Call Flow CS

UMTS Bearer Services

Communication between the UE, RNC and circuit switched core network (CN) makes use ofUu interface protocol stackIub interface protocol stackIu-CS interface protocol stackA interface protocol stackProtocol stacks include both user and control planesThe control plane of one protocol stack may make use of the user plane of another protocol stack e.g. RRC messages which form the control plane of the radio interface protocol are communicated to and from the BTS using the user plane of the Iub protocol stackProtocol Stacks

CS Radio Interface Protocol (RIP) User PlaneRadio Interface Protocol is responsible for setting up, reconfiguring and releasing radio bearersThe 3G MSC provides connectivity to the circuit switched core and PSTNThe multimedia gateway provides transcoding forSpeech calls: between AMR and A Law PCMVideo calls: no transcoding is required i.e. vocoder appears only in the UETransparent mode RLC is used between the UE and RNCAAL2 based ATM is used to transfer user plane data across the Iub and Iu,cs interfaces

The user plane is responsible for encapsulating all data to and from the UEATM Adaptation Layer 5 (AAL5) is used for the control planes whereas AAL2 is used for the user planeIu-CS Protocol StackThe Iu-CS protocol stack has three planesThe radio network control plane uses the RANAP protocol and completes tasks such as configuring a RAB or assigning Iu-CS resourcesThe transport network control plane is responsible for setting up/tearing down Iu transport bearers

UERNCNodeBMGW/CNRRC: RRC Connection Request (RACH)NBAP: Radio Link Setup RequestNBAP: Radio Link Setup ResponseALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)RRC: RRC Connection Setup (FACH) [RRCconnRepTimer1/2(100ms,1s)]L1 SynchronizationNBAP: Synchronization IndicationRRC: RRC Connection Setup Complete (DCH)RRC: Initial Direct Transfer (MM: CM Service Request)SCCP: CR (Connection Request)RANAP: Initial UE Message (MM: CM Service Request)SCCP: CC (Connection Confirm)RANAP: Direct Transfer (MM: Authentication Request)RRC: Downlink Direct Transfer (MM: Authentication Request)RRC: Uplink Direct Transfer (MM: Authentication Response)RANAP: Direct Transfer (MM: Authentication Response)RANAP: Common IDRANAP: Security Mode CommandRRC: Security Mode CommandFP: Downlink SynchFP: Uplink SynchRRC Connection Establishment CELL DCH StateRNC checks if resources are available: BTS, AC, Transmission.If not it sends RRC Connection RejectT300=2s ; N300=3L1 SynchronizationT312=6s ; N312=4MOS CS Message Flow

UERNCNodeBMGW/CNRRC: Security Mode CompleteRANAP: Security Mode CompleteRRC: Uplink Direct Transfer (CC: Setup)RANAP: Direct Transfer (CC: Setup)RANAP: Direct Transfer (CC: Call Proceeding)RRC: Downlink Direct Transfer (CC: Call Proceeding)RANAP: RAB Assignment RequestNBAP: Radio Link Reconfiguration PrepareNBAP: Radio Link Reconfiguration ReadyALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)NBAP: Radio Link Reconfiguration Commit)RRC: Radio Bearer SetupRRC: Radio Bearer Setup CompleteRANAP: RAB Assignment ResponseALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)RAB EstablishmentFP: Downlink SynchFP: Uplink SynchRL modification procedure:SRB+DCH, HW resources checkedPossible failure in AAL2 setup (Iub, Iur and Iu)Soft handover is not allowed during the RAB establishment procedure (The mobile can not add or remove cells in AS) this makes the UE and Node B particularly sensitive to mobility and dominance Timer wf_rb_setup_cpl (6s) is started when the RRC: Radio Bearer Setup message is sent to the UE In case the timer expires Iu Release Request is sent to the CN with release cause (radio_conn_lost)

