Making networks more energy efficient requires optimizations at many different levels. One of those levels is the access layer for service provider networks that power millions of homes and businesses around the world.
The current method for deploying fibre delivery is not as energy efficient as it could be, according to research from the Alcatel-Lucent led GreenTouch initiative.
"We realized that that the way protocols are designed today, actually 99 percent of the data is processed unnecessarily," Peter Vetter, department head at Alcatel-Lucent, Bell Labs, told EnterpriseNetworkingPlanet.com. "So this is a huge opportunity for efficiency improvements."
Vetter is also the wireline working group chief for the GreenTouch effort. Alcatel-Lucent and a consortium of partners launched GreenTouch back in January of 2010 as an effort to help reduce power consumption in networking technologies.
Today, many service providers deliver fiber using a technology known as passive optical network (PON). In a PON deployment, data is sent to all end points broadcast in a passive manner. As such, a PON optical network unit (ONU) has to process all the data for all the end points in order to find the relevant data for a specific home or end point.
"The equivalent is as if the mailman came to your door and opens his mailbag and then asks you to go through all the mail, so you can select the mail that is for you," Vetter explained.
That wastefulness requires the ONU to draw more power, which is where the new research is looking to find efficiencies. One way to achieve better efficiency is by replacing the current PON standard with a new emerging approach call Bit-Interleaved PON (Bi-PON).
"With Bi-PON, instead of organizing the data in packets, we organize the data in bits that are spaced with properties that match the speed of the subscriber," Vetter said. "This allows us to drop the data right behind the receiver so only relevant data is processed."
According to Vetter, Bi-PON offers the opportunity to improve power efficiency by a factor of 30. Moving to Bi-PON, however, is not going to be an immediate option for service providers. Vetter noted it will require new hardware and it will also require new standards to fully implement Bi-PON.
"So this is long term research," Vetter said.
Getting a new Bi-PON standard approved is a process that has its own set of challenges. Vetter explained that the first step to build industry consensus with a group of people that recognize the importance of making a change. GreenTouch has one such working group going to help ensure a roadmap to standardization.
In the interim, there are improvements to PON and ONU deployments that GreenTouch is also working on that provide an enhanced sleep mode that regulates the power based on usage activity. The enhanced sleep mode can work with existing equipment and can potentially be deployed by service providers this year.
"Bi-PON shows how GreenTouch works, by having a fresh look at the protocols, you can get significant savings which you would not get from trying to use stop-gaps like sleep mode," Vetter commented.