Abstract: A method of anchoring a packet switched session of a subscriber comprises receiving a packet switched request for a session setup, and anchoring the packet switched session in a control node (MSC-S) of a visited network of the subscriber.

Abstract: Exemplary methods for establishing an emergency call and an emergency call-back for a first User Equipment (UE) communicatively coupled to a visited Internet Protocol Multimedia Subsystem (IMS) network includes establishing an emergency call by the first UE sending an emergency call request to a Proxy Call Session Control Function (P-CSCF) in the visited IMS network. The methods further include providing, from the P-CSCF to a Serving CSCF (S-CSCF) in a home IMS network for the first UE, information comprising an indication that the emergency call has been performed and an equipment identifier of the first UE. The methods further include receiving, in the S-CSCF, an emergency call-back request from an emergency call-center, and using, in the S-CSCF, information comprised in the received emergency call-back and the information provided by the P-CSCF, to route the emergency call-back to the first UE and/or to a second UE.

Abstract: In a mobile network with a plurality of access networks (210, 220), a control node (110) which is controlling access of a user equipment (300) to that one of the access networks (210, 220) which is currently used by the user equipment (300) determines an access capability of the user equipment (300) in said access network (210, 220), e.g. support of voice communication over packet switched access. The control node (110) provides an indication of the determined access capability to a subscriber database (150) associated with the user equipment (300). The indication may then be retrieved from the subscriber database (150) and be used to control termination of a connection to the user equipment (300).

Abstract: A method and arrangement is disclosed for managing session keys for secure communication between a first and at least a second user device in a communications network. The method is characterized being independent of what type of credential each user device implements for security operations. A first user receives from a first key management server keying information and a voucher and generates a first session key. The voucher is forwarded to at least a responding user device that, with support from a second key management server communicating with the first key management server, resolves the voucher and determines a second session keys. First and second session keys are, thereafter, used for secure communication. In one embodiment the communication traverses an intermediary whereby first and second session keys protect communication with respective leg to intermediary.

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: 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: Aspects of the present invention provide a mechanism to utilize IMS media security mechanisms in a CS network and, thereby, provide end-to-end media security in the case where the media traffic travels across both a CS network and a PS network.

Abstract: Techniques and apparatus are described for controlling set up of a terminating call from an IMS to a UE, in a Circuit Switched Fallback (CSFB) situation. A first MSC receives a terminating call from IMS and tries to page the UE. The UE has moved to the second MSC and performs a Location Update to the second MSC. The second MSC informs the first MSC with a Send Identification message comprising an address of the second MSC. The first MSC maintains the IMS subscription of the UE at Cancel Location and forwards the terminating call to the second MSC. The first MSC acts as relay for subsequent call control messages for calls of the UE. The first and second MSCs are supervising the ongoing calls and as soon as all calls are completed the second MSC registers the UE into IMS and the first MSC de-registers the UE from IMS.

Abstract: A method and arrangement is disclosed for managing session keys for secure communication between a first and at least a second user device in a communications network. The method is characterized being independent of what type of credential each user device implements for security operations. A first user receives from a first key management server keying information and a voucher and generates a first session key. The voucher is forwarded to at least a responding user device that, with support from a second key management server communicating with the first key management server, resolves the voucher and determines a second session keys. First and second session keys are, thereafter, used for secure communication. In one embodiment the communication traverses an intermediary whereby first and second session keys protect communication with respective leg to intermediary.

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.

Abstract: A method and apparatus for maintaining service continuity for User Equipment accessing an IP Multimedia Subsystem communication network. A routing identifier is established that identifies a Service Centralization and Continuity Application Server allocated to the User Equipment. The routing identifier is sent to the User Equipment. In the event of disruption to the service between the User Equipment and the Service Centralization and Continuity Application Server, a handover message is sent from the User Equipment via a Circuit Switched access network. The handover message includes the routing identifier, and is then forwarded to the identified Service Centralization and Continuity Application Server. This allows the same Service Centralization and Continuity Application Server to be used after the handover as was used before the handover, thereby providing service continuity.

Abstract: A method and apparatus for transferring a session from a packet switched access network to a circuit switched access network. A Mobility Management Entity receives a service type indicator from a gateway node. The service type indicator indicates a type of service for the session, and is associated with bearers used for the session. The Mobility Management Entity subsequently receives, from an eNodeB, an indication that the session is to be transferred from the packet switched network to the circuit switched access network. The Mobility Management Entity determines the bearers associated with the session using the service type indicator, and initiates transfer of the session using those bearers. This ensures that the correct bearers are transferred regardless of whether or not identifiers such as QCI values have been ascribed to other types of service.

