San Jose, Calif. -- Some of the same engineers who helped create power consumption standards for PCs and printers are turning their attention to network gear and consumer electronics. A team of researchers at Lawrence Berkeley National Laboratory hopes to suggest new power standards and practices for large network switches, wireless access points, set-top boxes, home control systems and other consumer gear as part of a two-year effort.
The lab's Energy Efficient Digital Networks initiative aims to reduce the estimated 200 terawatt-hours of energy consumed annually in the United States by electronic devices, at a cost of some $16 billion. The group--which is working with the Environmental Protection Agency's Energy Star program and with academics at the University of South Florida--has already helped kick off a low-power standard for Ethernet. It expects to soon create a Web site for its overarching initiative, which includes a handful of efforts, many of them not yet formally announced.
"All parts of the program are on a two-year time frame, but if some of them get done sooner, that's great," said Bruce Nordman, a principal research associate at Lawrence Berkeley Lab who oversees the work. "I'm sure not everything will pan out as we hope, but if most of it does, that could have a significant impact."
Researchers think they could save as much as 10 percent of the energy consumed by an average California home--70 of 700 W--with a new proxy feature alone. With proxying, a network card or external network system could maintain a PC's presence on the Net while the computer goes into sleep mode.
The technique builds on work done a decade ago in approaches such as wake-on-LAN and directed packet filtering. Large businesses sometimes use those existing features on their private networks, but the techniques typically don't work well for consumers and smaller businesses. They often wake computers unintentionally or fail to wake them when needed. Internet routers often don't forward the so-called magic packets meant to wake up a PC.
"We are trying to define the functionality we want here and then get it into products," said Nordman.
Once they have a proposal, researchers may turn to the Internet Engineering Task Force or the Distributed Management Task Force to make it a standard.
"A lot of network cards may already have the processing capability and memory needed to handle this, so it could be a software exercise, but we don't have that nailed down yet," Nordman said.
As underpinnings for a proxy feature, researchers are studying the distributed discovery protocol defined by the Universal Plug and Play Forum. They are also investigating a capability in the peer-to-peer (P2P) service run by Gnutella.
In a technical paper, University of South Florida researchers described a method for building smart network interface cards using a low-power microcontroller, along with Bloom filters and security techniques to radically compress the data needed for a proxy function. "We estimate that if only 25 percent of PCs running P2P applications contained smart NICs with proxy capability, a savings of over $85 million per year in the U.S. could be achieved," the paper said.
Separately, Lawrence Berkeley Lab is in the process of selecting a few network systems for which it will suggest power consumption standards and test procedures. Large network switches for businesses as well as Wi-Fi access points and cable/DSL gateways for homes are likely to be the first targets. Once complete, the work will be handed off to the Energy Star program. "Industry can help accelerate and approve this work at all stages," said Nordman. "We want to work with the industry from the get-go on all of this."
Lab researchers also hope to set similar standards for set-top boxes, perhaps by building reference designs for low-power set-tops. The Energy Star program withdrew a power spec for set-tops about two years ago when cable TV providers and set-top makers could not reach a consensus on voluntary specs. However, the EPA is gearing up for another attempt, with hopes of launching an effort by April.
"We're ready to make a fresh run at this," said an EPA spokeswoman.
More generally, the lab aims to push consumer electronics systems and standards from a two-state (on/off) to a three-state (on, sleep and off) model. The effort would set techniques to let OEMs automatically put systems in sleep or off states based on user activity. It would also empower consumers to understand and choose those states explicitly with new remote-control buttons.
"I don't know how many times I've walked into my living room to find the DVD player in menu mode even though we haven't played a DVD in days. The TV just doesn't know how to shut it off," Nordman said. "You really want to just let the consumer turn the TV on or off and let everything else happen automatically."
The effort could involve changes to a wide range of consumer standards, including links such as infrared and HDMI. "We want to start a process that hopefully industry can take up. This will be an incremental effort over a number of years," said Nordman.
Dialing down data rates
As another part of the program, the lab helped kick off the Energy-Efficient Ethernet study group under IEEE 802.3. An inaugural meeting in mid-January in Monterey, Calif., attracted about 30 engineers from a cross section of chip and systems companies, including AMCC, Broadcom, Cisco, Hewlett-Packard, Intel and Nortel. "My initial impression is [that] it looks like there is enough interest in starting a project," said Mike Bennett, a networking engineer at Lawrence Berkeley Lab who chairs the study group.
According to IEEE rules, the group must submit a request to start a formal standard effort by June or ask for a six-month extension. Actually drafting a final standard could take another two years.
Initial discussions have focused on finding a common mechanism to shift from 10-Gbit to gigabit to 100-Mbit Ethernet speeds without losing the link. By leveraging existing techniques in multispeed physical-layer chips, the approach would not add significant cost, according to a Cisco presenter at the Monterey event.
"People are talking about other things as well, such as defining a low-power mode where Ethernet devices maintain a link without transmitting anything," said Bennett. "But most of the effort at this stage has been around exploring ways to automatically switch speeds."
At its next meeting in Orlando, Fla., in March, the study group will consider how its work might leverage existing techniques, such as Ethernet's autonegotiation capabilities. It will also consider the feasibility of different switching mechanisms.
Plenty of outstanding questions remain open, such as whether 100- or 10-Mbit/second speeds should be considered a floor and whether 1 millisecond is a fast enough switching time for 10-Gbit links. It's also unclear whether the standard would leave room for companies to compete on the basis of power consumed or switching speed. "I still haven't figured out where people may get a competitive edge here yet," said Bennett.
Backers estimate that Energy-Efficient Ethernet could save $450 million in energy costs a year in the United States alone. Interestingly, the brunt of the savings--$200 million--could come from home computers, with another $170 million from offices and $80 million from data centers. Nordman estimates that a Gigabit interface card could shave up to 1.5 W off its power consumption and a 10-Gbit card up to 10 W by scaling back data rates at times of low traffic.
The EPA has already written draft requirements for the 2009 version of its Energy Star program mandating that "all computers shall reduce their network link speeds during times of low data traffic levels in accordance with any industry standards that provide for quick transitions among link rates."
Whether the IEEE can produce a standard and vendors ship products by then is not clear. "The timing will be challenging," said Nordman.
Finally, Lawrence Berkeley Lab has two educational efforts in the works. A consultant will be going to the OEM community to encourage companies to implement the low-power features of the 1394 interconnect, which researchers have discovered are rarely used.
Separately, the lab hopes to compile a list of "green" smoke alarms, garage door openers, security systems and home control devices, and provide it as a suggested buyer's guide to new-home builders. "Builders don't have time to research these issues, yet these systems can consume anywhere from 50 to 100 W in a new home," Nordman said.
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