翻了下36.331 5.2.2.6节
Upon receiving the MasterInformationBlock message the UE shall:
1> apply the radio resource configuration included in the phich-Config;
1>if the UE is in RRC_IDLE or if the UE is in RRC_CONNECTED while T311 is running:
2> if the UE has no valid system information stored according to 5.2.2.3 for the concerned cell:
3> apply the received value of dl-Bandwidth to the ul-Bandwidth until SystemInformationBlockType2 is received;
楼主是问这里存在的问题吗？
原因其实很简单，sib2中含有freqInfo IE：
freqInfo SEQUENCE {
ul-CarrierFreq ARFCN-ValueEUTRA OPTIONAL, -- Need OP
ul-Bandwidth ENUMERATED {n6, n15, n25, n50, n75, n100}
OPTIONAL, -- Need OP
additionalSpectrumEmission AdditionalSpectrumEmission
},
而且在331的IE注释里写的比较清楚：
ul-Bandwidth
Parameter: transmission bandwidth configuration, NRB, in uplink, see TS 36.101 [42, table 5.6-1]. Value n6 corresponds to 6 resource blocks, n15 to 15 resource blocks and so on. If for FDD this parameter is absent, the uplink bandwidth is equal to the downlink bandwidth. For TDD this parameter is absent and it is equal to the downlink bandwidth.