Voice Interruption during Handover means that there is a discontinuity of voice packets or voice media flow in both directions i.e., Downlink (DL) and Uplink (UL).
If the Handover is successful, still there could be some voice interruption even though not noticeable by the human ear. During HO scenario the interruption which takes place in both directions can be computed as shown in the schematics below.
Core, Transport, IMS and service networks are all shown in the cloud description of the diagram.
Using the above schematics for the VoLTE architecture at high, the voice interruption in Upink and Downlink can be computed as follows.
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