Understanding how 5G QoS requirements are met in the RAN code

[hpate063]

Hi,

I am wondering about how the QoS requirements are fulfilled when multiple flows with different 5QI values are served by RAN.

My understanding is that scheduling by common MAC scheduler and Logical Channel Prioritization by per UE MAC entity will ensure Guaranteed Flow Bit Rate (GFBR) for higher QoS priority flows first before serving lower QoS priority flows.

The default/only scheduling policy at MAC is "Round Robin" and I am unable to find any code which would prioritize the high QoS flows / DRBs over lower priority flows.

Can someone explain how this is achieved?

[jjose001]

I am having the same doubts, which in turn triggers various problems in enabling this functionality through srsUE + zmq interfaces + srsGNB + open5gs.
Have any news?

[hpate063]

No.

I am still working on something theoretical and trying to understand if and how the code achieves it.
I might start working on the actual setup in a month or so.

Hoping someone can clarify at least what is the supported functionality.

[jjose001]

Hi @hpate063, Thank you for your answer.
Let's wait for the changes and see how to actually implement this functionality, which a priori does not seem to work very well with the UE emulator (srsUE).

[frankist]

Hey, I will answer your question in 1 or 2 weeks, as there will be significant changes to the scheduler, in terms of QoS, that will be pushed to the main branch soon.

[jjose001]

Hi @frankist
Great, we will wait for your response.
When using srsUE as an emulator (from srsRAN_4G) does this support QoS management through PCC rules or not?

[jjose001]

Hi @frankist,

Any news?
Thank you!

[frankist]

Hi @jjose001,

So, we finally released new features related with QoS in the scheduler.

Now, the proportional fair scheduler was renamed to QoS scheduler. Its priority weight function is a combination of several subweights, namely the proportional fair weight, the GBR bearer weight, bearer priority and the delay budget delay. You can enable/disable any of these subweights individually via the config file. You can also configure them independently for each RAN slice.

Have a look and let me know if you have more questions.

[jjose001]

Hi @frankist,

Thank you for your reply, I was looking in the code and the new release is the Commit a041e31, right?
I'm going to download this new version and test the functionality, if I have any questions I'll let you know.
Thanks for the help