The present document gives the stage 2 description of the call barring services. The possibility for a mobile subscriber to have certain categories of calls barred originated from or terminated at his access: Barring of outgoing calls (clause 1):

• Barring of all outgoing calls (BAOC) (Barring program 1);
• Barring of outgoing international calls (BOIC) (Barring program 2);
• Barring of outgoing international calls EXCEPT those directed to the home PLMN country (BOIC-exHC) (Barring program 3).

Barring of incoming calls (clause 2):

• Barring of all incoming calls (BAIC) (Barring program 1);
• Barring of incoming calls when roaming outside the home PLMN country (BIC-Roam) (Barring program 2);
• Anonymous Call Rejection (ACR) (Barring program 3).

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.

For the purposes of the present document, the abbreviations given in TR 21.905 apply.

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

• Barring of outgoing calls;
• Barring of incoming calls.

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 (clauses 6.6 and 7.6) 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.

The following data are stored in the HLR in common for all call barring services other than ACR:

• The "notification to CSE flag". This flag applies for all call barring services. When the data for any Call Barring 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 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 barring services. See TS 23.078.