Telefonaktiebolaget Lm Ericsson (publ)

Karl-Peter Ranke

Ralf Keller

Jari Tapio Vikberg

Fredrik Lindholm

Andreas Witzel

Jan Holm

Chunbo Wang

Oliver Speks

Joerg Christian Ewert

Martin Israelsson

Branko Djordjevic

Jan Erik Lindquist

Fredrik Alriksson

Sharokh Amirijoo

Robert Schnell

Anders Nohlgren

Kari-Pekka Perttula

Sven Gemski

Michael Nils Olov Lindström

Fredrik Lndholm

Methods, nodes, computer programs and a mobile network for handling a terminating circuit switched signaling service to a terminal in a mobile network are described. A method of handling a terminating circuit switched signaling service to a terminal in a mobile network is described. The signaling service is distinct from a call. The mobile network comprises a first control node and a second control node. The method is performed by the first control node. The method comprises receiving signaling information for terminating the circuit switched signaling service to the terminal, subsequent to the step of receiving, detecting that the terminal has requested a location update from a second control node of the mobile network, and, based on the step of detecting, forwarding the received signaling information to the second control node.

Handling a terminating circuit switched signaling service to a terminal in a mobile network

A technique for controlling set up of a terminating call to a UE in a CSFB situation involving a first MSC paging the UE and a second MSC where the UE is performing a Location Update is described. A method implementation of this technique comprises receiving, from an HLR, a PRN message and forwarding information received in the PRN message to the second MSC.

Technique for terminating call set up in a CSFB situation

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

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.

A technique for handling mobile terminating connection attempts for a mobile terminal for which a change of an association from a first routing node to a second routing node is accompanied by a Circuit Switched (CS) fallback is described. In one exemplary embodiment, a method may be performed by a Circuit Switched Fallback Interworking Function (CSFB-IWF) for handling mobile terminating connection attempts for a mobile terminal for which a change of an association from the CSFB-IWF to a Mobile Switching Center (MSC) is accompanied by a Circuit Switched Fallback (CSFB). The method may include receiving a mobile terminating connection attempt to the mobile terminal. In response to receiving the mobile terminating connection attempt, the method may include paging the mobile terminal using a Mobility Management Entity (MME). In response to paging the mobile terminal, the method may include triggering the mobile terminal to initiate a CSFB procedure. Further, the method may include determining an identity of the MSC based on a message received by the CSFB-IWF from the MSC. Also, the method may include transmitting, to the MSC, a second mobile terminating connection attempt for a CS connection to the mobile terminal.

Technique for connection attempt handling in a circuit switched fallback situation

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 products for handling paging of a user equipment for delivery of a terminating transaction are described. A user equipment is located in a radio coverage area, wherein the radio coverage area is controlled by the control node. The method includes initiating a paging request broadcast in the radio coverage area and opening, triggered by the initiating of the paging request broadcast, a paging response reception window. The method further includes storing, while the paging response reception window is open, all received paging responses. Furthermore, authenticating, if more than one paging response has been received, at least one user equipment which has provided a paging response, and continuing delivery of the terminating transaction to the user equipment which could be successfully authenticated.

Paging procedure in a control node

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.

Routing terminating call to user equipment via control nodes

A technique for operating a network node during a Mobile Terminating Roaming Forwarding (MTRF) procedure is described. The MTRF procedure involves a first MSC paging a Mobile Subscriber (MS) and a second MSC where the MS is performing a location update. A method implementation of the technique performed by the first MSC includes receiving an information request message, receiving from the second MSC, a Mobile Subscriber Roaming Number (MSRN) associated with the call to the MS, and sending, in response to the information request message, the MSRN towards a Gateway MSC.

Technique for operating a network node during a mobile terminating roaming forwarding procedure

A mechanism is presented for performing a session transfer with Single Radio Voice Call Continuity, SRVCC, from a Packet Switched, PS, access to a Circuit Switched, CS, access of a telecommunications session that has been established over the PS access via an IP Multimedia Subsystem, IMS, network. The method includes receiving a request for the transfer of the session to the CS access. An indication of an already-seized media gateway, MGW, that has been established for use in one or more other sessions over the CS access is obtained from the IMS network. A MGW is selected as a Mobile-Media Gateway, M-MGW, for the session based on the obtained indication. Allocation of resources for the session in the CS access network is initiated, including specifying the MGW to be used as the Mobile-Media Gateway, M-MGW. Transfer of the session to the CS access is then initiated.

SRVCC handover of calls between access networks with efficient media gateway selection

A technique for handling mobile terminating connection attempts for a mobile terminal for which a change of an association from a first routing node to a second routing node is accompanied by a Circuit Switched (CS) fallback is described. A method implementation of this technique comprises the following steps carried out by the first routing node: receiving a first mobile terminating connection attempt to the mobile terminal, in response to receipt of the first mobile terminating connection attempt, determining that the mobile terminal cannot be reached by the first routing node, determining an identity of the second routing node, and transmitting, to the second routing node, a second mobile terminating connection attempt for a CS connection to the mobile terminal.

A method and application server for supporting a communication established between a first mobile terminal towards a telecommunications network that includes first and second radio access networks. When a session setup is initiated with respect to the first mobile terminal, the application server receives a session identifier. The application server enters the identifier into an identifier list comprising one or more identifiers for identifying sessions with respect to the first mobile terminal. If the application server receives an indication of a session transfer from the first radio access network to the second radio access network, the application server provides the identifier list to the second radio access network in response to the indication.

Method, apparatus and computer program for supporting a session identifier in case of a transfer between different radio access networks

A method is provided of performing a session transfer with Single Radio Voice Call Continuity, SRVCC, from a Packet Switched, PS, access to a Circuit Switched, CS, access of a telecommunications session that has been established over the PS access via an IP Multimedia Subsystem, IMS, network. A request for the transfer of the session is received. An indication of a voice codec that is currently being used for the session is obtained from the IMS network. Allocation of resources for the session in the CS access network is initiated, including specifying the voice codec to be used based on the obtained codec indication. Transfer of the session to the CS access is initiated so that the session continues with use of the specified voice codec.

Handover of calls between access networks

A method of providing in a packet switched telecommunications network, for a communications session involving a user of said packet switched telecommunications network a value added service associated with a circuit switched telecommunication network. The method comprises the steps of establishing a first signaling data stream of a first basic call state model of a packet switched dedicated protocol type between the packet switched telecommunications network and a service interface adapter unit, and establishing a second signaling data stream of a second basic call state model of a circuit switched dedicated protocol type between the service interface adapter unit and the circuit switched telecommunications network, based on information from the first signaling data stream, for providing the value added service from the circuit switched telecommunications network. The information is augmented with further information for establishing the second signaling data stream, and for exchanging data between the first and second signaling data stream for providing the value added service to the user through the packet switched telecommunications network.

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Herzogenrath, Germany

Karl-Peter Ranke