Abstract: Disclosed are methods, systems, and computer-readable medium to perform operations including: receiving, by an access stratum (AS) layer of a user equipment (UE) and from a non-access stratum layer (NAS) layer of the UE, a Public Land Mobile Network (PLMN) search request; determining, by the AS layer, that a first connection instance is in radio resource control (RRC) connected mode; responsively determining, by the AS layer, whether a second connection instance is available; and in response to determining that the second connection instance is available, triggering, by the AS layer, the PLMN search on the second connection instance, wherein the PLMN search comprises one or more frequency scans.

Abstract: A wireless device may transmit, using a first SIM associated with a first radio, a first attach request to a network node and transmit, using a second SIM associated with a second radio, a second attach request to the network node. Additionally, the wireless device may receive, operating in a multiple-subscriber identity module (MSIM) mode, an attach reject message including an attach reject cause code from the network node. The wireless device may transition, based at least in part on reception of the attach reject message, the second SIM to a limited service camped state, disable one of the first radio or second radio, transition to a single-SIM mode, and communicate with the network node via the first SIM.

Abstract: This disclosure describes a user equipment device (UE). The UE includes one or more antennas; one or more radios, where each of the radios is configured to perform cellular communication using a plurality of radio access technologies (RATs) that support voice over an Internet protocol (IP) multimedia subsystem (IMS); one or more processors coupled to the one or more radios, where the one or more processors are configured to cause the UE to perform operations including: sending, via a first RAT, a first request for IMS registration to an IMS server; receiving, from the IMS server, an IMS rejection message indicating failure of the IMS registration; determining, based on the IMS rejection message, that the IMS registration failure is temporary; responsively re-attempting IMS registration with the IMS server; and determining to camp on the first RAT in response to receiving an IMS acceptance message from the IMS server.

Abstract: The present application relates to devices and components including apparatuses, systems, and methods for signal level enhanced network selection.

Abstract: Disclosed herein are system, method, and computer program product embodiments for implementing prioritized return of a UE to NR RAT from a GSM/UMTS RAT through RAT reselection based approach. An embodiment operates by determining whether the UE is camped on a first radio access technology (RAT), and in response to a determination that the UE is camped on the first RAT, stores a list of frequencies and a plurality of cell reselection parameter values corresponding to the first RAT. The embodiment determines whether the UE is camped on a second RAT and whether one of a plurality of trigger conditions is satisfied, and in response to a determination that the UE is camped on the second RAT and that one of the plurality of trigger conditions is satisfied, performs measurements on one or more frequencies of the list of frequencies. The embodiment performs cell reselection to a cell of the first RAT based at least in part on the measurements and the plurality of cell reselection parameter values.

Abstract: A user equipment (UE) transmits a registration request message to a first public land mobile network (PLMN), wherein the first PLMN is a roaming PLMN, receives a registration accept message from the first PLMN, determines that the registration accept message includes a manipulated steering of roaming (SoR) container or does not include a SoR container, wherein the SoR container is configured by a home PLMN (HPLMN) of the UE and transmitted to the first PLMN from the HPLMN, determines that the registration accept message includes an indication that the first PLMN does not support voice over packet switching (VoPS) and adds the first PLMN to a first list of PLMNs in which voice service is not possible in an N1 mode.

Abstract: Systems and methods of enabling access for non-emergency voice calls are described. A UE operates in a network supporting voice services via a multitude of RATs. The UE attempts to access the network via a first RAT offering voice services and data services. If the UE does not receive a response from the network within a first time period, the UE re-attempts the access to the network via the first RAT. If the number of access attempts for which the UE does not receive a response is at least a threshold value, the UE refrains during a second time period from further access attempts via the first RAT for the purpose of receiving data services, and continues to attempt access via the first or second RAT for the purpose of receiving voice services.

Abstract: Systems and methods provide steering of roaming (SoR) information during a user equipment (UE) mobility registration process. In other systems and methods, instead of triggering mobility and periodic registration, a UE performs initial registration until a valid SoR is received in a visited country or network as long as a subscriber identification module (SIM) or a universal SIM (USIM) of the UE indicates that the UE is expected to receive SoR information due to initial registration in a visited public land mobile network (VPLMN).

Abstract: A user equipment (UE) that initiates a periodic update timer, wherein the UE is configured to perform a periodic registration update procedure in response to a periodic update timer expiry event, identifies that the periodic update timer has expired, wherein the periodic update timer expiry event occurs when the UE is out of coverage, selects a cell to camp on, wherein the cell is known to be in a non-allowed area and initiates the periodic registration update procedure in response to the periodic update timer expiry event, wherein the UE delays the periodic registration update procedure until the UE enters a fifth generation mobility management (5GMM) operating substate associated with camping on the cell that is known to be in the non-allowed area.

Abstract: A user equipment (UE) transmits a registration request message to a first public land mobile network (PLMN), wherein the first PLMN is a roaming PLMN, receives a registration accept message from the first PLMN, determines that the registration accept message includes a manipulated steering of roaming (SoR) container or does not include a SoR container, wherein the SoR container is configured by a home PLMN (HPLMN) of the UE and transmitted to the first PLMN from the HPLMN, determines that the registration accept message includes an indication that the first PLMN does not support voice over packet switching (VoPS) and adds the first PLMN to a first list of PLMNs in which voice service is not possible in an N1 mode.

