Concept Guide

Term Definition
802.11g Offers transmission over relatively short distances at up to 54 Mbps,
compared with the 11 Mbps theoretical maximum of 802.11b. 802.11g
operates in the 2.4 GHz band and employs orthogonal frequency
division multiplexing (OFDM), the modulation scheme used in 802.11a,
to obtain higher data speed. Computers or terminals set up for 802.11g
can fall back to speeds of 11 Mbps, so that 802.11b and 802.11g devices
can be compatible within a single network.
802.11n Wireless networking standard to improve network throughput over the
two previous standards 802.11a and 802.11g with a significant increase
in the maximum raw data rate from 54 Mbps to 600 Mbps with the use
of four spatial streams at a channel width of 40 MHz. 802.11n operates
in the 2.4 and 5.0 bands.
AP An access point (AP) connects users to other users within the network
and also can serve as the point of interconnection between the WLAN
and a fixed wire network. The number of access points a WLAN needs is
determined by the number of users and the size of the network.
access point mapping The act of locating and possibly exploiting connections to WLANs while
driving around a city or elsewhere. To do war driving, you need a
vehicle, a computer (which can be a laptop), a wireless Ethernet card set
to work in promiscuous mode, and some kind of an antenna which can
be mounted on top of or positioned inside the car. Because a WLAN may
have a range that extends beyond an office building, an outside user
may be able to intrude into the network, obtain a free Internet
connection, and possibly gain access to company records and other
resources.
ad-hoc network A LAN or other small network, especially one with wireless or temporary
plug-in connections, in which some of the network devices are part of
the network only for the duration of a communications session or, in the
case of mobile or portable devices, while in some close proximity to the
rest of the network.
band A specified range of frequencies of electromagnetic radiation.
DHCP The Dynamic Host Configuration Protocol (DHCP) is an auto-
configuration protocol used on IP networks. Computers or any network
peripherals that are connected to IP networks must be configured,
before they can communicate with other computers on the network.
DHCP allows a computer to be configured automatically, eliminating the
need for a network administrator. DHCP also provides a central
database to keep track of computers connected to the network. This
database helps in preventing any two computers from being configured
with the same IP address.
Table 80: List of Terms
Dell Networking W-Series Instant 6.4.3.1-4.2.0.0 | User Guide Terminology | 400