--An AP operates within a specific frequency
spectrum and uses an 802.11 standard modulation technique. It also informs the
wireless clients of its availability and authenticates and associates wireless
clients to the wireless network. An AP also coordinates the wireless clients’
use of wired resources. It should be noted that there are several kinds of APs,
including single radio and multiple radios, based on different 802.11
--An antenna radiates the modulated
signal through the air so that wireless clients can receive it. Characteristics
of an antenna are defined by propagation pattern (directional versus
omnidirectional), gain, transmit power, and so on. Antennas are needed on the
APs, bridges, and clients.
--A PC or workstation uses a client adapter
or wireless NIC to connect to the wireless network. The NIC scans the available
frequency spectrum for connectivity and associates to the AP or another
wireless client. The NIC is coupled to the PC or workstation operating system
(OS) using a software driver. Various client adapters are available from Cisco.
--Extensible Authentication Protocol. EAP
is a flexible protocol used to carry authentication information. It is defined
in RFC 2284.
--The Institute of Electrical and
Electronic Engineers is, among other things, a standards body. IEEE publishes
standards for many types of systems, and is well known for its standards on
information exchange between computers--from best practices to IT
infrastructure to LAN and MAN standards to portable applications standards.
--Media Access Control address. A unique
48-bit number used in Ethernet data packets to identify an Ethernet device,
such as an AP or client adapter.
--Message Integrity Check algorithm.
--Service Set Identifier. A unique
identifier used to identify a radio network and which stations must use to be
able to communicate with each other or with an AP.
--Temporal Key Integrity Protocol.
Developed to fix the problems with WEP. TKIP consists of three protocols: a
cryptographic message integrity algorithm, a key mixing algorithm, and an
enhancement to the initialization vector (IV).
--Wired Equivalent Privacy. An optional
security mechanism defined within the 802.11 standard designed to make the link
integrity of wireless devices equal to that of a wired Ethernet.