Modem pooling new for ADSL Netspeed makes a case for 6-to-1 user concentration

Until now, asymmetrical digital subscriber line hookups have been proposed as a one-to-one system-one modem on each customer premises connects to one corresponding modem in the central office.

Several Internet service providers studying or using ADSL have said they could pool the high-speed modems the same way they pool analog modems.

Enter NetSpeed, a one-year-old access company in Austin, Texas, that has engineered an ADSL solution using a 6-to-1 concentration of user modems to CO modems. The company is expected to announce the system today.

NetSpeed's system uses on-demand ADSL technology to let the end user or business appear to be permanently connected. However, the connection is actually torn down when the user is idle. Loop characteristics are stored on both the customer and CO device, which allows a short connect time-up to only three seconds-when a user goes back on-line.

"It's seamless to the user. You don't know when your connection is down or up," said Kieran Taylor, broadband consultant with TeleChoice, Verona, N.J.

Oversubscribing modems in a pool also solves many of the most common problems with ADSL, Taylor said. By simply reducing the number of modems in the CO, costs are cut, heavy power use is reduced-as well as the accompanying heat dissipation problem-and less space is needed in an already crowded environment, he said.

John McHale, chief executive officer and co-founder of NetSpeed, said his company is in technology licensing discussions with several others and is aggressively courting carriers and ISPs with end-to-end solutions.

The inverse multiplexer is another unique component when compared with other ADSL solutions. It aggregates three 8 Mb/s ADSL lines into one 24 Mb/s pipe and can dynamically adjust bandwidth. McHale believes businesses will consider the inverse multiplexer an alternative to private line T-3 service, which is more expensive.