Glossary - Toshiba GN-1060 Operator's Manual

2 APPENDIX

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 / IEEE802.11n
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.
48 Glossary