Understanding the TB size determination in scheduler

[Sangwon Seo]

Hi,

I have a difficulty to understand the TB size determination in scheduler. I am studying DL schedulers. In the implementation, there is UePtrAndBufferReq object that has mapping information between UE and its RLC buffer status in DL. However, I have a question how TB size is actually decided...

This is because if TDD frame is set to 7 Downlink and 3 uplink, there is difference of TB size among UEs with RR scheduling.

For example, the TB size of some UE are 350 and others are 291 after 3 uplink has been finished (while the first DL slot). My expectation was there are same TB size allocation among all UEs. (I fixed channel state and link adaptation is fixed as 20.)

Could you let me know how TB size for each UE is determined in one slot and which class should I analyze it?

Best regards,

Sangwon

[Biljana B.]

Hi Sangwon,

please look at the function that determines the TB size: CalculateTbSize in NrAmc, when you run the simulation enable NrAmc logs to understand the differences when this function is called for these users that you are comparing. Check in the ns-3 manual how to enable specific logs. Hope this helps.

Kind regards,

Biljana