Quality of service (QoS) extensions to the 802.11 (Wi-Fi) protocol that give real-time audio and video preference over other data. Also known as "Wi-Fi Multimedia" (WMM) and "wireless multimedia extensions" (WME), the 802.11e enhancements were developed to give the transmission of voice over IP (VoIP) and video streaming a higher priority than Web browsing and file downloads. See Wi-Fi Alliance.
The IEEE standard (2005) for wireless LAN (WLAN) quality of service (QoS) based on access priority classes. 802.11e introduces a coordination function that provides a station with high priority traffic such as voice with more frequent network access than a station with low priority traffic such as e-mail. The station with the high priority traffic also is granted a longer transmit opportunity, or window, in which to transmit as many frames as possible. In all, 802.11e defines four access priority classes, which the Wi-Fi Alliance terms Wi-Fi MultiMedia Extensions (WMMs, or WMEs).Those classes are as follows.