Wireless LAN (Local Area Network) Glossary of Terms
Part of the Wireless Home Networking For Dummies Cheat Sheet
Wireless LANs are just like any other technology in one way — they're full of acronyms and obscure jargon that make no sense to the average person who hasn't spent a lifetime in technology. Heck, even the term "wireless LAN" contains an acronym. When you go to buy, configure, and use wireless networking equipment, you're going to run into these words. To reduce the stress of all this technobabble, here's a glossary that'll help you quickly get on your way:
802.11: The general standard, developed by the IEEE (the Institute of Electrical and Electronics Engineers — the folks who create many of the standards for networking equipment), for wireless local area networks. Within the 802.11 standard are various substandards, including 802.11b (11 Mbps using the 2.4 GHz spectrum), 802.11a (54 Mbps using the 5 GHz spectrum), 802.11g (54 Mbps using the 2.4 GHz spectrum), and 802.11n (300 Mbps using the 2.4 GHz spectrum, the 5 GHz spectrum, or both).
access point (AP): A wireless LAN base station that connects a wired network (such as the wired Ethernet connection on a broadband modem or router) to the wireless network. The AP contains a radio transceiver (which transmits and receives radio signals), and most APs contain a router that directs your networked devices' data to and from the Internet.
Bluetooth: A standard system for wireless personal area networks (PANs). Bluetooth provides speeds of up to 3 Mbps at short ranges (typically less than 10 meters). PAN technologies, such as Bluetooth, are complementary to LAN technologies (like 802.11) and are typically used to connect peripheral devices, such as keyboards to computers or wireless headsets to mobile phones.
Ethernet: A standard data communications protocol enabling computers and computer peripheral devices, such as printers, to interface with one another and across networks for the exchange of information. The most common variation of Ethernet found in home networks is the 100 Mbps 100BaseT variant, although many of other variations exist with speeds of 1,000 Mbps and beyond.
IP address: The "phone number" of the Internet, the IP address is used to identify computers and devices connected to the Internet and allows traffic to be routed across the Internet. Most wireless home networks have two IP addresses: a public IP address (used by your modem and access point or router) that identifies your network to other computers on the Internet, and a set of private IP addresses, used only within your network. Your access point (or separate router, if you have one) translates between your public and private IP addresses to send data to the right computer within your network.
local area network (LAN): A computer data communications network used within a limited physical location, such as a house.
network adapter (also network interface card, or NIC): A device that connects to an internal bus in a PC, which provides an interface between the computer or device and the LAN. For wireless networks, network adapters typically connect to the PC Card bus or to the USB bus of the device being networked. Most computers today already have the wireless network adapter built in.
Network Address Translation (NAT): A process performed in your access point (or separate router, if you use one) to translate, or create a tie, between your internal network's private IP addresses and the public IP address assigned to your network by your Internet service provider (ISP). A NAT router is a device that performs this translation and lets devices on your network using nonroutable private IP addresses communicate with devices on the Internet.
service set identifier (SSID): Also referred to as ESSID, network name, service area, and other names, this term identifies a specific wireless LAN. To connect to a network, a device must "know" the SSID of the network.
Wi-Fi Protected Access (WPA): An improvement to WEP, WPA adds — among other changes — a key (TKIP, or Temporal Key Integrity Protocol) that changes dynamically over time, which eliminates the greatest shortcoming of WEP. WPA is the minimum level of security you should choose, if at all possible. WPA-Enterprise adds 802.1x authentication to make the network even more secure.
Wi-Fi Protected Access 2 (WPA2): WPA2 adds even further enhancements to WPA, including AES (Advanced Encryption Standard), which makes the encryption key almost impervious to current cracker attacks.
Wired Equivalent Privacy (WEP): The encryption system used by wireless LANs to provide security on the network. WEP uses an encryption key (which can be 40 or 104 bits long — these keys are often referred to as 64- and 128-bit keys because of some extra bits used in the WEP system) to encrypt data flowing across the network. Without the WEP encryption key, unauthorized users see only garbled data and cannot read what is being sent across the network.
wireless Ethernet bridge: A device that connects to an Ethernet port on a networked device (such as a PC, game console, or networked audio system) and provides wireless network adapter functionality for that device.
wireless LAN repeater: A device that extends the range of a wireless LAN by receiving signals from an access point (and other devices on a wireless LAN) and retransmitting them. A wireless LAN repeater is often placed in a separate part of the house and is used to allow devices that are too far from the access point to "get on" the wireless LAN.