Enhancing DSL: A carrier’s view

Israeli incumbent, Bezeq, joined the recently formed Dynamic Spectrum Management (DSM) Consortium to determine the bandwidth potential it can expect from its access network. “We want to use our copper infrastructure as long as we can,” Aharon Arbiv, R&D manager for Bezeq told NGN.

The DSM consortium is tasked with developing an adaptive spectrum management technology that enhances DSL performance. DSM promises to enhance DSL data rates over a given distance, or extend the distance over which a given data rate can be delivered.

Bezeq is upgrading its DSL access network using ADSL2+ technology. Over half its users are over 1.5km away from the central office. Bezeq is also interested in VDSL technology as it considers video on demand and possibly IPTV services.

The average distance of Bezeq's street cabinets, that will house VDSL equipment, is 500m from the home. This compares to an average distance of 700m in France and 300m in Germany. The closer the cabinet is to the home, the greater the broadband data rates.

ECI Telecom, which is leading the DSM technology initiative, says having the likes of Bezeq and Telefonica involved will provide valuable practical information as it develops a prototype DSM system. “It will help us in terms of what to focus on, the data rate they [the carriers] can achieve and the distances they want,” says Ariel Shuper, director, product management at ECI Telecom (pictured).

"DSM is a technology that will enhance the DSL performance in any of the parameters the telco would like to use," says Shuper. "We anticipate double the performance over short distances - greater than 200m, 50 to 60 percent for distances greater than 700m, or a 20 to 30 percent improvement for distances greater than 1300m. Alternatively, it can enhance the effective range for a given rate: 50Mbit/s from 300m to 500m, and 25Mbit/s from 750m to 1100m."

The DSM work will be completed by early 2009.

Isn’t that too late given that most European carriers will have decided their broadband strategies by then? “If there is market pressure, we will know how to give an adequate response to the carriers,” says Shuper. "We are co-operating with all the leading European telcos and they are following [the work] closely."

For more information of DSM, click here