I was trying to understand and implement basic version of 29.213 Section 6.3 QoS parameter mapping Functions at PCRF especially for non GBR bearers.
Non GBR bearers have QCI, ARP, APN-AMBR and UE-AMBR. And also MBR associated with each bearer in the PGW..So when a new bearer is added, the UE and Ennode-b dynamically take care that total rate of all bearers doesnot exceed APN-AMBR (for each APN) and UE-AMBR for all Non GBR bearers in UE..
So not sure PCRF can alter any params related to BW in case of non GBR.. This is my understanding..If you have any comments will be very helpful.