Clarification on Downlink Bitrate Estimation in srsENB Scheduler

[Wellingtonwang]

Hello srsRAN Team,

I hope you're doing well. I've been exploring the srsRAN codebase, specifically looking into the UE scheduling mechanisms within srsenb. My attention was particularly drawn to the implementation of the get_expected_dl_bitrate function in sched_time_pf.cc.

From what I understand, the function name suggests that it's designed to estimate the expected downlink bitrate. However, upon reviewing the internal workings, I noticed that the count_prb_per_tb_approx function called during the nof_re calculation seems to invariably return cc.cell_cfg->nof_prb(). This has led me to wonder if the function actually performs as its name indicates – estimating the downlink bitrate.

Could you please confirm if my observation is accurate? If there's a different mechanism at play, could you kindly elucidate how get_expected_dl_bitrate truly operates?

I am eager to understand the intricacies of the scheduling strategy better and would appreciate any insights you can provide.

Thank you for your time and the incredible work you're doing with srsRAN!