LTE空口信令流程详解
1、附着信令流程
1.1 、Attach附着信令流程
（统计时延：红色的为开始和结束信令）
EPS MM EPS MM UL CCCH DL CCCH UL DCCH DL DCCH DL DCCH UL DCCH EPS MM EPS MM EPS MM EPS MM UL DCCH DL DCCH EPS MM EPS MM EPS MM EPS MM UL DCCH DL DCCH UL DCCH DL DCCH DL DCCH UL DCCH EPS MM EPS MM EPS SM EPS SM EPS MM EPS MM UL DCCH DL DCCH UL DCCH
Attach request Unknown(0x0734)
rrcConnectionRequest rrcConnectionSetup
rrcConnectionSetupComplete rrcConnectionReconfiguration dlInformationTransfer
rrcConnectionReconfigurationComplete Security protected NAS message Authentication request Authentication response Unknown(0x077B)
ulInformationTransfer dlInformationTransfer
Security protected NAS message Security mode command Security mode complete Unknown(0x0790)
ulInformationTransfer ueCapabilityEnquiry ueCapabilityInformation securityModeCommand
rrcConnectionReconfiguration
rrcConnectionReconfigurationComplete Security protected NAS message Attach accept
Activate default EPS bearer context request Activate default EPS bearer context accept Attach complete Unknown(0x072D)
ulInformationTransfer
rrcConnectionReconfiguration
rrcConnectionReconfigurationComplete
1.2、Detach去附着信令流程
（统计时延：红色的为开始和结束信令）
EPS MM EPS MM UL DCCH DL DCCH EPS MM EPS MM DL DCCH EPS SM Detach request Unknown(0x0734)
ulInformationTransfer dlInformationTransfer
Security protected NAS message Detach accept
rrcConnectionRelease PDN connectivity request
1.3、前台测试中Detach& Attach信令流程
2、呼叫业务信令流程
2.1、UE主叫信令流程
（统计时延：红色的为开始和结束信令）
EPS MM UL CCCH DL CCCH UL DCCH DL DCCH Extended service request rrcConnectionRequest rrcConnectionSetup
rrcConnectionSetupComplete rrcConnectionReconfiguration
UL DCCH DL DCCH DL DCCH UL DCCH DL DCCH UL DCCH rrcConnectionReconfigurationComplete securityModeCommand
rrcConnectionReconfiguration
rrcConnectionReconfigurationComplete rrcConnectionReconfiguration
rrcConnectionReconfigurationComplete
2.2、UE被叫信令流程
（统计时延：红色的为开始和结束信令）
DL PCCH EPS MM UL CCCH DL CCCH UL DCCH DL DCCH UL DCCH DL DCCH DL DCCH UL DCCH DL DCCH UL DCCH
Paging
Extended service request rrcConnectionRequest rrcConnectionSetup
rrcConnectionSetupComplete rrcConnectionReconfiguration
rrcConnectionReconfigurationComplete securityModeCommand
rrcConnectionReconfiguration
rrcConnectionReconfigurationComplete rrcConnectionReconfiguration
rrcConnectionReconfigurationComplete
2.3、前台测试中UE主叫、切换L3信令流程