Abstract: A subscriber database maintains a data record related to a user equipment. The subscriber database receives an indication from a control node which is responsible for controlling a plurality of packet switched network accesses, The indication indicates whether voice communication with the user equipment over circuit switched access is supported or unsupported homogeneously for all the network accesses controlled by the control node. The subscriber database stores the indication in the data record. If the subscriber database receives a request from a termination control node which is responsible for controlling termination of a voice session with the user equipment, it processes the request depending on the stored indication. In some cases, if the indication indicates that voice communication with the user equipment over circuit switched access is unsupported homogeneously, the subscriber database may reject the request without further interaction with other nodes.

Abstract: According to a first aspect there is provided a method of operating an entity within an IMS network. The method comprises, receiving a message sent by a UE, determining if media other than voice can be supported for IMS emergency sessions involving the UE,and sending a response to the UE, the response indicating if media other than voice can be supported for IMS emergency sessions involving the UE.

Abstract: A method is provided of performing a handover with SRVCC to a target PS access network of an emergency call to a PSAP from a UE accessing a CS access network. The method includes sending a handover request from the CS access network towards an IMS network to transfer the emergency call. A CS to PS emergency handover command is sent to the UE, including an emergency STN identifying an access transfer control function. The UE sends a SIP INVITE to establish an emergency IMS session over the PS access network. The SIP INVITE includes the emergency STN so that the INVITE is routed to the access transfer control function. The emergency call sent over the CS access network with the emergency IMS session are correlated and the emergency call is switched to the emergency IMS session over the PS access network to complete the handover.

Abstract: A method and apparatus for key management in a communication network. A Key Management Terminal KMS Terminal Server (KMS) receives from a first device a request for a token associated with a user identity, the user identity being associated with a second device. The KMS then sends the requested token and a user key associated with the user to the first device. The KMS subsequently receives the token from the second device. A second device key is generated using the user key and a modifying parameter associated with the second device. The modifying parameter is available to the first device for generating the second device key. The second device key is then sent from the KMS to the second device. The second device key can be used by the second device to authenticate itself to the first device, or for the first device to secure communications to the second device.

Abstract: Methods and apparatus are described for use in handling session establishment in a home network or visited network. IMS roaming is described for a UE of the home network that is roaming in the visited network. On receipt of a session establishment request associated with an originating call from the UE the home network determines whether to perform home routing and/or direct home routing of the originating call to the called party. When home routing, execution of service invocation is suspended and the home network sends a session establishment request including a routing number of an application server in the home network back to the visited network, which performs visiting service invocation of the call and routes the signaling and media to the home network-based on the routing number. The network node in the home network resumes execution of service invocation and routing of the originating call to the called party.

Abstract: An IMS system includes an IMS initiator user entity. The system includes an IMS responder user entity that is called by the initiator user entity. The system includes a calling side S-CSCF in communication with the caller entity which receives an INVITE having a first protection offer and parameters for key establishment from the caller entity, removes the first protection offer from the INVITE and forwards the INVITE without the first protection offer. The system includes a receiving end S-CSCF in communication with the responder user entity and the calling side S-CSCF which receives the INVITE without the first protection offer and checks that the responder user entity supports the protection, inserts a second protection offer into the INVITE and forwards the INVITE to the responder user entity, wherein the responder user entity accepts the INVITE including the second protection offer and answers with an acknowledgment having a first protection accept.

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 enabling delivery of a message in a communication system comprising an IMS domain and a circuit switched domain. Upon receiving a registration message in the IMS domain from a user equipment operated by a user, wherein the message comprises an Equipment Identifier valid for the user equipment and an IMPI valid for the user, the Equipment Identifier and the IMPI are extracted from the received message. Then a creation or an update of a mapping of the Equipment Identifier to the IMPI and a C-MSISDN is initiated. Upon receiving a message, relating to the user, which is to be communicate between the IMS and circuit switched domains in the communication system, a use of the mapping for translating between the Equipment Identifier, IMPI and the C-MSISDN is initiated.

Abstract: The invention related to handling core network entities of a radio core communications network comprising a first network entity and a second network entity. The said second network entity differs from the first network entity in that it is capable of processing interworking between messages exchanged with said radio core communications network and messages exchanged with an IP multimedia subsystem. In other words, one network entity is capable of performing inter-working while the other one not. The first and/or second network entities are provided (S200) with configuration information indicating a relationship between the two network entities. The invention then foreseen routing (S300) messages relating to calls established between the at least one user terminal attached to the entity non capable of inter-working and a further user terminal attached to said IP multimedia subsystem according to said configuration information.

Abstract: A method of informing a control node in a serving communication network of address information about a session anchor node in the serving communication network is described. The control node is accessible by a terminal via a circuit switched access of the serving communication network. The serving communication network of the terminal is different from an internet protocol based home communication network of the terminal. The method is executed by a session anchor node in the home communication network. The method includes receiving an update request for the control node being updated of address information about the session anchor node in the serving communication network, receiving address information about the session anchor node in the serving communication network, and sending the received address information based on the received update request.

