Linksys WPCI54G Benutzerhandbuch

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Wireless-G Notebook Adapter
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Hop - The link between two network nodes.
IEEE (The Institute of Electrical and Electronics Engineers) - The IEEE
describes itself as "the world's largest technical professional society, promoting
the development and application of electrotechnology and allied sciences for
the benefit of humanity, the advancement of the profession, and the well-being
of our members." 
The IEEE fosters the development of standards that often become national and
international standards. The organization publishes a number of journals, has
many local chapters, and several large societies in special areas, such as the
IEEE Computer Society.
Infrastructure Network - An infrastructure network is a group of computers
or other devices, each with a wireless adapter, connected as an 802.11 wireless
LAN.  In infrastructure mode, the wireless devices communicate with each
other and to a wired network by first going through an access point.  An infra-
structure wireless network connected to a wired network is referred to as a
Basic Service Set (BSS).  A set of two or more BSS in a single network is
referred to as an Extended Service Set (ESS).  Infrastructure mode is useful at
a corporation scale, or when it is necessary to connect the wired and wireless
networks.
IP (Internet Protocol) - The method or protocol by which data is sent from one
computer to another on the Internet. It is a standard set of rules, procedures, or
conventions relating to the format and timing of data transmission between two
computers that they must accept and use to be able to understand each other.
IP Address - In the most widely installed level of the Internet Protocol (IP)
today, an IP address is a 32-binary digit number that identifies each sender or
receiver of information that is sent in packet across the Internet. When you
request an HTML page or send e-mail, the Internet Protocol part of TCP/IP
includes your IP address in the message (actually, in each of the packets if more
than one is required) and sends it to the IP address that is obtained by looking
up the domain name in the Uniform Resource Locator you requested or in the
e-mail address you're sending a note to. At the other end, the recipient can see
the IP address of the Web page requestor or the e-mail sender and can respond
by sending another message using the IP address it received. 
IRQ (Interrupt  ReQuest) - A hardware interrupt on a PC. There are 16 IRQ
lines used to signal the CPU that a peripheral event has started or terminated.
Except for PCI devices, two devices cannot use the same line. 
Driver - A workstation or server software module that provides an interface
between a network interface card and the upper-layer protocol software running
in the computer; it is designed for a specific card, and is installed during the
initial installation of a network-compatible client or server operating system.
DSSS (Direct-Sequence Spread Spectrum) - DSSS generates a redundant bit
pattern for all data transmitted. This bit pattern is called a chip (or chipping
code).  Even if one or more bits in the chip are damaged during transmission,
statistical techniques embedded in the receiver can recover the original data
without the need for retransmission. To an unintended receiver, DSSS appears
as low power wideband noise and is rejected (ignored) by most narrowband
receivers.  However, to an intended receiver (i.e. another wireless LAN end-
point), the DSSS signal is recognized as the only valid signal, and interference
is inherently rejected (ignored).
Encryption - A security method that applies a specific algorithm to data in
order to alter the data's appearance and prevent other devices from reading the
information. 
Ethernet - IEEE standard network protocol that specifies how data is placed
on and retrieved from a common transmission medium. Has a transfer rate of
10 Mbps. Forms the underlying transport vehicle used by several upper-level
protocols, including TCP/IP and XNS.
FHSS (Frequency  Hopping Spread Spectrum) - FHSS continuously changes
(hops) the carrier frequency of a conventional carrier several times per second
according to a pseudo-random set of channels. Because a fixed frequency is not
used, and only the transmitter and receiver know the hop patterns, interception
of FHSS is extremely difficult.
Fragmentation - Breaking a packet into smaller units when transmitting over
a network medium that cannot support the original size of the packet. 
Gateway - A device that interconnects networks with different, incompatible
communications protocols. 
Hardware - Hardware is the physical aspect of computers, telecommunica-
tions, and other information technology devices. The term arose as a way to dis-
tinguish the "box" and the electronic circuitry and components of a computer
from the program you put in it to make it do things. The program came to be
known as the software.
Wireless-G Notebook Adapter
Passphrase - Used much like a password, a passphrase simplifies the WEP
encryption process by automatically generating the WEP encryption keys for
Linksys products.
PCI (Peripheral Component Interconnect) - A peripheral bus commonly used
in PCs, Macintoshes and workstations. It was designed primarily by Intel and
first appeared on PCs in late 1993. PCI provides a high-speed data path
between the CPU and peripheral devices (video, disk, network, etc.). There are
typically three or four PCI slots on the motherboard. In a Pentium PC, there is
generally a mix of PCI and ISA slots or PCI and EISA slots. Early on, the PCI
bus was known as a "local bus."
PCI provides "plug and play" capability, automatically configuring the PCI
cards at startup. When PCI is used with the ISA bus, the only thing that is gen-
erally required is to indicate in the CMOS memory which IRQs are already in
use by ISA cards. PCI takes care of the rest.
PCI allows IRQs to be shared, which helps to solve the problem of limited IRQs
available on a PC. For example, if there were only one IRQ left over after ISA
devices were given their required IRQs, all PCI devices could share it. In a PCI-
only machine, there cannot be insufficient IRQs, as all can be shared.
Plug-and-Play - The ability of a computer system to configure expansion
boards and other devices automatically without requiring the user to turn off
the system during installation.
Port - A pathway into and out of the computer or a network device such as a
switch or router. For example, the serial and parallel ports on a personal com-
puter are external sockets for plugging in communications lines, modems and
printers.
Roaming - In an infrastructure mode wireless network, this refers to the abili-
ty to move out of one access point's range and into another and transparently
reassociate and reauthenticate to the new access point.  This reassociation and
reauthentication should occur without user intervention and ideally without
interruption to network connectivity.  A typical scenario would be a location
with multiple access points, where users can physically relocate from one area
to another and easily maintain connectivity.
RTS (Request TSend) - An RS-232 signal sent from the transmitting station
to the receiving station requesting permission to transmit. 
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ISM band - The FCC and their counterparts outside of the U.S. have set aside
bandwidth for unlicensed use in the ISM (Industrial, Scientific and Medical)
band. Spectrum in the vicinity of 2.4 GHz, in particular, is being made avail-
able worldwide. This presents a truly revolutionary opportunity to place con-
venient high-speed wireless capabilities in the hands of users around the globe.
LAN (Local Area Network) - A group of computers and associated devices that
share a common communications line and typically share the resources of a
single processor or server within a small geographic area (for example, within
an office building). 
MAC (Media Access Control) Address - A unique number assigned by the
manufacturer to any Ethernet networking device, such as a network adapter,
that allows the network to identify it at the hardware level.
Mbps (Megabits per second) - One million bits per second; unit of measure-
ment for data transmission.
Motherboard - A motherboard is the physical arrangement in a computer that
contains the computer's basic circuitry and components. 
Network - A system that transmits any combination of voice, video and/or data
between users. 
Node - A network junction or connection point, typically a computer or work
station.
OFDM - Developed for wireless applications, Orthogonal Frequency Division
Multiplexing (OFDM) technology offers superior performance-increased data
rates and more reliable transmissions-than previous technologies, such as
DSSS. OFDM is a scheme in which numerous signals of different frequencies
are combined to form a single signal for transmission on the medium. 
OFDM works by breaking one high-speed data stream into a number of lower-
speed data streams, which are then transmitted in parallel. Each lower speed
stream is used to modulate a subcarrier. Essentially, this creates a multi-carrier
transmission by dividing a wide frequency band or channel into a number of
narrower frequency bands or sub-channels. OFDM is also used for other appli-
cations, including powerline networking.
Packet - A unit of data routed between an origin and a destination in a network.