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Hub
A multiport device used to connect PCs to a network via Ethernet
cabling or via WiFi. Wired hubs can have numerous ports and can
transmit data at speeds ranging from 10 Mbps to multigigabyte
speeds per second. A hub transmits packets it receives to all the
connected ports. A small wired hub may only connect 4 computers; a
large hub can connect 48 or more.
HZ
The international unit for measuring frequency, equivalent to the
older unit of cycles per second. One megahertz (MHz) is one
million hertz. One gigahertz (GHz) is one billion hertz. The standard
US electrical power frequency is 60 Hz, the AM broadcast radio
frequency band is 535—1605 kHz, the FM broadcast radio frequency
band is 88—108 MHz, and wireless 802.11b LANs operate at 2.4
GHz.
IEEE
Institute of Electrical and Electronics Engineers, New York, www.ieee.
org. A membership organization that includes engineers, scientists
and students in electronics and allied fields. It has more than 300,000
members and is involved with setting standards for computers and
communications.
Infrastructure
mode
A client setting providing connectivity to an AP. As compared to
Ad-Hoc mode, whereby PCs communicate directly with each other,
clients set in Infrastructure Mode all pass data through a central AP.
The AP not only mediates wireless network traffic in the immediate
neighborhood, but also provides communication with the wired
network. See Ad-Hoc and AP.
I/O
The term used to describe any operation, program or device that
transfers data to or from a computer.
Internet
appliance
A computer that is intended primarily for Internet access, is simple
to set up and usually does not support installation of third-party
software. These computers generally offer customized web browsing,
touch-screen navigation, e-mail services, entertainment and personal
information management applications.
IP
A set of rules used to send and receive messages at the Internet
address level.
IP (Internet
Protocol)
telephony
Technology that supports voice, data and video transmission via IP-
based LANs, WANs, and the Internet. This includes VoIP (Voice over
IP).