Abstract: According to a first aspect of the present invention there is provided a method of operating a mobility management node to provide location and/or status information for a user terminal connected to an Evolved Packet Core network. The method comprises receiving a request for location and/or status information for the user terminal from a subscriber register, determining the location and/or status information for the user terminal, and sending a response to the subscriber register including the determined location and/or status information.

Abstract: An apparatus configured to operate as a Backup system in a Data Layered Architecture Public Land Mobile Network. The apparatus comprises an interface for enabling a data exchange between the apparatus and a plurality of Authentication Centre Front Ends, and a memory for storing subscriber authentication data. The apparatus further comprises a processor for detecting a failure of a Data Back End and for receiving a redirected authentication data set request from an Authentication Centre Front End via the interface. The processor is further configured, in the event of a detected failure of Data Back End, to generate one or more authentication data sets in response to the request using the data stored in the memory, and send the generated data set(s) to the Authentication Centre Front End via the interface.

Abstract: A method and apparatus for maintaining service continuity for User Equipment accessing an IP Multimedia Subsystem communication network. A routing identifier is established that identifies a Service Centralization and Continuity Application Server allocated to the User Equipment. The routing identifier is sent to the User Equipment. In the event of disruption to the service between the User Equipment and the Service Centralization and Continuity Application Server, a handover message is sent from the User Equipment via a Circuit Switched access network. The handover message includes the routing identifier, and is then forwarded to the identified Service Centralization and Continuity Application Server. This allows the same Service Centralization and Continuity Application Server to be used after the handover as was used before the handover, thereby providing service continuity.

Abstract: A method and apparatus for handling emergency signalling in an IP Multimedia Subsystem network. A Proxy-Call Session Control Function receives a message requesting set up of a session. The message is associated with an IP Multimedia Private Identity. The P-CSCF determines that the message relates to an emergency call. If an emergency override tag associated with the IMPI is provisioned or set at the P-CSCF, then the message is forwarding the SIP message to a Serving-Call Session Control Function (S-CSCF) for further handling. However, if an emergency override tag associated with the IMPI is not provisioned or set at the P-CSCF, the message is forwarded to an Emergency-Call Session Control Function (E-CSCF). The invention allows the P-CSCF to exercise control over the handling of emergency signalling.

Abstract: A method and apparatus for transferring a session from a packet switched access network to a circuit switched access network. A Mobility Management Entity receives a service type indicator from a gateway node. The service type indicator indicates a type of service for the session, and is associated with bearers used for the session. The Mobility Management Entity subsequently receives, from an eNodeB, an indication that the session is to be transferred from the packet switched network to the circuit switched access network. The Mobility Management Entity determines the bearers associated with the session using the service type indicator, and initiates transfer of the session using those bearers. This ensures that the correct bearers are transferred regardless of whether or not identifiers such as QCI values have been ascribed to other types of service.

Abstract: Exemplary methods for establishing an emergency call and an emergency call-back for a first User Equipment (UE) communicatively coupled to a visited Internet Protocol Multimedia Subsystem (IMS) network includes establishing an emergency call by the first UE sending an emergency call request to a Proxy Call Session Control Function (P-CSCF) in the visited IMS network. The methods further include providing, from the P-CSCF to a Serving CSCF (S-CSCF) in a home IMS network for the first UE, information comprising an indication that the emergency call has been performed and an equipment identifier of the first UE. The methods further include receiving, in the S-CSCF, an emergency call-back request from an emergency call-centre, and using, in the S-CSCF, information comprised in the received emergency call-back and the information provided by the P-CSCF, to route the emergency call-back to the first UE and/or to a second UE.

Abstract: A method and apparatus for allocating an identifier to a terminal in a communications network. A core network controlling node, such as a Mobility Management Entity (MME) receives an International Mobile Subscriber Identity (IMSI) and an International Mobile Equipment Identity (IMEI) from the terminal. Subscription information is determined using both the IMSI and the IMEI. A temporary identifier that can be used to identify the terminal is then allocated to the subscription information.

Abstract: The invention relates to a method for providing service continuity with respect to a registration of a mobile terminal, UE (1), at a control server (3) of an IP Multimedia Subsystem, IMS, network, while a CS-communication session between the UE (1) and a switching server, MSC (2), of a circuit-switched, CS, network is established. The control server (3) comprises a registration timer which is used for initiating a termination of the registration of the UE (1) at the IMS network, when the registration timer expires, wherein the control server (3) updates the registration timer in dependence of a control information received (11, 24) from the MSC (2). The invention further relates to a MSC (2) providing such service.