Communication Management

Communication Management Connection management (call control CC) for CS mode Session management (SM) for PS mode References: Kaaranen, Ahtiainen, Laitinen, Naghian, Niemi: UMTS Networks Architecture, Mobility and Services. Wiley 2001, ch. 5.3 3G 23.060 GPRS, Service Description, ch. 9 3G 24.007 Mobile radio interface signalling layer 3, General aspects 1

Fundamental Difference Between CS and PS Communication Connection (e.g. voice, CS data) clearly defined start and end no burstiness Differences require different solutions to mobility mgmt and communication mgmt connection setup connection release minutes Packet session (e.g. web surfing) start and end times are typically unknown to the UMTS system traffic is highly bursty hours seconds 2

Connection Management CS Mode Basic activities of connection management number analysis (check called number for correctness, check of call barring of calling number) set up of connection (according to routing rules) collection of charging information release of connection Types of calls normal voice call emergency call data call (FAX, etc.) 3 o

Connection Management Access Domain MOC MSC/VLR Other Elements PTC MTC Connection Management POC A call consists of several call legs (parts of the call) Mobile Originated Call (MOC) Mobile Terminated Call (MTC) PSTN Originated Call (POC) PSTN Terminated Call (PTC) 4 o

Connection Management Network Interworking echo cancelation (2/4-line conversion echo, acustic echo) modems and rate adapters Charging Collection of charging information for each leg due to UMTS commercial model (subscriber, network operator, service provider, content provider) Fraud control between serving and home network Cost control by charged party Itemized billing Call Detail Record (CDR) Charged party Terminal identity and class called address Used 3G resources QoS parameters Serving 3G network and network element identities Time stamps MM information CDR identity 5 o

Ca ll Control of Mobile-Terminated Call (CS) 6

Service graph of Call Control entity - Network side (excerpt) SETUP- SETUP- 0 NULL ALERT- PROGRESS- 1 CALL PROC- CALL INIT REJ- 19 RELEASE UEST REL- REL-CNF REL DISC- REJ- CALL- CONF- 11 DISCONNECT 12 DISONNECT UEST ICATION NO CALL 3 9 PROCEEDING ALERT- DISC- DISC- ALERT- 4 CALL DILIVERED STATES 4,6,8,9,10 7 CALL RECEIVED 6 SETUP- 28 CONNECT RSP ICATION SETUP-CNF CALL PRESENT MT CALL CONFIRMED SETUP- CNF Output des Automaten: Request (), Response (RSP) Input des Automaten: Indication (), Confirmation (CNF) 10 ACTIVE SETUP-COMPL- 8 CONNECT UEST FACILITY- ANY STATE EXCEPT 0 ANY STATE REL- 0 ANY STATE EXCEPT 0,19 FACILITY 7

Service graph of Call Control entity - MS side (excerpt) SETUP- 0 NULL SETUP- PROGRESS- REJ- 1 CALL INIT RELEASE 19 REL- UEST 6 REL- CNF REJ- CALL PROC- DISC- DISC- REL- DISC- DISONNECT 3 NO CALL 11 DISCONNECT 12 9 PROCEEDING UEST ICATION CALL PRESENT CALL CONF- MT CALL CONFIRMED 19 ALERT- REL- RELEASE UEST 4 DISC- CALL DELIVERED SETUP- CNF DISC- 7 SETUP- COMPL- (ERR) STATES 3,4,7,8,9,10 ALERT- CALL RECEIVED SETUP-RSP SETUP- RSP 8 CONNECT UEST SETUP- CNF 10 ACTIVE SETUP-COMP- FACILITY- ANY STATE EXCEPT 0 ANY STATE REL- 0 ANY STATE EXCEPT 0,19 FACILITY 8 o

Session Management PS Mode States of SM (state of PDP contexts) inactive: no packet data transfer, no valid routing information active: packet data transfer possible, valid routing information Support for various packet data protocols (PDP) Examples: IP, PPP, X.25 Attributes of packet session: PDP context defines all parameters of the packet data session by end-to-end attributes and QoS one PDP context per PS services with a certain QoS, e.g. for web serving, streaming video, packet voice, etc. 9

