4 CAT Service Requirements

22.1823GPPCustomized Alerting Tones (CAT) requirementsRelease 17Stage 1TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

4.1 Basic functionality of the CAT service

The Customized Alerting Tone Service (CAT service) is an operator specific service by which an operator enables the subscriber to customize the alerting tone which is played to the calling party. The calling party does not need to be a CAT subscriber to experience the CAT set by called subscriber. CAT service should not negatively affect the conversation between calling and called parties, e.g. no voice/video clipping, no longer communication setup time.

– The service shall support the CAT content types of audio, video, image, graphic, text, location and electronic business card.

– CAT can contain one or several content types, and at most one element of each type.

– The calling party should be able to simultaneously experience multiple CAT contents, e.g. audio and video.

– The service user shall be able to subscribe the CAT service, activate the CAT service, update the settings, e.g. to change his active CAT.

– The calling party shall be able to experience the CAT set by the called CAT service subscriber.

– The CAT shall override the default alerting tone towards the calling party.

– The operator should have the capability to store multiple CATs per CAT service subscriber.

– The CAT subscriber should be able to configure the CAT service. The CAT service should be able to select the appropriate CAT according to the rules. The CAT subscriber profile is based on the following parameters:

1. CAT content descriptor – Pointing to the right content or combination of contents (e.g. personal prompt plus chosen music track).

2. CAT timing descriptor – Time of day, day of week, specific date and intervals based on each of those parameters.

3. User (called/calling party) descriptor – user ID (or group ID of users), user presence, user location, CAT user charging mode

Note 1: As location information may be restricted in some instances, the default user location may be a generic "unknown".

Note 2: Presence information for a CS user is limited to attached or detached

– The CAT service shall be able to select the appropriate CAT according to the CAT user profile.

– The operator shall be able to verify that the party is authorised to store and update CAT content.

– The operator shall be able to set limitations on file type, file size, etc. for storing the CAT content.

– It should be possible to inform the user about status and changes in his CAT service, e.g. close expiry date for the CAT service or a particular CAT content.

Note: In the CS domain, this information may be provided by existing means such as SMS and web access.

– The operator shall be able to charge for the CAT service on event, volume or media type basis.

– The called party shall be able to pre-configure the CAT service. The preconfigured service is played upon receipt of an incoming communication notification. This may be based upon the calling party identity.

– The calling party should be able to reject the CAT service based on rules e.g. time, the identity of the called party.

– It shall be possible for a CAT subscriber to subscribe to a CAT that is provided by a third party content provider.

4.1.1 CAT functionality in IMS domain

The functions identified here are specific to communications made between users within the IMS.

– The calling party shall be able to experience the CAT set by the calling CAT service subscriber, both when the calling party is within HPLMN and when roaming.

– The calling party’s operator shall be able to configure which CAT should have priority, the one set by the called or calling CAT service subscriber. The calling party’s operator shall be able to take into account the calling CAT service subscriber’s preferences. By default, if no preference is set, the CAT set by the calling party has priority.

– When the called party answers the communication the CAT shall stop or continue to play during the conversation, depending on operator or user preferences.

– When the called party is notified about an incoming communication, the called party shall be able to send an indication to the CAT service which CAT to play to the calling party. This CAT-B indication shall have priority over a pre-configured CAT-B.

Note 1: The default alerting tone may be a CAT selected by the operator in the event of e.g. CAT STOP.

– The calling user shall have the possibility to copy the CAT of the called user as his own while the CAT is being played. The pre-requisites are that the called user has enabled CAT sharing, if applicable, for that instance of CAT and that both users are subscribers to the same HPLMN.

Note 2: A CAT might also be copied offline via e.g. web interface but that functionality does not require standardisation.

Note 3: The expression "to copy the CAT" does not necessarily mean that the CAT is actually copied. It may also mean that a purchase request is being sent to the CAT service provider.

4.1.2 CAT functionality in the CS domain

The functions identified here are specific to communications made between users within the CS domain.

– The calling party shall be able to experience the CAT set by the calling CAT service subscriber when in the HPLMN. When roaming this function may not be available.

– The calling party’s operator shall be able to configure which CAT should have priority, the one set by the called or calling CAT service subscriber. By default, if no preference is set, the CAT set by the calling party has priority.

– When the called party answers the communication the CAT shall stop.

– When the CAT is playing, the calling party shall be able to stop it, subject to service provider policy, and then he shall experience the default alerting tone for the duration of the communication establishment. The pre-requisites are that both called and calling user are subscribers to the same HPLMN and the calling user is within the HPLMN.

Note 1: The default alerting tone may be a CAT selected by the operator in the event of e.g. CAT STOP.

Note 2: A CAT might also be copied offline via e.g. web interface but that functionality does not require standardisation.

Note 3: The expression "to copy the CAT" does not necessarily mean that the CAT is actually copied. It may also mean that a purchase request is being sent to the CAT service provider.

– The calling party UE shall be able to start automatically downloading and streaming CAT content through PS domain during the call setup. Downloaded CAT content shall not be used for other purposes except CAT service.

