RRC
As in physical layers, in RRC there has been drastical changes for LTE-NB introducing a lot of new RRC messages and IE (Information Elements) dedicated for LTE-NB. Understandably some of the functions of normal LTE function are not supported in LTE-NB.
< RRC Functions Not in LTE-NB >
Followings are the functionality that are supported in normal LTE but not supported in LTE-NB. These are based on 36.331 4.4 Functions.
- ETWS Notification, CMAS Notification
- InterRAT Mobility including e.g security activation transfer of RRC context information
- Measurement Configuration and Reporting
- Self-configuration and Self-optimization
- Measurement logging and reporting for network performance optimization
< LTE-NB RRC Messages at High Level >
Following is the high level RRC messages defined for NB-IoT. Just take a brief look at the overall message structure and refer to 36.331 6.7 NB-IoT RRC messages for the details.
BCCH-BCH-Message-NB ::= SEQUENCE {
message BCCH-BCH-MessageType-NB
}
BCCH-BCH-MessageType-NB::= MasterInformationBlock-NB
BCCH-DL-SCH-Message-NB ::= SEQUENCE {
message BCCH-DL-SCH-MessageType-NB
}
BCCH-DL-SCH-MessageType-NB ::= CHOICE {
c1 CHOICE {
systemInformation-r13 SystemInformation-NB,
systemInformationBlockType1-r13 SystemInformationBlockType1-NB
},
messageClassExtension SEQUENCE {}
}
PCCH-Message-NB ::= SEQUENCE {
message PCCH-MessageType-NB
}
PCCH-MessageType-NB ::= CHOICE {
c1 CHOICE {
paging-r13 Paging-NB
},
messageClassExtension SEQUENCE {}
}
DL-CCCH-Message-NB ::= SEQUENCE {
message DL-CCCH-MessageType-NB
}
DL-CCCH-MessageType-NB ::= CHOICE {
c1 CHOICE {
rrcConnectionReestablishment-r13 RRCConnectionReestablishment-NB,
rrcConnectionReestablishmentReject-r13 RRCConnectionReestablishmentReject,
rrcConnectionReject-r13 RRCConnectionReject-NB,
rrcConnectionSetup-r13 RRCConnectionSetup-NB,
spare4 NULL, spare3 NULL, spare2 NULL, spare1 NULL
},
messageClassExtension SEQUENCE {}
}
DL-DCCH-Message-NB ::= SEQUENCE {
message DL-DCCH-MessageType-NB
}
DL-DCCH-MessageType-NB ::= CHOICE {
c1 CHOICE {
dlInformationTransfer-r13 DLInformationTransfer-NB,
rrcConnectionReconfiguration-r13 RRCConnectionReconfiguration-NB,
rrcConnectionRelease-r13 RRCConnectionRelease-NB,
securityModeCommand-r13 SecurityModeCommand,
ueCapabilityEnquiry-r13 UECapabilityEnquiry-NB,
rrcConnectionResume-r13 RRCConnectionResume-NB,
spare2 NULL, spare1 NULL
},
messageClassExtension SEQUENCE {}
}
UL-CCCH-Message-NB ::= SEQUENCE {
message UL-CCCH-MessageType-NB
}
UL-CCCH-MessageType-NB ::= CHOICE {
c1 CHOICE {
rrcConnectionReestablishmentRequest-r13 RRCConnectionReestablishmentRequest-NB,
rrcConnectionRequest-r13 RRCConnectionRequest-NB,
rrcConnectionResumeRequest-r13 RRCConnectionResumeRequest-NB,
spare1 NULL
},
messageClassExtension SEQUENCE {}
}
UL-DCCH-Message-NB ::= SEQUENCE {
message UL-DCCH-MessageType-NB
}
UL-DCCH-MessageType-NB ::= CHOICE {
c1 CHOICE {
rrcConnectionReconfigurationComplete-r13 RRCConnectionReconfigurationComplete-NB,
rrcConnectionReestablishmentComplete-r13 RRCConnectionReestablishmentComplete-NB,
rrcConnectionSetupComplete-r13 RRCConnectionSetupComplete-NB,
securityModeComplete-r13 SecurityModeComplete,
securityModeFailure-r13 SecurityModeFailure,
ueCapabilityInformation-r13 UECapabilityInformation-NB,
ulInformationTransfer-r13 ULInformationTransfer-NB,
rrcConnectionResumeComplete-r13 RRCConnectionResumeComplete-NB,
spare8 NULL, spare7 NULL,
spare6 NULL, spare5 NULL, spare4 NULL,
spare3 NULL, spare2 NULL, spare1 NULL
},
messageClassExtension SEQUENCE {}
}