Abstract: An IP-based group communication feature in a mobile communication network is based on the pre-established logical connections established between a gateway node (GGSN) and members of a group in the mobile communication network. No separate call establishment procedures using VoIP signaling are used for connecting a user equipment (UE) logically to group(s), but the procedure is preferably based on the normal logical connection establishment signaling (e.g. PDP context creation) as used for data service. The UE implements a host supporting the IP multicasting, and the next IP layer peer for the UE host is located in the gateway node. The gateway node provides an IP interface towards an external multicast router so that the UE host looks like a normal IP host supporting IP multicasting. The IP-based voice traffic is mapped and transferred over pre-established connections between the gateway and the UEs of the specific group.

Abstract: A method of activating a packet data protocol context for a roaming terminal in a telecommunication system including a home network, a gateway support node to external packet networks, the node being used in the home network, at least one terminal and a visited network. When the terminal requests for packet data protocol context activation in the visited network, the visited network defines the gateway support node address on the basis of the network identifier and a subscriber identifier transmitted by the terminal. On the basis of the defined address, a request for packet data protocol context activation is transmitted from the visited network to the gateway support node and the activation of the packet data protocol context is finished.

Abstract: A method of activating a packet data protocol context for a roaming terminal in a telecommunication system comprising a home network, a gateway support node to external packet networks, said node being used in the home network, at least one terminal and a visited network. However, there is no signalling interface between the home network and the visited network to support mobility management. In the method and system of the invention, a network identifier of an access point served by the gateway support node is stored in the visited network for a roaming terminal. When the terminal requests for packet data protocol context activation in the visited network, the visited network defines the gateway support node address on the basis of the network identifier and a subscriber identifier transmitted by the terminal.

Abstract: An IP-based group communication feature in a mobile communication network is based on the pre-established logical connections established between a gateway node (GGSN) and members of a group in the mobile communication network. No separate call establishment procedures using VolP signallings are used for connecting a user equipment (UE) logically to group(s), but the procedure is preferably based on the normal logical connection establishment signalling (e.g. PDP context creation) as used for data service. The user equipment (UE) implements a host supporting the IP multicasting, and the next IP layer peer for the UE host is located in the gateway node (GGSN). The gateway node (GGSN) provides an IP interface towards an external multicast router (22, 23) so that the UE host looks like a normal IP host supporting IP multicasting. The IP-based voice traffic is mapped to and transferred over the pre-established connections between the gateway (GGSN) and the UEs of the specific group.