ATIS/3GPP Common IMS Emergency Calling

Transcription

1 ATIS/3GPP Common IMS Emergency Calling Randall Gellens Qualcomm Incorporated

2 ATIS in Brief Established in 1983, a technical planning and standards development organization committed to rapidly developing and promoting global technical and operations standards for the Information and Communications Technologies (ICT) industry. Uses a market-driven pragmatic, flexible and open approach to develop end-to-end, implementable, interoperable standards and a broad array of solutions ATIS Member Companies Represent a Wide Cross Section of the Global Information, Entertainment, and Communications Industry. With more than 20 committees and over 600 participants, ATIS actively formulates worldwide technical and operations standards for the global ICT Industry The CTO/Senior Executive Level Board of Directors identifies priorities, needs and opportunities at the intersection of business and technology North American Organizational Partner for the 3rd Generation Partnership Project (3GPP), a member of and major contributor to the ITU-R/ITU-T, and a member of the Inter-American Telecommunication Commission (CITEL). Accredited by the American National Standards Institute (ANSI). 2

3 ATIS/3GPP IMS EC Architecture IMS is upper-layer control-plane signaling Uses SIP Same for all access types (e.g., UMTS, ehrpd, LTE) Wireless and wired (i.e., fixed, nomadic, mobile) Supports authorization, charging, services, etc. Handles call setup and teardown (using SIP signaling) Handles media path allocation/deallocation Location determination may differ by access SUPL is User Plane and does not differ by access type Control Plane (CP) location differs by access type 3

4 IMS Elements, Oversimplified User equipment (UE) Call Session Control Functions (SIP proxies) Proxy-, Emergency-, Serving-, Interrogating- Various specialized functional elements Location Retrieval Function (LRF) Includes Route Determination Function (RDF) Emergency Access Transfer Function (EATF) Anchors media for Single Radio Voice Call Continuity (SRVCC) between Circuit Switched (CS) and Packet Switched (PS) modes Media Gateway Control Function (MGCF) for CS interworking Media Gateway (MGW) for CS interworking Home and visited (serving) networks P-CSCF, E-CSCF, LRF, and EATF always in serving network for emergency calls 4

5 IMS Emergency Call Architecture LRF Le (e.g. E2) UE From private network via IBCF/I-CSCF Gm P-CSCF Mx/ MI E-CSCF I4 Mm/Mx Mi/Mg to PSAP or ECS (via IBCF/IP multimedia Network) to PSAP (via PSTN via BGCF/ MGCF) From AS EATF I5 from I-CSCF ISC/ S-CSCF Mm/Mx/ from 3GPP TS

6 ESInet Termination 6

7 Architecture for IMS w/ Location E-SMLC GMLC SLP LRF ECRF UE enodeb MME P-CSCF E-CSCF ESRP i3 PSAP ESInet S-CSCF Serving Gateway PDN Gateway VPLMN (Visited Public Land Mobile Network) VPLMN contains 3GPP and OMA architecture elements ESInet contains NENA i3 architecture elements VPLMN-to-ESInet interfaces are being evaluated by ATIS UE and internal VPLMN interfaces are defined by 3GPP and OMA 7 ECRF ESRP Emergency Call Routing Function Emergency Services Routing Proxy SIP related signaling Voice/data Control Plane (CP) LCS Signaling SUPL LCS Signaling Not yet defined

8 IMS Network Call Flow Example ESInet UE P-CSCF S-CSCF E-CSCF ESRP PSAP Emergency registration (depending on circumstances) SIP INVITE with emergency indication Retrieve location Session setup and initial media exchange Retrieve route SIP INVITE SIP 200 OK Exchange media in the User Plane SIP BYE Session and media Release 8

9 3GPP IMS Emergency Call Status Release 9: Supports IP based emergency calls for voice and can support Real Time Text (e.g. using TTY if there is handover to the CS domain) Release 10: Enhancements added to support emergency calls using private numbering in an Enterprise network Release 11 and later: Non-Voice Emergency Services (NOVES) Improved support for location by reference is expected Network-provided cell ID for more reliable PSAP routing is expected ATIS: North American (NA) specific standards to augment 3GPP IMS solution E.g., define portions that are left to national variation or need more detail WTSC Issue P0030: Implementation of 3GPP Common IMS Emergency Procedures for IMS Origination and ESInet/Legacy Selective Router Termination 9

10 Differences from IETF ECRIT (1) IMS Originating device Performs emergency registration (unless UE knows it is in home network and already registered) Does not need to obtain own location No provision for performing LoST query Only SUPL and/or CP support required for location for mobile UE 10

