TBF = group of PDCHs allocated to one user for one transfer in one direction. In normal situation, a user needs to transfer data in downlink and uplink at the same time (useful data in dl, “clicks” and ack in uplink) –> one user usually gets 1 UL TBF and 1 DL TBF.
The TBF is released a bit after the transfer is finished. One transfer, for example, is one webpage, or one MMS, or one file.
PDCH = one physical timeslot, configured for packet transfer
1 TBF = 1 user = n consecutive PDCHs
1 PDCH can be shared by several TBF at the same time.
1 TBF = n consecutive PDCHs, but those PDCHs may or may not be only allocated to this TBF only.
Utilization of FRL = volume of LLC frames transmitted or received.