Abstract: A method is proposed for providing a mobile terminal associated with a user with access to a visited Internet Protocol based mobile communication network. The mobile terminal generates a network information element that comprises a home network identifying element that identifies a home network of the user, and a domain name of the visited IP based mobile communication network as a base domain identifier. The mobile terminal then provides this special network information element to visited IP based mobile communication network, which executes a subscription generating procedure for generating a subscription for the user upon recognizing the special network information element and provides the mobile terminal access based on the generated subscription.

Abstract: A method of handling a Session Initiation Protocol (SIP) communication at a SIP application server within an IP Multimedia Subsystem, the method including handling a message received from a Serving Call/State Control Function node based upon a header of the message containing the URI of the served user. The SIP message is handled according to one of an originating case based upon a P-Asserted Identity contained in the SIP message or a terminating case using a Request-Uniform Resource Identifier (R-URI) of the SIP message, the appropriate case being identified in said header.

Abstract: A method of handling a Session Initiation Protocol (SIP) communication at a SIP application server within an IP Multimedia Subsystem, the method including handling a message received from a Serving Call/State Control Function node based upon a header of the message containing the URI of the served user. The SIP message is handled according to one of an originating case based upon a P-Asserted Identity contained in the SIP message or a terminating case using a Request-Uniform Resource Identifier (R-URI) of the SIP message, the appropriate case being identified in said header.

Abstract: A method is proposed for providing a mobile terminal associated with a user with access to a visited Internet Protocol based mobile communication network. The mobile terminal generates a network information element that comprises a home network identifying element that identifies a home network of the user, and a domain name of the visited IP based mobile communication network as a base domain identifier. The mobile terminal then provides this special network information element to visited IP based mobile communication network, which executes a subscription generating procedure for generating a subscription for the user upon recognizing the special network information element and provides the mobile terminal access based on the generated subscription.

Abstract: A Session Initiation Protocol Application Server of an IP Multimedia Subsystem having processing means for handling a message received from a Serving Call/State Control Function, the means being arranged to handle the message based upon a header of the message containing the URI of the served user, this header having been introduced by the Serving Call/State Control Function and being other than the P-Asserted Identity and the R-URI.

Abstract: A method and apparatus for establishing a communication session in an IMS Centralized Services communication network. A Service Centralization and Continuity Application Server (SCC AS) receives a request from an originating device to establish a session with a target device. The request includes a plurality of codec identifiers that could be used by the originating device. The SCC AS sends a second request to establish the session to the target device. The SCC AS subsequently receives, from an intermediate node between the SCC AS and the target device, an invite message. The invite message includes an indication that a codec identifier has been selected from the plurality of codec identifiers. The SCC AS then sends a message to the intermediate node instructing the intermediate node to establish the session.

Abstract: A method and apparatus for use in a communications network whereby an Instance Identifier (ID) is created to uniquely identify a device such as a mobile device or User Equipment (UE) in the communications network.

Abstract: The invention relates to session control in an IMS domain of a communications network and more particularly to techniques for performing session transfer in an IMS control node (SCC AS) for controlling centralized services in an IMS domain. One embodiment of an SCC AS (200) may be adapted to store, for each of a plurality of ongoing communication sessions, a session information item (218) comprising a user identity (222) identifying a user device involved in the session and a first identifier (216) of the user device in a CS domain of the communications network, wherein the user identity is associated with multiple user devices and the first identifier comprises at least one of an MSISDN (216), an IMSI, and a GRUU.

Abstract: A method and apparatus for use in a communications network whereby an Instance Identifier (ID) is created to uniquely identify a device such as a mobile device or User Equipment (UE) in the communications network.

Abstract: A node in an IMS network receives circuit switched signalling relating to a communication session sent from a terminal over a circuit switched access network, and also receives packet switched signalling relating to the communication session sent from the terminal over a packet switched access network. The packet switched signalling comprises an identifier, and the node uses the identifier to correlate the circuit switched signalling with the packet switched signalling. This allows terminals using ICS to send signalling over both packet switched and circuit switched access networks, and a receiving node to correlate those signals.

Abstract: A method of evaluating Initial Filter Criteria (IFC) at a terminating Serving Call Session Control Function (S-CSCF) in an IP Multimedia Subsystem network. Upon receiving a Session Initiation Protocol (SIP) message containing a destination Uniform Resource Identifier (URI), the S-CSCF applies an Initial Filter Criterion to the message, sends the message to an Application Server (AS), and suspends further IFC evaluation. When a return message is received from the AS, the S-CSCF determines whether the AS changed the URI. If so, the S-CSCF makes a determination of whether to resume IFC evaluation. If the AS did not change the URI, the S-CSCF resumes IFC evaluation.

