User`s manual

U.S. Robotics I-modem Command Reference

Glossary • Page G-23

High-Speed Technology (HST)

U.S. Robotics' proprietary signaling scheme, design, and error- control protocol for high-

speed modems. HST incorporates trellis-coded modulation, for greater immunity from

variable phone line conditions, and asym-metrical modulation for more efÞcient use of the

phone channel at speeds of 4800 bps and above. HST also incorporates MNP-compatible

error-control procedures adapted to asymmetrical modulation.

HST

See High-Speed Technology.

Hz (Hertz)

A frequency measurement unit used internationally to indicate one cycle per second.

ISDN

See Integrated Services Digital Network.