In the last chapter we saw about MIB. In this chapter we shall learn about SIB.
After initial cell synchronization and reading Master information block, UE will proceed to read system information blocks to obtain important cell access related parameters.
There are 13 SIB in 3GPP standard specification. Each SIB is used for specific type.
Below image shows different types of SIBs and their functions.
The above list defines the functionality of all the SIB’s.
There are additional SIBs that has been added in the Release 15. They are:
SIB 14 : Extended Access Barring
SIB 15/SIB 20 : MBMS
SIB 16 : GPS
SIB 17 : WLAN
SIB 18/SIB 19/SIB 21 : Sidelink
SIB 24 : NR Neighbour Cell
We require these many SIBs to maintain interoperability between other radio technology.
SIB 1 and SIB 2 are most important ones to know about.
We shall look at the details of SIB1 and SIB2 in the next chapter.
Now as we know about both SIB and MIB, we shall see what system information is required by UE when it is powered on.
The information required varies upon the RRC state of the UE.
For RRC Idle
UE requires:
MIB,
SIB 1
SIB 2
For RRC Connected
UE requires:
MIB,
SIB 1
SIB 2
SIB 8, if the UE needs CDMA support.