Instruction Sheet

O
Orthogonal Frequency Division Multiplexing (OFDM): A modulation technique for transmitting
large amounts of digital data over radio waves. 802.11a uses OFDM, as will 802.11g.
P
Peer-to-Peer Mode: A wireless network structure that allows wireless clients to communicate
with each other without using an access point.
Personal Area Network (PAN):
Peripheral Connect Interface (PCI):
Preamble: A preliminary signal transmitted over a WLAN to control signal detection and clock
synchronization.
R
Radio Frequency (RF) Terms (GHz, MHz, Hz): The international unit for measuring frequency is
Hertz (Hz), which is equivalent to the older unit of cycles per second. One Mega-Hertz (MHz) is
one million Hertz. One Giga-Hertz (GHz) is one billion Hertz. For reference: the standard US
electrical power frequency is 60 Hz, the AM broadcast radio frequency band is 0.55 -1.6 MHz, the
FM broadcast radio frequency band is 88-108 MHz, and microwave ovens typically operate at
2.45 GHz.
Range: The distance over which a given system can communicate. This subject is discussed in
detail below.
RC4: An encryption algorithm designed at RSA Laboratories; specifically, a stream cipher of
pseudo-random bytes that is used in WEP encryption.
Remote Authentication Dial-In User Service (RAID): An authentication and accounting system
that verifies users' credentials and grants access to requested resources.
Roaming: Movement of a wireless node between two microcells. Roaming usually occurs in
infrastructure networks built around multiple access points.
S
Service Set Identifier (SSID): Used to identify clients on a wireless network.
Shared key An encryption key known only to the receiver and sender of data.
Site Survey: A process where you set up one transceiver in a fixed location, and then use
another unit to plot the field strength of the first unit’s transmitted signal. By moving the
transmitter around, and repeating the plots, you can develop a plan as to the best locations for
access points. You will also identify dead zones and other areas in need of special attention. This
can be a long, slow process, but it beats ripping up an unsatisfactory installation and starting
over. These tests require special software commands. Refer to your manual for specific
instructions. If you have a very large, or unusually complex installation situation, you might want