Proof-of-presence indicator

A method performed by a user equipment, UE, present in a visited public land mobile network, VPLMN, comprising:

• generating a proof-of-presence indicator that represents the UE as being present in the VPLMN by using a secret shared between the UE and at least a home public land mobile network, HPLMN, of the UE;
• sending the proof-of-presence indicator to the VPLMN, the proof-of-presence indicator used by the HPLMN for verification as to whether or not the UE is present in the VPLMN, the verification including a determination regarding whether or not the proof-of-presence indicator was generated by the UE using the secret;
• and
• wherein generating the proof-of-presence indicator comprises generating verification information, wherein the verification information comprises a freshness value, and wherein the freshness value is updated only where a failure indication corresponding to an HPLMN verification is not received during a particular time duration after sending the proof-of-presence indicator to the VPLMN.

A network node of a home public land mobile network, HPLMN, of a user equipment, UE, the network node comprising:

• a processor and a memory, the memory containing instructions executable by the processor whereby the network node is configured to:
• obtain, from a visited public land mobile network, VPLMN, a proof-of-presence indicator that represents the UE as being present in the VPLMN, the proof-of-presence indicator generated by the UE, by using a secret shared between the UE and at least the HPLMN;
• verify whether or not the UE is present in the VPLMN by determining whether or not the proof-of-presence indicator was generated by the UE using the shared secret;
• and
• wherein generating the proof-of-presence indicator, at the UE, comprises generating verification information, wherein the verification information comprises a freshness value, and wherein the freshness value is updated only where a failure indication corresponding to an HPLMN verification is not received, by the UE, during a particular time duration after obtaining the proof-of-presence indicator from the VPLMN.

A user equipment, UE, present in a visited public land mobile network, VPLMN, the UE comprising:

• a processor and a memory, the memory containing instructions executable by the processor whereby the network node is configured to:
• generate a proof-of-presence indicator that represents the UE as being present in the VPLMN by using a secret shared between the UE and at least a home public land mobile network, HPLMN, of the UE;
• send the proof-of-presence indicator to the VPLMN, the proof-of-presence indicator used by the HPLMN for verification as to whether or not the UE is present in the VPLMN, the verification including a determination regarding whether or not the proof-of-presence indicator was generated by the UE using the secret;
• and
• wherein generating the proof-of-presence indicator comprises generating verification information, wherein the verification information comprises a freshness value, and wherein the freshness value is updated only where a failure indication corresponding to an HPLMN verification is not received during a particular time duration after sending the proof-of-presence indicator to the VPLMN.