DSL Vendors Agree on Code

Eleven leading DSL suppliers commit to discrete multi-tone (DMT) modulation as the line code for standard-compliant VDSL

June 3, 2003

5 Min Read

ATLANTA -- Eleven leading DSL semiconductor and system vendors today announced their support of discrete multi-tone (DMT) modulation as the line code for standard-compliant very-high-bit-rate digital subscriber lines (VDSL). This vendor group, who together supply the dominant share of ADSL ports shipped worldwide, have paved the way for seamless migration to VDSL broadband access. The supporting companies include Alcatel (NYSE: ALA - News), Analog Devices, Inc. (NYSE: ADI - News), Broadcom Corporation (Nasdaq: BRCM - News), Ericsson (Nasdaq: ERICY - News), Ikanos Communications, Intel Corporation (Nasdaq: INTC - News), LSI Logic Corporation (NYSE: LSI - News), Nokia (NYSE: NOK - News), STMicroelectronics (NYSE: STM - News), Texas Instruments Incorporated (NYSE: TXN - News) and Thomson Multimedia (NYSE: TMS - News).

"DMT line coding for VDSL has been promoted for many years," said Matt Davis, Director of Broadband Access Technologies for The Yankee Group. "With 11 of the leading DSL silicon and systems providers supporting DMT, which represents the majority of the DSL market, it is clear that DMT is on track to become the favored modulation for standardized VDSL deployments worldwide."

DMT is the most widely deployed DSL line code, with more than 36 million ADSL lines deployed worldwide at the end of 2002, according to a study by Point Topic. Extending DMT capabilities from ADSL to VDSL sets the stage for a multi-DSL infrastructure capable of providing a wide range of services from Internet access and packet telephony to high-quality digital video. The unified line code approach also supports evolution toward a strong retail model for universal DSL.

"Alcatel has supported DMT ADSL from the very beginning," said Willem Verbiest, Vice President of the Access Business Unit for Alcatel, the world leading DSL supplier with 37.7 percent of the global market. "The best option to move this installed base forward with new DSL technologies, including VDSL, is to build on that same DMT technology base. DMT technology provides optimal performance in the field, while facilitating common management of all DSL flavors."

The overwhelming industry support for DMT stems from several key technical advantages, which include superior performance under real-world noise and wiring conditions, ADSL interoperability, unmatched flexibility in spectrum and power management, and use of existing and emerging DSL line testing and qualification methods. DMT VDSL also provides a pathway to dynamic spectrum management, which is generally viewed as one of the next major advancements in DSL.

"DMT was selected for ADSL because other candidate line codes could not match its performance, which was verified in independent testing by Telcordia (then Bellcore) in what was known as the 'ADSL Olympics'," remarked John Cioffi, Hitachi America Endowed Chair and Professor of Electrical Engineering at Stanford University. "Those same performance benefits and advantages are magnified at higher speeds, particularly in VDSL."

Notes Behrooz Rezvani, founder and CTO at Ikanos Communications and Chairman of the VDSL Alliance, "Today, Ikanos has shipped over 500,000 DMT VDSL ports to major carriers worldwide to offer over 50 Mbps services to consumers. In many evaluations, carriers and system vendors selected DMT VDSL due to its superior performance and overall cost benefits."

"As one of the first vendors to offer DMT VDSL solutions, Nokia believes in open standards to enable the whole industry to move forward. Nokia believes DMT provides the best technology opportunity for open global standards which will enable high-value broadband services to be deployed by operators, while allowing subscribers to get the services they want," comments Markku Hynninen, Vice President, Broadband Systems, Nokia Networks.

"A pioneer in the development of DMT DSL solutions, STMicroelectronics offers today a DMT VDSL chipset," commented Leon Cloetens, General Manager of STMicroelectronics' Access Division. "It demonstrates DMT flexibility to address the different band plans with one single reference design, environment robustness, loop diagnostic capabilities and a common management interface for ADSL/VDSL systems."

Supporting more than 70 Mbps downstream and over 50 Mbps upstream on telephone lines, DMT VDSL provides network operators the bandwidth to deploy competitive voice, video and data services and other emerging applications, including Ethernet in the First Mile (EFM). DMT VDSL reduces capital expenditures significantly and saves network build-out time when compared with fiber-to-the-home (FTTH) networks.

"After pioneering QAM VDSL chipset development for many years, Broadcom now supports DMT as the right choice for the VDSL line code," said Dan Marotta, Vice-President and General Manager of Broadcom's Broadband Communications Business Unit. "Since we have expertise in both QAM and DMT technology we could have gone either way, but based on our analysis of the latest advancements, we chose DMT as the winning technology."

"Consolidating ADSL/VDSL into a single line code is key to streamline networks allowing lower operational costs," said Ragnar Erkander, Vice President of Broadband Access Portfolio Management at Ericsson AB. "Creating a common line code for ADSL and VDSL will also lay the foundation for software- configured DSL ports, which is crucial to reaching high network utilization rates."

"DMT VDSL is a win for the entire industry," said Greg Jones, General Manager of the DSL Business Unit of Texas Instruments. "All major semiconductor vendors offer ADSL chipsets, so choosing the same line code for VDSL will speed time to market, enabling rapid growth of high-speed service offerings."

Jacques Ruch, Product Line Director, High-Speed Network Access Products for Analog Devices, Inc. adds, "DMT VDSL provides key benefits such as interoperability and compatibility with today's installed base of ADSL equipment. These features will provide a seamless migration path and cost savings for operators."

"LSI Logic enthusiastically supports DMT line coding for VDSL to leverage all the knowledge derived in evolving ADSL to a mass market technology," said Siva Sivakumar, Senior Director, DSL Business Unit of LSI Logic Corporation.

The sources of this release support the selection of DMT as the line code standard for VDSL. Standards bodies currently working toward a line code selection include the Committee T1 Working Group T1E1.4, the IEEE 802.3ah Ethernet First Mile Task Force and the ITU-T Study Group 15. All three groups have stated their intention to select a VDSL line code for standardization within the next two months.

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