Dallas -- Tele-Communications Inc. and @Home Network are
putting the final touches into a way to deliver Web-based services to the TV that they
hope will minimize potential digital set-top obsolescence.
While terms still need to be worked out, the technical
pieces are rapidly falling into place. The companies will support set-tops' computer
processing at the headend, which will work with whatever types of boxes the MSO places in
the field, said Ralph Brown, @Home's chief architect for set-top systems.
Brown said @Home is building an architecture that tailors
the division of processing tasks to the type of set-top.
"What people will be interested in viewing from the
Web on their television sets is not necessarily the same as the things that people do with
PCs [personal computers] when they're online," Brown said.
Cable engineers are facing the challenges posed by ever
advancing hardware technology as operators seek to exploit the capabilities of Internet
protocol-based content, as well as MPEG-based content. That was a prevailing theme at last
week's Emerging Technologies Conference here, which was sponsored by the Society of Cable
"It's very difficult to design a platform that
synthesizes hardware and software functionalities to maximum advantage for applications
that haven't been thought of yet," said Tom Quigley, director of the
residential-business unit at chip-maker Broadcom Corp.
For example, Quigley charted an evolution of CMOS
(complementary metal oxide semiconductor) technology that will quickly lead to the
creation of a single microprocessor performing the full range of functions of an OpenCable
next-generation set-top box by sometime next year.
This level of integration -- based on a move to shrink
circuit widths from 0.25 microns to 0.18 microns -- promises to push OpenCable set-top
costs into the range of today's analog set-tops, Quigley said.
But combining ever more functions into a single chip
confronts cable operators with ever more choices as to what set-tops should be able to do.
Just listing the capabilities of an 0.18-micron chip
indicates the complexities of the choices. They include:
The full range of DOCSIS (Data Over Cable System
Interface Specification) modem capabilities;
All 18 digital-TV-display formats;
Central-processing-unit tasks at a rate of hundreds
of MIPS (millions of instructions per second); and
Interfaces to a variety of applications, such as the
universal-serial-bus architecture in PCs, 10- and 100-baseT Ethernet connections and the
IEEE 1394 fire-wire port.
In TCI's case, the goal isn't to create the most highly
functional integrated set-top imaginable. TCI wants to create a software architecture that
allows the entire network to be used to deliver what consumers want, no matter what
generation of set-tops they are using, said Sid Gregory, vice president of advanced
technology for NDTC Technology Inc., the development arm of TCI's Denver-based National
Digital Television Center.
Advising subscribers that they need to "reboot"
their computerized set-tops when something goes wrong "is not a business that we want
to be in," Gregory added.
Further complicating cable's challenge in devising a
future-proof architecture is the great variety of hardware in an OpenCable environment
that is likely to appear in cable-ready digital-TV sets, as well as in retail-distributed
set-tops, Gregory noted.
"When OpenCable goes to retail, there are some very
nasty implications for operators," he said.
For example, in the interest of capitalizing on the
economies of advanced integrated chip design, a TV manufacturer might design the built-in
OpenCable platform in such a way where a popular service that an operator has devised for
a specific type of set-top doesn't work with that TV set. That would happen because the
tight integration of functionalities in the set-top is built differently from that in the
"Who are the subscribers going to call when that
particular application doesn't work?" Gregory asked. "They're going to call the
person who delivers the service" -- namely, the operator.
Such considerations make for "very, very hard issues
that we have to get through in the OpenCable process," he said.
Gregory reported that TCI has had considerable success in
getting teams from Microsoft Corp.'s Windows CE operating-system group and Sun
Microsystems Inc.'s Java unit to work together, despite the intense market and legal
battles being waged between the two companies.
"A lot of this effort is being coordinated through the
organization that Ralph [Brown] manages at @Home," he said.
As described by Brown, IP-based content that the company
deems suited to viewing on the TV will be transcoded to TV-display formats; compressed and
framed in MPEG transport; and processed in other ways at the headend for delivery over a
digital-TV channel to the set-top.
@Home is also devising a broadband national video-streaming
network to accommodate delivery of 300- to 500-kilobit-per-second IP to end-users. But
this video element will be part of the cable-modem data channel, requiring PC
functionalities and display architecture that aren't intrinsic to the set-top, Brown
"Whether [IP video over the data channel] is relevant
to the set-top environment is up in the air," Brown said. "But it's not an issue
in the forefront of our planning."
The architectural model under development for what Brown
called "Web-top" services relies heavily on the middleware API (application
HTML (HyperText Markup Language) as the two primary formats in defining what those APIs
The architecture is also closely linked with the
broadcast-IP model being defined through the Advanced Television Enhancement Forum, which
is focused on ways of linking Web content with advertising and other elements of broadcast
"There's a shift in thinking toward recognition that
the set-top is not acceptable as a PC," Brown said. The key issue isn't so much cost
as it is the desire not to load the set-top with moving parts that diminish reliability,
But such thinking leaves the industry with the dilemma of
how best to cope with the economies of scale and the ever mounting computer power that are
intrinsic to the level of integration mapped out by Quigley.
Ironically, to protect against the kinds of
incompatibilities stemming from different manufacturers' approaches to integration that
Gregory warned against, the industry is opting for simplicity, just as the ability to
increase functionality through tight integration at the chip level is opening a path to
ever more cost efficiencies in the boxes.
Given the rising power of network-centric computing, the
evolutionary path seems set toward creating an environment for ever-thinner clients,
leaving open to question how manufacturers will benefit from the gains in integration that
are anticipated by Broadcom.