Once AR remote cooperation application is launched, the local UE sends a SIP re-INVITE request with an SDP offer which includes a video media description with an
"a=sendonly" attribute line to establish a video stream (see B001 in
Figure C.2.1.1-1) as specified in
TS 24.229 and
TS 24.173 and a data channel media description with
"a=dcmap" attribute line containing
"stream-id" parameter set to the values starting at 1000 and
"a=3gpp-req-app" attribute line to establish an application data channel (see A001 in
Figure C.2.1.1-1) as specified in
clause 9.3. The
"a=3gpp-req-app" attribute line indicates that the newly established application data channel is used for AR Remote Cooperation application.
After application data channel and video stream established, the local UE may decide to start split rendering. If the local UE decides to split rendering, the UE shall use the procedure defined in
TS 26.264.
After split rendering negotiation procedure finished, both the local UE or remote UE extracts the original AR anchors input by the user and transmits it to MF through the established application data channel.
When receiving the updated AR anchors transmitted via application data channel from the MF, both the local UE and the remote UE displays the updated AR anchors based on video stream.
When receiving the SIP re-INVITE request from local UE, IMS AS shall notify the DCSF about media change request related to local UE requesting to setup an application data channel and a new video.
When receiving media reservation instruction from DCSF, the IMS AS shall convert the media instructions to the corresponding media resource operations and request MF to create or update media resources, and reserve media processing resources for AR Remote Cooperation.
When receiving response from MF on the media resources reservation or update, IMS AS sends media reservation response to DCSF, indicating the URL addresses of each stream involved AR Remote Cooperation service control, which is specified in 3GPP TS 29.175 [18].