Why Wi-Fi?


The Wireless Ethernet Compatibility Alliance, now known as the Wi-Fi Alliance, was formed specifically to test 802.11-based wireless network products from different manufacturers to ensure interoperability. The brand name chosen by the Wi-Fi Alliance for these products is Wi-Fi (Wireless Fidelity). You can access the organization's Web site at www.weca.net or www.wi-fi.org.

Although the Wi-Fi Alliance was originally created to encourage testing for interoperability for 802.11b products, the scope of the organization has continued to expand to include new wireless products and standards. Table 19.3 lists the current certifications supported by the Wi-Fi Alliance.

Table 19.3. Wi-Fi Alliance Certifications

Certification

Type

Features/Definition

Notes

IEEE 802.11a

Wireless Ethernet

5GHz frequency, 54Mbps maximum signal rate

See also IEEE 802.11d and IEEE 802.11h certifications

IEEE 802.11b

2.4GHz frequency, 11Mbps maximum signal rate

Compatible with 802.11g

IEEE 802.11g

 

2.4GHz frequency, 54Mbps maximum signal rate

Backward-compatible with 802.11b; see also IEEE 802.11d and IEEE 802.11h certifications

IEEE 802.11d

Optional WLAN features

Enables configuration changes to Media Access Control (MAC) layer to meet requirements of different countries

Supported by some 802.11a and multimode (802.11a/g) hardware

IEEE 802.11h

 

Dynamic frequency selection (DFS) and Transmit power control (TPC) to improve coexistence between 802.11a and other 5GHz RF devices

Supported by some 802.11a and multimode (802.11a/g) hardware

WPA Enterprise

Security

Uses 802.1x authentication with TKIP encryption and an authentication server

See also WPA2 Enterprise

WPA Personal

 

Uses a shared key with TKIP encryption

See also WPA2 - Personal

WPA2 Enterprise

Improved version of WPA Enterprise using AES encryption

Based on IEEE 802.11i

WPA2 Personal

 

Improved version of WPA Personal using AES encryption

Based on IEEE 802.11i

EAP-TLS

 

Extensible Authentication Protocol Transport Layer Security

Used for WPA/Enterprise authentication

EAP-TTLS/MSCHAPv2

EAP-Tunneled TLS/Microsoft Challenge Authentication Handshake Protocol

Used for WPA/WPA2 Enterprise authentication

EAP-SIM

 

Version of EAP for GSM-based mobile phone services

Used for WPA/WPA2 Enterprise authentication

WMM

Multimedia

Certification for VoIP and various types of media players; prioritizes traffic into four categories (voice, video, best effort, background)

Subset of 802.11e WLAN Quality of Service (QoS) draft standard


Because of the popularity of Wi-Fi Certification, many 802.11-compatible products are now referred to as Wi-Fi products, even if they have not passed Wi-Fi Alliance testing. However, only products that have passed Wi-Fi Alliance certification testing are permitted to use the Wi-Fi Certified logo. Thus, when you hear a product advertised as Wi-Fi Certified, you can be assured that it's based on one of the IEEE 802.11 standards supported by the Wi-Fi Alliance and that it should work with other products that have the Wi-Fi logo and use the same frequency.

Note

Although it is common usage to equate Wi-Fi and 802.11, this is not correct. Although every Wi-Fi Certified device corresponds to one of the 802.11 standards, some 802.11-compatible devices have not been Wi-Fi Certified. You can mix-and-match Wi-Fi Certified and non-certified 802.11 devices, but to avoid problems, you're better off using only Wi-Fi Certified devices.





Upgrading and Repairing Networks
Upgrading and Repairing Networks (5th Edition)
ISBN: 078973530X
EAN: 2147483647
Year: 2006
Pages: 411

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