Embodiments of this application disclose a service establishment method and a device. The method includes: an access network device receives an establishment request from a core network device or a service application server, where the request carries a requirement of a to-be-established service. When determining that radio channel quality of a first cell of a first network in which the UE is located does not meet the requirement of the service, the access network device sends an establishment response to the core network device or the server, where the response notifies the core network device or the server that the radio channel quality of the first cell does not meet the requirement; or the access network device hands over the UE to a second cell of the first network; or the access network device hands over the UE to a third cell of a second network.

In some implementations, a telecommunications network can include an authorization server, e.g., a Diameter Routing Agent. The authorization server can receive service data associated with a network terminal from a home authorization server. The authorization server can determine that a portion of the service data corresponds with a predetermined network service and remove the portion of the service data to provide modified service data. The authorization server can transmit the modified service data to a control device of the network. In some examples, the control device can determine a gateway device identified in the modified service data and transmit an association message to the gateway device on behalf of the terminal. In some examples, the control device can receive a request for a network service from the terminal, determine that the modified service data does not authorize the network service, and transmit a rejection message to the terminal.

In an embodiment, there is provided a method for session transfer between Access Networks for a User Equipment UE, said method including insertion in a signaling path of a Service Continuity Application Server anchoring said session in IMS, said method including: insertion of a Service Continuity Application Server V-SCC-AS located in a Visited PLMN V-PLMN for a UE roaming in said V-PLMN.

A disclosure of the present specification provides a method for establishing a packer data network (PDN) connection by a user equipment (UE). The method may comprise the steps of: transmitting a session initiation protocol (SIP)-based request message for requesting sending of a voice over LTE (VoLTE) call through a first type PDN connection; receiving, from a network node, a message including information directly or indirectly indicating that there is a problem in the first type PDN connection, instead of a normal response message to the SIP-based request message; determining to change the PDN type from the first type to a second type, on the basis of the information in the received message; and transmitting, to a mobility management entity (MME), a PDN connection request message including information on the changed second type.

Embodiments of the present application disclose a switching method and a switching apparatus. The method comprises: determining voice service quality of at least one position in a movement path of at least one UE; determining a position of the at least one UE; and triggering, in response to that the voice service quality of the at least one position meets a preset condition, and the at least one UE fails to arrive at the at least one position corresponding to the voice service quality that meets the preset condition, the at least one UE to switch from a first voice communication mode to a second voice communication mode. In the method and apparatus of the embodiments of the present application, switching is triggered, by determining a movement path and a position of a UE, in advance before the UE arrives at a position/position range at which the switching of a voice communication mode should be performed, so as to avoid relatively poor communication quality or even an interrupted communication service caused by a state that a normal switching process cannot be completed in a short time, thereby improving user experiences.

A method is provided for handling Internet Protocol Multimedia Subsystem (IMS) services in a roaming scenario of a user equipment. The user equipment is assigned to a home mobile communication network, and the user equipment is connected to a visited mobile communication network. The visited mobile communication network comprises at least one specific first network node among a plurality of first network nodes of the visited mobile communication network. In order to provide IMS services to the user equipment while roaming in the visited mobile communication network, the at least one specific first network node communicates with a second network node of the home mobile communication network. The method comprises: relating the user equipment to the at least one specific first network node in order to provide IMS services to the user equipment while roaming in the visited mobile communication network.

A method for call processing comprising processing telecommunications data with an Over-The-Top (OTT) client on a handset, determining whether to use a voice over long term evolution (VoLTE) client or a WiFi client in response to an operational change and reconfiguring the handset to use the VoLTE client or the WiFi client if the determination is made to use the VoLTE client or the WiFi client, respectively.

A communication device for handling a redirection comprises at least one storage device storing instructions of receiving a redirection message from a first base station (BS) of the first radio access technology (RAT) via a first cell, wherein the redirection message comprises RAT information indicating a second RAT and indicates a first core network (CN); entering an idle state in response to the redirection message; selecting a second cell of the second RAT according to the RAT information; establishing a radio resource control (RRC) connection via the second cell to a second BS in the idle state; generating a non-access-stratum (NAS) message for the first CN according to the redirection message; and transmitting the NAS message on the RRC connection via the second cell to the second BS.

Embodiments of the present disclosure describe methods, apparatuses, storage media, and systems for single radio voice call continuity handover from next-generation radio access network to universal terrestrial radio access network, and return to the next-generation radio access network after single radio voice call continuity service. Other embodiments may be described and claimed.

User equipment (UE) includes processing circuitry, where to configure the UE for Single Radio Voice Call Continuity (SRVCC) handover from an LTE network to a legacy network with circuit switched (CS) communications, the processing circuitry is to encode a Session Description Protocol (SDP) message for transmission to a second UE within the LTE network. The SDP message includes a voice codec selection for voice over LTE communication with the second UE and a maximum end-to-end packet loss rate (E2E_MAX_PLR) that can be tolerated by the UE when using the voice codec. The UE decodes an SRVCC handover command from an eNB within the LTE network, the handover command based on at least one packet loss rate (PLR) associated with a packet switched voice communication link between the UE and the second UE exceeding a PLR threshold that is determined based on the E2E_MAX_PLR that can be tolerated by the UE.