11.   MMC Networks, which is based in Sunnyvale, Calif., designs chips to speed the connections between fiber optic communications lines and electrical circuits.

12.   Monterey makes equipment that increases the capacity of fiber optic lines so that networks can handle larger amounts of phone calls and Internet traffic.

13.   One is Teleport Communications Group, which operates high-speed fiber optic lines for corporate customers in many cities and which is part of an alliance with Sprint.

14.   Qtera is developing technology that allows fiber optic lines to carry signals farther than they usually do now without regeneration.

15.   So it became necessary to amplify the signal in fiber optic lines.

16.   Some major companies have paid Bell Atlantic for access to those fiber optic lines.

17.   Still, the market was so promising that the company started digging up ground and laying fiber lines anyway.

18.   That includes putting a value on hundreds of miles of fiber optic lines, computerized switches and the like.

19.   The base station is connected through a leased fiber optic line to a Teligent switch in San Antonio.

20.   The company leases fiber optic lines from Metropolitan Fiber Systems and Wiltel, but UUNet operates its own network switches and software to connect users to Internet services.