Nomadix AG 5500, User Manual, Page: 319 / 338

AG 5500
Glossary of Terms 307
Glossary of Terms
802.11x
Refers to a family of specifications developed by the IEEE for wireless LAN technology. 802.11 specifies an over-the-
air interface between a wireless client and a base station, or between two wireless clients. The
IEEE
accepted the
specification in 1997. There are several specifications in the 802.11 family:
802.11
Applies to wireless LANs and provides 1 or 2 Mbps transmission in the 2.4 GHz band using either Frequency Hopping
Spread Spectrum (
FHSS ) or Direct Sequence Spread Spectrum ( DSSS ).
802.11a
An extension to 802.11 that applies to wireless LANs and provides up to 54 Mbps in the 5GHz band. 802.11a uses an
Orthogonal Frequency Division Multiplexing (
OFDM
) encoding scheme rather than FHSS or DSSS.
802.11b
(also referred to as 802.11 High Rate or
Wi-Fi™
) An extension to 802.11 that applies to wireless LANs and provides
11 Mbps transmission (with a fallback to 5.5, 2 and 1 Mbps) in the 2.4 GHz band. 802.11b uses only DSSS . 802.11b
was a 1999 ratification to the original 802.11 standard, allowing wireless functionality comparable to Ethernet.
802.11g
Applies to wireless LANs and provides 20+ Mbps in the 2.4 GHz band.
802.1Q
An IEEE standard for providing a virtual LAN capability within a campus network. 802.1Q establishes a standard
format for frame tagging (Layer 2 VLAN markings), enabling the creation of VLANs that use equipment from
multiple vendors.
10/100 Ethernet
See Ethernet .
AAA
(Authentication, Authorization, and Accounting) A combination of commands used by Nomadix Gateways to
authenticate, authorize, and subsequently bill subscribers for their use of the customer’s network. When a subscriber
logs into the system, their unique MAC address is placed into an authorization table. The system then authenticates the
subscriber’s MAC address and billing information before allowing them to access the Internet and make online
purchases. See also,
MAC Address .
Access Concentrator
A type of multiplexor that combines multiple channels onto a single transmission medium in such a way that all the
individual channels can be simultaneously active. For example, ISPs use concentrators to combine their dial-up
modem connections onto faster T-1 lines that connect to the Internet. Concentrators are also used in Local Area
Networks (LANs) to combine transmissions from a cluster of nodes. In this case, the concentrator is often called a hub.
Access Router
A router at a customer site, which connects to the network service provider. Also known as a Customer Premises
Equipment (CPE) router. See also,
Router
.
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