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More Home Networking Standards Advance

Two home-networking groups have announced new specifications less than a week after the ratification of the G.hn standard for networking over all types of household wires.

On Tuesday, MoCA (Multimedia over Coax Alliance) said it had completed the MoCA 2.0 specification, which will at least double the speed of the system for sending video and other content over the wires usually used for cable TV. On Monday, the HomePlug Powerline Alliance announced its Green PHY specification, which is a use profile for the HomePlug AV and IEEE 1901 standards that is intended for home energy management.

As service providers send more high-definition multimedia into homes over fast broadband connections, several standards groups have competed to define how that content will be distributed among all the TVs and other devices within homes. G.hn is designed to offer relatively high-speed links over coaxial cable, electrical wires and phone lines, but some service providers and chip manufacturers have already adopted specifications from MoCA and HomePlug. The new standard, approved by the International Telecommunication Union, will not be backward compatible with those technologies.

G.hn is designed for throughput as high as 800M bps (bits per second) over coaxial cable and between 200M bps and 400M bps for electrical wires. MoCA 2.0 will match G.hn's 800M bps speed in its Enhanced mode, while also being offered with a Basic mode that should average 400M bps, according to MoCA. The previous version of MoCA had an average speed of 200M bps. Another mode, which could be used for links between optical network terminals outside a home to a router indoors, can deliver speeds as high as 1G bps. This could be used with fiber-to-the-home services.

MoCA also said its new specification has a lower packet error rate and also gains sleep and standby modes for networked devices, which can lower power consumption.

The HomePlug Green PHY (HomePlug GP) specification is designed for networking devices such as home air conditioners, heaters, appliances, plug-in vehicles and smart power meters. It will work with devices using the existing HomePlug AV standard, such as TVs and other consumer electronics, and with those using the emerging IEEE 1901 standard, which is based on HomePlugAV, according to the HomePlug Powerline Alliance. That compatibility will make it easier for chip manufacturers to come out with HomePlug GP chips, the group said.

"More standards do make sense in this case," said Parks Associates analyst Kurt Scherf. That's because carriers' implementations of technology are often largely custom-built and proprietary, he said. As a result, the G.hn standard is unlikely to sway many carriers from their chosen paths, he said.

"The bottom line is that MoCA and HomePlug work -- and seem to work well -- for the service providers that have chosen them. They'd be very reluctant to make a wholesale move to a technology that's not proven in large field deployments," Scherf said.

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