11 Differences from IETF ECRIT (2) Originating IMS network Must be capable of performing position determination Since originating device may not supply location May choose to validate a location supplied by device How location is delivered to PSAP Location-by-value vs. location-by-reference Route determination (especially for mobile) Not specified in 3GPP (no mention currently of ECRF) ATIS is expected to specify for North America Support for delivering calls to ESInet (SIP/IMS) and legacy CS No LIS LRF performs location dereference function (resolve location URI) No mechanism for originating device to obtain own location Location validation function (for fixed) not in scope for ATIS 11

12 Thank You 12

13 Abbreviations CP: Control Plane CS: Circuit Switched E-CSCF: Emergency Call Session Control Function EATF: Emergency Access Transfer Function E-SMLC: Evolved Serving Mobile Location Server ehrpd: Evolved High-Rate Packet Data EVDO: Evolution Data Optimized HRPD: High-Rate Packet Data GMLC: Gateway Mobile Location Center I-CSCF: Interrogating Call Session Control Function IMS: IP Multimedia Subsystem IP: Internet Protocol MGCF: Media Gateway Control Function MGW: Media Gateway 13 LTE: Long-Term Evolution LRF: Location Retrieval Function P-CSCF: Proxy Call Session Control Function PS: Packet Switched RDF: Route Determination Function S-CSCF: Serving Call Session Control Function SIP: Session Initiation Protocol SLP: SUPL Location Platform SUPL: Secure User-Plane Location UE: User Equipment UMTS: Universal Mobile Telephone Service UP: User Plane VCC: Voice-Call Continuity VPLMN: Visited Public Land Mobile Network

14 Backup Slides Call flows in more detail 14

15 Generalized Call Flow LRF Le (e.g. E2) UE From private network via IBCF/I-CSCF Gm P-CSCF Mx/ MI E-CSCF I4 Mm/Mx Mi/Mg to PSAP or ECS (via IBCF/IP multimedia Network) to PSAP (via PSTN via BGCF/ MGCF) From AS EATF I5 from I-CSCF ISC/ S-CSCF Mm/Mx/ 15

16 Ingress attributes Directory Number MDN/MSISDN Cell ID maybe: L-by-V (PIDF-LO) maybe: L-by-R (Location URI, pani, etc.) LRF Le (e.g. E2) UE From private network via IBCF/I-CSCF Gm P-CSCF Mx/ MI E-CSCF I4 Mm/Mx Mi/Mg to PSAP or ECS (via IBCF/IP multimedia Network) to PSAP (via PSTN via BGCF/ MGCF) From AS EATF I5 from I-CSCF ISC/ S-CSCF Mm/Mx/ 16

17 Location Retrieval Cell Site Location Lat/Lon Location Civic Location LRF Le (e.g. E2) UE From private network via IBCF/I-CSCF Gm P-CSCF Mx/ MI E-CSCF I4 Mm/Mx Mi/Mg to PSAP or ECS (via IBCF/IP multimedia Network) to PSAP (via PSTN via BGCF/ MGCF) From AS EATF I5 from I-CSCF ISC/ S-CSCF Mm/Mx/ 17

18 Routing Determination ESRK/ESQK PSAP URI (Routing URI) RDF LRF Le (e.g. E2) UE From private network via IBCF/I-CSCF Gm P-CSCF Mx/ MI E-CSCF I4 Mm/Mx Mi/Mg to PSAP or ECS (via IBCF/IP multimedia Network) to PSAP (via PSTN via BGCF/ MGCF) From AS EATF I5 from I-CSCF ISC/ S-CSCF Mm/Mx/ 18

19 Call Delivery Directory Number ESRK/ESQK PIDF-LO Location URI LRF Le (e.g. E2) UE From private network via IBCF/I-CSCF Gm P-CSCF Mx/ MI E-CSCF I4 Mm/Mx Mi/Mg to PSAP or ECS (via IBCF/IP multimedia Network) to PSAP (via PSTN via BGCF/ MGCF) From AS EATF I5 from I-CSCF ISC/ S-CSCF Mm/Mx/ 19

20 Location acquisition DN, ESRK, ESQK, URI E2 format, PIDF-LO LRF Le (e.g. E2) E2, HELD UE From private network via IBCF/I-CSCF Gm P-CSCF Mx/ MI E-CSCF I4 Mm/Mx Mi/Mg to PSAP or ECS (via IBCF/IP multimedia Network) to PSAP (via PSTN via BGCF/ MGCF) From AS EATF I5 from I-CSCF ISC/ S-CSCF Mm/Mx/ 20