4.2 Normal procedures with successful outcome

4.2.1 Provisioning and Withdrawal

The CAT Service can be provisioned and withdrawn by the operator per subscriber. Procedures for provisioning and withdrawal are out of scope of standardisation.

4.2.2 Activation and Deactivation and Update

4.2.2.1 Activation

When a subscriber activates his CAT Service he shall be able to specify which CAT a calling user should experience, or use the operator’s default setting.

After a subscriber has activated his CAT Service a calling user should experience the CAT that was chosen by the subscriber.

4.2.2.2 Deactivation

After a subscriber has deactivated his CAT Service a calling user should experience the default alerting tone.

4.2.3 Basic scenarios

4.2.3.0 CAT to be supported in the CS domain

Alerting the called subscriber constitute the basic CAT service requirements, while other CATs may be considered optional

The following table summarize these cases:

Table 0: Normal Operation Scenarios

Scenarios	CAT Support
The called subscriber is being alerted	Mandatory
The progress of communication request (Call Forward, Call Wait, User busy etc.)	Mandatory
Others	Optional

4.2.3.1 Only called party has activated the CAT service

In the following scenarios, contained in table 1, it is assumed that the called party (B) has activated his CAT Service. Calling party (A) is calling B. The calling party has not subscribed and/or activated the CAT service.

The Customized Alerting Tone of B is CAT-B.

Table 1: Normal Operation Scenarios

	Called party B (condition)	Required behaviour
1	B, ringing	A experiences CAT-B
2	B, busy	A experiences busy indication.
3	B, no answer	First A experiences CAT-B and then the ‘no answer’ indication after B’s ‘no answer’ timer has expired
4	B, not reachable	A experiences ‘not reachable’ indication

4.2.3.2 Only calling party has activated the CAT service

In the following scenarios, contained in table 2, it is assumed that only the calling party (A) has activated his CAT Service. Calling party (A) is calling B. The called party has not subscribed and/or activated the CAT service.

The Customized Alerting Tone of A is CAT-A,

Table 2: Normal Operation Scenarios

	Called party B (condition)	Required behaviour
1	B, ringing	Depending on A settings, subscriber A will experience either CAT-A or the default alerting tone.
2	B, busy	Depending on A settings, subscriber A will experience either CAT-A or the default busy tone.
3	B, no answer	Depending on A settings, subscriber A will experience either CAT-A or the default alerting tone and then the ‘no answer’ indication after B’s ‘no answer’ timer has expired
4	B, not reachable	A experiences ‘not reachable’ indication

4.2.3.3 Both parties have activated the CAT service

In the following scenarios, contained in table 3, it is assumed that both the calling party (A) and called party (B) have activated the CAT Service. Calling party (A) is calling B.

The Customized Alerting Tone of B is CAT-B, the Customized Alerting Tone for A is CAT-A.

Table 3: Normal Operation Scenarios

	Called party B (condition)	Required behaviour
1	B, ringing	Depending on A settings, A experiences CAT-A, CAT-B or the default alerting tone.
2	B, busy	Depending on A settings, subscriber A will experience either CAT-A or the default busy tone.
3	B, no answer	Depending on A settings, subscriber A will experience either CAT-A, CAT-B or the default alerting tone and then the ‘no answer’ indication after B’s ‘no answer’ timer has expired
4	B, not reachable	A experiences ‘not reachable’ indication

4.2.4 Interaction with Supplementary Services

The following section describes the interaction between CAT and the IMS Multimedia Telephony supplementary services defined in [22.173] and the equivalent CS supplementary services.

4.2.4.1 Originating Identification Restriction (OIR)

The OIR service takes precedence over the CAT service subscribed by the calling party or by the called party. If the called party has a CAT associated to the calling party’s identity, the service will not be invoked. If the called party has a CAT not associated to the calling party’s identity then the service is invoked.

NOTE: OIR service itself is independent from CAT service. The service logic providing CAT will handle the privacy request of the originator’s identity for invoking OIR service and decide whether to invoke CAT service.

4.2.4.2 Terminating Identification Restriction (TIR)

The TIR service takes precedence over the CAT service subscribed by the calling party or by the called party. If the calling party has a CAT associated to the called party’s identity, the service will not be invoked. If the calling party has a CAT not associated to the calling party’s identity then the service is invoked. The CAT service can take precedence over the TIR service when the calling party has an override category, such as the police, for which the TIR service is not applied.

4.2.4.3 Communication Diversion (CDIV)

Additionally, for call-forwarding scenarios, it is assumed that Forwarded-to-party (C) has activated his CAT Service. The Customized Alerting Tone of C is called CAT-C. The Customized Alerting Tone of D is called CAT-D. The calling party has not subscribed and/or activated the CAT service. If applicable, the CAT experienced by the calling user should be the one customized for the user by the connected-to-party

In the following table, all the CATs that A experiences in the column "Required behaviour" may be replaced by CAT-B, if the operator wants to deploy so.

