Home net chip does UWB, coax, Ethernet

SAN JOSE, Calif. — Sigma Designs has developed a second-generation ultrawideband chip set for home networks that can simultaneously run UWB over wireless and coax at rates up to 370 Mbits/second while maintaining a Gbit Ethernet link. CoAir is aimed to serve a variety of set-top boxes, routers and gateway devices on home networks.

Consumer systems will use the chip to ship data and media around a home over coax at distances of up to 330 feet while streaming content wirelessly within a room at distances up to 20 meters, said Hung Nguyen, general manager of Sigma's wireless group. By providing a Gbit Ethernet link, the company hopes its silicon becomes the single networking chip set needed for many home systems.

Sigma is announcing CoAir at the Connections conference on home networking starting Tuesday (June 24). At the event, Panasonic's chief technology officer will give a keynote address on the value of unifying home nets around the pending ITU G.hn standard.

Home networks have long been fragmented into options for a variety of different media. A number of top computer and consumer companies are backing the ITU G.hn effort as the best hope to unify the options.

"We are a contributing member to G.hn, but it is in a very early stage," said Nguyen.

Sigma's CoAir chip delivers higher data rates and more flexibility than competing parts based on the Multimedia over Coax standard. PulseLink, Inc. (Carlsbad, Calif.) offers a UWB chip that handles transmission over wireless or coax at rates up to a Gbit/s. However, the chip uses proprietary technology and does not conform to the WiMedia Alliance specifications that the CoAir chip uses.

The WiMedia group is still defining a standard for UWB over coax. Nguyen said Sigma will modify CoAir as needed to comply with that spec when it is done. An initial draft is expected to be available to WiMedia members by the end of the year.

The CoAir chip set includes a 9x9mm RF chip and a 15x15mm baseband. Together they consume up to 1.5W and are sampling with production costs expected to be $20-$30, depending on volume.

Nguyen would not detail the approach Sigma is using to allow the chip to send data over wireless and coax simultaneously. However, he did say the channels share some common silicon components.

Sigma released its first UWB chip a year ago. The Windeo device is aimed at point-to-point links within a room and was based on technology the company acquired from Blue7 Communications.

"Over the next few years we expect to increase the data rates for our chips over both wireless and coax links and reduce the cost of the chips," said Nguyen. "It's very feasible to get well below $20 and even below $10 for simple adapter devices that don't support higher speeds," he said.

CoAir uses WiMedia's WiNet standard for carrying IP over UWB to stream media wirelessly. The chip can also support a separate protocol adaptation layer (PAL) for wireless USB.

The WiMeda group is working on a standard that would let chips simultaneously support multiple PALs so, for example, they could link to wireless USB devices such as digital cameras while streaming media to a TV or computer over WiNet.