After initial synchronization of UE with the network, it starts to receive information blocks where the first and most essential one is Master Information Block. It carries less, but important information to UE from the network. MIB (Master Information Block) is transmitted through BCCH –> BCH –> PBCH channels and PBCH occupies 6 PRB in OFDMA system where MIB can use these channels for transmission.
Used symbols by MIB in OFDMA, first “4 symbols” of the second time-slot of first sub-frame.
MIB is always sent in sub-frame #0 of the Radio-Frame, and continues re-transmitting the same message in each 10 ms with different redundancy versions. Each 40ms a new MIB is transmitted.
Carried information by MIB:
Downlink Channel Bandwidth:
• Number of PRB: 6, 15, 25, 50, 75, 100.
PHICH configuration:
• PHICH Duration: ‘normal’ or ‘extended’
• PHICH Resource: can be 1/6, 1/2, 1, 2.
System Frame Number: eNodeB transmits SFN value through PBCH and UE can synchronize its SFN number from this value.