What Is Wi-Fi ? Is It the Same as IEEE 802.11?

What Is Wi-Fi^™? Is It the Same as IEEE 802.11?

Wi-Fi^™ is a registered trademark of the Wi-Fi^™ Alliance. Wi-Fi^™ is a brand, in a way, that represents a certification program, and is the associated logo that represents that brand. End users can have confidence that any two products that display the Wi-Fi^™ logo will interoperate. The moniker "Wi-Fi^™" is to IEEE 802.11 as "Ethernet" is to IEEE 802.3, although Ethernet never really had an industry consortium that was testing and certifying standards compliance, then conferring a logo on devices. Wi-Fi^™ stands for "wireless fidelity," and is a user-friendly name that has been created to refer to a common type of WLAN products.

The Wi-Fi^™ Alliance is a nonprofit organization that certifies the interoperability of products based on the IEEE 802.11 standards. The Wi-Fi^™ Alliance was founded in 1999 the same year that the updated WLAN base specification was finalized (designated IEEE 802.11-1999), along with IEEE 802.11b-1999 and IEEE 802.11a-1999. The initial members of the Wi-Fi^™ Alliance^[21] were Agere Systems, Cisco Systems, Intersil Corporation, Nokia Inc., Symbol Technologies, and 3Com Corporation. By July 1, 2003, over 180 companies had become members of the Wi-Fi^™ Alliance. The Wi-Fi^™ Alliance's Web site is located at www.wi-fi.org.

^[21] The original name of the Wi-Fi^™ Alliance was WECA, which stood for the Wireless Ethernet Compatibility Alliance. WECA changed its name in July 2002.

Originally, the Wi-Fi^™ logo only applied to products based on the IEEE 802.11b-1999 standard. Such products may operate at speeds of 1, 2, 5.5, and 11 Mbps in the 2.4 GHz unlicensed Industrial, Scientific, and Medical (ISM) band (specifically, 2400 to 2500 MHz). The Wi-Fi^™ logo has been extended to apply to other types of physical layers that can be used with IEEE 802.11.

The Wi-Fi^™ Alliance certifies those products from member companies that have been certified as complying with the applicable IEEE 802.11 standard(s), as well as meeting some basic performance and throughput targets. Once certified, a product is granted the right to display the Wi-Fi^™ logo, as shown in Figure 1-8. ^[22]

^[22] Note well: The display of this logo in no way confers endorsement of this book by the Wi-Fi^™ Alliance.

Figure 1-8. The Wi-Fi^™ logo^[22]

For a product to become Wi-Fi^™-certified, which enables the vendor to display the Wi-Fi^™ logo on the certified product's packaging, the vendor must pay annual membership dues to the Wi-Fi^™ Alliance, on the order of $25,000 per year, and submit their product for certification testing by the Wi-Fi^™ Alliance. Having paid the annual membership fee, a company can certify any number of it products, provided the company pays the Wi-Fi^™ Alliance a per-product testing and certification fee of $15,000. However, if a company terminates its Wi-Fi^™ Alliance membership, it can no longer display the Wi-Fi^™ logo.^[23]

^[23] Note that the membership fee and per-product testing fees may have changed by the time you read this. The information cited here was the latest available on the Wi-Fi^™ Alliance's Web site, as of July 1, 2003. Future versions of the Wi-Fi^™ Alliance's Frequently Asked Questions (FAQ) document may have updated information. This FAQ can be viewed at www.wi-fi.org.

Products conforming to IEEE 802.11a operate in the 5 GHz unlicensed ISM band (in the United States, from 5725 through 5875 MHz), and must be able to transmit at speeds of 6, 12, and 24 Mbps. IEEE 802.11a products may optionally also support transmission at speeds of 9, 18, 36, 48, and 54 Mbps. Subsequent sections of the book will cover all the relevant technical details of IEEE 802.11a-1999 and IEEE 802.11b-1999, as well as the emerging IEEE 802.11g-2003.

The Wi-Fi^™ Alliance had been planning to create another logo, for IEEE 802.11a products, known provisionally as "Wi-Fi5" (where the "5" refers to the fact that the IEEE 802.11a products operate in a subset of the 5 GHz radio frequency spectrum, as opposed to IEEE 802.11 and IEEE 802.11b, which both operate in portions of the 2.4 GHz spectrum). However, due to the overwhelming market awareness of the Wi-Fi^™ logo, it was decided to extend the Wi-Fi^™ logo to cover products based on IEEE 802.11a, rather than create a new logo. The first Wi-Fi^™-certified IEEE 802.11a products became available in late 2002.