Abstract: A method and apparatus for use in a communications network whereby an Instance Identifier (ID) is created to uniquely identify a device such as a mobile device or User Equipment (UE) in the communications network.

Abstract: A method and Serving Call/State Control Function (S-CSCF) for handling a Session Initiation Protocol (SIP) communication within an IP Multimedia Subsystem (IMS), wherein the communication is subject to a call-forwarding operation handled by a SIP Application Server (AS). An INVITE is received at the S-CSCF, which serves a user equipment (UE) identified by an R-URI. The S-CSCF adds a URI for the S-CSCF to the INVITE route header together with an Original Dialog Identifier (ODI) mapped to the R-URI. The S-CSCF forwards the INVITE to the AS, which changes the R-URI to a URI of a UE to which the call is to be forwarded. The AS adds a forwarding indicator to the INVITE and returns it to the S-CSCF. The S-CSCF identifies the forwarding indicator and determines the original R-URI based on the ODI received in the returned INVITE. The S-CSCF determines call restrictions and Initial Filter Criteria (IFCs) based on the original R-URI.

Abstract: The invention relates to session control in an IMS domain of a communications network and more particularly to techniques for performing session transfer in an IMS control node (SCC AS) for controlling centralized services in an IMS domain. One embodiment of an SCC AS (200) may be adapted to store, for each of a plurality of ongoing communication sessions, a session information item (218) comprising a user identity (222) identifying a user device involved in the session and a first identifier (216) of the user device in a CS domain of the communications network, wherein the user identity is associated with multiple user devices and the first identifier comprises at least one of an MSISDN (216), an IMSI, and a GRUU.

Abstract: A method and apparatus for establishing a communication session in an IMS Centralized Services communication network. A Service Centralization and Continuity Application Server (SCC AS) receives a request from an originating device to establish a session with a target device. The request includes a plurality of codec identifiers that could be used by the originating device. The SCC AS sends a second request to establish the session to the target device. The SCC AS subsequently receives, from an intermediate node between the SCC AS and the target device, an invite message. The invite message includes an indication that a codec identifier has been selected from the plurality of codec identifiers. The SCC AS then sends a message to the intermediate node instructing the intermediate node to establish the session.

Abstract: A method is proposed for providing a mobile terminal associated with a user with access to a visited Internet Protocol based mobile communication network. The mobile terminal generates a network information element that comprises a home network identifying element that identifies a home network of the user, and a domain name of the visited IP based mobile communication network as a base domain identifier. The mobile terminal then provides this special network information element to the visited IP based mobile communication network, which executes a subscription generating procedure for generating a subscription for the user upon recognizing the special network information element and provides the mobile terminal access based on the generated subscription.

Abstract: A system and method of providing an enhanced service in a telecommunications network. The system includes a telecommunications network utilizing a circuit switched and packet switched access capability. The system also includes a sending User Equipment (UE) originating a call to a receiving UE. The sending UE sends an indicator informing the network to wait for further call information before proceeding with a call request towards the receiving UE. The system also includes a control node for routing calls within the network. The control node combines the call information received from the sending UE with call routing information of the call for connecting the call with the receiving UE to form a call request to the receiving UE. Upon receiving the call request message by the receiving UE, the call is connected and a media path is established between the receiving UE and the sending UE.

Abstract: A node in an IMS network receives circuit switched signalling relating to a communication session sent from a terminal over a circuit switched access network, and also receives packet switched signalling relating to the communication session sent from the terminal over a packet switched access network. The packet switched signalling comprises an identifier, and the node uses the identifier to correlate the circuit switched signalling with the packet switched signalling. This allows terminals using ICS to send signalling over both packet switched and circuit switched access networks, and a receiving node to correlate those signals.

Abstract: A method and apparatus for managing access domain selection for a user device accessing an IP Multimedia Subsystem (IMS) network. A Call Session Control Function (CSCF) in the IMS network stores an access domain indicator associated with a user s contact address. The access domain indicator is associated with the user s contact address when the user registers with the IMS network. The CSCF sends the access domain indicator to an Access Domain Selection (ADS) function in the IMS network, the access domain indicator to be used by the ADS function in selecting an access domain. This allows the ADS function to select the correct access domain to use when sending messages to the user device.

Abstract: A method of evaluating Initial Filter Criteria (IFC) at a terminating Serving Call Session Control Function (S-CSCF) in an IP Multimedia Subsystem network. Upon receiving a Session Initiation Protocol (SIP) message containing a destination Uniform Resource Identifier (URI), the S-CSCF applies an Initial Filter Criterion to the message, sends the message to an Application Server (AS), and suspends further IFC evaluation. When a return message is received from the AS, the S-CSCF determines whether the AS changed the URI. If so, the S-CSCF makes a determination of whether to resume IFC evaluation. If the AS did not change the URI, the S-CSCF resumes IFC evaluation.