3GPP2 IMS Supplementary Services Transfer to 3GPP

Common IMS

Gap Analysis and Actions Proposed

3GPP-3GPP2 Common IMS Workshop

24-25 January 2008

Puerto Vallarta, Mexico

Tdoc CIMS-080010

15 January 2008 2

Presentation Overview

• Survey of Relevant Specifications for Gap Analysis

• Summary of 3GPP2 X.P0055 Services Reviewed

• Gap Analysis

• Summary of Actions Proposed by 3GPP2

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Relevant Specifications

• 3GPP2 Specifications (Source)– S.P0125 – VoIP Supplementary Services Stage 1– X.P0055 – VoIP Supplementary Services Stage 2/3

(information flows and signaling requirements)

• 3GPP Specifications(Target)– TS 22.173 – IMS Multimedia Telephony Service and

Supplementary Services Stage 1– TS 24.173 – IMS Multimedia Telephony Comm. Service and

Supplementary Services Stage 3– TS 22.182 – Customized Alerting Tones Requirements

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Services Reviewed From 3GPP2 X.P0055

• Call Hold• Call Waiting• Call Transfer• Call Forwarding• Identity Presentation/Restriction Services (CIP/CIR/TIP/TIR)• Three-Way Conferencing• Message Waiting Indication• DTMF Support• User Provisioning• Customized Ring Back Tones (CRBT)• Voice Mail Deposit (VMD)/Voice Mail Retrieval (VMR)• Flexible Alerting• Outbound Call Restriction (OCR)/Inbound Call Restriction (ICR)/Anonymous Call Rejection (ACR)• Address Resolution Services (Directory Assistance/Short Code Dialing/Abbreviated Dialing)

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Call Hold

• Requirements: Same

• Stage 3: Aligned, except for a minor difference in the case of “Call Hold with Announcement”:

– In 3GPP2 X.P0055, within the response to the SIP INVITE, the SDP “a=” attribute is allowed to be set by the AS either to value “recvonly” or “inactive”.

– In TS 24.173, within the response to the SIP INVITE, the SDP “a=” attribute is set by the AS to value “recvonly” only.

• No modifications are proposed at this time.

15 January 2008 6

Call Waiting

• Requirements: Aligned

• Stage 3: Work in 3GPP is not yet concluded. TISPAN R2 work is also ongoing (focusing on interworking with legacy terminals).

• In 3GPP2 X.P0055, there is no service logic specified at the AS for this service.

• No modifications are proposed at this time.

15 January 2008 7

Call Transfer

• Requirements: Same

• Stage 3: Aligned for end-to-end REFER, but…

• 3GPP2 X.P0055 has a 3pcc (third party call control) implementation variant which is not included in 3GPP 24.173.

• Associated CRs are available for the workshop.

• Note: TISPAN R2 work in progress includes “REFER Interworking”.

15 January 2008 8

Call Forwarding

– Requirements:• Call forwarding unconditional – MMTel Communication Diversion

(CDIV) has richer requirements but essence the same

• Call forwarding on busy – 3GPP has richer requirements but essence the same

• Call forwarding no answer – combination of 3GPP CFNoReply & CFNotLoggedIn; same

• 3GPP has additional CDIV flavours: – Not Logged In (CFNL),

– Communication Deflection (CD),

– Not Reachable (CFNRc)

• CDIV supports a served user notification capability that 3GPP2 does not specify.

– Stage 3: Aligned

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Identity Presentation/Restriction Services

• Requirements: Same (OIP/OIR in 3GPP are known as CIP/CIR in 3GPP2)

• Stage 3: 3GPP and 3GPP2 are aligned

15 January 2008 10

Three-Way Conferencing (3WC)

• 3GPP2’s 3WC is covered by CONF in 3GPP/MMTel

• Requirements: Aligned, although CONF places no limitation on the number of conference participants or how the conference is created.

• Stage 3: Aligned, with the exceptions mentioned below:– X.P0055 has a 3pcc implementation variant whereas 24.173 does not– X.P0055 assumes that in order to invite another user to join a conference,

the conference creating UE REFERs the other end point[s] to the conference server whereas 24.173 illustrates (by way of signalling flow) only the case in which the conference creating UE REFERs the conference server to the other end point[s].

