Chip could offer bandwidth advantage

A new low-cost transceiver chip could provide carriers an inexpensive way to bring broadband Internet access and multiple voice, data and fax lines to residential users.

The Bt8960 ZipWire chip, a $20 component announced this week by Brooktree Corp. of San Diego, Calif., uses high bit rate digital subscriber line coding technology to increase bandwidth over standard copper lines. This provides Internet access at rates as high as 384 kb/s, three times faster than basic rate ISDN service.

Because the chip's low price will allow the manufacture of modem cards that cost less than $100, the chip could provide carriers with cost savings over other technologies for high-bandwidth Internet access such as ISDN, asymmetrical digital subscriber lines and cable modems, said Ron Cates, senior project manager at Brooktree.

The chip will be able to support symmetrical data transport at 384 kb/s across the full 18,000-foot span of the residential ISDN loop, he said.

The chip could give carriers an alternative to emerging cable modem technology and allow them to compete with cable TV companies in the high-bandwidth arena, Cates said.

The chip can also be implemented for digital pair gain services, supporting up to six 64 kb/s channels for fax and data services over the same voice-grade twisted-pair telephone wire at distances of 16,500 feet, enabling carriers to deliver multiple lines to residential users for fax, data, voice and Internet connections.

For both digital pair gain or Internet access applications, carriers would install a Bt8960-based modem at the customer premises and a Bt8960-based line card at the central office. Devices using the chip could be available within six months, Cates said.