ABSTRACT
Signalling Radio Bearers are the Radio Bearers that are used by User Equipment (UE) for transmitting and receiving Radio Resource Control (RRC) messages with the eNodeB. Cell Selection refers to the procedure the UE performs when selecting a cell for the first time. Cell Reselection is different from cell selection as the latter is done during the first time or after the UE is powered on so that the UE can camp on a serving cell. RRC has two states: either IDLE state or CONNECTED. After the RRC constructs or receives a message exchanged with eNodeB, it either encodes or decodes it, respectively, using ASN.1 PER format. RRC Protocol Data Unit is exchanged with Packet Data Convergence Protocol sublayer if security is activated. It uses Packed Encoding Rule, which is a compact form of converting the message from human-readable format to binary format.
