Content for TS 23.088 Word version: 19.0.0
8 Anonymous Call Rejection
8.1 General
8.2 Procedures
8.3 Interactions with other supplementary services
8.4 Interactions with other network features and services
$ Change history
8 Anonymous Call Rejection p. 36
8.1 General p. 36
Anonymous Call Rejection (ACR) is a supplementary service of the CS domain that allows a mobile subscriber to reject incoming calls from users who have restricted the presentation of their calling line identity according to the CLIR supplementary service (see TS 23.081).
The ACR supplementary service shall reject all calls with CLI marked "presentation restricted" according to CLIR. The calls shall be rejected regardless of the current state (e.g. free or busy) of the served subscriber's access. The called mobile subscriber shall not be alerted.
The ACR supplementary service shall not reject calls terminated for the mobile subscriber without a CLI or when the CLI presentation is not available, is allowed, or is restricted by the network.
The ability of the mobile subscriber to set-up outgoing calls shall remain unaffected.
The calling user shall be given an appropriate indication that the call has been rejected due to the application of the ACR supplementary service.
The telecom services to which ACR applies are defined in TS 22.004. The service may be valid for all incoming calls or just associated with a specific basic service group.
8.2 Procedures p. 36
8.2.1 Provision and withdrawal p. 36
The ACR supplementary service may be provisioned to or withdrawn from a subscription by administrative actions in the HLR. The HLR shall update the subscription information accordingly. This is transparent to the VLR and thus does not require any transfer of updated subscription information to the VLR.
8.2.2 Registration and erasure p. 36
Not applicable.
8.2.3 Activation and deactivation p. 36
8.2.3.1 General p. 36
When provisioned in the subscription, the mobile subscriber should be able to activate or deactivate the ACR supplementary service by USSD procedure (see TS 23.090). The USSD strings to be used to activate or deactivate the service are operator specific and should be operator configurable in the HLR.
The mobile subscriber may be able to activate or deactivate ACR per basic service group, subject to the capabilities of the HLR. An activation or deactivation request without any specific basic service group information shall be interpreted as applying to all basic service groups (applicable to ACR).
Calls that are on-going at the time the ACR supplementary service is activated shall not be affected. Any new incoming call not allowed by the ACR supplementary service shall be barred.
8.2.3.2 Interactions with other incoming call barring programs p. 36
ACR may be active simultaneously with Barring of incoming calls when roaming outside of the home PLMN country (BIC-Roam) but can not be active simultaneously with Barring of all incoming calls (BAIC), per basic service group. The HLR shall ensure that exclusive barring programs are not active simultaneously per basic service group. The activation of one specific barring program will override an already active exclusive one (i.e. the old one shall be permanently deactivated).
If ACR and BIC-Roam are active simultaneously for a specific basic service group, BIC-Roam shall apply when the mobile subscriber is roaming outside the HPLMN.
8.2.3.3 Logical states in the HLR for the ACR supplementary service p. 37
Table 8.2.3.3.1 shows the logical states that the ACR supplementary service may have in the HLR (see TS 23.011 for an explanation of the notation).
| Provisioning State | Registration State | Activation State | HLR Induction State |
|---|---|---|---|
| Not Provisioned | Not Applicable | Not Active | Not Induced |
| Provisioned | Not Applicable, | Not Active | Not Induced |
| Provisioned | Not Applicable | Active and Operative | Not Induced |
The activation state may be different for each applicable elementary basic service group.
The provisioning state shall be on a per subscriber basis, and hence the same for all basic service groups.
Figure 8.2.3.3.1 shows the successful cases of transition between the applicable logical states of the ACR supplementary service. The state changes are either caused by actions of the service provider or the mobile user. Error cases are not shown in the diagram as they normally do not cause a state change. The diagrams only show operations on an elementary basic service group.
8.2.4 Invocation p. 37
8.2.4.1 General p. 37
When the ACR supplementary service has been activated, then the ACR supplementary service shall automatically be invoked by the HLR. If the HLR receives a request for routing information for a call directed to a mobile subscriber who is subject to ACR for the corresponding basic service group, the HLR shall return a negative response to the request for routing information, with the indication that the call is rejected because of ACR, if the calling line identity is marked as "presentation restricted" according to the CLIR supplementary service. ACR shall not be invoked for incoming calls that do not have their CLI or that have their CLI marked "not available","presentation allowed" or "presentation restricted by network".