Call EstablishedUERNCNodeBRANAP: Direct Transfer (CC: Connect)RRC: Downlink Direct Transfer (CC: Connect)RRC: Uplink Direct Transfer (CC: Connect Acknowledge)RANAP: Direct Transfer (CC: Connect Acknowledge)RRC: Uplink Direct Transfer (CC: Release Complete)RANAP: Direct Transfer (CC: Release Complete)RANAP: Iu Release CommandRRC: Uplink Direct Transfer (CC: Disconnect)RANAP: Direct Transfer (CC: Disconnect)RANAP: Direct Transfer (CC: Release)RRC: Downlink Direct Transfer (CC: Release)RANAP: Iu Release CompleteMGW/CNRANAP: Location ReportRRC: Measurement ControlCall DisconnectRRC: Downlink Direct Transfer (CC: RRC Connection Release)RRC: Uplink Direct Transfer (CC: Release Complete)RRC: Uplink Direct Transfer (CC: Release Complete)NBAP: Radio Link Deletion RequestNBAP: Radio Link Deletion ResponseALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)RANAP: Direct Transfer (CC: Alerting)RRC: Downlink Direct Transfer (CC: Alerting)

UERNCNodeBMGW/CNRRC: RRC Connection Request (RACH)NBAP: Radio Link Setup RequestNBAP: Radio Link Setup ResponseALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)RRC: RRC Connection Setup (FACH)L1 SynchronizationNBAP: Synchronization IndicationRRC: RRC Connection Setup Complete (DCH)RRC: Initial Direct Transfer (MM: Paging Response)SCCP: CR (Connection Request)RANAP: Initial UE Message (MM: Paging Response)SCCP: CC (Connection Confirm)RANAP: Direct Transfer (MM: Authentication Request)RRC: Downlink Direct Transfer (MM: Authentication Request)RRC: Uplink Direct Transfer (MM: Authentication Response)RANAP: Direct Transfer (MM: Authentication Response)RANAP: Common IDRANAP: Security Mode CommandRRC: Security Mode CommandFP: Downlink SynchFP: Uplink SynchRRC Connection Establishment CELL DCH StateL1 SynchronizationMTC CS Message FlowRANAP: PagingRRC: Paging Type 1

UERNCNodeBMGW/CNRRC: Security Mode CompleteRANAP: Security Mode CompleteRRC: Uplink Direct Transfer (CC: Setup)RANAP: Direct Transfer (CC: Setup)RANAP: Direct Transfer (CC: Call Confirmed)RRC: Downlink Direct Transfer (CC: Call Confirmed)RANAP: RAB Assignment RequestNBAP: Radio Link Reconfiguration PrepareNBAP: Radio Link Reconfiguration ReadyALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)NBAP: Radio Link Reconfiguration Commit)RRC: Radio Bearer SetupRRC: Radio Bearer Setup CompleteRANAP: RAB Assignment ResponseALCAP: ERQ (Establish Request)ALCAP: ECF (Establish Confirm)RAB EstablishmentFP: Downlink SynchFP: Uplink SynchRL modification procedure:SRB+DCH, HW resources checkedPossible failure in AAL2 setup (Iub, Iur and Iu)Soft handover is not allowed during the RAB establishment procedure (The mobile can not add or remove cells in AS) this makes the UE and Node B particularly sensitive to mobility and dominance Timer wf_rb_setup_cpl (6s) is started when the RRC: Radio Bearer Setup message is sent to the UE In case the timer expires Iu Release Request is sent to the CN with release cause (radio_conn_lost)

Call EstablishedUERNCNodeBRANAP: Direct Transfer (CC: Connect)RRC: Downlink Direct Transfer (CC: Connect)RRC: Uplink Direct Transfer (CC: Connect Acknowledge)RANAP: Direct Transfer (CC: Connect Acknowledge)MGW/CNRANAP: Location ReportRRC: Measurement ControlRANAP: Direct Transfer (CC: Alerting)RRC: Downlink Direct Transfer (CC: Alerting)

MOCMTCMOC/MTC Call Flow timing

RRC messages informationVoice and Video are bothConversational Call

RRC messages informationDL SRB

RRC messages informationUE in DUAL MODE

RRC messages informationVoice AMR

RRC messages informationCS call, 64Kbps,Transparent

Video Call

RRC messages informationVideo CS 64:DL SF 32UL SF 16Voice AMR:DL SF 128UL SF 64