VoLGA Function Entity HOSF:
*HOSF = Handover Selection Function*
- In case of handover, the HOSF decides if the HO request from the MME is for VoLGA or for IMS/SRVCC and routes the request accordingly (i.e. either to the serving VANC or to the MSC Server enhanced for SRVCC).
- HOSF shall support the VANC-UE binding creation and deletion procedures so that it can make these decisions based on the stored record of the serving VANC for the UE.
- HOSF is a logical functional entity, which can be deployed according to operator's requirements (e.g. separate entity, embedded in MME or VANC).