Abstract: A method for setting-up a data connection during a group voice service between several group members as a user of a mobile communication network. In a first method, functions of an IP multimedia subsystem (IMS) are used and a session initiation protocol (SIP) and a controlled data connection between an emitter, a terminal and one or several receivers is produced. Each user is allocated to a group voice service identity (VGCS-ID) an IMS group identity (IMS group ID) and is routed to an application server in the IMS with the aid of the user. A data group voice service is developed between the users. In a second method, each user is routed to the service nodes via GPRS using a group voice service identity (VGCS-ID) and an IP address of a service node, which acts as a relay and a data group voice service is carried out between the users.