Telefonaktiebolaget Lm Ericsson (publ)

Optis Wireless Technology, LLC

Jan Holm

Henrik Albertsson

Fredrik Lindholm

Magnus Hallenstål

Ivo Sedlacek

Jan Dahl

Mats Ola Stille

Karl-Peter Ranke

Oliver Speks

Chunbo Wang

Susana Fernandez Alonso

Per Synnergren

Hubert Przybysz

Christer Boberg

Anders Lindgren

Johan Svedberg

Ros-Marie Furtenback

Gert Öster

Christer Holmberg

Jörgen Axell

Cormac Hegarty

Hans Ake Lindgren

Fredrik Tystad

Børge Nilsen

Johan Philip Steller

Hans Åke Lindgren

Richard Michael Collin

Leif Gustavsson

Magnus HALLENSTÅL

A method of notifying one or more network nodes in a communications network, comprising an Internet Protocol Multimedia Subsystem, IMS, of a change in RAT used by a user equipment for a communications session, the method comprising at a CSCF prior to set-up of the communications session, indicating by the CSCF to a PCRF that the CSCF requires RAT change notifications for the user equipment, providing a capability indication by the CSCF to the one or more network nodes that the CSCF supports RAT change notifications and receiving from at least one of the one or more network nodes a requirement indication, which indicates that the network node requires RAT change notifications. The method further comprises on receipt of a RAT change notification by the CSCF propagating the RAT change notification to each of the nodes from which a requirement indication has been received.

Notifying changes in radio access technology

A telecommunications network has a packet switched domain for handling packet based calls and a circuit switched telephony domain for handling circuit switched calls. A node of the packet switched telephony domain decides whether to terminate a call to a user equipment using a packet based connection to the user equipment or using a circuit switched connection to the user equipment. In response to deciding to terminate the call using the circuit switched connection, the node sends, to a further node controlling routing of calls between the packet switched telephony domain and the circuit switched telephony domain, an indication that services related to the call are controlled in the packet switched telephony domain. In accordance with the indication, the further node may then adapt its control signalling with respect to a node of the circuit switched telephony domain.

Service control awareness for call routing between packet switched telephony domain and circuit switched telephony domain

A method of handling SIP session initiation requests in an IP Multimedia Subsystem, IMS, network. The method is performed at an application server, AS, within the network. The AS receives a session initiation request containing a destination address, where that destination address is currently associated with a plurality of registered User Equipments, UEs. The AS then determines whether or not a UE associated with the destination address, is already involved in a session. If so, the AS causes the session initiation request to be forwarded only to that UE. If not, the AS causes the session initiation request to be forwarded to all UEs registered in respect of the address.

Session initiation handling

A method of authenticating a request to change IMS supplementary service data stored at an application server within an IMS network. The method comprises sending from a user equipment to the application server a request for current IMS supplementary service data, on receipt by the user equipment of a response containing the IMS supplementary data in an XML configuration document, and an indication that an access code is required to change the supplementary service data. The method further comprises constructing an amended XML configuration document, incorporating the amended XML document into an Extensible Mark-up Language, XML, Configuration Access Protocol, XCAP, message, incorporating an access code into the XCAP message at a location external to the XML document, and transmitting the XCAP message from the user equipment to the application server.

Changing IMS supplementary service data in an IMS network

A technique is provided for synchronizing a first call state of a network component and a second call state of a mobile device. The mobile device is connectable to a network via a first Radio Access Technology (RAT) and a second RAT. The network forwards towards a callee an invitation for a call originating via the first RAT from the mobile device. The network sends a first message corresponding to a callee response towards the mobile device. The network component triggers a transfer of the call session of the mobile device from the first RAT to the second RAT. The first call state is set by the response of the callee. Information indicative of the second call state is received from the mobile device, and a second message for changing the second call state by the response is provided to the mobile device when inconsistent first and second call states.

Synchronizing call states of network component and mobile device at session transfer

Dual Radio Access Transfer of an IMS in an alerting phase for the Packet Switched to Circuit Switched direction includes initiating an IMS media session towards UE and, during a session alerting phase, making a determination that a DRVCC transfer is required from a PS to CS, access, sending a SIP message from the UE to a 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 MSC. The SIP INVITE includes an identity of the UE as a called party identity and the STN as the calling party identity. The Transfer includes sending from the MSC to the UE a CS Setup message, whereupon the MSC is placed in a state in which it expects a CS Answer from the UE.

Access transfer for a DRVCC mobile terminal

A method of managing a media path for a media session established between users across a plurality of interconnected Internet Protocol (IP) networks which utilize Session Initiation Protocol (SIP) and Session Description Protocol (SDP) signaling. The method comprises, at session establishment via a signaling path over the IP networks, making a determination that a shortcut media path is available, wherein the shortcut media path deviates from the signaling path. The method further comprises making a further determination that nodes in the signaling path will subsequently be able to maintain the shortcut media path in the event of a subsequent session update or re-invite and, at a subsequent session update or re-invite, including within update or re-invite signaling an indication that the shortcut media path is to be maintained.

