7.11 Procedures over Nt reference point

23.2033GPPPolicy and charging control architectureRelease 17TS

7.11.1 Negotiation for future background data transfer

This procedure enables the negotiation between the SCEF and the H-PCRF about the time window and the related conditions for future background data transfer (as described in clause 6.1.16). The interaction between the SCEF and the H-PCRF is not related to an IP-CAN session and the H-PCRF associates the information provided by the SCEF to the policies belonging to the ASP and stored in the SPR.

Figure 7.11.1-1: Negotiation for future background data transfer

1. Based on an AF request, the SCEF sends a Background data transfer request to the H-PCRF. The background data transfer request contains ASP identifier, the volume of data to be transferred per UE, the expected amount of UEs, the desired time window and optionally, network area information (e.g. list of cell ids, TAs/RAs).

NOTE 1: The SCEF does not provide any information about the identity of the UEs potentially involved in the future background data transfer.

NOTE 2: A 3rd party application server is typically not able to provide any specific network area information and if so, the AF request is for the whole operator network.

2. The H-PCRF requests from the SPR all existing transfer policies.

3. The SPR provides all existing transfer policies and corresponding network area information to the H-PCRF.

4. The H-PCRF determines, based on information provided by the AF and other available information (see clause 6.1.16) one or more transfer policies. A transfer policy consists of a recommended time window for the background data transfer, a reference to a charging rate for this time window and optionally a maximum aggregated bitrate.

NOTE 3: The maximum aggregated bitrate is not enforced in the network.

5. The H-PCRF sends a Background data transfer response to the SCEF with the possible transfer policies and a reference ID.

NOTE 4: The SCEF forwards the information to the AF. The AF stores the reference ID for the future transfer of AF session information related to this background data transfer via the Rx interface.

6.-7. If the SCEF receives more than one transfer policy, the AF selects one of them and send another Background data transfer request to inform the H-PCRF about the selected transfer policy. The H-PCRF sends a Background data transfer response to the SCEF to acknowledge the selection.

NOTE 5: If the SCEF receives only one transfer policy, the AF is not required to confirm.

8. The H-PCRF stores the reference ID together with the new transfer policy and the corresponding network area information in the SPR.

9. The SPR sends an acknowledgement to the H-PCRF.