Multi Frequency Band Indicator

MFBI indicates the support of multiple bands in one radio frequency cell
A cell is broacasting on a frequency that may belong to several overlapping bands of one technology
Some LTE overlapping bands : 2 / 25 or 4 / 66 or 5 / 26 or 12 / 17 or TDD 38 / 41; list available for LTE bands (Band overlap) or UMTS bands

For instance :
MFBI


eNb System Information Type 1

The serving cell broadcasts in SIB 1 the list of overlapping bands supported, in SIB 5 for the neighbor cells
MFBI may also be applied to UMTS bands in SIB 6

    SystemInformationBlockType1
      freqBandIndicator = 25
      SystemInformationBlockType1-v8h0-IEs
        multiBandInfoList
        freqBandIndicator = 2
        SystemInformationBlockType1-v1250-IEs
          freqBandIndicatorPriority-r12 = True
    

UE Capability Information

The UE indicates the support of MFBI in the FGI bit 31
The UE can connect to the cell using the arfcn of any of the bands supported by the UE and listed in SIB1

    UE-EUTRA-Capability
      featureGroupIndicators '11111111 00001101 11001000 100000 1 0'
      freqBandPriorityAdjustment-r12 supported
    

Cell System Info UE Capabilities
Band 2 Band 25 Band 2
FGI MFBI
Band 25
FGI MFBI
Band 2 + 25
FGI MFBI
Band 2 B2 - B2 - B2
Band 2
+ MFBI B25
B2 - B2 B25 B2
Band 2
+ MFBI B25
+ FBI Priority
B2 - B2 B25 B25
Band 25 - B25 - B25 B25
Band 25
+ MFBI B2
- B25 B2 B25 B25
Band 25
+ MFBI B2
+ FBI Priority
- B25 B2 B25 B2

RRC downlink, the eNb will calculate the arfcn of the RRC signalling according to the band(s) supported by the UE
RRC uplink, the eNb accepts any of UE uplink arfcn
An example of earfcn range for B2 / B25 for the PCS band