At the recent Boston meeting of the IEEE P1901 group, members voted to accept proposals for access and in-home networking co-sponsored by HomePlug and Panasonic. They voted against proposals from the Universal Powerline Association and Mitsubishi based on technology from DS2.

The HomePlug/Panasonic proposal requires a physical layer protocol which can recognize either company's products and prevent interference. It included an option for supporting both companies' PHYs so that the networks can share data.

"There were many members of the HomePlug Alliance present and they did a good job lobbying for their proposal, as did Panasonic," said said Jean-Philippe Faure, who chairs the group.

The vote as reported "is not the understanding between the parties now in discussions," said Chano Gomez, vice president of tech and strategic partnerships at DS2. "There are still a lot of conversations in 1901 about reaching a consensus, and we don't want to put these conversations in jeopardy by discussing them publicly," he added.

Before the Boston meeting, UPA and DS2 representatives said they were putting on a full court press to get all sides to agree to a new unified physical layer that would require all sides to make changes in their silicon.

"A last-minute push is not very sincere," said Oleg Logvinov, chief strategy officer of HomePlug and chief executive of chip designer Arkados, Inc.

Logvinov said he had proposed a unified PHY three years ago at a time when HomePlug was defining its 200 Mbit/second technology. But at that time DS2 already was a leap ahead in the market, shipping its own 200 Mbit/s products and declined to participate, Logvinov said.

The HomePlug proposal must win a vote from at least 75 percent of members when it comes up for confirmation at a December meeting in San Diego, a hurdle which is not seen as high given the proposal won nearly that many votes in Boston. The P1901 chairman said the situation is still fluid, but it appears the proposal will become the basis for a standard that could force all sides to modify their chips . "We will follow our customers and I think they will demand full interoperabilityso all companies probably will have to update their chips," said Faure. "There is a reasonable chance we will have a final baseline standard by March," he added.

Faure is a vice president for standards in a French subsidiary of Schneider Electric which makes a variety of powerline systems based on DS2 chips.

"There's a very high demand from customers for standards so we will have to move to it. We made this analysis very early on in the process and that's why I am chairing the group," he said.

Others, including an anonymous commenter on the EE Times blog on interconnects, agreed. "There are plenty of service providers holding back on [powerline] deployments until there is a ratified standard. That's why P1901 is seen as very important," the commenter wrote. "Not being part of the standard will be a blow to any of the companies," he added.

Still up for debate are rival co-existence proposals from HomePlug and UPA. Faure proposed the concept of developing a mechanism that would let separate networks share powerline media by using separate frequencies and transmission times. He envisions a mechanism defined by IEEE that regulators such as the Federal Communications Commission could use to set sharing policies they monitor.

Vendors balked at the idea because it would eat into their bandwidth budget. Nevertheless, HomePlug and UPA submitted competing proposals on the issue.

"It was a contentious thing and has been since the beginning," said Faure.

Just before a vote on the proposal came up in Boston, the HomePlug group announced changes that won the support of Japan's powerline trade association, the Consumer Electronics Powerline Communications Alliance (CEPCA). The vote was deferred to the December meeting, and Faure asked the various parties to re-submit proposals by November 20 in hopes a single approach may emerge

"They have a month to merge," Faure said.

Meanwhile, DS2 is planning another leap ahead for its technology. The company will demonstrate in New York in November versions of its chip running at up to 400 Mbits/s at the PHY layer. The company provided few details on the new technology or products based on it, but it did say systems using the chips should be available to ship in 2009.

"The increase is obtained by changing many parameters," said Gomez of DS2. In a statement the company added the chips, aimed at supporting multiple high and standard definition video streams in the home, will be backward-compatible with its current 200 Mbit/s parts.

The statement also implied the chips will be able to handle transmissions over powerline or coax media. While the new generation is in the works, DS2 said it will add new and undisclosed features to its current products and lower manufacturing costs to maintain competitive pricing.

The HomePlug proposal to P1901 also details an improved physical layer design. Using powerline spectrum from 2-50MHz it will deliver peak rates up to 330 Mbits/s at the PHY layer, said Logvinov.