Hi Ganesh, As per specification, three types of Session and Service Continuity mode (SSC) modes have been defined yet. These three difference types of SSC mode is used for an UE based on the PDN session characteristics. During the establishment of PDN session, SSC mode is selected either by UE or network.
SSC mode 1 is used for PDU session which requires all time connectivity regardless of UE mobility events.
SSC mode 2 is used for PDU sessions which does not have requirement of all time connectivity. In this case, network may ask UE to release the active PDU session and immediately connect to the same data network through new PDU session.
SSC mode 3 is slightly differ from the mode 2, in this mode UE may be asked to establish a new PDU session for the same data network before release the previous PDU session.
These are basic differences what I know but as of now I am not aware about the real use cases. I will share once I come across use cases details.
