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 Level 2 low power mode has been in the standard for years, but rarely used. Switching modes caused enough noise that other lines in the binder would reset, and the customer would be disconnected. The modems would automatically re-sync, but meanwhile a angry IPTV viewer may have missed a goal in an important football game.
Alcatel's solution is "artificial noise" for ADSL and "virtual noise" for VDSL2 service, which causes the modem to sync at lower power and lower speeds. Some IPTV operators are willing to sacrifice performance for stability. The noise at startup provides more margin to the connection, so it's less likely to drop due to interference. Their early trials resulted in a large drop in calls to help centers, according to data I believe was from Telecom Italia. This appears to be standard in their forthcoming VDSL line cards.
I've asked Alcatel for the data on how much speed needs to be sacrificed for this extra reliability. The data I saw more than a year ago involved a 10-25% drop in speed on some lines. Their spokesman believe that's changed,
and I'll update this when I get the data. The respected Fraunhofer ESK finds the speed loss may be as little as 1% under certain lab condition. I'm getting follow-up detail from them as well.(below)
Alcatel claims energy savings of "up to 25%," good for the planet and reducing OPEX by 2-3%. The stability and avoided truck rolls probably yield further cost savings. I know the technology works, and I'd guess that Alcatel's 25% claim is possible. I've no way to compare Alcatel against DSLAMs from other manufacturers, many of whom also claim power savings. In the field, the results will vary significantly depending on the system.
(Alcatel's main competitor, ASSIA, is an advertiser as you can see. Since I both sell the ads and write the stories, I've no way to separate the two aspects of the publication. Readers will have to judge whether I'm succeeding in being close to the truth.)
Alcatel also implements VDSL bonding in this release. Telephony reports that will be rarely used until more modems are available.
Susanne Baumer writes from Fraunhofer, and the Alcatel release
The Fraunhofer ESK has a Measurement and Test Laboratory that hosts the components of an DSL infrastructure from the home connection to the switching center including 6 kilometers of real cable. In this facility we tested our methods and discovered that by using the artificial / virtual noise, we loose less than 1 percent of the DSL capacity. E.g. in one test sequence the capacity of the DSL line amounted to 19.7 megabit. By adding the artificial/ virtual noise in combination with the L2 mode, we measured a capacity of 19.56 megabit.
The trick is, that trough the artificial / virtual noise we can reduce the peek of a new established DSL line from up to 20 db to 3 db maximum.
Alcatel is one of the key players in the area of artificial / virtual noise. Our achievement is employing this already known method in a new context. We started with the challenge on how to save energy in the access network, found that there is a standardized mode (L2 mode) that is not used. By investigating the reasons we found an increased instability of the system and searched for a solution, which we found in artificial / virtual noise.
Alcatel-Lucent launches world’s first “green DSL”
Alcatel-Lucent’s Intelligent Services Access Manager (ISAM) provides more bandwidth with 25% less power
Paris, July 1, 2009 – Alcatel-Lucent (Euronext Paris and NYSE: ALU) today launched a very innovative high-capacity and eco-efficient digital subscriber line (DSL) platform – enabling service providers to deliver tomorrow’s applications over their installed copper base, all while consuming up to 25% less power compared to conventional DSL solutions.
Alcatel-Lucent’s green DSL leverages the reduced power consumption of its latest generation of DSL line cards, the company’s unique distributed DSLAM concept and Alcatel-Lucent’s Smart DSL technology.
“Today, standards exist that allow modems to go in a low-power mode when user traffic is low. However, re-activating these modems causes power fluctuations – resulting in crosstalk and destabilizing the network,” said Jürgen Lison, Vice-President of Alcatel-Lucent's ISAM product unit. “Alcatel-Lucent’s green DSL provides operators with a unique, end-to-end solution that overcomes these issues – enabling a significant reduction of the modems’ power consumption across a service provider’s subscriber base without causing any line stability issues. This is a value proposition that cannot be provided by any other vendor in the industry today.”
Not only does Alcatel-Lucent’s latest ISAM release support a significant power reduction compared to conventional DSL solutions, it is also the first commercially-available DSL platform for ETSI markets that delivers 50Mbs to all users – with peaks up to 100Mbs - anywhere in the network because of its new, high-capacity, very high-speed DSL (VDSL) line cards and its support of VDSL bonding technology across the line card. This ISAM release incorporates the company’s third generation of VDSL line cards, highlighting Alcatel-Lucent’s innovative technology and market leadership in the DSL space, while supporting its applications enablement strategy through physical layer synchronization for mobile backhaul and enhanced support for business services.
“Operators challenged by recessionary and fiber business case limitations want to optimize investment in their existing copper networks while also offering sustained higher bandwidth over an extended reach. In conjunction with the expected growth of FTTB, VDSL2 remains an important option to support higher bandwidth services to residences and enterprises and for mobile backhaul,” noted Kamalini Ganguly, broadband analyst at Ovum, Inc. “The new release of Alcatel-Lucent’s ISAM platform addresses the operator constraints and objectives we have noted in our research. Our research further shows that greener access technologies are a critical need for operators, and lower-power products are a critical component of meeting this need.”
“Release-4 of the ISAM platform puts Alcatel-Lucent more than one year ahead of its competitors,” said Dave Geary, President of Alcatel-Lucent’s Wireline Networks activities. “The ISAM platform enables our customers to deliver the most bandwidth-intensive services over their copper architectures, by leveraging – for instance - last-mile bonding support, which is a first in ETSI markets. We are confident that our ‘more bandwidth with less power’ value proposition will again create a big stir in the DSL industry – just as the launch of the ISAM platform five years ago.”
This release supports Alcatel-Lucent’s comprehensive eco-sustainability program that includes using innovation to build smarter, eco-sustainable networks at all layers (access, transport and core) with a framework that addresses hardware, software, network and site innovation.
Alcatel-Lucent’s leadership in DSL builds on its award-winning ISAM product family. The ISAM family has now been deployed at more than 210 customers worldwide. Since its launch five years ago, the ISAM family has been adopted by approximately one customer per week, consolidating Alcatel-Lucent’s number-one position in IP broadband access.
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