Abstract: A user terminal for use with a communications system. The user terminal comprises a non-volatile memory and a subscriber identity authentication unit configured in use to communicate with a removable subscriber identity module and with said communications system in order to authenticate a subscriber identity stored in said subscriber identity module. A recording unit is provided for recording a used and authenticated subscriber identity in said non-volatile memory, while an emergency call initiation unit is configured to initiate an unauthenticated emergency call in the absence of a subscriber identity module, and to retrieve said used and authenticated subscriber identity from said non-volatile memory and to provide the retrieved subscriber identity to the communications system during the initiation.

Abstract: The invention relates to password-based authentication in group networks. Each device has an authentication token irreversibly based on the password. The authentication involves a first device at which the password P is entered and a second device towards which the authentication occurs. The first device determines a check token Mj for the second based on the password and its own authentication token Rl and this check token is sent to the second device, where it is compared with the authentication token of that device. The procedure may include update of a device to exclude a non-trusted device from the group or change the password. Advantageous features are that the information in one device does not allow retrieval of the password and that the password is only exposed at one device, and only temporarily, during the authentication.

Abstract: A method of sending protected data from a sender unit to a receiver unit via an intermediate unit. The intermediate unit stores information associated with a certificate belonging to the receiver unit, and information associated with a certificate belonging to the intermediate unit, which has previously been signed by the receiver unit. The intermediate unit receives a request from the sender unit to send protected data to the receiver unit, and so it sends a response to the sender unit. The response includes the information associated with the certificate belonging to the receiver unit, which allows the sender unit to verify that the intermediate unit is authorized to receive data on behalf of the receiver unit. The intermediate unit then receives data from the sender unit that is protected using the information associated with the certificate belonging to the receiver unit for subsequent forwarding to the receiver unit.

Abstract: A method of Dual Radio Access Transfer of an IP Multimedia session, IMS, in an alerting phase for the Packet Switched to Circuit Switched direction. The method comprises initiating an IMS media session towards a terminating mobile station, UE and, during a session alerting phase, making a determination at the UE that a DRVCC transfer is required from a Packet Switched, PS, to a Circuit Switched, CS, access. The method comprises sending a SIP message from the UE to a Service Centralization and Continuity Application Server, SCC-AS, over the PS access, informing the SCC-AS of the DRVCC transfer, and responding to receipt of the SIP message at the SCC-AS by sending a SIP INVITE from the SCC-AS towards a Mobile Switching Centre, MSC, serving the UE in the CS access, the INVITE including an identity of the UE as a called party identity and the STN as the calling party identity.

Abstract: A method and apparatus for handling a call transfer from a circuit switched access network to a packet switched access network. A Mobile Switching Centre Server receives a notification that a call for a terminal requires handover from a circuit switched access network to a packet switched access network. The MSC Server determines whether the terminal is currently registered in an IMS network and/or whether the MSC Server is registered such that it can perform handover from the circuit switched access network to the packet switched access network. If so, then return Single Radio Voice Call Continuity is invoked to perform a handover of the call from the circuit switched access network to the packet switched access network. If not then the MSC Server invokes error handling procedures.

Abstract: A method of facilitating access to services of an IP Multimedia Subsystem, by users groups that require alternative handling in relation to the standard handling of IP Multimedia Subsystem users. Functioning instructions are added to the user group s subscription maintained in the IP Multimedia Subsystem, instructing nodes in the IP Multimedia Subsystem to adapt their standard functioning for this specific group of users. The instructions in a subscription of a specific user group, provide a node of the IP Multimedia Subsystem that does no longer need to be specific for certain types of users, but has a standard way of operation, that is modified by instructions for dedicated operation for only that specific user group. In further aspect embodiments are disclosed providing improved solutions for known problems of IP Multimedia Subsystems making use of functioning instructions included in the subscription.

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 for routing a terminating call to a user equipment via a first control node for controlling the call, wherein the user equipment is attached to a second control node which is adapted to provide routing information. The method comprises determining, by the second control node, if the user equipment is attached to the second control node over a third control node, wherein the attachment over the third control node indicates that call control shall be performed by a specific service domain. Based on the determining, the provided routing information is selected by the second control node, wherein the routing information indicates to the first control node if the further call establishment to the user equipment is controlled either by the second control node or by the third control node. The call is then routed, by the first control node, according to the selected routing information.

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 handling a call transfer from a circuit switched access network to a packet switched access network. A Mobile Switching Center Server receives a notification that a call for a terminal requires handover from a circuit switched access network to a packet switched access network. The MSC Server determines whether the terminal is currently registered in an IMS network and/or whether the MSC Server is registered such that it can perform handover from the circuit switched access network to the packet switched access network. If so, then return Single Radio Voice Call Continuity is invoked to perform a handover of the call from the circuit switched access network to the packet switched access network. If not then the MSC Server invokes error handling procedures.