User's Manual

GLOSSARY

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234839, Revision 2.2

Glossary

Alphanumeric

Roman Letters (alphabetic) and Arabic numbers (numeric).

ARQ

Automatic Request Repeat - A form of error correction that uses retries to correct bad packets of data.

ARQ Retries

The number of times the radio modem will try to send a packet of lost information before it gives up.

ASCII

American Standard Code for Information Interchange. Pronounced as-kee. A code by which alphanumeric, punctuation and

control characters, commonly found on computer keyboards, are each assigned a unique value between 0-127 (decimal).

Asynchronous

A data transmission in which the time between characters may vary. Characters are delimited by start and stop bits.

Attention Commands (AT Commands)

A group of commands created by Hayes

that are recognised by the modem and that begin with AT (or at).

Attenuation

The loss of power through transmission equipment, lines or other communication devices.

Auto answer

A modem capability that allows it to automatically pick-up.

Auxiliary Port (Aux Port)

Port connected to 3-wire modem cable. Cable contains Rx, Tx and ground wires. Only supports software flow control (no

hardware flow control).

Bandwidth

The range of signal frequencies that are accepted or passed by a circuit or network.

Base Frequency

The frequency band occupied by a signal in its original or un-modulated form.

Baud

This term represents the number of discrete signaling events per second. If each signal element has more than one bit

associated with it then this will not be the same as BPS. Compare with bit rate. Also called Baud Rate.

Binary

A number system with a base of two, using the digits 0 and 1. Commonly used in computers since the values 0 and 1 can

easily be represented as OFF and ON in electrical circuits.

Bit

The smallest piece of information in a binary number system. The word stands for Binary digit.

Bit rate

The speed at which bits are transmitted, usually expressed as bits per second (BPS).

Block

Group of characters treated as a unit for the purpose of data transmission.

BPS

An acronym for Bits Per Second. Transmission rate of binary numbers (bits).