Sierra Wireless DART 200 CDPD Modem manual Sierra Wireless, Inc Glossary-10

DART 200 CDPD Modem User’s Guide Glossary

full duplex

half duplex

handshaking

parity

port

power product

Restart

roaming

Status Registers or S-Registers

stack

start bit

stop bit

Communications operation where simultaneous two-way data transmission occurs across the data link. Devices using this method can send and receive at the same time.

Communications operation where data transmission occurs in either direction but not at the same time. Devices using this method can’t receive while sending or vice versa.

Another term for flow control.

A simple method of detecting if the character just received over the link is what was transmitted. A single bit is added to the binary string of bits representing the character to be transmitted. This bit is set to make the total number of binary ones in the character string plus the parity bit equal to an even or an odd number. There are three types of parity: (E)ven, (O)dd, or (N)one.

A standard piece of the Internet Protocol address structure. The port serves as an extension of the IP Address to permit a single host (one IP Address) to provide multiple servers (applications) each defined by its unique port number.

A carrier configurable MDBS parameter defining the desired relationship between received and transmitted signal strength.

To turn off and then turn on a computer.

Used to describe the situation where a user from carrier A is operating in the service area of carrier B.

RAM locations inside the modem that hold information about certain functions that the modem performs. An example is S9 (the ninth S-Register) that holds the information on how long to wait for the modem tone (carrier) to show up before hanging up.

Refers to the TCP protocol stack, so-called because it is composed of a number of protocol layers (physical, data link, network, transport, and so on). Required to operate with Internet Protocol. Can be implemented in software (PC), or hardware (DART firmware). Trumpet is a software stack.

The bit preceding each asynchronous character. Signals the receiving modem that a new character is starting. There is always 1 start bit.

There is at least 1 stop bit at the end of each character to be transmitted (sometimes two). One is typical. Resets the modem chip in preparation for receiving the next character.

Sierra Wireless, Inc. Glossary-10