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Wi-Fi Alliance is a trade association that promotes Wi-Fi technology and certifies Wi-Fi products if they conform to certain standards of interoperability. Not every IEEE 802.11-compliant device is submitted for certification to the Wi-Fi Alliance, sometimes because of costs associated with the certification process. The lack of the Wi-Fi logo does not necessarily imply a device is incompatible with Wi-Fi devices.
The Wi-Fi Alliance owns the Wi-Fi trademark. Manufacturers may use the trademark to brand certified products that have been tested for interoperability.
Early 802.11 products suffered from interoperability problems because the Institute of Electrical and Electronics Engineers (IEEE) had no provision for testing equipment for compliance with its standards. In 1999, pioneers of a new, higher speed variant, endorsed the IEEE 802.11b specification to form the Wireless Ethernet Compatibility Alliance (WECA) and branded the new technology Wi-Fi.
The group of companies included 3Com, Aironet (acquired by Cisco), Harris Semiconductor (now Intersil), Lucent (now Alcatel-Lucent), Nokia and Symbol Technologies (now Motorola). As key sponsors, the alliance lists Apple inc., Comcast, Samsung, Sony, LG, Intel, Dell, Broadcom, Cisco, Qualcomm, Motorola, Microsoft, Texas Instruments, and T-Mobile. The charter for this independent organization was to perform testing, certify interoperability of products, and to promote the technology.
Most producers of 802.11 equipment became members, and as of 2012[update], the Wi-Fi Alliance had over 550 member companies. Wi-Fi Alliance extended Wi-Fi beyond wireless local area network applications into point-to-point and personal area networking, and enabled specific applications such as Miracast.
The Wi-Fi Alliance owns and controls the "Wi-Fi Certified" logo, a registered trademark, which is permitted only on equipment which has passed testing. Purchasers relying on that trademark will have greater chances of interoperation than otherwise. Testing is rigorous because the standards involve not only radio and data format interoperability, but security protocols, as well as optional testing for quality of service and power management protocols. From a Wi-Fi Alliance paper on Wi-Fi Certification A focus on user experience has shaped the overall approach of the Wi-Fi Alliance certification program: Wi-Fi Certified products have to demonstrate that they can perform well in networks with other Wi-Fi Certified products, running common applications, in situations similar to those encountered in everyday use. This pragmatic approach stems from three tenets, around which certification is centered:
- Interoperability is the primary target of certification. Rigorous test cases are used to ensure that products from different equipment vendors can interoperate in a wide variety of configurations.
- Backward compatibility has to be preserved to allow for new equipment to work with existing gear. Backward compatibility protects investments in legacy Wi-Fi products and enables users to gradually upgrade and expand their networks.
- Innovation is supported through the introduction of new certification programs as the latest technology and specifications come into the marketplace. These certification programs may be mandatory (e.g. WPA2) or optional (e.g. WMM). Equipment vendor differentiation and inventiveness are preserved in areas that are not covered by certification testing.
The Wi-Fi Alliance definition of interoperability goes well beyond the ability to work in a Wi-Fi network. To gain certification under a specific program, products have to show satisfactory performance levels in typical network configurations and have to support both established and emerging applications. A user that purchases a Wi-Fi enabled laptop, for instance, would not be satisfied if the laptop established a connection with the home network, only to get the throughput of a dial-up connection. Similarly, subscribers using a Wi-Fi enabled mobile phone would be disappointed, if a voice call could not go through or was dropped. The Wi-Fi Alliance certification process includes three types of tests to ensure interoperability. Wi-Fi Certified products are tested for:
- Compatibility: certified equipment has been tested for connectivity with other certified equipment . Compatibility testing has always been, and still is, the predominant component of interoperability testing, and it is the element that most people associate with "interoperability". It involves tests with multiple devices from different equipment vendors. Compatibility testing is the program component that helps to ensure devices purchased today will work with Wi-Fi Certified devices already owned or purchased in the future.
- Conformance: the equipment conforms to specific critical elements of the IEEE 802.11 standard. Conformance testing usually involves standalone analysis of individual products and establishes whether the equipment responds to inputs as expected and specified. For example, conformance testing is used to ensure that Wi-Fi equipment protects itself and the network when the equipment detects evidence of network attacks.
- Performance: the equipment meets the performance levels required to meet end-user expectations in support of key applications. Performance tests are not designed to measure and compare performance among products, but simply to verify that the product meets the minimum performance requirements for a good user experience as established by the Wi-Fi Alliance. Specific performance tests results are not released by the Wi-Fi Alliance.
The Wi-Fi Alliance provides certification testing in two levels:
- Core MAC/PHY interoperability over 802.11a, 802.11b, 802.11g, and 802.11n. (at least one)
- Wi-Fi Protected Access 2 (WPA2) security, which aligns with IEEE 802.11i. WPA2 is available in two types: WPA2-Personal for consumer use, and WPA2 Enterprise, which adds EAP authentication.
- Tests corresponding to IEEE 802.11h and 802.11d.
- WMM Quality of Service, based upon a subset of IEEE 802.11e.
- WMM Power Save, based upon APSD within IEEE 802.11e
- Wi-Fi Protected Setup, a specification developed by the Alliance to ease the process of setting up and enabling security protections on small office and consumer Wi-Fi networks.
- Application Specific Device (ASD), for wireless devices other than Access Point and Station which has specific application, such as DVD players, projectors, printers, etc.
- Converged Wireless Group–Radio Frequency (CWG-RF, offered in conjunction with CTIA), to provide performance mapping of Wi-Fi and cellular radios in converged devices.
In October 2010, the Alliance began to certify Wi-Fi Direct, that allows Wi-Fi-enabled devices to communicate directly with each other, without going through a wireless access point or hotspot. Since 2009 when it was first announced, some suggested Wi-Fi Direct might replace the need for Bluetooth on applications that do not rely on Bluetooth low energy.
- Marlyn Kemper Littman (2002). Building Broadband Networks. CRC Press. pp. 406–407. ISBN 9781420000016.
- Wireless Access 2000. Information Gatekeepers. 2002. p. 111. ISBN 9781420000016.
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- "An overview of Wi-Fi Alliance certification".
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- "WMM – Article from Wi-Fi Alliance".
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- "WPS – Article from Wi-Fi Alliance".
- "Wi-Fi gets personal: Groundbreaking Wi-Fi Direct launches today". Press release (WiFi Alliance). October 25, 2010. Retrieved November 7, 2013.
- Tony Bradley (October 15, 2009). "Wi-Fi Direct could be death of Bluetooth". PC World. Retrieved November 7, 2013.
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