Android 17 has a secret weapon to fix laggy video and voice calls

Google recently rolled out Android 17 to Pixel devices. While the update brings plenty of noteworthy changes, like App Bubbles and Screen Reactions, a network-related upgrade has quietly flown under the radar. Android 17 supports automatic routing of over-the-top (OTT) voice and video calls to premium network connections via 5G network slicing, and that’s big news for your next WhatsApp or Zoom video call over mobile data.

What is 5G network slicing?

5G network slicing is a core network feature that allows carriers to partition, i.e., slice, one 5G network into multiple isolated virtual networks with different characteristics. Thus, instead of treating all internet traffic equally, network slicing enables carriers to allocate different resources to different types of traffic and even to specific customer segments. This opens up carriers and network operators to provide customized lanes for specific use cases, such as ultra-low latency or high bandwidth, on their 5G Standalone (5G SA) networks.

In the US, T-Mobile has created a Video calling slice to optimize mobile apps that provide OTT video calling or conferencing features. Developers who want to beta-test the video calling slice can manually add support for it to their mobile app, test routing traffic through it, and evaluate performance using latency, packet loss, jitter, and other metrics. Verizon also has an Enhanced Video Calling network slice. T-Mobile, Verizon, and AT&T also have network slices for public safety use.

Android’s progress on 5G network slicing features so far

Google has spent the past few years incrementally laying the groundwork for 5G network slicing capabilities. Android 12 introduced support for 5G network slicing, but it was restricted to data routed through enterprise work profiles. Android 13 added support for per-app routing controls for IT admins. However, these 5G network slicing features have been available only to enterprise users.

Android 14 (QPR 1) added support for 5G slicing upsell feature, which lets carriers offer enhanced network capabilities (mainly prioritized latency) to their users through 5G network slicing. This feature required apps to make specific changes to offer the carrier’s upsell if the user wasn’t already subscribed to the slice, and then subsequently use it.

As you can imagine, this was a decent amount of legwork for app developers to handle, and expecting a third-party app developer to interrupt the user and present the carrier’s purchase flow isn’t great UX either.

Android 17 introduces auto-routing on 5G network slices

Android 17 makes 5G network slicing more easily accessible to app developers and, consequently, to users. It introduces support for auto-routing of OTT voice and video calls over premium network connections. As Google mentions, this feature lets the system automatically steer traffic from voice and video calls to a dedicated premium 5G slice without requiring changes to the app’s networking stack.

The Android system uses existing Telecom Jetpack APIs used by OTT apps to detect the start and end of voice or video calls. During the call, the OS identifies the app by its UID and automatically routes its traffic to the premium network connection if one is available. When the call ends, the OS removes the routing rule, and the app’s traffic returns to the system default network for non-calling traffic (such as messaging).

Essentially, this platform-level solution eliminates the need for app developers to explicitly request and build network slicing capabilities or offer upsells, providing a seamless experience for both app developers (as long as they use the Telecom Jetpack API) and end users.

As a second-order effect, this also improves monetization opportunities for carriers, potentially driving the popularity of network slices and creating a positive feedback loop.

For Pixel owners on a supported network with a compatible mobile plan that offers these premium network slices, Android 17’s call-routing feature will kick in seamlessly behind the scenes. When they enter a highly congested area, like a concert ground or a stadium, their standard data might slow down, but their VoIP call can potentially remain stable and jitter-free because it is isolated in its own premium fast lane.

Once Android 17 rolls out to more devices, we hope to see carriers capitalize on these new capabilities, as it gives them another networking feature to upsell.