Maintaining optimal media routing

A technique for triggering a change of a call state of a mobile device is presented. A network forwards towards a callee an invitation for a call originating via a first Radio Access Technology (RAT) from the mobile device, and forwards a response of the callee via the first RAT towards the mobile device. The response indicates a change of the call state from a first state to a second state. A first network component changes via a second RAT the call state of the mobile device when receiving information indicative of the first state followed by receiving a message indicative of the second state. A second network component receives from the first network component an invitation for a transfer of the call of mobile device from the first RAT to the second RAT.

Technique for transferring a session with changeable session state

System, methods, nodes, and computer program for determining a home network of a UE roaming in a visited network are described. The UE sends a session invitation to a further UE. The method comprises receiving, by a control node in the home network, the session invitation. The method further comprises adding, by a control node in the home network, an indication of the home network identity and an indication for session invitation loopback routing, to the session invitation. The method further comprises sending, by a control node in the home network, the session invitation towards the visited network. The method further comprises receiving, by a control node in the visited network, a session invitation from the home network. The method further comprises determining, by the control node in the visited network, the home network based on the indication of the home network identity.

Home communication network determination

A method and apparatus for handling a communication session in a communications network. An Application Function node receives a request to register a user terminal in the communication network. The Application Function identifies an Access Point used by the terminal to register with the network, and send a request message to a Policy and Charging Register Function (PCRF). The request message includes an Access Point Name identifying an Access Point used by the user terminal. The AF receives a response message from the PCRF, including an indicator indicating whether the Access Point is an Emergency-Access Point. The AF subsequently receives a message from the user terminal that identifies a non-emergency terminating node. If the indicator indicates that the Access Point is not an Emergency-Access Point, the AF allows the communication session. If the indicator indicates that the Access Point is an Emergency-Access Point, then the AF rejects the communication session.

Handling communication sessions in a communications network

A Push-to-talk over Cellular (PoC) communication session is established between an inviting PoC client and at least one invited PoC client using an IP Multimedia Subsystem network. Establishment involves using a pre-established session procedure to negotiate media parameters between the inviting PoC client and a participating PoC server for the inviting PoC client. At the inviting PoC client, a Talk Burst Control Protocol (TBCP) or Media Burst Control Protocol (MBCP) message is sent directly to its participating PoC server, the TBCP or MBCP message containing the PoC address of the at least one invited PoC client. At the participating PoC Server, in response to receipt of the TBCP or MBCP message, a SIP INVITE message is generated and sent towards a participating PoC server for the at least one invited PoC client.

Method and apparatus for establishing a PoC session

According to a first embodiment of the present invention there is provided a method of operating a node of a communications network that is configured to provide an IP Multimedia Subsystem Access Transfer Control Function. The method comprises storing information regarding IMS Service Continuity features that are supported by Mobile Switching Center servers within the network. Upon receipt of a message requesting IMS registration of a user equipment using the information to determine the IMS Service Continuity features that may be available to the user equipment, and, for any IMS Service Continuity features that may be available, including an indication that the IMS Service Continuity feature may be available in the message, and forwarding the message towards a Service Centralization and Continuity Application Server.

Methods and apparatus for supporting the implementation of IMS service continuity

The present invention relates to a Push to talk Over Cellular [PoC] Server for providing PoC communication services in mobile radio communications system, the PoC Server being arranged to perform at least one Controlling PoC Function for a PoC Session between PoC Clients in mobile terminals. The PoC Server is characterized in that it is arranged to: receive a first information indicating the PoC Session priority order for the PoC Session for each of the PoC Clients participating in the PoC Session; receive a second information, if any one of the PoC Clients is also participating in other simultaneous PoC Sessions, indicating the PoC Session priority order for the other simultaneous PoC Sessions for each of the PoC Clients participating in the other simultaneous PoC Sessions; store the first and second information for enabling control of the transmission of Media in the PoC Session based on the first and second information. The present invention also relates to a method, a mobile terminal comprising a PoC Client and a method thereof, a mobile radio communications system and a computer program product.

PoC server and a mobile terminal comprising a PoC client for providing PoC communication services

A method and apparatus for indicating to a node in an IMS network a transfer between two endpoints. A node in a first network determines that a communication session is to be transferred from a first endpoint to a second endpoint. The node includes an indication of at least one of the endpoints, and an explicit communication transfer indicator, in a message. The message is then sent towards the node in the IMS network. This allows the node in the IMS network to determine that a transfer has taken place and, if necessary, take further action.

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Gävle, Sweden

Jan Holm