Section: 5.3.4.3.2 Successful completion of in-call modification
Content: If the destination network/mobile station receives a MODIFY message with a new mode which is already the actual one of the call the network/mobile station shall remain in the "active" state; send a MODIFY COMPLETE message with the actual mode; and shall not initiate anything else. If the requested mode is speech and if during call establishment the network received a Supported Codec List IE, the network shall use this list to select the codec for UTRAN. If no Supported Codec List information element is received, then for UTRAN the network shall select the default UMTS speech codec according to subclause 5.2.1.11. Codecs for GERAN shall be selected from the codecs indicated in the Supported Codec List information element or in the Bearer Capability information element. If neither a Supported Codec List information element nor a Bearer Capability information element is received, then for GERAN the network shall select GSM full rate speech version 1. If the Supported Codec List IE is received, then the network shall indicate the codec selected for Iu mode to the mobile station via RANAP and RRC protocol in the NAS Synchronisation Indicator IE (see subclause 5.2.1.11). If the in-call modification was originated by the mobile station, the mobile station and the network shall proceed as follows: If the requested mode is not the actual one and can be supported by the network it shall change the channel configuration, if required, and step on to any internal resources necessary to support the next call mode. If the requested mode is a data or facsimile mode, it shall also perform the appropriate means to take the direction of the data call into account. After successful change of the channel configuration it shall start sending user information according to the next call mode and start interpreting received user channel information according to the next call mode; send a MODIFY COMPLETE message with the new call mode included and enter the "active" state (network side). If the MODIFY message had contained a reverse call setup direction IE, the same IE shall be included in the MODIFY COMPLETE message. Upon receipt of the MODIFY COMPLETE message the mobile station shall: initiate the alternation to those resources necessary to support the next call mode; stop timer T323; and enter the "active" state (mobile station side). If the in-call modification was originated by the network, the mobile station and the network shall proceed as follows: If the requested mode is not the actual one and can be supported by the mobile station it shall reserve any internal resources necessary to support the next call mode. NOTE: For a change from speech to a different call mode, user interaction may be required, before the mobile decides that the requested mode can be supported. If the requested mode is a data or facsimile mode, it shall also perform the appropriate means to take the direction of the data call into account. The mobile station shall send a MODIFY COMPLETE message with the new call mode included, stop timer T324 and enter the "active" state (mobile station side). If the MODIFY message had contained a reverse call setup direction IE, the same IE shall be included in the MODIFY COMPLETE message. If the old call mode is speech, the mobile station shall continue sending Bm-channel information and interpreting received Bm-channel information for speech until the network modifies its channel configuration. After receipt of the MODIFY COMPLETE message the network shall: reserve any internal resources necessary to support the next call mode, stop sending Bm-channel information, and stop interpreting received Bm-channel information according to the old call mode, unless these actions were already performed earlier. Furthermore, the network shall change the channel configuration, if required; after successful change of the channel configuration initiate the alternation to those resources necessary to support the next call mode; stop timer T323; and enter the "active" state (network side). The mobile station shall start sending user information according to the next call mode and start interpreting received user channel information according to the next call mode as soon as a suitable channel for the new mode is available. In both cases: For an alternate speech/facsimile group 3 service (refer to subclause 5.3.4) the old resources may still be kept reserved. The reaction of the originating side if it had included a reverse call setup direction IE in the MODIFY message, but the destination side did not include the IE in the MODIFY COMPLETE message is implementation dependent.