Is there any scheme for eNodeB to inform UEs to change their UL bit-rate?

Question

Is there any scheme for eNB to inform UEs to change their UL bit-rate? Or is it entirely dependent on the bandwidth/PRBs allocated??

Answer 1

UL bit rate is controled by allocated PRBs and MCS. However, per logical channel, eNodeB can control using PBR and BSD.

Please go through the 3GPP 36.321 and check BSR part, eNB can prioritize logical channel by put LCs in different LCG , and UE report BSR based on LCG. e.g if UE start a new app with dedicated bearer , let's say QCI4 with has LCG 2 , eNB will satisfy QCI4 bandwidth request first since the default bearer with QCI9 normally assign to LCG3.

Answer 2

Each time, when an UE wants to send some amount of data in the uplink direction direction, it sends a resource grant request by using PUSCH or PUCCH channel. UE side's stack takes care of bearer requirements or parameter and based on that only, UE makes a request for radio resources. Similar bearers are also established at the eNodeB side and eNodeB always try to give what it has promised with UE.

Now comes to your question, UE should not make a request of radio resources which is cumulative more than what it can suppose to ask from eNodeB. EnodeB can grant less than what UE has asked for a particular TTI .
Please correct me if I am wrong.