• CRs are available for the workshop.

15 January 2008 11

Message Waiting Indication

• Requirements: Same for 3GPP and 3GPP2.

• Stage 3: Aligned.– 3GPP functionality distributed across 3GPP TS 24.173 and 23.204

– 3GPP2 functionality within 3GPP2 X.P0055

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DTMF Support

• 3GPP does not call this capability out as an MMTel service since it leverages a standard SDP capability (“telephone-event” payload type).

• No modifications are proposed at this time for DTMF Support.

15 January 2008 13

User Provisioning

• In 3GPP user configuration is done using the Ut (XCAP) interface.

– 3GPP2 does not specify user configuration via the Ut interface.

• 3GPP2 defines only a SIP-based user provisioning (configuration) mechanism (one in which the Request-URI: header in the SIP INVITE carries an operator-specific feature or ‘star’ code).

– Neither 3GPP nor TISPAN specifies such a mechanism.

• CRs are available for the workshop.

15 January 2008 14

Customized Ring Back Tones

• 3GPP2 has Customized Ring Back Tones (CRBT) service; 3GPP has Customized Alerting Tones (CAT) service.

• Requirements for CRBT and CAT:– CRBT is a terminating network only service.

– CAT also includes an originating network component.

• Status of CAT: – Requirements stable (described in TS 22.182)

– TR started for stage 2/3 work in CS domain. No work on IMS CAT yet.

• Associated CRs are available for the workshop.

15 January 2008 15

Voice Mail Deposit/Retrieval

• Voice Mail Deposit – is covered by Call Forwarding on Busy in 3GPP

– there is no need for 3GPP to have separate feature

• Voice Mail Retrieval – is an AS-based address resolution service, which leverages IMS

services concepts.

• No modifications are proposed at this time.

15 January 2008 16

Flexible Alerting

• This feature is not defined by 3GPP or TISPAN.

• Feature is defined in X.P0055. – Feature is an Application Server-based group termination service.

• Associated CRs are available for the workshop.

15 January 2008 17

Outbound/Inbound Call Restriction

• In 3GPP/TISPAN these services come under the heading of Communication Barring (CB).

• Requirements: Aligned, although in 3GPP the barring rule set is standardised whereas in 3GPP2 it is not.

• Stage 3: Aligned

• No modifications are proposed at this time.

15 January 2008 18

Number/Address Resolution Features

• In this class, 3GPP2 specifies the Directory Assistance, Short Code Dialling and Abbreviated Dialling services. These services are Application Server-based number/address resolution features.

• 3GPP does not call these out explicitly as services since they only leverage IMS services concepts (in particular, functionality described in “Support of numbers in non-international format in IMS” clause in TS 23.228).

• No modifications are proposed at this time.

15 January 2008 19

Summary of Actions Proposed (1 of 3)

S.P0125/X.P0055 Service/Service Class Action Proposed at This Time

Call Hold None

Call Waiting None

Call Transfer Add 3pcc AS signaling variant to ECT

Call Forwarding None

ID Presentation Services (CIP/CIR/TIP/TIR) None

Three-Way Conferencing Add flow for alternative UE signaling method for join-conference operation to CONF

15 January 2008 20

Summary of Actions Proposed (2 of 3)

S.P0125/X.P0055 Service/Service Class Action Proposed at This Time

Message Waiting Indication None

DTMF Support None

User Provisioning Introduce SIP-Based User Configuration capability to 3GPP

Customized Ring Back Tones (CRBT) Introduce stage 3 for IMS CAT based on CRBT source material

Voice Mail Deposit (VMD/Voice Mail Retrieval (VMR)

None

Flexible Alerting Introduce new service to 3GPP (stage 1 to 22.173; stage 3 to 24.173)

15 January 2008 21

Summary of Actions Proposed (3 of 3)

S.P0125/X.P0055 Service/Service Class Action Proposed at This Time

Outbound Call Restriction (OCR)/Inbound Call Restriction (ICR)/Anonymous Call Rejection (ACR)

None

Address Resolution Services (Directory Assistance/Short Code Dialing/Abbreviated Dialing)

None