WBA highlights strategies to ensure end-to-end Wi-Fi quality of service

Quality of service (QoS) is key for virtually every time-sensitive Wi-Fi application, from videoconferencing to gaming to streaming, and looking to show enterprises how they can use QoS as a market differentiator to attract and retain customers, Wi-Fi trade association the Wireless Broadband Alliance (WBA) has published a whitepaper on the topic. 

E2E QoS improvement: optimizing QoS over Wi-Fi explores how network operators can meet the unique QoS requirements for a wide variety of use cases and deployments, including gaming, residential broadband, live 4K video, enterprise, airports and stadiums, end to end (E2E).

The paper was produced by the WBA E2E Wi-Fi QoS project group, led by wireless technology firms Airties and Intel. It presents a phased approach for enabling E2E QoS for residential, enterprise and public use cases, including the unique key performance indices (KPI) for each one, such as latency, packet loss, jitter and frame rates. The paper explores how application-specific QoS mechanisms can co-exist on the same network with applications that aren’t QoS sensitive, such as streaming video alongside email.

Putting the publication into context, the association said enterprises need Wi-Fi networks that can provide the right QoS for each application, such as prioritising HD video collaboration sessions over email and file transfers. And home Wi-Fi networks need to balance a variety of bandwidth-intensive, latency-sensitive applications, including multiplayer gaming, 4K streaming and remote work conferencing – often all simultaneously.

The WBA said its E2E concept is about providing both visibility into and control over the user experience by leveraging QoS mechanisms at each step of a packet’s journey across the Wi-Fi ecosystem. 

E2E QoS covered includes the applications, such as cloud gaming or streaming video, Wi-Fi network elements such as access points (APs), and Wi-Fi client devices such as mobile phones and laptops. It discusses the use of ITU-T SG12 recommendations and corresponding tools to access objective mean opinion scores (MOS) the QoS streams during the trials.

The paper also describes potential KPIs for gaming such as freeze count, which is two consecutive rendered frames that are not received by the client within a defined amount of time, such as 180 milliseconds in the case of Facebook’s Wild Hunt.

Another example is motion to photon latency, the time interval between when a player takes an action and the moment at which the player can see the corresponding frame on screen. If these KPI’s aren’t met, it lays out mitigation strategies for the different scenarios.

Two key outcomes from the trials are discussed. The first is quantifying how to improve QoS application performance and reliability, and user experiences. The second is potentially identifying performance bottlenecks that may require enhancements to existing QoS mechanisms or totally new QoS mechanisms. With these discoveries, WBA intends to work with standards organisations – such as IETF, IEEE802.1, IEEE802.11, WFA – to develop enhancements to existing or new, QoS mechanisms.

The paper also identifies and spells out future WBA QoS initiatives with a focus on creating enhancements and defining new mechanisms. For example, it outlines the usage scenarios for Wi-Fi networks prioritising QoS traffic based on Wi-Fi Alliance QoS Management Technical Specification. 

Additional future WBA work includes expanding network topology to incorporate Wi-Fi mesh (Wi-Fi Alliance EasyMesh), extending QoS management to non-Wi-Fi links for E2E QoS and integrating new QoS management mechanisms from ongoing work in the IEEE802.11 Working Group and/or Wi-Fi Alliance QoS Management TG, and/or IETF.

Commenting on the publication, Wireless Broadband Alliance CEO Tiago Rodrigues said: “Each application has its own unique QoS requirements, and this diversity creates challenges for Wi-Fi network operators. This WBA whitepaper outlines how enhanced and new QoS mechanisms can ensure that each application gets exactly the right bandwidth, prioritisation and other resources it needs to provide end users with consistently great experiences.”