Session Management: States of PDP Context GPRS subscription PDP address PDP context A GPRS subscription contains the subscription of one or more PDP addresses e Each PDP address is described by one or more PDP contexts in the MS, SGSN, and GGSN Each PDP context is associated with A QoS profile a traffic flow template (TFT) to discriminate flows sharing the same PDP address Every PDP context exists independently in one of two PDP states PDP state active PDP state inactive The PDP state indicates whether data transfer is enabled for that PDP address and TFT or not Reference: 3G 23.060, ch 9 10

Field Description GSM UMTS IMSI International Mobile Subscriber Identity. X X maintain ned by GGSN elds m ress ntext fie P Addr DP con r a PDP PD for.060-4.1.0, Ch 13 Sour rce: 3GPP 23 NSAPI Network layer Service Access Point Identifier. X X MSISDN The basic MSISDN of the MS. X X PDP Type PDP type; e.g. PPP or IP. X X PDP Address PDP address; e.g. an IP address. X X Dynamic Address Indicates whether PDP Address is static or dynamic. X X APN in Use The APN Network Identifier currently used. X X TEID Tunnel Endpoint Identifier. X X TFT Traffic flow template. X X QoS Profile Negotiated The quality of service profile negotiated. X X SGSN Address The IP address of the SGSN currently serving this MS. X X MNRG Indicates whether the MS is marked as not reachable for PS at the X X HLR. Recovery Indicates if the SGSN is performing database recovery. X X GTP-SND GTP-U sequence number of the next downlink N-PDU to be sent X X to the SGSN. GTP-SNU GTP-U sequence number of the next uplink N-PDU to be received X X from the SGSN. Charging Id Charging identifier, identifies charging records generated by X X SGSN and GGSN. Charging Characteristics The charging characteristics for this PDP context, e.g. normal, X X prepaid, flat-rate, and/or hot billing. Trace Reference Identifies a record or a collection of records for a particular trace. X X Trace Type Indicates the type of trace. X X Trigger Id Identifies the entity that initiated the trace. X X OMC Identity Identifies the OMC that shall receive the trace record(s). X X 11 o

Session Management: States of PDP Context Activate PDP Context PDP Context INACTIVE Deactivate PDP Context or PMM-DETACHED PDP Context ACTIVE Inactive state: no valid routing or mapping information to process data related to PDP address -> no data transfer -> no updates due to location changes (even in GPRS-attached states) PDP context activation (transition to active state): MS-initiated PDP context activation network-requested PDP context activation Reference: 3G 23.060, ch 9 12

Session Management: States of PDP Context Activate PDP Context PDP Context INACTIVE Deactivate PDP Context or PMM-DETACHED PDP Context ACTIVE Reference: 3G 23.060, ch 9 Active state: valid routing or mapping information to process data related to PDP address (MS, SGSN, GGSN) Requires MM state PMM-idle or PMM-connected -> data transfer possible -> updates due to location changes PDP context deactivation: PDP context deactivation procedure MM state changes to PMMdetached PDP context modification, e.g. to modify QoS profile 13

Relation between PDP Context and MM GPRS subscription Relation between MM and PDP states: PDP context PDP address PDP context PDP context Single MM context PDP context All PDP contexts of a subscriber are associated with the same MM context for the IMSI of that subscriber The MM state is independent of the number and state of PDP contexts for the subscriber PDP state active PDP state inactive In both the PMM-IDLE and the PMM-CONNECTED states, session management may or may not have activated a PDP context 14

ket Fl low Exam mple of Sta ates During Pac RRC PMM SM idle detached inactive Cell_ DCH detached inactive Cell_DCH connected inactive Cell_DCH connected active Cell_DCH connected active Cell_ DCH connected active URA_PCH connected active Cell_FACH connected active Cell_DCH connected active Cell_DCH connected active URA_PCH connected active For details see Kaaranen, ch 5.3.2 UE UTRAN SGSN GGSN RRC conn. establishment GPRS attach (incl. authentication & security) PDP context establishment (UE originated) RAB allocation CN bearer allocation Packet data transfer RAB clearing CN bearer clearing... UE initiated service request RAB allocation CN bearer allocation Packet data transfer RAB clearing CN bearer clearing..... 15

