IMS/SIP - Specification                                   Home : www.sharetechnote.com

 

 

 

IMS is made up of a lot of different set of specification interplaying each other which create a lot of confusions. Following is only major chunk of the specification and you would need to refer to additionals specs (e.g, LTE Radio Specfication, ITU specs etc) to find the details for each IMS application.

 

Recently (As of Mar 2017), most of basic IMS feature (e.g, REGISTRATION, VoLTE, SRVCC, SUPPLEMENTARY SERVICE) are finalized in 3GPP specification. This is good news at least to me. It was hard for me to make a clear meaning out of other specifications. Even though there are many cases where even 3GPP specification about IMS is not as clear as Radio Protocol specification, still 3GPP description looks much clearer to me.

In this post, I will try to put down some pointers to 3GPP specification to help you find informations related to a specific IMS applications that you are working on. It means, this page would work as just a point to other documents. I would not put any details for each subject.

 

 

TS 23.167 - IP Multimedia Subsystem (IMS) emergency sessions

TS 23.204 - Support of Short Message Service (SMS) over generic 3GPP Internet Protocol (IP) access; Stage 2

TS 23.216 - LTE; Single Radio Voice Call Continuity (SRVCC);Stage 2

TS 23.228 - IP Multimedia Subsystem (IMS) ; Stage 2

TS 23.237 - IP Multimedia Subsystem (IMS) Service Continuity; Stage 2

TS 24.173 - IMS Multimedia telephony service and supplementary services; Stage 3

TS 24.229 - IP Multimedia callcontrol protocol based on SIP and SDP; Stage 3

TS 24.237 - IP Multimedia Subsystem (IMS) Service Continuity; Stage 3

TS 24.341 - Support of SMS over IP networks; Stage 3

TS 24.604 - CDIV and IM Core Network(CN) subsysteml Protocol Specification

TS 26.114 - IP Multimedia Subsystem (IMS); Multimedia telephony; Media handling and interaction

TS 29.292 - Interworking between the IP Multimedia (IM),

                 Core Network (CN) subsystem (IMS), and MSC Server for IMS Centralized Services (ICS)

TS 31.103 - Characteristics of the IP Multimedia Services Identity Module (ISIM) application

TS 34.229-1 SIP and SDP ; Part 1 : UE Protocol Conformance Specification

TS 36.508 - Section 4.5A Other generic procedures (4.5A.3,4.5A.4,4.5A.5,4.5A.6,4.5A.7)

TS 36.523-3 Section 4.2.5, 4.2.4.6.2

GSMA IR.64 - IMS Service Centralization and Continuity Guidelines

GSMA IR.92 - IMS Profile for Voice and SMS

 

 

TS 24.229-1

 

IP Multimedia call control protocol based on SIP and SDP; Stage 3

: This is a kind of skeleton specification of IMS in 3GPP. You can get the big pictures from this spec and then refer to other specification for a specific service and functionalities.

 

Followings are the high level test case group(sections) defined in this specification.

    6.  PDP Context Activation

    7.  P-CSCF Discovery

    8.  Registration

    9.  Authentication

    10. Subscription

    11. Notification

    12. Call Control

    13. Signalling Compression (SIGComp)

    14. Emergency Service

    15. Supplementary Services

    16. Codec selecting

    17. Media use cases

    18. SMS over IMS

    19. Emergency Service over IMS

    20. Customized Alerting Tones (CAT)

 

 

TS 24.604

 

CDIV and IM Core Network(CN) subsysteml Protocol Specification

: You can get various signal flow diagram and message format especially related to IMS Supplimentary Services

Followings are some message formation and signal flow diagrams that I recommend you to look into every time you are working with IMS supplimentary service.

  • 4.9.1.2 Communication Diversion Rules
  • 4.9.1.5 Supported Actions and Conditions for Communication Diversion
  • 4.9.2 XML Schema
  • 4.9.3 XML schema for indication of supported conditions and actions
  • A.1.1 Communication Forwarding unconditional
  • A.1.2 Communication Deflection
  • A.1.3 Communication forwarding on no reply
  • A.1.4 Communication Forwarding on Busy
  • A.1.5 Communication Forwarding Not Logged-in (CFNL)
  • A.1.7 Service configuration
  • A.2.1 Communication Forwarding unconditional
  • A.2.2 Communication Deflection

 

 

TS 36.523-1

 

User Equipment (UE) conformance specification; Part 1: Protocol conformance specification

: SRVCC and CSFB for Emergency service test cases are defined in this specification.

 

Followings are the list of IMS related test cases defined in this specification :

    11.2.10 LIMITED-SERVICE / EPS does not support IMS Emergency / Emergency call using the CS domain

    11.2.11 LIMITED-SERVICE / Inter-system mobility / E-UTRA to UTRA CS / SRVCC Emergency Call Handover to UTRAN

    11.2.12 LIMITED-SERVICE / Inter-system mobility / E-UTRA to GSM CS / SRVCC Emergency CallHandover to GERAN

     

    13.4.3.1 Inter-system mobility / E-UTRA voice to UTRA CS voice / SRVCC

    13.4.3.2 Inter-system mobility / E-UTRA PS voice + PS data to UTRA CS voice + PS data / SRVCC

    13.4.3.3 Inter-system mobility / E-UTRA voice to GSM CS voice / SRVCC

    13.4.3.4 Inter-system mobility / E-UTRA voice to UTRA CS voice / Unsuccessful case / Retry on old cell/SRVCC

    13.4.3.5 Inter-system mobility / E-UTRA voice to GSM CS voice / Unsuccessful case / Retry on old cell/SRVCC

    13.4.3.6 Inter-system mobility / E-UTRA PS voice + PS Data / HO cancelled / Notification procedure /SRVCC

    13.4.3.7 Inter-system mobility / E-UTRA voice to UTRA CS voice / aSRVCC / MO call

    13.4.3.8 Inter-system mobility / E-UTRA voice to UTRA CS voice / aSRVCC / MO call / Forked responses

    13.4.3.9 Inter-system mobility / E-UTRA voice to UTRA CS voice / aSRVCC / MO call / SRVCC HO failure

    13.4.3.10 Inter-system mobility / E-UTRA voice to UTRA CS voice / aSRVCC / MT call

    13.4.3.11 Inter-system mobility / E-UTRA voice to UTRA CS voice / aSRVCC / MT call / SRVCC HO failure

    13.4.3.13 Inter-system mobility / E-UTRA voice to UTRA CS voice / aSRVCC / MT call / SRVCC HO cancelled / User answers in PS domain

    13.4.3.14 Inter-system mobility / E-UTRA PS voice + PS data to UTRA CS voice + PS data / aSRVCC/MO call

    13.4.3.15 Inter-system mobility / E-UTRA PS voice + PS data to UTRA CS voice + PS data / aSRVCC / MO call / SRVCC HO cancelled

    13.4.3.16 Inter-system mobility / E-UTRA PS voice + PS data to UTRA CS voice + PS data / aSRVCC / MT call

    13.4.3.18 Inter-system mobility / E-UTRA PS voice + PS data to UTRA CS voice + PS data / bSRVCC / MO call

 

 

TS 36.523-3

 

User Equipment (UE) conformance specification; Part 3: Test suites

: As you know, this is a protocol conformance test specification, but you would find various useful information about some IMS functionalities like PDN allocation, IP Sec, CSCF structure etc as listed below.

  • 4.2.5 IP model extension for IMS
  • 4.2.5.1 IPsec
  • 4.2.5.1.1 Security Association
  • 4.2.5.1.2 SAD and SPD
  • 4.2.5.2 Signalling Compression (SigComp)