Table 4: Supplementary Service Interaction Scenarios

	Called party B (condition)	Forwarded-to-party (condition)	Required behaviour
1	B has activated Call Forwarding Unconditional (CFU) to C and A’s call is forwarded to C	C, ringing	A experiences CAT-C
2	B has activated Call Forwarding on Busy (CFB) to C, B is busy and A’s call is forwarded to C	C, ringing	A experiences CAT-C
3	B has activated Call Forwarding on No Reply (CFNRy) to C and A’s call is forwarded to C	C, ringing	A experiences CAT-B until B’s CFNRy timer has expired. Then experiences CAT-C.
4	B has activated Call Forwarding on Not Reachable (CFNRc) to C and A’s call is forwarded to C	C, ringing	A experiences CAT-C
5	B has activated a Call Forwarding to C and C has activated a Call Forwarding to D so A’s call is forwarded to D	Tandem Forwarding: C has activated a Call Forwarding to D and A’s call is forwarded to D	A experiences CAT-D

Table 5 describes when the calling party has subscribed and activated the CAT service.

Table 5: Supplementary Service Interaction Scenarios

Called party B
(condition)

Forwarded-to-party
(condition)

Required behaviour

A has activated CAT-A and B has activated Call Forwarding Unconditional (CFU), Call Forwarding on Busy (CFB) or Call Forwarding on Not Reachable (CFNRc) to C.

A’s call is forwarded to C

C, ringing

Depending on operator settings, subscriber A will experience the CAT set for user B, C or the default ringing tone.

B has activated Call Forwarding on No Reply (CFNRy) to C and A’s call is forwarded to C

C, ringing

A experiences CAT-A for user B until B’s CFNRy timer has expired. Then experiences CAT-A for user C.

– It should be possible to configure the CAT service so that different CATs are used according to user profile (e.g. Date, Time, Call status)

4.2.4.4 Communication Waiting (CW)

If the called party has activated the communication waiting and he is busy, depending on the operator’s settings, the calling party will experience either the CAT service or the default communication waiting indication.

Table 6: Supplementary Service Interaction Scenarios

	Called party B (condition)	Forwarded-to-party (condition)	Required behaviour
1	A has activated CAT and B has activated call waiting. B is engaged in an active or held call.		Depending on A settings, subscriber A will experience either CAT-A or the default call waiting tone.
2	B has activated CAT and B has activated call waiting and B is engaged in an active or held call.		Depending on A settings, subscriber A will experience either CAT-B or the default call waiting tone.

4.2.4.5 Explicit Communication Transfer (ECT)

The called party (A) has activated the ECT service and the communication is transferred to C. The calling party will only experience the CAT from the C in case of blind transfer and if C has activated the CAT service. In case of consultative transfer the calling party will not experience the CAT service.

4.3 CAT service configuration

– A service subscriber, that has activated his CAT service, shall be able to select and update his CAT settings – e.g. select a different CAT than the current one. It should be possible to charge the subscriber for selection / update of the CAT settings.

– The calling user should be able to ‘copy’ the last CAT that was experienced in the ongoing call, as his own CAT.

Note: Operators should be aware that copyrights may be infringed and therefore the operator may need to take appropriate action.

4.4 The content of CAT

The content of CAT can be music, voice, text, or video.

In IMS the CAT may be composed of music, voice, text, video, which can be provided by the CAT content provider, operator or by the user himself.

If the calling party is in the CS domain the CAT may be composed of music, voice, video, which can be provided by the CAT content provider, operator or by the user himself.

The content of the CAT service may be dynamically created, possibly taking into account information available in the network, e.g. calling and/or called user’s location and/or presence information.

4.5 Inter-working CAT

4.5.1 CAT Interworking between different PLMNs

It is important for a good user experience that CAT works as predicted independently if the called or the calling user is roaming. A standardized CAT solution should therefore fulfil the following end user requirements:

– When calling a user of another PLMN, the calling party shall be able to experience the CAT set by the called party.

– When calling a user of another PLMN, the calling party shall be able to experience the CAT set by the calling party.

– When roaming to another PLMN, the calling party shall be able to experience the CAT set by the called party.

– The calling party shall be able to experience the CAT set by the called party who is roaming to another PLMN.

4.5.2 Interworking between CS and IMS based CAT services

The CS and IMS based CAT services should fulfil the following end user requirements:

– When calling a user in the other domain (CS or IMS), the calling party shall be able to experience the CAT set by the called party.

– When calling a user in the other domain (CS or IMS), the calling party shall be able to experience the CAT set by the calling party.

– When calling a CAT service subscriber of another domain (CS or IMS), the calling party should be able to copy the CAT of the called user as his own CAT. The pre-requisites are that the called user has enabled CAT sharing, if applicable, for that instance of CAT and that both users are subscribers to the same HPLMN.

– When calling a CAT service subscriber of another domain (CS or IMS), the calling party should be able to stop an ongoing CAT.

The scope of this interoperability may result in a limited service capability.