Index
38
Appendix B: Glossary
This appendix contains terms and definitions that are used within this manual. The
glossary is meant to assist you by providing definitions for terms as they pertain to
Nextel’s iR1200 data modem and is by no means exhaustive of terms that you may come
across.
Asynchronous
Data without an accompanying time signal. Timing is built into data characters as start
and stop bits.
AT Command
An order entered into the computer to request your modem to perform certain actions,
such as dial a telemodem number. AT commands are Hayes-compatible modem
commands.
Baud
The signaling rate of a line, which is the number of transitions (voltage or frequency
changes) that are made per second.
Baud Rate
Signaling speed of the modem. Common baud rates are 2400, 4800, 9600, 19200, and
56k.
Byte
A data unit of eight bits.
Circuit Switched Data
A networking technology that provides a temporary, but dedicated, connection between
two stations no mater how many switching devices the data is routed through. Circuit
Switch was originally developed for the analog-based telephone system in order to
guarantee steady, consistent service for two people engaged in phone conversation.
Command Mode
The mode that accepts AT commands. Also known as Terminal Mode. When your
modem is in this mode, it is waiting to receive AT commands that you type from your
communication software.
