Packet-based conversational service for a multimedia session in a mobile communications system

A method for establishing a session that includes a packet-based voice communication involving a mobile radio terminal that is configured to access a General Packet Radio Services (GPRS) network via a radio access network, comprising:

• establishing for the session a first Packet Data Protocol (PDP) context for session messages relating to a packet-based voice service and supporting a first quality of service selected for session messages;
• establishing for the session a second PDP context for voice packets and supporting a second quality of service selected for voice packets;
• and
• establishing for the session a third PDP context for control messages associated with the voice packets and supporting a third quality of service selected for control messages.

A mobile terminal for use in a mobile communications system that includes a packet-based access network, comprising electronic circuitry configured to perform the following tasks related to establishing an IP session:

• coordinate with a node in the packet-based access network to establish a first bearer extending between the mobile terminal and the packet-based access network;
• use the first bearer to initiate an IP session including a conversational IP service, the first bearer for carrying one or more session messages for implementing the conversational IP service;
• coordinate with the packet-based access network node to establish a second bearer for the IP session extending between the mobile terminal and the packet-based access network to carry voice packets associated with the conversational IP service;
• and
• coordinate with the packet-based access network node to establish a third bearer for the IP session extending between the mobile terminal and the packet-based access network to carry control messages associated with the conversational IP service.

A mobile terminal for use in a mobile communications system that includes a radio access network coupled to a General Packet Radio Services (GPRS) network, comprising electronic circuitry configured to perform the following tasks related to establishing an IP session:

• coordinate with a GGSN node in the GPRS network to establish a first Packet Data Protocol (PDP) context for session messages relating to a conversational IP service that supports a first quality of service selected for session messages;
• coordinate with a Gateway GPRS Support Node (GGSN node in the GPRS network to establish a second PDP context for voice packets that supports a second quality of service selected for voice packets;
• and
• coordinate with the GGSN node to establish a third PDP context for control messages associated with the voice packets that supports a third quality of service selected for control messages.

A node for use with a packet-based access network, comprising electronic circuitry configured to perform the following tasks related to establishing an IP session:

• coordinate with a mobile radio terminal to establish a first bearer extending between the mobile radio terminal and the packet-based access network, wherein the first bearer is useable to establish the IP session including a conversational IP service and to carry one or more session messages for implementing the conversational IP service;
• coordinate with the mobile radio terminal to establish a second bearer for the IP multimedia session extending between the mobile radio terminal and the packet-based access network to carry voice packets associated with the conversational IP service;
• and
• coordinate with the packet-based access network node to establish a third bearer for the IP session extending between the mobile radio terminal and the packet-based access network to carry control messages associated with the conversational IP service.

A method for establishing a session involving a mobile radio terminal configured to access a packet-based access network via a radio access network comprising:

• establishing a first bearer extending between the mobile terminal and the packet-based access network;
• using the first bearer to initiate a session that includes a packet-based voice communication and to carry one or more session messages for implementing a packet-based voice service;
• establishing a second bearer for the session extending between the mobile terminal and the packet-based access network and carrying voice packets associated with the packet-based voice service;
• and
• using the first bearer to carry control messages associated with the packet-based voice service.

A node for use a mobile communications system that includes in a packet-based access network, comprising electronic circuitry configured to perform the following tasks related to establishing an IP session:

• coordinate with a mobile radio terminal to establish a first bearer extending between the mobile radio terminal and the packet-based access network configured to establish the IP session including a conversational IP service and to carry one or more session messages for implementing the conversational IP service;
• coordinate with the mobile radio terminal to establish a second bearer for the IP multimedia session extending between the mobile radio terminal and the packet-based access network to carry voice packets associated with the conversational IP service;
• and
• coordinate with the packet-based access network node to configure the first bearer to carry control messages associated with the conversational IP service.