26.1143GPPIP Multimedia Subsystem (IMS)Media handling and interactionMultimedia telephonyRelease 18TS
End-to-end delay and jitter performance plays an important role in determining MTSI quality of experience. MTSI sender and MTSI receiver may perform adaptation based on delay budget adjustments, including jitter buffer size adaptation at the receiver, air interface delay adjustments at both sender and receiver using RAN delay budget reporting as specified in TS 36.331  for E-UTRA and TS 38.331  for NR. MTSI sender and MTSI receiver may also exchange delay budget information (DBI) with each other as described in clause 7.3.8, to signal available delay budget as well as to request delay budget.
This clause provides various example informative signalling flows on delay adaptation using these mechanisms.
Figure V.2.1 presents a signaling flow example for RAN delay budget reporting usage for voice in MTSI without DBI signalling.
Figure V.2.2 and V.2.3 present signaling flow examples for RAN delay budget reporting usage in MTSI involving uni-directional DBI signalling with only indication of available delay budget from MTSI receiver to MTSI sender.
Figure V.2.4 presents a signaling flow example for RAN delay budget reporting usage in MTSI involving bi-directional DBI signalling with indication of available delay budget from MTSI receiver to MTSI sender and requested delay budget from MTSI sender to MTSI receiver.
Figure V.2.5 presents a signalling flow example on usage of RAN delay budget request in MTSI with bi-directional DBI signalling and with jitter buffer adjustment.