increasingly high-definition—and loudspeakers are installed in several rooms, and people expect to be able to view on-demand and stored A/V content on any screen;
- Home networking has been installed in many homes, and people increasingly expect to include the A/V world as part of the networked home;
- Intel is introducing Viiv, the next generation of PC hardware, designed for high-definition TV;
- Microsoft will introduce Vista, the next generation of Windows PC software, with many features for the TV; and
- Content owners are afraid of illicit copying, and increasingly insist on securing content with digital rights management (DRM) encryption and usage rules.
Interconnecting the equipment in the new digital home is a huge challenge:
- New digital audio/video cables are required to provide the interconnects between digital A/V devices
- A huge installed base of legacy A/V equipment—VCRs, DVD players, and TV sets—will be around for a long time, so A/V receivers need to support both analog and digital A/V interconnects and need to provide analog-to-digital "up-conversion" for legacy analog devices;
- DRM has pushed A/V interconnects to uncompressed digital formats, which require very high data rates and short cable lengths
- Audio/video "sources" (such as CD players, DVD players, set-top boxes, VCRs, PVRs and PCs) and "sinks" (monitors, TVs and loudspeakers) are likely to be in several different rooms.
As the A/V and PC worlds come together, neither the new digital interconnects nor the new home networking technologies address all the problems. A/V content is "isochronous", requiring close time coordination between video and audio channels; PC data is "asynchronous", with no time coordination. The media networked home needs multi-point distant isochronous connections. Digital interconnects, while isochronous, are optimized for close point-to-point connections. Although home networking technologies are designed for multi-point distant connections, nearly all are asynchronous and few if any have sufficient capacity for multi-channel uncompressed high-definition digital video.