A CCESS GATEWAY299Glossary of Terms802.11xRefers 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 thespecification in 1997. There are several specifications in the 802.11 family:802.11Applies to wireless LANs and provides 1 or 2 Mbps transmission in the 2.4 GHz band using either Frequency HoppingSpread Spectrum (FHSS) or Direct Sequence Spread Spectrum (DSSS).802.11aAn extension to 802.11 that applies to wireless LANs and provides up to 54 Mbps in the 5GHz band. 802.11a uses anOrthogonal 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 provides11 Mbps transmission (with a fallback to 5.5, 2 and 1 Mbps) in the 2.4 GHz band. 802.11b uses only DSSS. 802.11bwas a 1999 ratification to the original 802.11 standard, allowing wireless functionality comparable to Ethernet.802.11gApplies to wireless LANs and provides 20+ Mbps in the 2.4 GHz band.802.1QAn IEEE standard for providing a virtual LAN capability within a campus network. 802.1Q establishes a standardformat for frame tagging (Layer 2 VLAN markings), enabling the creation of VLANs that use equipment frommultiple vendors.10/100 EthernetSee Ethernet.AAA(Authentication, Authorization, and Accounting) A combination of commands used by Nomadix Gateways toauthenticate, authorize, and subsequently bill subscribers for their use of the customer’s network. When a subscriberlogs into the system, their unique MAC address is placed into an authorization table. The system then authenticates thesubscriber’s MAC address and billing information before allowing them to access the Internet and make onlinepurchases. See also, MAC Address.Access ConcentratorA type of multiplexor that combines multiple channels onto a single transmission medium in such a way that all theindividual channels can be simultaneously active. For example, ISPs use concentrators to combine their dial-upmodem connections onto faster T-1 lines that connect to the Internet. Concentrators are also used in Local AreaNetworks (LANs) to combine transmissions from a cluster of nodes. In this case, the concentrator is often called a hub.Access RouterA router at a customer site, which connects to the network service provider. Also known as a Customer PremisesEquipment (CPE) router. See also, Router.
