Enhancement on voice call continuity during handover

A Serving GPRS Support Node (SGSN), comprising:

• one or more hardware elements;
• wherein said one or more hardware elements are configured to:
• receive a request for registering in the SGSN from a user equipment UE upon a handover from a source radio access network, RAN, to a target RAN, the source RAN providing voice service via a packet switched domain and the target RAN providing voice service via a circuit switched domain;
• obtain mobility management for the UE from the target RAN;
• inquire of a Home Location Register/Home Subscriber Server (HLR/HSS), about a first Mobility Management Entity (MME) for mobility management for the UE in the source RAN if the mobility management for the UE fails to be transferred from a second MME to the SGSN, wherein the first MME is determined based on a correlation between the UE and the first MME registered in the HLR/HSS, and the second MME is determined from the request for registering from the UE.

A method for enhancing voice call continuity during a handover of a user equipment UE from a source radio access network, RAN, to a target RAN, the source RAN providing voice service via a packet switched domain and the target RAN providing voice service via a circuit switched domain, the method comprising:

• receiving a request for registering in a first node for mobility management in the target RAN from the UE;
• if the mobility management for the UE fails to be transferred from a second node for mobility management in the source RAN to the first node, inquiring of a Home Location Register/Home Subscriber Server (HLR/HSS) about a third node for mobility management for the UE in the source RAN, wherein the second node is determined from the request for registering, and the third node is determined based on a correlation between the UE and the third node;
• and
• sending to the third node a request for transferring the mobility management for the UE from the third node to the first node.