A.2 Charging Characteristics in Gn/Gp SGSN

32.2513GPPCharging managementPacket Switched (PS) domain chargingRelease 17Telecommunication managementTS

The Gn/Gp SGSN applies a pre-configured default if no Charging Characteristics are supplied by the HLR/HSS.
The SGSN shall support three different Charging Characteristics default configurations:

– the home default behaviour for subscribers of the SGSN’s PLMN;

– the visiting default behaviour for visitors using a P-GW belonging to the same PLMN as the SGSN;

– the roaming default behaviour for visitors using a P-GW belonging to their home PLMN.

The SGSN can determine the P-GW PLMN from the operator identifier part of the APN. Optionally the SGSN may support several visiting and roaming default behaviours based on the MNC/MCC combination of the subscriber.

In the case of a home subscriber, the Charging Characteristics are selected by the SGSN according to the following procedures. For IP-CAN bearer specific Charging Characteristics (i.e. those used for the S-CDRs that are generated for this IP-CAN bearer):

• If the MS requests a particular APN then:

* If the SGSN accepts this request (i.e. it has been verified against the subscription) then:

• If it has been matched against the wildcard APN then:

– If Charging Characteristics for the wildcard APN are present in the subscription information then they shall be used;

– If no Charging Characteristics are present for the wildcard APN but subscription related Charging Characteristics are present, then they shall be chosen;

– If neither of the two are present then the SGSN home default shall be applied.

• If it has been matched against a specific subscribed APN then:

– If Charging Characteristics for this APN are present in the subscription information then they shall be used;

– If no Charging Characteristics are present for the APN but subscription related Charging Characteristics are present, then they shall be chosen;

– If neither of the two are present then the SGSN home default shall be applied.

* If the SGSN rejects the request then Charging Characteristics selection does not apply.

• If the MS does not request an APN then:

* If the SGSN chooses a subscribed APN then:

– If Charging Characteristics for this APN are present in the subscription information then they shall be used;

– If no Charging Characteristics are present for the APN but subscription related Charging Characteristics are present, then they shall be chosen;

– If neither of the two are present then the SGSN home default shall be applied.

* If only the wildcard APN is present in the subscription, i.e. the SGSN applies its configured default APN then:

– If Charging Characteristics for the wildcard APN are present in the subscription information then they shall be used;

– If no Charging Characteristics are present for the wildcard APN but subscription related Charging Characteristics are present, then they shall be chosen;

– If neither of the two are present then the SGSN home default shall be applied.

For the non-IP-CAN bearer specific CDR types, i.e. the M-CDRs and the SMS CDRs, the SGSN applies the subscription specific Charging Characteristics, or, if not supplied, it shall choose the home default behaviour as defined above.

In case of subscribers from other PLMNs, the SGSN may be configured to either apply the "home subscriber case" Charging Characteristics selection procedure defined above, or to ignore Charging Characteristics provided by the subscriber’s HLR, and apply a default configuration instead. If default Charging Characteristics are selected for the foreign subscriber, then the SGSN shall choose either the visiting or roaming default behaviour for the IP-CAN bearer specific Charging Characteristics, according to the roaming or visiting scenario, as described above. For M-CDRs and SMS CDRs, the operator can configure if the roaming or the visiting behaviour shall be applied, since no P-GW is involved.

Upon activation of a IP-CAN bearer, the SGSN forwards the Charging Characteristics to the P-GW according to the following rules:

– if Charging Characteristics were received from the HLR/HSS, then they shall be sent as provided by the HLR/HSS, regardless of the home, visiting, or roaming case, and regardless of whether the SGSN applies the HLR/HSS supplied Charging Characteristics or chooses to ignore them;

– if no Charging Characteristics were received from the HLR/HSS, then the SGSN does not forward any Charging Characteristics to the P-GW.

If no charging characteristics were received from the HLR/HSS or from another MME or SGSN, then SGSN does not provide any charging characteristics to any MME or SGSN in mobility cases.

If charging characteristics were received from HLR/HSS, but not for all the IP-CAN bearers, then SGSN does not provide any charging characteristics to any MME or SGSN in mobility cases occuring through GTPv1.