ket Fl low Exam mple of Sta ates During Pac (cont d ) RRC PMM SM URA_PCH connected active Cell_FACH connected active Cell_DCH connected active Cell_DCH connected active Cell_DCH connected active URA_PCH connected active Cell_DCH connected active Cell_DCH connected inactive idle detached inactive UE UTRAN SGSN GGSN... (packet) paging incoming data UE initiated service request RAB allocation CN bearer allocation Packet data transfer RAB clearing CN bearer e clearing... PDP context t deactivation and IMSI detach RRC connection release Instead of cell_dch, cell_fach may be used for small messages PDP ctxt deletion 16

Service Request Procedures Usage of procedure: MS in PMM-IDLE state: -> request the establishment of a secure connection to a SGSN to send uplink signalling messages (e.g. PDP Context Activation Request) or to send user data or as paging response or after regain of radio coverage MS in PMM-CONNECTED state: -> request resource reservation for active PDP contexts Source: 3GPP 23.060-4.1.0, Ch 6.12 17

Service Request Procedure Initiated by MS MS RNC 1. RRC Connection Request 1. RRC Connection Setup 2. Service Request 3. Security Functions 4. Service Accept 5. Radio Bearer Setup 6. Radio Bearer Setup Complete 8. Uplink PDU If none exists 4. Radio Access Bearer Assignment Request 6. Radio Access Bearer Assignment Response SGSN HLR GGSN Service type: data setup of signaling connection allocation of resources for active PDP context(s) Service type: signaling setup of signaling connection, e.g. to activate PDP context For PMM-idle mode only 7. SGSN-Initiated PDP Context Modification Fo r service type data only 18

Service Request Procedure Initiated by Network MS RNC SGSN HLR GGSN 2. Paging 2. Paging 1. Downlink PDU 3G-SGSN sends a paging request to UTRAN when it receives a downlink packet (e.g., a request for 4. Service Request PDP context activation, MT SMS, user data) for 5. Security Functions an MS in PMM-IDLE state 6. Radio Access Bearer Assignment Request The paging request 6. Radio Bearer Setup triggers the Service Request procedure in the 6. Radio Bearer Setup MS 3. RRC Connection Request 3. RRC Connection Setup Complete 6. Radio Access Bearer Assignment Response 7. SGSN-Initiated PDP Context Modification Procedure 8. Downlink PDU 19

NAS Protocol Architecture Supporting PS Mode, MS side Source: 3GPP 24.007, Ch 5 RAB1-SAP RAB2-SAP RABn-SAP SMREG-SAP MNSMS-SAP MNSMS-SAP RAB Entity 1 RAB Entity 2 RAB Entity n RABM RAB Control RABMSM-SAP SESSION MANAGEMENT GMMRABM_SAP MM-sublayer PDP GMMSM-SAP CM GMMREG- SAP GSMS TI PMMSMS-SAP Suplemen. Services (SS) TI GMMSS-SAP GMM PD PDCP1-SAP PDCP2-SAP PDCPn-SAP RABMAS-SAP GMMAS-SAP PDCP Access Stratum sublayer BMC RRC 20 o

NAS Protocol Architecture Supporting CS/PS Mode, MS side Source: 3GPP 24.007, Ch 5 RAB1-SAP RAB2-SAP RABn-SAP CM SMREG-SAP MNSMS-SAP SAP MNSS-SAP RAB Entity 1 RAB Entity 2 RAB Entity n RABM RAB Control P RABMSM-SAP SM MM-sublayer GSMS GMMREG PMMSMS GMMSM- -SAP GMMSMS- -SAP SAP SAP CC PDP TI TI TI SS MMSMS- MMCC-SAP GMMSS2SAP GMMSSSAP MMSSSAP SAP TI TI GMMRABM-SAP GMM GMM coord PD MM coord MM PD PDCP1-SAP PDCP2-SAP PDCPn-SAP RABMAS-SAP GMMAS-SAP RR-SAP Access Stratum sublayer PDCP BMC RRC 21 o