WASHINGTON -- The Alliance for Telecommunications Industry Solutions (ATIS) announced that its Standards Committee T1 Technical Subcommittee Working Group, T1E1.4, will specify only Discrete Multi-Tone (DMT) line coding in its American National Standard (ANS) for Very-High-Bit-Rate Digital Subscriber Line (VDSL). The DMT modulation method will be specified in the American National Standard, and the Quadrature Amplitude Modulation (QAM) modulation method will be specified in a Committee T1 Technical Requirement (TRQ).

ATIS' Technical Subcommittee T1E1.4 made its decision after spearheading performance testing on the two technologies - known within the industry as the "VDSL Olympics." Telcordia Technologies and BT performed the testing and provided test reports to Committee T1 in order to evaluate DMT and QAM's compatibility with VDSL.

DMT VDSL supports data transmission speeds of up to 50 Mbps via existing copper telephone wires, and will allow for simultaneous transmission of video, data and voice. DMT is currently utilized for Asymmetric Digital Subscriber Line (ADSL).

ATIS' T1E1 - the Interfaces, Power and Protection of Networks Technical Subcommittee develops and recommends standards and technical reports related to power systems, electrical and physical protection for the exchange and interexchange carrier networks, and interfaces associated with user access to telecommunications networks.

Alliance for Telecommunications Industry Solutions (ATIS)