With Standard Sure, Vendors Rush Cable Modems to Market
By Michelle V. Rafter
January 19, 1998
Slightly more than a year after the first draft of a cable-modem standard was issued, close to two dozen vendors have built working prototypes based on it, and equipment is expected to be commercially available by midyear.
The standard is one reason that industry executives and analysts believe cable-modem deployment will skyrocket to 1 million households by year's end, from 100,000 in 1997.
"It's been 10 years since the first ISDN prototype, and they just hit 1 million. We'll do that in one-tenth the time," said Bob Cruickshank, digital network technologies director at CableLabs, the cable industry's nonprofit research consortium.
Toshiba and Time Warner are among the first testing the Data Over Cable Service Interface Specifications (DOCSIS) protocol. The partners are field-testing DOCSIS-compatible equipment in Litchfield, Conn., and expect to commence a full trial in February, with commercial rollout in April, said analyst Michael Harris of Kinetic Strategies, which publishes Cable Datacom News.
Hayes Microcomputer Products, which is developing consumer cable modems as well as encoders and routers for cable operators, expects to have DOCSIS cable modems in field tests by the second quarter of 1998 and shipping in the last half of the year, said Larry Hancock, Hayes marketing and communications director.
"Then you're ready for retail," he said. "Most cable modem operators want to get out of [leasing equipment]."
3Com is selling DOCSIS-compatible one-way cable modems with telephone returns--first- generation technology most insiders believe will eventually be outmoded by two-way systems--with cable operators Charter Communications in St. Louis, Insight Communications in Indianapolis, and Northern Cable in Sudbury, Ontario.
Those and other equipment vendors continue to take part in interoperability tests at CableLabs' headquarters in Louisville, Colo. CableLabs expects to see the first wave of products go through the lab's DOCSIS certification program by May, Cruickshank said.
When it became apparent that cable-TV operators were headed into the Internet access business, vendors joined forces to develop a cable-modem standard rather than duke it out over competing technologies--as they had done with 56-Kbps dial-up modems, with disastrous results.
Work began in 1995, when operators Comcast Cable Communications, Cox Communications, Tele-Communications Inc., and Time Warner Cable formed Multimedia Cable Network Systems (MCNS) Partners.
In conjunction with CableLabs and consulting firm A.D. Little, MCNS introduced a draft standard in late 1996 and a final version in spring of 1997. The standard spells out internal and external network interfaces that allow the bidirectional transfer of IP traffic between a cable operator's head end and customers' homes over a hybrid fiber and coaxial cable system.
DOCSIS is designed to transmit IP data from a cable operator's head end over one or two unused cable channels at up to 38 Mbps, and from a customer's home back to the head end at up to 10 Mbps. Included in the spec are security provisions for shielding sensitive data, such as credit card numbers.
The standard also includes provisions for levels of Quality of Service (QoS), which eventually would allow cable operators to offer such services as IP-based video and service-level guarantees. DOCSIS also uses MPEG-2 transport streams, which eventually could allow a single cable modem to support multiple sessions or multiple users.
For now, DOCSIS exists as a de facto standard. (Industry groups plan to submit it to official standards-setting bodies, including the International Telecommunication Union and IEEE.) By the end of 1997, nearly two dozen network and cable-TV equipment makers, including Cisco Systems, Bay Networks, 3Com, Intel, Hayes, Motorola, Sony, and Toshiba, had introduced prototype gear based on DOCSIS.
An early market leader is Broadcom, an Irvine, Calif., chip maker that sells silicon for cable-TV digital set-top boxes. In early December, Broadcom introduced one of the first DOCSIS-compatible two-way cable-modem chipsets. The company will begin supplying chips this quarter to at least a dozen partners, including 3Com, Bay Networks, and Cisco.
Some industry observers think cable modems won't really take off until they are available as inexpensive plug-and-play PC cards built around a single chip--something analysts predict could be out as early as 1999.
"When that happens, you'll see under-$200 cable modems," said Kinetic Strategies' Harris. |
