Making use of 5G network slicing

[youennf]

5G network slicing is being deployed for various services and could be of use for WebRTC connections. One question is whether 5G network slicing should be a decision made by the User Agent or whether it would be good for the web application to enable/disable it.

API wise, if one is needed, a simple approach would be a boolean in RTCConfiguration, something like:

partial dictionary RTCConfiguration {
    boolean disableNetworkSlicing = false;
}

[youennf]

The same issue could also be discussed for WebTransport as well.

[alvestrand]

Wouldn't the API have to say how the app makes use of 5G network slicing? What API does the network offer?

[youennf]

I was thinking about 5G network slicing to improve latency, given the scope is RTC.

[steely-glint]

I'm not convinced this is necessary - don't the Camara APIs cover this ? (https://camaraproject.org/qos-profiles/ ) Or are there situations where : a) camara won't be available b) network slices will be available c) they will be within the control of the phone/endpoint (rather than the network core)?

We found that the uplink/downlink ratio was a more interesting metric than latency for WebRTC over 5g slices.

Are you thinking of a specific private 5g deployment/use-case ?

[alvestrand]

I'm not familiar with Camara - if I read it right, it's specified in terms of HTTP operations (POST/GET). In that case, the "use 5G network slicing" spec would have to say how a WebRTC JS API implementation causes events to happen on the Camara API. Lots of text to be written....

[youennf]

Agreed that 5G slices can improve both latency and bandwidth.

FWIW, the potential use cases for an API I heard of:

• A web application that does not care about high performance (maybe only interested by peer-to-peer data channels) and might prefer the UA to optimise for power consumption for instance.
• A/B testing If we expose something, it would only be a hint really.

Looking at how this could be done in WebTransport, if https://w3c.github.io/webtransport/#enumdef-webtransportcongestioncontrol is set to either low-latency or throughput, it would make sense for the UA to try to use 5G network slicing.

[lgrahl]

Apologies if this is a dumb question, but what kind of standard or API does that refer to? How does one use 5G network slicing?

[dontcallmedom-bot]

This issue had an associated resolution in WebRTC October 2025 meeting – 21 October 2025 (WebRTC-extensions 5G network slicing):

RESOLUTION: Craft a PR to webrtc-extensions to reflect discussion