4.3.1 Handling of FM control in HLRa

23.0943GPPFollow-Me (FM)Release 17Stage 2TS

The FM USSD application in HLRa is the process FM_initiating_subscriber_handling_in_HLR (figure 4.2). It receives the FM-Request from the initiating subscriber. This FM-Request is an USSD-string containing:

– the operation code (register, erase, interrogate);

– the remote number;

– an additional operator specific information field.

The HLR checks:

– the provisioning of FM to the initiating subscriber;

– whether the FFN can be deduced from the remote number;

– whether any operator specific restrictions to engage in FM activity with the remote party apply;

– if the initiating subscriber requires forced erasure, the HLR checks Whether the initiating subscriber is entitled to do it, i.e. Whether the initiating subscriber is a FM service supervisor.

The basic MSISDN of the initiating subscriber is sent together with the original USSD string to the FFN of the remote party.

The HLR forwards the response from the FFN to the initiating subscriber.

For successful forced erasure by a service supervisor, the HLR of the previously registered subscriber (HLRp) shall relay the USSD Notify to the VLR when the USSD Notify from the FFN is received. The VLR will then forward the USSD Notify towards the MS of the previously registered service subscriber.

On receipt of an USSD response from the MS of the previously registered subscriber, the HLRp shall relay it to the FFN.

Figure 4.2: Process: FM_Initiating_Subscriber_Handling_in_HLR

Figure 4.2a: Process Notification_for_previously_registered_subscriber_in_HLRp