AirPort Extreme is the successor of AirPort, a wireless local area networking brand introduced by Apple, Inc. It was introduced by Apple on January 7, 2003. While AirPort was based on the IEEE 802.11b, AirPort Extreme was based on the IEEE 802.11g standard, and it is compatible with other devices under the 802.11g standard.
Another family of AirPort Extreme products was later introduced, based on the draft-IEEE 802.11n standard. AirPort is sold under the name "AirMac" in Japan, since the name "AirPort" had already been registered by another company known as I-O DATA. In common usage, the term "AirPort Extreme" may refer to the 802.11g protocol, the expansion card or the base station.
With AirPort Extreme, theoretical peak data transmission rates may be up to 54 Mbps. It is fully backward-compatible with all other 802.11b wireless network cards and base stations, provided that they conform to the 802.11b networking standards.
As of May 2006, it is standard for AirPort Extreme to be included in a number of the current desktop computers and portable computers produced by Apple, such as the MacBook, MacBook Pro, Mac mini and the iMac ship, while other modern Macs feature an expansion slot for the card. However, AirPort Extreme cards cannot be installed in older Apple models, and they are not physically compatible with AirPort cards, which were discontinued in June 2004.
The base station of AirPort Extreme functions as a means to connect AirPort-enabled computers to other devices, a wired local area network (LAN), or to the Internet. Unlike the original AirPort, AirPort Extreme features an external antenna port, which allows the addition of a signal-boosting antenna, and a USB port, which allows the sharing of a USB printer.
The AirPort Extreme card, used to connect to wireless networks, is based on the Broadcom 802.11g chipset, housed in a mechanically proprietary custom enclosure. This housing, however, is electrically compatible with the Mini PCI standard, and is capable of being user-installed.
It has the Media Access Control (MAC) layer in software. The latest versions of the PowerPC-based PowerBooks and iBooks featured a different 802.11g card, which included both 802.11g and Bluetooth, and was not user-installable.
For security, AirPort Extreme base stations make use of Wi-Fi Protected Access (WPA) and WPA2 (also known as IEEE 802.11i), as an improvement on Wired Equivalent Privacy (WEP) which was used in the original family of AirPort base stations, since WEP has been proven to have a lot of security holes, and WEP keys were easily cracked.
Cryptography is important in network security since wireless networks broadcast over radio, making them vulnerable to unwanted eavesdropping.