Network service providers and application developers both work to provide their users with the best possible quality of experience (QoE) for their respective services. Although many segments of the service/application layer of end-to-end networks are out of the operator’s control, the segments between the user’s device and the internet are not.
One such critical and consistent segment within the home network is Wi-Fi — the preferred and most commonly used network access technology in the home. This last link has become synonymous with the overall internet. Ensuring the best throughput and latency of these services/applications will reflect on the user’s experience and therefore determine how good or bad the internet service is.
Not all applications have similar traffic needs with regard to throughput, latency and jitter. One such category of applications is Real Time Communication (RTC), examples of which include voice/video calling applications such as Messenger and online meeting applications such as Zoom and Microsoft Teams. To ensure necessary throughput, low latency and managed jitter for RTCs, providers might consider the use of the Wi-Fi Multimedia (WMM) feature.
Wi-Fi Multimedia in Test Scenarios
WMM has four categories of traffic: Voice (VO), Video (VI), Best Effort (BE) and Background (BG). Traffic within each of the categories is given different priorities. Without WMM enabled, all traffic is treated equally, meaning that web browsing and email exchange, for example, are treated the same as time-sensitive applications such as RTCs.
A collaboration between CableLabs and Meta examined the WMM feature to determine the potential for overall improvements to an RTC application. The results of this testing showed that — with WMM enabled on the access point (AP) — RTC applications had improved quality of video and audio, even with varying traffic-load conditions on the Wi-Fi network. In addition to weathering changing traffic loads, RTC quality was maintained as the RTC device moved over varying distances from the AP.
Testing involved emulating a single-family dwelling using three locations. At each location, the RTC client was placed close to the AP (near), midway from the AP (mid) and at the AP’s serving edge (far). Test scenarios consisted of two types of contention traffic: The first introduced typical traffic as seen in a home setting, representing the use of various home applications, and the second fully loaded the Wi-Fi network with simulated traffic. Throughout the testing, the RTC device was shifted to different static distances from the AP (near, mid, far) and QoE was measured in every case. Testing also included a sweeping test case in which the RTC client was moved from near, mid and far locations (in relation to the AP) and then returned to the near location simulating a person moving within the home (sweep). Tests were conducted in the 2.4 GHz band using a 20 MHz channel, as well as the 5 GHz band using an 80 MHz channel.
The results showed that, with WMM enabled, RTC applications experienced improved performance compared with RTC applications not using WMM. This outcome was consistent over all testing: static at near, mid and far locations, and while moving the device from near to edge and back.
Reporting on WMM Testing Results
The details of the testing and results are available in a technical report, “Impacts of WMM on Wi-Fi — Study of Real-Time Communication Quality and WMM.” CableLabs is eager to take these positive lab results and test them in the field to prove the benefits of WMM in real-world environments. After downloading and reviewing the test reports and results, members are encouraged to contact me if they are interested in participating in trials to prove the benefits in a real-world environment.
