Broadcom Completes One-Chip Cable Modem

Author:
Publish date:
Updated on

Wrapping up a three-year development cycle, Broadcom Corp.
is expected to make good on its single-chip promise for cable modems this week.

The $50 chip should come as welcome news to cable-modem
manufacturers and their MSO customers, because it represents another step in a steep
integration curve that will result in lower end-unit prices.

Broadcom officials also said the single chip, dubbed the
BCM3300, is poised to find its way into advanced cable set-top boxes for applications like
Internet-based electronic commerce and Web-surfing via the TV.

Several manufacturers, including General Instrument Corp.
and Scientific-Atlanta Inc., plan to include standards-based cable modems in their
advanced-digital set-top lines.

The chip development collapses from three to one the number
of chips necessary to handle DOCSIS (Data Over Cable Service/Interoperability
Specification) cable-modem functions, said Rich Nelson, director of cable television for
Broadcom.

The chip currently supports the DOCSIS 1.0 specification,
as well as several features needed by MSOs that want to differentiate the types of
high-speed-data services that they offer to customers.

Specifically, the 256-pin BCM3300 addresses advanced
quality-of-service capabilities, so that operators can offer multiple access speeds at
different price points -- important for situations where work-at-home users want
guaranteed levels of speed or service.

It also includes data fragmentation, so that MSOs can
provision constant-bit-rate services, like IP (Internet-protocol) telephony and
videoconferencing.

"That element is critical, because it solves the issue
of latency," Nelson said, referring to how IP calls need to happen in real-time, like
circuit-switched calls.

And the chip supports multiple-destination addresses and
multicast filters, he said, which are useful for "push" types of services, like
live stock tickers, news and sports scores.

Nelson said Broadcom developed a cable-modem-reference
design, the BCM93300, which supports DOCSIS specs, as well as interfaces for 10baseT
Ethernet, universal serial bus, voice-over-IP and video teleconferencing.

The BCM3300 is available now in "sample
quantities," Nelson said, and it will be available in volume quantities later this
year.

Related