As small telcos and policymakers continue to debate the optimum target speed for broadband deployments, equipment manufacturers continue to work on enhancements to existing copper infrastructure with the goal of minimizing the need for fiber in the network. Nokia Siemens Networks today claimed it has set a world record for copper DSL speeds, obtaining data rates of 825 Mb/s over 400 meters of copper phone wiring.
In the test, NSN used phantom DSL—an approach that bonds two physical wires together to create a virtual, or “phantom” channel. The manufacturer also said it obtained a speed of 750 Mb/s over 500 meters. This is a significant gain over the 300 Mb/s over 400 meters that Alcatel-Lucent demonstrated several months ago, also using phantom DSL.
At that time, Alcatel-Lucent said the technology also could support 100 MB/s over distances of up to 1 kilometer. But NSN’s announcement today did not address speeds over distances greater than 500 meters.
Copper access lines deployed by U.S. telcos often are considerably longer than 400 or 500 meters (1,312 to 1,640 feet)—or even 1 kilometer–which means that to use the phantom DSL technology, many service providers would still need to deploy fiber in local networks to support the new technology, just not as much fiber.
Neither NSN nor Alcatel-Lucent has provided an estimate of when phantom DSL might be available—although NSN appears a bit more certain about making it available some day. “Nokia Siemens Networks’ Phantom DSL will become an integral part of the company’s DSLAM products hiX 562x/3x,” the company said in today’s announcement.
The company made a point of positioning phantom DSL as an interim solution, however. “Laying down new optical fiber to the home remains costly, though it is capable of delivering very high speeds and is a definite solution for long-term bandwidth requirements,” said Eduard Scheiterer, head of broaband access for NSN, in the announcement.. “However, the innovative use of technologies such as phantom circuits helps operators provide an efficient last mile connectivity with existing copper wires.”