AT&T details its advanced digital set-top requirements
By Junko Yoshida
EE Times
(06/01/00, 8:30 p.m. EST)
eetimes.com
MONTREUX, Switzerland? AT&T Broadband (Englewood, Colo.) will pursue a retail distribution business model for its advanced digital cable set-tops and work with Motorola and two as yet-unnamed consumer electronics manufacturers to bring products to market, its chief technology officer said Thursday.
Tony Werner also sketched out details of hardware and software components of the company's advanced digital set-top, in a speech to the World Television Forum Montreux 2000 here.
Werner said AT&T has selected its new consumer electronics suppliers but won't announce them for 30 days.
The AT&T's move is expected to open the door for the consumer electronics industry to enter?long at last?the U.S. cable market, traditionally dominated by proprietary systems developed by proprietary technology suppliers, namely, General Instruments and Scientific-Atlanta.
Winning a contract with AT&T will be a significant step for consumer electronics companies, since the cable giant, after the merger of MediaOne, will own 30 percent of the U.S. broadband cable market.
Signing up the consumer electronics manufacturers' help is also very important to AT&T, as the cable company hopes to see the integration of advanced set-top into a variety of consumer electronics products "by late 2002 or early 2003," Werner said. The two new consumer electronics manufacturers are expected to launch their first hardware on the first quarter of 2001.
Although Werner declined to give out company names, a few industry sources confirmed that Matsushita, Philips and Thomson Consumer Electronics, besides Motorola, made the short list, out of many who responded to AT&T's request for proposal issued late last year. AT&T further narrowed the list to two consumer electronics manufacturers, besides Motorola, largely because "there wouldn't be enough volume" for the time being to make the business attractive to its set-top suppliers, Werner explained.
Looking out for future technologies, Werner also talked about the cable industry's high expectations for home networking technologies. AT&T is planning to first feature Home PNA 2.0-based home networking technology into its DOCSIS cable modem later this year. But "what we are really excited about is the wireless home networking technologies," he added.
AT&T will not select a particular wireless technology as its preferred home networking implementation. "We want to leave the choice up to consumers," he said.
AT&T, however, won't be able to embrace the wireless home networking technology, unless either 802.11 or Bluetooth properly addresses quality of service (QoS) issues, he cautioned. You can't have a situation in which one cannot make a life critical phone call, when others in the same household is tying up the bandwidth by downloading MTV clips and watching cable TV at the same time, he explained.
Both wireless home network groups are working on QoS extensions, he said.
Thinking inside the box
According to Werner, AT&T-specified advanced set-top system architecture?typically represented by GI's DCT-5000+ box?requires: three tuners, one tuned for MPEG-2 video, another tuned for DOCSIS cable modem, and one more tuner dedicated for sending out of band data; QAM demodulator; conditional access; and video and graphics processing. The CPU power of advanced set tops must be "considerably higher than that of a basic digital set top: 100, 200 and even 300MIPS," Werner said. The processor may be required to host process the DOCSIS cable modem in addition to the several other functions such as parts of MPEG decoding and graphics.
Memory requirements are also a function of several factors, including profile decode requirement, operating system size, graphics requirements and resident applications. MPEG-2 decoding at main profile at high level for HDTV decoding alone can require 8 to 10 Mbytes (MB) of RAM. Meanwhile, operating systems vary in size greatly and can range from very small requiring less than 2MB all the way up to 12 MB. Resident applications such as guides and browsers all require memory, ranging from 1 to 4MB for each. Other resident applications?typically need to be resident in set-tops for performance reasons?could range from 8 to 24MB, Werner added. All in all, the advanced digital set-top AT&T is rolling out this fall contains "48MB of memory," according to Werner.
The real complexity of advanced digital set-tops, however, "has moved from hardware to software issues," Werner pointed out.
AT&T Broadband advanced set-tops, now being developed for field deployment by year's end, will support the high-speed DOCSIS cable modem and the next generation of interactive TV services. The box also incorporates both HTML engine and a full-blown Java Virtual Machine.
Werner explained that the set-top box software will contain five software layers: set-top manufacturers' firmware; operating system; middleware; browser, electronic program guide & applications; and Java Virtual Machine. For this advanced set-top project, AT&T is using "a unique version of the Windows CE based on CE 2.12," said Werner. The operating system will provide the Microsoft standard Win32 programming interface.
The box comes with middleware to provide several functions, including interface between the application providers and the operating system. The middleware will also define the HTML engine. "In our case we will be using a modified version of the Internet explorer," said Werner. The box is also incorporating Electronic Program Guide by TV Guide.
Integrated in the box is Sun Microsystems-provided complete Java environment, capable of running standalone Java applications or web page based Java applets. |
