Linksys WPC55AG User Manual page 23

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.
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.
ISP (Internet Service Provider) - A company that provides individuals and
companies access to the Internet and other related services such as Web site
building and virtual hosting.
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).
LEAP (Lightweight Extensible Authentication Protocol) - Cisco's proprietary,
mutual authentication method using the Extensible Authentication Protocol
(EAP) and a username and password system. LEAP authentication supports
dynamic WEP key management for wireless networking using 802.1x.
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.
Network - A system that transmits any combination of voice, video and/or data
between users.
Notebook (PC) - A notebook computer is a battery-powered personal comput-
er generally smaller than a briefcase that can easily be transported and conve-
niently used in temporary spaces such as on airplanes, in libraries, temporary
offices, and at meetings. A notebook computer, sometimes called a laptop com-
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puter, typically weighs less than five pounds and is three inches or less in thick-
ness.
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.
Passphrase - Used much like a password, a passphrase simplifies the WEP
encryption process by automatically generating the WEP encryption keys for
Linksys products.
PC Card - A credit-card sized removable module that contains memory, I/O,
or a hard disk.
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.
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