Jun 182009
UE can read System Information from BCCH mapped on BCH in IDLE, CELL_FACH, CELL_PCH and URA_PCH state.
When the System Information gets changed MIB value tag is updated and Paging message is transmitted indicating that System Information has changed. Then, the UE’s in IDLE, CELL_PCH and URA_PCH will be able to read the updated System Information.
In CELL_FACH state, the change of system information is notified through FACH channel by means of System Information Change Indication message.
This is why BCCH is mapped into FACH channel.
In Cell_PCH and URA_PCH, a paging type I message in a PCH channel will notify UEs.
Then, what about CELL_DCH? No system information change indication ?
