Abstract: System, methods, entities, and computer program for handling timers in a communication network are described. The communication network comprises a plurality of entities (100-108). The method in a first entity (100) comprises determining (301) whether a supervision condition for supervising a communication procedure is fulfilled. The method further comprises adding (308), based on a result of the step of determining the supervision condition (301), a timer validity information to a signaling message related to the communication procedure, and sending (308) the signaling message to a second entity (102). The method in a second entity (102-108) comprises receiving (400) a signaling message associated with a communication procedure, the signaling message containing a timer validity information.

Abstract: There is provided a method of processing an IMS session originated by a UE after restart of a S-CSCF that was previously assigned to a user of the UE during registration with the IMS, when a further S-CSCF is currently assigned to the user. The method comprises, at a HSS, receiving a request to register a user identity of the user from the previously assigned S-CSCF, determining that the previously assigned S-CSCF is not the same as a S-CSCF currently assigned to the user, determining if IMS restoration procedures are supported for the UE, and, if IMS restoration procedures are not supported for the UE, sending a response to the previously assigned S-CSCF, the response identifying the further S-CSCF currently assigned to the user.

Abstract: A Serving Call Session Control Function, S-CSCF, within an IP Multimedia Subsystem, IMS, core network. Notifications are sent to a Home Subscriber Server, HSS, of the IMS core network, indicating IMS registration state changes of users. Delivery failure of a notification of an IMS registration state change sent to a HSS and relating to a given user is detected. An association between an identifier of the given user and an indication of said delivery failure is stored in order to indicate a loss of IMS registration state synchronization for the given user between the S-CSCF and the HSS. An event requiring an IMS registration state change for the user is detected. A determination is made that a delivery failure indication associated with the user's identifier is stored. The HSS is notified indicating the required IMS registration state change and of a previous loss of the IMS registration state synchronization.

Abstract: A method of handling traffic within an IP Multimedia Subsystem, IMS, network. The method comprises registering an IMS user with a first Serving Call Session Control Function, S-CSCF, of the IMS network. Subsequently, at the first S-CSCF, a decision is made or instruction received to transfer said user to an alternative, second S-CSCF within the IMS network. A notification is sent from said first S-CSCF to a further IMS node, the notification including an explicit instruction to select a second S-CSCF and, upon receipt of said notification at the further IMS node, an S-CSCF reselection initiated for the user in order to select a second S-CSCF.

Abstract: Embodiments of the present invention provide a network entity of an IMS network, in which a registered user is being served by an assigned Serving-Call Session Control Function, S-CSCF. The network entity includes a memory storing data that includes an identity of at least one better-matching S-CSCF in the IMS network having capabilities better suited for serving the registered user than the assigned S-CSCF. The network entity is configured to obtain an indication of the availability of the better-matching S-CSCF, and when the better-matching S-CSCF entity is available to initiate a transfer so that the registered user is served by the better-matching S-CSCF. The network entity may be the assigned S-CSCF, or may be an I-CSCF. Embodiments of the present invention provide a method of transferring a registered user to a better-matching S-CSCF.

Abstract: System, methods, entities, and computer program for handling timers in a communication network are described. The communication network comprises a plurality of entities (100-108). The method in a first entity (100) comprises determining (301) whether a supervision condition for supervising a communication procedure is fulfilled. The method further comprises adding (308), based on a result of the step of determining the supervision condition (301), a timer validity information to a signaling message related to the communication procedure, and sending (308) the signaling message to a second entity (102). The method in a second entity (102-108) comprises receiving (400) a signaling message associated with a communication procedure, the signaling message containing a timer validity information.

Abstract: A Serving Call Session Control Function, S-CSCF, within an IP Multimedia Subsystem, IMS, core network. Notifications are sent to a Home Subscriber Server, HSS, of the IMS core network, indicating IMS registration state changes of users. Delivery failure of a notification of an IMS registration state change sent to a HSS and relating to a given user is detected. An association between an identifier of the given user and an indication of said delivery failure is stored in order to indicate a loss of IMS registration state synchronization for the given user between the S-CSCF and the HSS. An event requiring an IMS registration state change for the user is detected. A determination is made that a delivery failure indication associated with the user's identifier is stored. The HSS is notified indicating the required IMS registration state change and of a previous loss of the IMS registration state synchronization.

Abstract: According to a first aspect there is provided a method of processing an IP Multimedia Subsystem (IMS) session originated by a User Equipment (UE) after failure of a Serving Call Session Control Function (S-CSCF) that was previously assigned to a user of the UE during registration with the IMS. The method comprises, at a Proxy Call Session Control Function (P-CSCF), upon determining that the P-CSCF is unable to forward a session establishment request for the session to the previously assigned S-CSCF, selecting an alternative S-CSCF from a S-CSCF pool, and sending the session establishment request for the session to the alternative S-CSCF.

