what are all possible information can be transfered in CCCH?

Question

When we talk about CDR (charging data record) in LTE or any other technology, following questions come in my mind.
- Is CDR generated per UE ? or Is per session per UE or generated for group of UEs ?
- What information is captured in CDR ? Does 3GPP define any standard format and IEs that need to be captured or is it completely operator dependent ?

Answer 1

CCCH is a common control channel through which UE messages are exchanged in downlink and uplink direction. This channel is used for UE signalling message exchange before establishment of dedicated channel (DCCH) for each UE.
Messages exchanged over this channel is categorized into two groups as following:

DL-CCCH messages : List of messages from eNodeB to UE
- RRC Connection Reject
- RRC Connection Setup
- RRC Re-establishment Reject
- RRC Connection Re-establishment

UL-CCCH messages: List of messages from UE to eNodeB
- RRC Connection Request
- RRC Connection Re-establishment Request

Answer 2

It can be RRC connection setup or re establishment message,