A VoLTE voice service continuity solution, mainly in order to solve problem of how to ensure that the voice call continuity when a single radio UE moves between the LTE / Pre-LTE network and 2G/3G CS network, i.e. to ensure a single RF UE smooth switching between IMS VoIP voice control and CS domain voice.
The simplest use model can be illustrated as in < Case 1 > of the following figure showing the SRVCC between LTE and UMTS (The detailed mechanism would vary depending on what kind of legacy technology is involved). A little bit complicated use-model can be illustrated as in < Case 2 >. In < Case 2 >, user is doing VoIP while he is using another packet transaction (e.g, email, browsing etc). In this case, the radio bearer on WCDMA side should be a multiple Radio Bearer (CS + PS). There may be many different type of use model as well.
- Vo Lte
- Vo Lte
