RRC:Radio Resource Control,无线资源控制。
S-TMSI:临时移动用户标识,由MMEC和M-TMSI组成,在一个MME内唯一标识一个UE。由核心网配置。
MMEGI:MME Group ID
RRC连接建立涉及的定时器:T300、T302、T303、T305
(1)建立SRB1
(2)发送NAS消息
(1)触发条件:
(2)准备工作:判断UE是否可以接入小区。
(3)发送内容:
(4)eNodeB处理:
eNodeB根据接纳控制来决定是否允许UE接入E-UTRAN。
若允许,发送RRC Connection Setup;否则,发送RRC Connection Reject。
(5)IE:
RRCConnectionRequest ::= SEQUENCE {
criticalExtensions CHOICE {
rrcConnectionRequest-r8 RRCConnectionRequest-r8-IEs,
rrcConnectionRequest-r15 RRCConnectionRequest-5GC-r15-IEs
}
}
RRCConnectionRequest-r8-IEs ::= SEQUENCE {
ue-Identity InitialUE-Identity,
establishmentCause EstablishmentCause,
spare BIT STRING (SIZE (1))
}
RRCConnectionRequest-5GC-r15-IEs ::= SEQUENCE {
ue-Identity InitialUE-Identity-5GC,
establishmentCause EstablishmentCause-5GC,
spare BIT STRING (SIZE (1))
}
InitialUE-Identity ::= CHOICE {
s-TMSI S-TMSI,
randomValue BIT STRING (SIZE (40))
}
InitialUE-Identity-5GC ::= CHOICE {
ng-5G-S-TMSI-Part1 BIT STRING (SIZE (40)),
randomValue BIT STRING (SIZE (40))
}
EstablishmentCause ::= ENUMERATED {
emergency, highPriorityAccess, mt-Access, mo-Signalling,
mo-Data, delayTolerantAccess-v1020, mo-VoiceCall-v1280, spare1}
EstablishmentCause-5GC ::= ENUMERATED {
emergency, highPriorityAccess, mt-Access, mo-Signalling,
mo-Data, mo-VoiceCall, spare2, spare1}
(1)触发条件:eNodeB收到来自UE的RRC Connection Request。
(2)发送内容:
(3)UE处理:
(4)IE:
RRCConnectionSetup ::= SEQUENCE {
rrc-TransactionIdentifier RRC-TransactionIdentifier,
criticalExtensions CHOICE {
c1 CHOICE {
rrcConnectionSetup-r8 RRCConnectionSetup-r8-IEs,
spare7 NULL,
spare6 NULL, spare5 NULL, spare4 NULL,
spare3 NULL, spare2 NULL, spare1 NULL
},
criticalExtensionsFuture SEQUENCE {}
}
}
RRCConnectionSetup-r8-IEs ::= SEQUENCE {
radioResourceConfigDedicated RadioResourceConfigDedicated,
nonCriticalExtension RRCConnectionSetup-v8a0-IEs OPTIONAL
}
RRCConnectionSetup-v8a0-IEs ::= SEQUENCE {
lateNonCriticalExtension OCTET STRING OPTIONAL,
nonCriticalExtension SEQUENCE {} OPTIONAL
}
(1)触发条件:UE完成SRB1配置后,向eNodeB发送RRC Connection Setup Complete。
(2)发送内容:
(3)IE:
RRCConnectionSetupComplete ::= SEQUENCE {
rrc-TransactionIdentifier RRC-TransactionIdentifier,
criticalExtensions CHOICE {
c1 CHOICE{
rrcConnectionSetupComplete-r8 RRCConnectionSetupComplete-r8-IEs,
spare3 NULL, spare2 NULL, spare1 NULL
},
criticalExtensionsFuture SEQUENCE {}
}
}
RRCConnectionSetupComplete-r8-IEs ::= SEQUENCE {
selectedPLMN-Identity INTEGER (1..maxPLMN-r11),
registeredMME RegisteredMME OPTIONAL,
dedicatedInfoNAS DedicatedInfoNAS,
nonCriticalExtension RRCConnectionSetupComplete-v8a0-IEs OPTIONAL
}
RegisteredMME ::= SEQUENCE {
plmn-Identity PLMN-Identity OPTIONAL,
mmegi BIT STRING (SIZE (16)),
mmec MMEC
}
(1)触发条件:eNodeB收到来自UE的RRC Connection Request,根据接纳控制算法,不允许UE接入。
(2)发送内容:wait time,定时器T302的时长。
(3)UE处理:
(4)IE:
RRCConnectionReject ::= SEQUENCE {
criticalExtensions CHOICE {
c1 CHOICE {
rrcConnectionReject-r8 RRCConnectionReject-r8-IEs,
spare3 NULL, spare2 NULL, spare1 NULL
},
criticalExtensionsFuture SEQUENCE {}
}
}
RRCConnectionReject-r8-IEs ::= SEQUENCE {
waitTime INTEGER (1..16),
nonCriticalExtension RRCConnectionReject-v8a0-IEs OPTIONAL
}