Wi-Fi Multi-Media (WMM) is a Wi-Fi feature designed to prioritize various types of data traffic, thereby enhancing Quality of Service (QoS).
Wi-Fi Multi-Media (WMM) is a Wi-Fi feature designed to prioritize various types of data traffic, thereby enhancing Quality of Service (QoS). It ensures that time-sensitive applications, such as voice, video, and gaming, are given higher priority over less critical traffic, such as file downloads or web browsing. The WMM parameters are defined by two key organizations: the Wi-Fi Alliance (WFA) and the Institute of Electrical and Electronics Engineers (IEEE).
Wi-Fi Alliance (WFA)
The WFA defines WMM parameters with an emphasis on practical implementation and device compatibility, ensuring seamless operation across certified devices. These parameters include Access Categories (AC) that prioritize traffic based on its nature: voice traffic (AC_VO) receives the highest priority, followed by video (AC_VI), standard internet traffic (AC_BE), and background tasks like large file transfers (AC_BK).
- AC_VO (Voice): Highest priority for voice traffic.
- AC_VI (Video): Second-highest priority for video streams.
- AC_BE (Best Effort): Default priority for typical internet traffic.
- AC_BK (Background): Lowest priority for tasks like large file transfers.
Institute of Electrical and Electronics Engineers (IEEE)
In contrast to the WFA, the IEEE focuses on the technical framework that governs QoS at the protocol level. This includes defining key elements such as the Arbitration Inter-Frame Space (AIFS), which specifies wait times before accessing the medium; the Contention Window Minimum/Maximum (CWmin/CWmax), which manages random backoff intervals to avoid collisions; and the Transmission Opportunity (TXOP), which sets limits on uninterrupted transmission time for devices.
- AIFS (Arbitration Inter-Frame Space): Defines the wait time before accessing the medium.
- CWmin/CWmax (Contention Window Minimum/Maximum): Determines the random backoff interval for avoiding collisions.
- TXOP (Transmission Opportunity): Sets limits on the time a device can transmit data without interruption.