User's Manual

SPEEDLAN 4100 & 4200 Installation and Operation User Guide
Glossary-14
Protocol
A network protocol is the standard that allows computers to communicate with each other. A protocol defines how com-
puters identify one another on the network, the form that the data should take in transit, and how this information is pro-
cessed once it reaches its final destination. Protocols also define procedures for handling lost or damaged transmissions or
“packets.” IPX (for Novell Netware), TCP/IP (for UNIX, Windows NT, Windows 95 and 98 and other platforms), DECnet
(for networking Digital Equipment Corp. computers), AppleTalk (for main Macintosh computers), and NetBIOS/NetBEUI
(for LAN and Windows NT networks) are some of today’s most popular networks. Although each network protocol is differ-
ent, they all share the same physical cabling. This common method of accessing the physical network allows multiple pro-
tocols to peacefully coexist over the network media, and allows the builder of the network to use common hardware for a
variety of protocols. This concept is known as “protocol independence,” which means that devices that are compatible at
the physical and data link layers allowing the user to run many different protocols over the same medium.
Pseudo-random Noise code (PN code)
A high rate digital code that mimics random noise-like properties. It is multiplied with a lower rate data signal in order to
achieve spread spectrum transmission signals. The receiver then multiplies the same code back into the transmission to
recover the data signal.
Public Switched Telephone Network (PSTN)
This refers to a worldwide voice telephone network accessible to all those with telephones and access privileges.
Quadrature Amplitude Modulation (QAM)
A method for modulating a signal by which more than one bit can be sent simultaneously.
Quadrature Phase Shift Keying (QPSK)
Phase-shift keying in which there are four phase states or positions in the time or frequency domains within a single period.
Radiation
The flow of electromagnetic energy from a transmitter.
Radiation Pattern
An illustration of the energy level radiated by an antenna in every direction.
Radio address
This is the physical location (street name) of the terminal. This is also displayed at the bottom of the web page.
Radio Frequency (RF)
The frequency at which microwave systems transmit.