Section: 5.2.3.2.1 Recall Alignment Procedure
Content: The recall alignment procedure consists of three parts: - basic service group alignment, - facility alignment, and - stream identifier alignment. Basic service group alignment: The mobile station shall check that the Bearer Capability, HLC and LLC and Repeat Indicator fields, which are embedded in the Setup Container IE, match a basic service group supported by the mobile station. If this check fails, then the recall alignment procedure has failed. The mobile station shall use the cause #88 "incompatible destination" afterwards. Otherwise, the mobile station is allowed to alter the content within the Bearer Capability, HLC and LLC Information Elements (e.g. the speech codec version(s), the data rate, the radio channel requirement) provided that the basic service group is not changed. Furthermore, for speech calls the mobile station is allowed to add or remove the Supported Codec List Information Element, or to alter the contents of this information element dependent on the codecs supported by the mobile station. The result shall be that the mobile station has derived Bearer Capability, HLC, LLC, and Supported Codec List Information Elements, which it can use for a later call setup according to its configuration and capabilities. Facility alignment: This only applies if the Setup Container contains 1 or more Facility IEs. Each Facility IE within the Setup Container will be associated with the common SS Version IE, if present. The handling for each Facility IE is defined below. The mobile station shall align each facility IE contained in the Setup Container. The rules defined in 3GPP TS 24.010[ Mobile radio interface  layer 3; Supplementary services specification; General aspects ]  [21] also apply. The Facility IE is encoded as 'simple recall alignment', 'advanced recall alignment' or 'recall alignment not essential' (see 3GPP TS 24.010[ Mobile radio interface  layer 3; Supplementary services specification; General aspects ]  [21]). If the encoding indicates, that - a simple recall alignment is required, the mobile station shall copy the Facility IE and the common SS version IE from the Setup Container to the SETUP message without modifying the content. - an advanced recall alignment is required, the mobile station must recognise and support the operation defined in the facility. If the mobile station does not recognise or support the operation, then the recall alignment procedure has failed and the mobile station shall use the cause #29 "facility rejected" in the subsequent rejection of the CC establishment request. - the recall alignment is not essential, then the facility operation is not an essential part of the SETUP. If the MS does not recognise the operation then the SS Version IE and Facility IE are discarded, and NOT copied into the SETUP message. NOTE: A mobile station may include a Facility IE without an associated SS Version IE. This would indicate that the SS operation is encoded using Phase 1 protocols. Further details on Facility handling are given in 3GPP TS 24.010[ Mobile radio interface  layer 3; Supplementary services specification; General aspects ]  [21]. Stream identifier alignment: The mobile station shall check whether the Stream Identifier field is contained in the Setup Container or not. If the Stream Identifier is contained in the Setup Container, the mobile station shall behave as one of the following. - the mobile station re-assign the Stream Identifier value, and modify the Stream Identifier field. - the mobile station remove the Stream Identifier field. If the Stream Identifier is not contained in the Setup Container, the mobile station may behave as follows. - the mobile station assign the Stream Identifier value, and add the Stream Identifier IE to the end of the SETUP message.