DAVIC does data

When the Digital Audio-Visual Council was first formed in January 1994, its focus reflected the immediate plans of the cable TV operators, telephone companies and vendors that composed it-a world of interactive video-on-demand delivered to the television set using industry standards.

But over the last few years, the telecommunications industry has put its VOD plans on hold, deterred by the absence of a viable business model and high costs.

Instead, the industry has turned to high-speed data access, motivated by consumers' seemingly insatiable demand for the Internet and on-line services. For DAVIC, that has meant turning its focus to the development of standards that are relevant to its members today.

Telcos' interest in asymmetrical digital subscriber line (ADSL) technology led to DAVIC's publication in January of an ADSL specification, covering ADSL/asynchronous transfer mode mapping and standards for customer premises equipment (CPE). Although the specification did not address line coding methods such as carrierless amplitude/phase modulation and discrete multitone, the group plans to consider that issue. Line coding is one of the most hotly debated topics in ADSL because the two currently available methods are not interoperable.

Cable modems DAVIC also plans to address the cable TV industry's demand for high-speed Internet access products, says John Thompson, chief operating officer at DAVIC.

"It's a lot of work to re-engineer the technology needed to provide more symmetrical access in a hybrid fiber/coax system," Thompson says. "We've done a lot of work in DAVIC to understand these requirements, and we're going into 1997 with a call for proposals for a whole range of technologies, including what people want of cable modems.

DAVIC had expected the IEEE to take the first steps in developing cable modem standards this summer, Thompson says, but the organization hasn't yet managed to create an industrywide specification. DAVIC plans to pick up where the IEEE left off and hopes to have a standard in place by the end of 1997, Thompson says.

But that DAVIC standard could very likely be one of many cable modem standards that are developed by various industry groups, says Doug Robertson, director of business development for Motorola's multimedia group.

"The cable modem industry is evolving so fast that we may have multiple standards out there, just like in wireless," Robertson says. "Some might be sanctioned by standards committees, or you could have different vendors' standards. Ultimately, what drives standards is customers' needs, as operators learn in the field what they want to incorporate into their feature sets. The jury is still out on what's going to happen.

Setting standards for cable modem technology will be high on the agenda at DAVIC's meeting in Hong Kong this month.

Switched digital services Switched digital video (SDV) vendors are also keeping a careful watch on DAVIC's actions. Recent decisions by Bell Atlantic and Nynex to adopt fiber-to-the-curb (FTTC) networks to deliver SDV has given credibility to these systems, but industry standards are key to widespread deployment of SDV technology, says Gordon McKenney, director of technology planning for NextLevel Communications, a subsidiary of General Instrument.

"If we don't have DAVIC standards, then the customer premises equipment is going to be high-cost," McKenney says. "It's critical for volume production of FTTC systems to have all equipment throughout the home, from the optical network unit to the network interface module, meet DAVIC standards, and volume will drive the costs down.

Developing DAVIC standards for the delivery of data-over-FTTC systems is also crucial, he says.

"Data to the home is a catalyst for getting SDV out there," he says. "Internet access and work-at-home applications have become a major part of the move forward on broadband services, and they are taking precedence over video, at least initially.

But while interactive video may be temporarily taking the back seat to high-speed data services, DAVIC's Thompson forecasts a renewed interest in VOD-this time to the personal computer-in the next two years, and he predicts that DAVIC will be ahead of the game when that happens.

"We've done a lot of work on real-time interactive broadband services that has been sort of shelved when DAVIC turned its focus to Internet issues that were driving the market," Thompson says. "This puts DAVIC in a good position next year or the year after to develop real-time interactive video over the Internet.