LONDON Alcatel-Lucent Sa (Paris, France) has announced that its research arm, Bell Labs, has demonstrated transmission speeds of up to 300-Mbit/s over 400 meters of a couple of digital subscriber line pairs.
DSL typically makes use of orthogonal frequency division multiplexing (OFDM) to transmit digital information at frequencies above the voice band. Bell Labs conducted a test whereby two copper pairs are linked and data is transmitted over an inferred third line in what is called a "DSL Phantom Mode."
Bell Labs achieved downstream transmission speeds of 300-Mbit/s over distances up to 400 meters and speeds of 100-Mbit/s at 1 kilometer. This promises to provide a boost for the installed base of copper and defer, yet again, the need to install fiber to the home.
The DSL Phantom Mode involves the creation of a virtual channel that supplements the two physical wires that are the standard configuration for copper transmission lines. Bell Labs has used "vectoring" to eliminates crosstalk between copper wires, and "bonding" to aggregate traffic on individual wires, Alcatel-Lucent said.
The company did not say what gauge wire was used for the research tests, whether trials are planned on publicly deployed copper lines, or when it expects Phantom Mode to be ready for deployment. It did say that further research is being conducted to refine deployment models and determine the requirements for customer premises equipment compatible with the DSL Phantom Mode technology.
"What makes DSL Phantom Mode such an important breakthrough is that it combines cutting edge technology with an attractive business model that will open up entirely new commercial opportunities for service providers, enabling them in particular, to offer the latest broadband IP-based services using existing network infrastructure," said Gee Rittenhouse, head of research for Bell Labs, in a statement issued by Alcatel-Lucent.
Alcatel-Lucent claims to have shipped its 200 million DSL lines and to serve one out of three fixed broadband subscribers around the world through its access network technology.
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