If the terminating party has connected line identification restriction provisioned and it is impossible to indicate to the originating network (due to interworking) that the number should not be presented to the originating party, the connected line identity shall not be delivered to the originating network.
Status check
The mobile subscriber can request the status of the supplementary service and be informed if the service is provided to him/her. This procedure is illustrated in
Figure 4.1.
The following Mobile Additional Functions have been identified for the PLMN:
Determination of the connected line identification restriction subscription
The ability of a PLMN component to determine whether the supplementary service is provisioned for the mobile subscriber. See
Figure 4.2.
Location: VLR.
Determination of the connected party number for offering to the calling party
The ability of a PLMN component to determine and to forward the connected line identity and related indications to the calling party. See
Figure 4.3.
Location: terminating MSC.
The information flow is shown in
Figure 4.4.
COLR may have the following logical states (refer to
TS 23.011 for an explanation of the notation):
The HLR shall store the logical state of COLR (which shall be one of the valid states listed above) on a per subscriber basis.
The following Figure shows the successful cases of transition between the applicable logical states of COLR. The state changes are caused by actions of the service provider.
Note that error cases are not shown in the diagram as they normally do not cause a state change. Additionally, some successful requests may not cause a state change. Hence they are not shown in the diagram.
When the subscriber registers on a VLR, the HLR shall send that VLR information about the logical state of COLR.
If the logical state of COLR is changed while a subscriber is registered on a VLR then the HLR shall inform the VLR of the new logical state of COLR.
For COLR, the VLR shall store the service state information received from the HLR.
Handover will have no impact on the control procedures and the operation of the service.
The VPLMN needs to distinguish three cases in order to meet data privacy requirements in an environment where support of COLP and COLR is optional:
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the HPLMN supports COLR, and COLR is provisioned for the subscriber;
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the HPLMN supports COLR, but COLR is not provisioned for the subscriber;
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the HPLMN does not support COLR.
In case a) the VPLMN must apply the COLR subscription as indicated by the data sent by the HPLMN.
In case b) the VPLMN must not apply COLR.
In case c) the VPLMN must apply an implicit COLR subscription.
To allow the VPLMN to make this distinction, the HLR and VLR behave as follows:
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If the HLR supports COLR, but COLR is not provisioned for the subscriber, the HLR shall inform the VLR that COLR is not provisioned.
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If the VLR supports COLR, but the HLR does not support COLR, the VLR shall behave in the same way as if COLR was provisioned for the subscriber, i.e. the connected line identity shall not be displayed to the calling subscriber unless the calling subscriber has COLR override capability. When interrogating the service status the subscriber shall be informed that COLR is provided to him and is active.