Is it necessary to do RAC (Radio admission control for non-GBR bearer(s)) at eNodeB ?

Question

Radio Resource Manager is one of the main component of an eNodeB. I want to know, Is there any specification which mentions the detail of messages ? If RRM is vendor specific then it means an eNodeB from a vendor "A" would not be inter-operable with RRM of vendor "B". Is my understanding correct in terms of vendor specific RRM implementation ?

Answer 1

Before Radio admission control for a non-GBR bearer, EPC first validate that either a user has already crossed max limit of 8 bearers or not. So there is no need to validate # of bearer at eNodeB app/RRM. Now question is that when there is no guarantee to provide a particular bit rate for a non-GBR bearer then why Radio admission control is in question for a non-GBR bearer. eNodeB App/RRM may perform Radio admission control since there is term "AMBR". if a user is already reaching AMBR with a already established non-GBR bearer then in that case eNodeB will send failure response to MME.

if someone who has worked on RRM module, can bring out more points here.