UL UE AMBR enforcement in LTE

Question

I understand the eNB enforces UE-AMBR(both UL and DL). I understand the DL rate can be measured by n/w side and enforced at n/w side.
Whatabout the UL data rate ? How do we tell UE , "not to exceed the UL rate".

Could some QOS experts help please ?

Answer 1

It is the job of eNodeB to achieve data rate enforcement for uplink and downlink both. To send every uplink data, UE asks for radio resources (PUSCH) from eNodeB MAC. eNodeB MAC knows the current uplink throughput of each bearer in GBR case and AMBR in non-GBR rate. Current ongoing rate is also an important parameter to take the decision onuplink resource grant at eNodeB MAC.

Comments

Thankyou very much Vimal. That answers my question. But now another doubt :)

How the maximum UE-AMBR for UL is enforced at eNB.
Can eNB divide the total with the number of non GBR bearers and send that info to MAC for each DRB ?
So MAC inturn enforces that for each DRB corresponding to UE (so MAC doesnot allocate resources for that DRB accordingly), so total doesnot exceed the UE-AMBR ?

My Q is how UE-AMBR is divided between the MeNB and SeNB.
Lets say total UE-AMBR=400kbps. MeNB has 4 non GBR bearers for this UE. And during the SeNB Addition, two get shifted to SeNB. So can we consider that each non GBR is  400kbps. Hence SeNB UE-AMBR is 200kbps ?

i havent worked much on radio side of LTE, so could some LTE radio people help me with this please ?