Upon receipt of that indication, the GMSC shall connect the call to a recorded announcement determined by the network operator or/and should relay this error indication to the calling user.
8.2.4.2 Terminating Network Information flow p. 38
The information flow for rejection of an anonymous MT call is shown in Figure 8.2.4.2.1. It applies to a mobile terminating call with CLI marked "presentation restricted", if the HLR and the GMSC supports the ACR supplementary service and the called mobile subscriber has activated ACR for the corresponding basic service group.
Figure 8.2.4.2.1: Information flow for rejection of an anonymous MT call
(⇒ copy of original 3GPP image)
(⇒ copy of original 3GPP image)
Step 1.
Upon receipt of an incoming call, the GMSC sends a MAP Send Routing Information request to the HLR. A GMSC that supports the ACR supplementary service shall pass to the HLR the Additional Signal Info IE including the CLI information if available as specified for the CLI supplementary service in clause 1.2.3 of TS 23.081.
Step 2.
Upon receipt of the MAP Send Routing Information request, an HLR that supports the ACR supplementary service shall return an SRI negative response with a cause indicating Anonymous Call Rejection if the mobile subscriber has activated ACR for the corresponding basic service group and the calling line identity is marked as "presentation restricted" according to the CLIR supplementary service.
The HLR shall determine whether the calling line identity is marked as "presentation restricted" using the 'Address presentation restricted indicator' of the Calling Party Number IE if received in the Additional Signal Info IE.
Step 3.
Upon receipt of a SRI negative response with the cause indicating Anonymous Call Rejection, the GMSC shall signal to the originating network that in-band information is available due to anonymous call rejection ("call rejected due to feature at destination" ) and play a specific in-band announcement towards the calling user to signal that the call has been rejected due to the application of the ACR supplementary service.
Step 4.
After the announcement has been completed, the GMSC shall initiate the call release with a cause indicating normal call release.
8.2.4.2a Originating Network behaviour p. 38
Upon receipt of the indication from the terminating network that in-band information is available, the originating MSC server shall request the MGW to through-connect the bearer terminations so that the bearer is backward through-connected unless already done. This allows the calling user to hear the announcement played by the terminating network when it rejects an anonymous call.
Upon receipt of a call release request with a cause indicating that the call has been rejected due to anonymous call rejection ("call rejected due to feature at destination"), the originating MSC may play an announcement towards the calling user to signal that the call has been rejected due to anonymous call rejection. If no local announcement is played, the originating MSC shall signal an appropriate cause (e.g. "call rejected due to feature at destination", "call rejected") when releasing the call towards the calling user. This allows the calling user to know why the call is rejected when an external terminating network rejects an anonymous call without providing in-band information towards the originating network.
8.2.4.3 Mobile Additional Function p. 39
The following Mobile Additional Function has been identified:
MAF024
ACR related authorizations examination
The ability of a PLMN component to determine the authorizations relating to ACR. See Figure 8.2.4.3.1.
Location: HLR
Figure 8.2.4.3.1: MAF024 Anonymous Call Rejection related authorisations examination (HLR)
(⇒ copy of original 3GPP image)
(⇒ copy of original 3GPP image)
8.2.5 Interrogation p. 40
When provisioned in the subscription, the mobile subscriber should be able to interrogate the network to determine the status of the ACR supplementary service by USSD procedure (see TS 23.090). The USSD string to be used to interrogate the status of the service is operator specific and should be operator configurable in the HLR.
8.2.6 Exceptional procedures p. 41
If the mobile subscriber attempts to activate, deactivate or interrogates the ACR supplementary service and the HLR can not comply to the request, the HLR shall reject the request.
Possible reasons for rejection are:
- the ACR supplementary service is not subscribed to.
8.3 Interactions with other supplementary services p. 41
8.4 Interactions with other network features and services p. 41
8.4.1 Operator Determined Barring (ODB) p. 41
The call shall be barred if the incoming call to the mobile subscriber is determined to be barred by either the Operator Determined Barring service or the ACR supplementary service.
8.4.2 Optimal Routeing p. 41
The calling user may not get an indication that the call is rejected due to the application of the ACR supplementary service if the GMSC does not support the ACR supplementary service.
$ Change history p. 42