Abstract: One aspect provides a method of storing charging data in an IMS network. A message is received at a network entity. A charging priority value of the message relating to charging data associated with the message id identified. The charging priority value is included in a charging request message and the charging request message is forwarded to a charging control system. Other aspects provide IMS network entities configured to implement the method.

Abstract: There is provided a method of processing an IMS session originated by a UE after restart of a S-CSCF that was previously assigned to a user of the UE during registration with the IMS, when a further S-CSCF is currently assigned to the user. The method comprises, at a HSS, receiving a request to register a user identity of the user from the previously assigned S-CSCF, determining that the previously assigned S-CSCF is not the same as a S-CSCF currently assigned to the user, determining if IMS restoration procedures are supported for the UE, and, if IMS restoration procedures are not supported for the UE, sending a response to the previously assigned S-CSCF, the response identifying the further S-CSCF currently assigned to the user.

Abstract: The present invention relates to a method for providing, to an S-CSCF, application server behaviour instructions. The application server behaviour instructions are applied by the S-CSCF when interworking with the application server that the instructions are for.

Abstract: A method of handling IP Multimedia Public Identity registration within an IP Multimedia Subsystem network. The method comprises receiving at a Call Session Control Function a SIP REGISTER message including a completed IP Multimedia Public Identity Attribute-Value-Pair and no IP Multimedia Private Identity. The method further comprises deriving at the Call Session Control Function an IP Multimedia Private Identity using the IP Multimedia Public Identity and sending a Cx query from the Call Session Control Function to a Home Subscriber Server, the query including the IP Multimedia Public Identity and the derived IP Multimedia Private Identity. The Home Subscriber Server identifies a subsubscription using the IP Multimedia Public Identity, and determines that the derived IP Multimedia Private Identity is not associated with said subscription.

Abstract: A method of handling traffic within an IP Multimedia Subsystem, IMS, network. The method comprises registering an IMS user with a first Serving Call Session Control Function, S-CSCF, of the IMS network. Subsequently, at the first S-CSCF, a decision is made or instruction received to transfer said user to an alternative, second S-CSCF within the IMS network. A notification is sent from said first S-CSCF to a further IMS node, the notification including an explicit instruction to select a second S-CSCF and, upon receipt of said notification at the further IMS node, an S-CSCF reselection initiated for the user in order to select a second S-CSCF.

Abstract: A method and apparatus for providing location information to a CSCF in an IMS network. An S-CSCF registers a first contact associated with an IMPU, and receives location information associated with the first contact. A second contact associated with the same IMPU, and also with a mobile access, is then registered at the S-CSCF. The S-CSCF receives location information associated with the second contact.

Abstract: Embodiments of the present invention provide a network entity of an IMS network, in which a registered user is being served by an assigned Serving-Call Session Control Function, S-CSCF. The network entity includes a memory storing data that includes an identity of at least one better-matching S-CSCF in the IMS network having capabilities better suited for serving the registered user than the assigned S-CSCF. The network entity is configured to obtain an indication of the availability of the better-matching S-CSCF, and when the better-matching S-CSCF entity is available to initiate a transfer so that the registered user is served by the better-matching S-CSCF. The network entity may be the assigned S-CSCF, or may be an I-CSCF. Embodiments of the present invention provide a method of transferring a registered user to a better-matching S-CSCF.

Abstract: One aspect provides a method of storing charging data in an IMS network. A message is received at a network entity. A charging priority value of the message relating to charging data associated with the message id identified. The charging priority value is included in a charging request message and the charging request message is forwarded to a charging control system. Other aspects provide IMS network entities configured to implement the method.

Abstract: A method of handling IP Multimedia Public Identity registration within an IP Multimedia Subsystem network. The method comprises receiving at a Call Session Control Function a SIP REGISTER message including a completed IP Multimedia Public Identity Attribute-Value-Pair and no IP Multimedia Private Identity. The method further comprises deriving at the Call Session Control Function an IP Multimedia Private Identity using the IP Multimedia Public Identity and sending a Cx query from the Call Session Control Function to a Home Subscriber Server, the query including the IP Multimedia Public Identity and the derived IP Multimedia Private Identity. The Home Subscriber Server identifies a subsubscription using the IP Multimedia Public Identity, and determines that the derived IP Multimedia Private Identity is not associated with said subscription.

Abstract: A method and apparatus for providing location information to a CSCF in an IMS network. An S-CSCF registers a first contact associated with an IMPU, and receives location information associated with the first contact. A second contact associated with the same IMPU, and also with a mobile access, is then registered at the S-CSCF. The S-CSCF receives location information associated with the second contact.