Toshiba GN-1060 Manual De Usuario

Descargar
Página de 52
2 APPENDIX
46    Glossary
Glossary
Ad hoc mode
A type of network for wireless LAN communications. In this mode a network is easily built because no access point is 
required. However, this mode is not available for multiple simultaneous communications due to its poor extensibility; in 
other words, it is unsuitable for wireless LAN communication connecting many devices.
AP (Access Point)
Stands for Access Point. Access points are required to relay terminals for a communication in the Infrastructure mode, 
explained later in this section.
Channel
A segment for 2.4 GHz frequency bandwidth for wireless LAN communications. When more than one access point exists 
in a narrow area in the Infrastructure mode, different channels are required for each in order to avoid radio wave 
interference. Communications among devices with different channels are not available even if their SSIDs (explained later 
in this section) are the same.
CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance)
A type of access controlling method for wireless LAN communications. In this method terminals constantly monitor their 
communication status with each other. When one terminal is communicating, others stop their communications and wait 
until they confirm that an available access route comes up, in order to avoid the collision of communication signals as 
much as possible. 
DSSS (Direct Sequence Spread Spectrum)
A type of signal transmission system for wireless LAN communications. As one of the characteristics of this system, less 
noise occurs during communication and thus DSSS communication interferes with other communications less, because 
signals are spread to a wide spectrum with a small amount of electric power. Also this system uses the Pseudo Noise 
Code for the modulation and demodulation of signals, so a confidential communication with less risk of being intercepted 
is available.
IEEE (Institute of Electrical and Electronics Engineers)
An organization that promotes studies for electronic related fields. The major activities of IEEE are holding academic 
conferences and publishing technical papers. Also its internal committees establish and recommend technical standards. 
The IEEE802 LAN/MAN Standard Committee of IEEE is in charge of technical standards for wireless LAN 
communications.
IEEE802.11b / IEEE802.11g
Technical standards established by IEEE for wireless LAN communications with a 2.4 GHz frequency bandwidth.
Infrastructure mode
A type of network for wireless LAN communications. This mode is suitable for a wireless LAN communication connecting 
more than one device because a simultaneous communication among these devices is available by installing access 
points. Also interface ports embedded in each access point can extend the range of communication by integrating wireless 
LAN and wired LAN. 
OFDM (Orthogonal Frequency Division Multiplexing)
A type of communication system for wireless LAN communications. This is one of the multi-carrier systems that transmits 
signals through multiple carriers with different center frequencies and makes these carriers orthogonal so that they will not 
interfere each other, and thus efficient communications will be available within a narrow bandwidth.
PSK (Pre-Shared Key) passphrase
“PSK” is a preset encryption key shared with terminals and “passphrase” is a character string required for PSK 
authentication. A passphrase consists of a number of words (phrase), while a general password is only a short single 
word. This means passphrases have a stronger tolerance toward security invasion than passwords.
RADIUS (Remote Authentication Dial In User Service)
A protocol for network service authentication. This protocol originally developed for authentication for dial-up connections 
is now used for authentication for various network services. The RADIUS server is an authentication server supporting 
RADIUS protocols. This server efficiently controls access to a network because the authentication information of network 
users and their accessing statuses are centrally controlled.
SSID (Service Set ID)
A network ID for wireless LAN communications. To identify terminals or access points that belong to the same wireless 
LAN network, the same SSID must be set for each device. Communications among devices with different SSIDs are not 
available.