DMT gets big VDSL vendor support

ATLANTA--The debate over the most appropriate line coding technique for VDSL took on a little more clarity today as 11 DSL semiconductor and system vendors threw their support behind discrete multi-tone (DMT) modulation.

While not a major surprise given the make up of the group, the move could defuse a potentially divisive issue in the VDSL market. Among those supporting DMT are Alcatel, Analog Devices, Broadcom, Ericsson, Ikanos Communications, Intel, LSI Logic, Nokia, STMicroelectronics, Texas Instruments and Thomson Multimedia.

DMT already is widely deployed with more than 36 million ADSL lines using the line coding at the end of 2002, according to a study by Point Topic. Extending that to VDSL allows vendors to develop multi-DSL infrastructures.

“From a business point of view, DMT is very proven and it can interoperate with ADSL, which is important,” said Piyush Sevalia, director of product marketing for Ikanos.

Using DMT, vendors will be able to provide equipment that can support up 70 Mb/s upstream at short ranges (about 1000 feet) and 1.5 Mb/s upstream at about 12,000 feet, and 6 Mb/s downstream , Sevalia said.