The long and winding road to digital television.

The digital video age is dawning. We currently have digital VCRs, optical discs, CD-ROMs and digital satellite video, all of which are available for display on analog TV receivers.

The picture, though, isn't yet clear. With the industry divided into five camps, a unified standard looms distant.

First there is the satellite TV sector, which in 1994 introduced DirecTV - the first digital TV transmission for direct-to-home services using the DDS technology - in the U.S. This digital technology was developed by Thomson and is now used by Galaxy Latin America and possibly Tele-TV. Last year, Sony came out with a different digital satellite TV technology.

Then there is the terrestrial TV sector, with all its problems. For terrestrial broadcasters, digital TV began as higher definition television (or HDTV, which has a 16:9 aspect ratio), and later took the form of ATV (developed by the Advanced Television Systems Committee) in the U.S. and the Eureka program in Europe.

Currently three FCC proceedings are taking place in the U.S.: one proceeding has the FCC considering a new national digital standard; the second deals with allocation of frequencies and whether the broadcaster should be charged for use; and the third is considering how much of the broadcast schedule should be HDTV programming and how much should be other services. In the U.K., the decision on whether to offer HDTV or regular TV with extra services is left to the broadcaster.

It is important to note that digital TV will allow broadcasters to deliver not only HDTV but also multiple lower-resolution programs and data services. Thus broadcasters will be able to use the same bandwidth to transmit four or even six different programs or data services simultaneously.

Naturally, the cable TV sector has different needs. Basically, what it wants from digital TV is interactivity. Digicipher, the first cable digital standard in the U.S., was introduced by General Instruments. To satisfy its needs, the cable industry has established its own digital committee, DAVIC.

In the middle of all this, one must also consider the digital needs of Multichannel Multipoint Distribution Systems (MMDSs), also called wireless cable, which are hybrids between cable and terrestrial services with microwave transmission frequencies close to those of satellites.

Finally, there are the various MPEG standards, which now number four, though MPEG-2 is the one used to make Philips' CD-i legible to CD-ROM players. MPEG-2 is also being considered by the ETSI (European Standards committee) as a transmission system. However, the winning standard may not be MPEG at all: a promising contender is HARC-C, developed by the Houston Advanced Research Center.

There are also several competing formats for recording and playback. These include the digital VHS system (DVHS), which allows the playback of analog tapes, and the Digital Video Cassette. The Digital Video Disc (DVD) standard seems to be unified, but even this is being challenged.

So the ball is now in the TV manufacturers' court. Manufacturers must develop and introduce a TV unit capable of receiving digital TV signals from any of these five sources: satellite, terrestrial, cable, MMDS and player/recorders.

Fortunately, the various digital committees are talking to each other. The European Digital Video Broadcasting (DVB) group, which has finalized a terrestrial, satellite and cable system, is meeting in Europe with the cable digital committee DAVIC to discuss unifying their systems.

In the U.S. it took color TV 11 years, the VCR six years and the CD player four years to be accepted by consumers at a wide level. Digital TV is not far over the horizon, and one can only guess how long it will take the public to accept it. Since no one yet knows which delivery system - satellite, terrestrial or cable - is going to dominate the market, manufacturers have to provide set-top boxes capable of accepting analog and digital signals from any source, at least until a unified standard emerges and analog fades out.

While manufacturers fight their digital battles, content providers are opening their own front.

Two of Europe's largest conglomerates, Veba of Germany and Metro of Switzerland, have joined forces to adopt a version of the DVB digital TV standard spearheaded by the Leo Kirch group. They will use the standard to offer TV services including video-on-demand and home shopping. Called the d-box, this technology will compete with the so-called MMBG consortium that includes ARD, ZDF, Deutsche Telekom Canal Plus (partly owned by Bertelsmann) and others.

On the U.S. side, even though the Telecommunications Act was recently passed, the issue of whether there will be spectrum auctions for the extra channels set aside for digital broadcasting still remains to be resolved. The critical question is whether the broadcaster will be given this second channel for free or whether he will have to pay for it. Critics, particularly the cable operators, feel that if the broadcasters can use this second channel any way they want (including as a subscriber channel), they should pay for it. Cable operators hope the FCC takes its time in deciding whether broadcasters can provide digital services because cable doesn't need the FCC's approval to get started on digital itself. And the sooner affordable digital set-top converter boxes are adapted, the sooner cable can get an edge against broadcasters' multiple channel offerings.

To be sure, broadcasters in the U.S. will be squirming in their seats until this spectrum issue is resolved. Mike Sherlock, executive vp of Technology for NBC, feels that if Washington auctions spectrums off to the highest bidder, it would be the end of free over-the-air broadcasting. "The networks are in a quandary about the spectrum issue," Sherlock commented. "If Washington does auction off the spectrum, technologically we can't convert our analog system to digital, unless you totally disenfranchise your audience. You either have analog or digital, not both."

Sherlock maintained that two things have to happen for NBC to make a transition to digital: people have to buy the digital TV sets and each individual station has to make a decision to spend the money to air digital. "Digital requires an investment from each station of $1.5 million to $2 million in order for it to just pass the signal," Sherlock pointed out. "However, I'm confident the small stations would do it." Sherlock added that initially NBC will feed in primetime film programming, which is relatively easy to air as HDTV. "Film is easier to put into digital and more than 60 percent of NBC's current schedule is on film. Eventually we will add live digitized sporting events; however, live events in HDTV will require buying new cameras, mobile units, switchers, etc. In other words, it will require a major investment."

Indeed, cost is a major factor to consider in the transition to digital. And, according to John Ball, chief technical officer of the consulting firm A.T. Kearney's Communications Electronics Practice, the cost would be prohibitive for many small channels in rural areas, which could mean that digital TV would only be available in highly populated urban areas. "Also, another question might be where public television would come into play. Public television has 20 percent of the channels and it lacks funds as it is. It would conceivably fit into the same category as the small rural stations," Ball added.

To be sure, the change to digital will affect not only broadcasters but the public, and Washington must determine where the public interest lies. The Electronics Industry Association reported that 24 million analog TV sets were purchased in 1995. Broadcasters must provide the public with analog broadcasting for a roughly 10-year overlap once digital TV is initiated. Even if set-top digital converter boxes were purchased for use with an analog set, the picture still wouldn't be as crisp as it would be from a digital receiver. Of course the digital switch will trigger the development of new digital TV sets, which in turn will trigger marketing of the new sets and a flow of money into the TV manufacturers' pockets.

While terrestrial digital is trying to get off the ground in the U.S., digital satellite television already exists in the U.S. and Europe. DirecTV, PrimeStar and USSB have been in the U.S. for a few years now, and in Europe, Germany's RTL Television is expected to enter the world of digital satellite TV this month. In Italy, Tele + will soon begin a digital pay-per-view service. MCI and The News Corporation recently banded together and will begin offering digital satellite services to U.S. viewers in late 1997. In the Middle East, Orbit's transmissions via satellite are fully digital. In addition, pan-Asian satellite broadcaster Star TV is scheduled to launch two of its three new movie channels via digital satellite.

Interestingly, the current satellite digital standard in the U.S. cannot be used for terrestrial or cable broadcasts. "We are mowing toward a digital standard for terrestrial digital, although not a full digital standard," Ball said. "Currently we have MPEG-2 (used with compact digital video disks), which could be considered as the de facto national standard, but how the signal is delivered by cable, satellite or TV will require different front-ends, like set-top boxes, to deliver their respective signals. Satellite signals come in at different frequencies than terrestrial and cable. Each signal, in a sense, has to be normalized."