LTE: System Information Block Type 2

Direction: E-UTRAN => UE
Signalling Radio Bearer: N/A
RLC Mode: TM
Logical Channel: BCCH
Transport Channel: DL-SCH

SystemInformationBlockType2 (SIB2) contains radio resource configuration information that is common for all UEs. It contains access barring information, radio resource configuration of common and shared channels, timers and constants which are used by UEs, uplink power control information etc.

SIB2 is not specifically included in the scheduling information in SIB1 but it is always mapped to the SI message that corresponds to the first entry in the list of SI messages in schedulingInfoList in SIB1

SIB2 also gives information about the uplink carrier frequency and the uplink channel bandwidth in terms of number of Resource Blocks

Some of the IEs in SystemInformationBlockType2:

UL-CarrierFreq: If this IE is absent (for FDD), the UL-Carrier Frequency value should be determined from the default TX-RX frequency separation defined in TS 36.101 [Table 5.7.3-1]. For TDD, this parameter is absent and it is equal to the downlink frequency

UL-Bandwidth: Transmission bandwidth configuration, N_RB, in uplink. The value n₆ corresponds to 6 resource blocks, n₁₅ to 15 resource blocks and so on. If this parameter is absent for FDD then the uplink bandwidth is equal to the downlink bandwidth. For TDD this parameter is absent and it is equal to the downlink bandwidth

defaultPagingCycle: Default paging cycle value rf32 corresponds to 32 radio frames, rf64 corresponds to 64 radio frames and so on

modificationPeriodCoeff: Actual modification period, expressed in number of radio frames= modificationPeriodCoeff * defaultPagingCycle.The value n2 corresponds to value 2, n4 corresponds to value 4, and so on

p-Max: Maximum power to be used in the target cell. If this IE is absent then the UE applies the maximum power according to the UE capability

UL-CyclicPrefixLength: The value len1 corresponds to normal cyclic prefix and len2 corresponds to extended cyclic prefix

RadioResourceConfigCommonSIB: The IE RadioResourceConfigCommonSIB is used to specify common radio resource configurations e.g., the random access parameters and the static physical layer parameters

Reference: 3GPP TS 36.331

Example: SystemInformationBlockType2 message