SIB4 in LTE

SIB4: Cell-reselection parameters for Neighbouring INTRA-Frequency

• contains neighbouring cell related information relevant only for intra-frequency cell re-selection
• includes cells with specific re-selection parameters as well as blacklisted cells
• All the contents of SIB4 are optional because UE's can automatically detect and complete neighbour INTRA_frequency cells

Signalling radio bearer: N/A
RLC-Mode: TM
Logical channel: BCCH
Direction: E‑UTRAN to UE

Important contents of SystemInformationBlockType4
intraFreqNeighCellList
      physCellId
      q-OffsetCell
intraFreqBlackCellList
     physCellId Range
Cellcsg_PhysCellId
     physCellId Range

Field Descriptions:

intraFreqNeighCellList [1-16 instances]	List of intra-frequency neighbouring cells with specific cell re-selection parameters
IntraFreqNeighCellInfo
physCellId	Physical CellID of the neighbour cell
q-OffsetCell	specifies the offset between the two cells. Value -24 - +24dB
intraFreqBlackCellList [1-16 instances]	List of blacklisted intra-frequency neighbouring cells. These type of cells are not considered for cell re-selection
csg_PhysCellIdRange	Set of physical cell identities reserved for CSG cells on the frequency on which this field was received. The received csg-PhysCellIdRange applies if less than 24 hours has elapsed since it was received and it was received in the same primary PLMN. This field is Optional (mandatory for CSG cell)