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A Home Network Based on Coaxial

Alliance of manufacturers, MSOs seeks to use existing infrastructure 1/11/2004 07:00:00 PM Eastern

The buzz in home networking has surrounded WiFi and other wireless communication methods, but the Multimedia Over Coax Alliance (MoCA) aims to make sure networking efforts are built around a much less exciting technology: coaxial cable.

Coaxial cable is already found in every home that has cable or satellite service, and making use of that existing infrastructure will make the deployment of next-generation TV services like networked digital video recording easier. Today, all TV sets, set-top boxes or DVRs in a household receiving cable or satellite signals are connected to each other via coaxial cable. But there is no way to use that coaxial cable as a network, which means the devices can't share content even though they are, ultimately, connected. The alliance, with the use of technology from partner Entropic Communications, plans to change that.

Entropic has spent three years developing the chip set, attracting $46 million from strategic investors like Time Warner, Comcast, Intel, Cisco and Panasonic. "The piece that was missing was, how do we standardize it?," says Vice President of Marketing Michael Librizzi. "Another proprietary system was not an acceptable market outcome for this. So that's why we took this approach of creating an alliance."

Mark Francisco, responsible for new media development for Comcast, another alliance member, explains, "This will enable sharing of multimedia content in the home, and coaxial cable is something that we find to be a good distribution medium. We're coming together and generating a specification for the use of coaxial cable in the home to distribute high-value content."

Working with Comcast and Entropic will be Panasonic, Toshiba, Motorola, Cisco, RadioShack, and EchoStar. All will work to integrate Entropic's two-chip set known as c.Link-270 into their products so that they can be used to turn coaxial cable into a 270-Mbps home network. The chip set includes an RF front end and baseband controller with an embedded media-access controller that supports three protocols over the same co-ax: Ethernet, MPEG transport stream and FireWire. It can support up to 10 simultaneous channels on one co-ax, with each having a data capacity of 270 Mbps, allowing multiple HD and SD transport streams and Ethernet connectivity.

Francisco says the goal of the alliance during the next year is to agree on a specification for how the c.Link-270 will be deployed in devices, to ensure interoperability and prevent interference. The c.Link-270 chip set is priced at $20 and will be sold in quantities of 100,000 with production ramping up the middle of this year. The chips are expected to first appear in Ethernet-to-coaxial cable or WLAN–to–co-ax bridges.

The move by Comcast and the others is to get ahead of the demand curve. Comcast is in the voice-, video- and data-delivery business and considers it important to keep pace with where customers want to go.

"Where they're gravitating is, they want to share content in the home, and that is only going to increase the demand for bandwidth," Francisco explains. "So we're looking at technology that can support 100 Mbps-plus data rates in the home. And, while Ethernet can do that, it doesn't exist in the right places in the home. And, frankly, as a cable company, we're much better at using coaxial cable."

An example of the type of service that could benefit from the network is a trial that Comcast is undertaking with Ucentric and Samsung. The trial is separate from the work being done by MoCA but is testing the viability of the multiroom DVR. Content is stored in a single place and then consumed anywhere on the network. The goal is to allow the sharing not only of video but also of HD material and even music and photos.

Librizzi envisions a wheel-type arrangement: the media server at the center of the home, with spokes connecting to other devices. Thin-client adapter boxes priced at less than $100 would enable more-expensive gear to connect in to the media center in a simple manner.