通信之路学习汇总 =>>UE 接入和释放

UE ATTACH

Msg Name	Entities	Comment
S1 SETUP REQUEST	eNB->NW	S1AP setup
S1 SETUP RESPONSE	NW -> eNB
MIB, SIB1, SIBX	eNB-> UEs	Broadcast Info
MSG1	UE->eNB	Preamble
MSG2	eNB->UE	With RA-RNTI
MSG3	UE->eNB	TM data (RRC Conn Request)
DL data	eNB-> UE	Copied from MSG3 48b
RRC Connection Setup	eNB->UE	TM data CCCH
RRC Connection Setup Complete	UE->eNB	AM data (include NAS Attach Request)
S1AP: NAS INITIAL UE MESSAGE	eNB->NW	Pass the NAS info to MME
S1AP: INITIAL CONTEXT SETUP REQUEST	NW->eNB	Include E-RAB, UE Radio Capability IE and etc. Attach Accept
RRC: UECapabilityEnquiry	eNB-> UE	AM: Enquiry RA capability for specific RAT (E-UTRA)
RRC: UECapabilityInformation	UE->eNB	AM: known by RAT only
S1: UE CAPABILITY INFO INDICATION	eNB->MME	Forward UE’s Capability Info
RRC:SecurityModeCommand	eNB->UE	Set securityConfigSMC
RRC: SecurityModeComplete	UE->eNB	To confirm the security setting
RRC: Connection Reconfiguration	eNB->UE	NAS pdu from initial context setup request to Establish DRB
RRC Connection Reconfiguration Complete	UE-> eNB	To confirm the Connection Reconfiguration
S1AP: Initial context setup response	eNB-> NW	E-RAB Setup & failed setup list
RRC: ULInformationTransfer	UE->eNB	NAS or non-3GPP info (Attach complete)
S1 AP: UL NAS TRANSPORT	eNB->MME	Forward UL Info Transfer

UE DETACH

UE initiate UE release

Msg Name	Entities	Comment
UL Information Transfer	UE->eNB	NAS Detach Request
UL NAS Transport	eNB->MME	NAS forwarding
DL NAS Transport	MME->eNB	NAS forwarding
DL Information Transfer	eNB->UE	NAS Detach Related
…
UE context release command	MME->eNB	UE S1AP ID pair or MME UE S1AP ID
RRC Connection Release	eNB->UE	To release UE with releaseCause
UE context release complete	eNB->MME	Confirm UE release

eNodeb initiated UE release（UE inactivity，UE lost）

Msg Name	Entities	Comment
UE context release request	eNB->MME	due to E-UTRAN generated reason, e.g. "User Inactivity", "Radio Connection With UE Lost"
UE context release command	MME->eNB	UE S1AP ID pair or MME UE S1AP ID
UE context release complete	eNB->MME	Confirm UE release

Note: UE ContextRelease procedure should be initiated upon reception of an UE CONTEXT RELEASEREQUEST message when the cause is different than "User Inactivity"

eNodeb initiated UE release（other cause）

Msg Name	Entities	Comment
UE context release request	eNB->MME	due to E-UTRAN generated reason, e.g. "User Inactivity", "Radio Connection With UE Lost"
DL NAS Transport	MME->eNB	NAS forwarding
DL Information Transfer	eNB->UE	NAS Detach Related
UL Information Transfer	UE->eNB	NAS Detach Request
UL NAS Transport	eNB->MME	NAS forwarding
…
UE context release command	MME->eNB	UE S1AP ID pair or MME UE S1AP ID
RRC Connection Release	eNB->UE	To release UE with releaseCause
UE context release complete	eNB->MME	Confirm UE releas

MME initiate UE release（UE context release procedure）

Msg Name	Entities	Comment
DL NAS Transport	MME->eNB	NAS forwarding
DL Information Transfer	eNB->UE	NAS Detach Related
UL Information Transfer	UE->eNB	NAS Detach Request
UL NAS Transport	eNB->MME	NAS forwarding
…
UE context release command	MME->eNB	UE S1AP ID pair or MME UE S1AP ID
RRC Connection Release	eNB->UE	To release UE with releaseCause
UE context release complete	eNB->MME	Confirm UE release

eNodeb initiated UE release （Reset, MME keep UE context）

Msg Name	Entities	Comment
RRC Connection Release	eNB->UE	To release UE with releaseCause

注：在LTE里面，SRB有三个，SRB0对应的是CCCH，在信令建立过程中不需要建立，对SRB1，SRB2，会在RRCconnectionsetup和RRCReconfig消息里面进行配置
rrcConnectionReqest是在SRB0上传输的，SRB0一直存在， 用来传输映射到CCCH 的RRC信令。
UE收到NodeB的rrcConnectionSetup信令后，UE和NodeB之间的SRB1就建立起来了。
eNodeB向UE发送RRCConnectionReconfiguration消息，建立SRB2和DRB