Such rates are only possible over short distances, but NTL says that 95 percent of homes are within one kilometer of its high-speed fiber network. This means ADSL2+, a faster version of Asymmetric Digital Subscriber Line technology, should run at high speeds over the copper wire that runs between NTL's roadside cabinets and individual homes.
"The field trials are to determine the technological potential of these next-generation broadband services and evaluate the operational benefits of ADSL2+," said an NTL spokesman. "Our fiber-rich network means that we have the potential to provide customers with multiple services through a single high-speed IP connection."
The company has also been testing streaming of high-definition broadcasts over its IP fibre network.
BT is planning to begin trialing ADSL2+ this year. However, only a small proportion of its customers live within one kilometer of their local telephone exchange, which could limit BT's ADSL2+ top speeds. Few details of BT's ADSL2+ trial have been released as yet.
BT's wholesale division is also about to begin testing ADSL at speeds up to 8 mbps--a four-fold increase on its current top speed. However, it is likely that only homes and businesses within a few kilometers of their local telephone exchange will be able to get such rates.
Dan Ilett of ZDNet UK reported from London.