0 Scope

23.0823GPPCall Forwarding (CF) Supplementary ServicesRelease 17Stage 2TS

The present document gives the stage 2 description of the call forwarding supplementary services.

The group of supplementary services call offering supplementary services is divided into 4 different supplementary services:

– Call forwarding unconditional (CFU) (clause 1);

– Call forwarding on mobile subscriber busy (CFB) (clause 2);

– Call forwarding on no reply (CFNRy) (clause 3);

– Call forwarding on mobile subscriber not reachable (CFNRc) (clause 4).

0.1 References

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

– References are either specific (identified by date of publication, edition number, version number, etc.) or non‑specific.

– For a specific reference, subsequent revisions do not apply.

– For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.

[1] 3GPP TR 21.905: "Vocabulary for 3GPP specifications".

[2] 3GPP TS 22.004: "General on supplementary services".

[3] 3GPP TS 22.082: "Digital cellular telecommunications system (Phase 2+); Call Forwarding (CF) Supplementary Services ‑ Stage 1".

[4] 3GPP TS 23.011: "Technical realization of Supplementary Services".

[5] 3GPP TS 23.015: "Technical realisation of Operator Determined Barring (ODB)".

[6] 3GPP TS 22.078: "Customised Applications for Mobile network Enhanced Logic (CAMEL); Service description, Stage 1".

[7] 3GPP TS 23.018: "Basic Call Handling; Technical ealization".

[8] 3GPP TS 23.078: "Customised Applications for Mobile network Enhanced Logic (CAMEL) Phase 3 – Stage 2".

[9] 3GPP TS 23.079: "Support of Optional Routeing (SOR); Technical realization".

[10] 3GPP TS 29.002: "Mobile Application Part (MAP) specification".

[11] 3GPP TS 23.093: "Completion of Calls to Busy Subscriber (CCBS) ; Stage2".

[12] 3GPP TS 23.088: "Call Barring (CB) Supplementary Service; Stage 2".

0.2 Abbreviations

For the purposes of the present document, the abbreviations defined in 3G TR 21.905 apply.

0.3 The forwarded-to number

As indicated in 3GPP TS 22.082 the forwarded-to numbers are stored in the international format.

If according to 3GPP TS 22.082 the served subscriber is provided with a Translation Information Flag (TIF-CSI) then the HPLMN shall treat the forwarded-to number transparently at the time of registration, i.e. not perform any checks or translations. In this case the forwarded-to number shall be stored in the format as it was received from the MS.

Therefore, if transferred, the forwarded-to number is transferred from the HLR to other network entities and stored in the VLR always in the format as stored in the HLR..

0.4 Cross phase compatibility

For the following supplementary services, a number of changes exist between the present document and the Phase 1 specification:

– Call forwarding unconditional;

– Call forwarding on mobile subscriber busy;

– Call forwarding on no reply;

– Call forwarding on mobile subscriber not reachable.

The main body of the present document assumes that all network entities comply with this version of the service. In each case an additional clause (clause x.6) defines the additional requirements for when one or more network entities or the MS complies with the Phase 1 specifications for the supplementary service procedures.

0.5 Support of Long Forwarded-to Numbers

For the following supplementary services, it shall be possible to register a long forwarded-to number which was not possible in previous versions of the services:

– Call forwarding unconditional;

– Call forwarding on mobile subscriber busy;

– Call forwarding on no reply;

– Call forwarding on mobile subscriber not reachable.

The main body of the present document assumes that all network entities comply with this version of the service. In each case an additional clause (clause x.10) defines the additional requirements when one or more network entities and/or the mobile station does not support Long Forwarded-to Numbers.

The functionality specified in this document does not imply any constraint on the length of a forwarded to number, except where such a constraint is explicitly stated.

0.6 Data stored in the HLR for all call forwarding services

The following data are stored in the HLR in common for all call forwarding services:

– The "notification to CSE flag". This flag applies for all call forwarding services. When the data for any Call Forwarding are changed, the HLR checks this flag. If the flag is set, the change is reported to the gsmSCF(s) defined by the gsmSCF address list. See 3GPP TS 23.078.

– The "gsmSCF address list", which is a list of gsmSCF addresses to which Notification on Change of Subscriber Data is to be sent. This list applies to all call forwarding services. See 3GPP TS 23.078.