Abstract: This disclosure describes a communication system associated with a radio access technology (RAT). The communication system includes an Internet protocol (IP) multimedia subsystem (IMS) server, and one or more processors configured to perform operations. The operations include receiving, from a user equipment device (UE) camped on the RAT, a request for IMS Packet Data Unit (PDU) establishment or IMS session initiation protocol (SIP) registration; sending to the UE a rejection message associated with the SIP registration or the IMS PDU establishment; receiving, from the UE, an IMS failure message that comprises an IMS failure cause; determining, based on the IMS failure message, whether the IMS failure cause is temporary or permanent; and responsive to determining that the IMS failure is temporary, temporarily disabling the RAT for the UE.

Abstract: If a paging or notification message is received by a user equipment (UE) when a UE-initiated 5GMM specific procedure or service request procedure is ongoing, a UE may buffer the paging or notification message. To buffer the paging or notification message, the UE may remember the pending mobile terminated transaction and re-attempt the registration or request procedure with the access category 0 (=MT_acc), if the ongoing UE-initiated 5GMM specific procedure or service request procedure fails due to access barring. If a 5GMM specific procedure or service request procedure is received by the network when a MT transaction is ongoing (i.e. a paging message with the access type set to 3GPP access or notification message via non-3GPP access with the access type indicating 3GPP access) the network may complete the incoming MT transaction and may remember the pending mobile terminated transaction and continue it once the MO transaction is completed.

Abstract: This application describes techniques for managing subscriber identity module (SIM) data for a wireless device, including secure storage and processing of SIM data. Select SIM data is encrypted using an encryption key by a processor external to a secure element, e.g., a universal integrated circuit card (UICC) or electronic UICC (eUICC), and at least a portion of the select SIM data is stored in the secure element. The select SIM data can be divided into multiple parts, where a first part of the encrypted SIM data is stored in the secure element, while a second part of the encrypted SIM data is stored external to the secure element, such as in a non-volatile memory (NVM) of the wireless device. The encryption key is stored in a secure NVM of the wireless device. The encrypted SIM data and the encryption key are required to decrypt and recover the SIM data.

Abstract: Systems and methods of enabling access for non-emergency voice calls are described. A UE operates in a network supporting voice services via a multitude of RATs. The UE attempts to access the network via a first RAT offering voice services and data services. If the UE does not receive a response from the network within a first time period, the UE re-attempts the access to the network via the first RAT. If the number of access attempts for which the UE does not receive a response is at least a threshold value, the UE refrains during a second time period from further access attempts via the first RAT for the purpose of receiving data services, and continues to attempt access via the first or second RAT for the purpose of receiving voice services.

Abstract: Some aspects of this disclosure relate to apparatuses and methods for the reselection of a Radio Access Technology (RAT) for a multi-mode user equipment (UE). A UE can determine that the UE camps on a first RAT for service by a first public land mobile network (PLMN) and that the UE camps on a second RAT for service by a second PLMN, and store information about the first RAT for the first PLMN. The UE can further determine whether there is a trigger event to enable the UE to switch from the second RAT to the first RAT. In response to a determination that there is the trigger event, the UE can determine whether a cell in the first RAT for the first PLMN is available for the UE to camp on to select the available cell in the first RAT to register the UE with the first PLMN.

Abstract: Methods and apparatuses for dynamically enabling and disabling one or more of a multimedia priority service (MPS) and a mission critical service (MCS) are disclosed. In some embodiments, a user equipment device (UE) comprises: at least one antenna; at least one radio coupled to at least one antenna, wherein at least one radio is configured to perform cellular communication; and one or more processors coupled to the at least one radio, wherein the one or more processors and at least one radio are configured to dynamically enable and disable use of a service from a group of services that includes a MPS and MCS.

Abstract: This disclosure describes a user equipment device (UE). The UE includes one or more antennas; one or more radios configured to perform cellular communication using a plurality of radio access technologies (RATs) that support voice over an Internet protocol (IP) multimedia subsystem (IMS); and one or more processors coupled to the one or more radios. The one or more processors are configured to cause the UE to perform operations including: sending, to a communications network associated with a first RAT of the plurality of RATs, a first request for IMS registration, wherein the UE is camped on a first cell of the first RAT; determining, based on an IMS rejection failure, that the IMS registration failure is due to a temporary radio failure; and responsively attempting to perform the IMS registration on at least one other cell of the first RAT.

Abstract: This disclosure describes a user equipment device (UE). The UE includes one or more antennas; one or more radios, where each of the radios is configured to perform cellular communication using a plurality of radio access technologies (RATs) that support voice over an Internet protocol (IP) multimedia subsystem (IMS); one or more processors coupled to the one or more radios, where the one or more processors are configured to cause the UE to perform operations including: sending, via a first RAT, a first request for IMS registration to an IMS server; receiving, from the IMS server, an IMS rejection message indicating failure of the IMS registration; determining, based on the IMS rejection message, that the IMS registration failure is temporary; responsively re-attempting IMS registration with the IMS server; and determining to camp on the first RAT in response to receiving an IMS acceptance message from the IMS server.

Abstract: This disclosure describes a communication system associated with a radio access technology (RAT). The communication system includes an Internet protocol (IP) multimedia subsystem (IMS) server, and one or more processors configured to perform operations. The operations include receiving, from a user equipment device (UE) camped on the RAT, a request for IMS Packet Data Unit (PDU) establishment or IMS session initiation protocol (SIP) registration; sending to the UE a rejection message associated with the SIP registration or the IMS PDU establishment; receiving, from the UE, an IMS failure message that comprises an IMS failure cause; determining, based on the IMS failure message, whether the IMS failure cause is temporary or permanent; and responsive to determining that the IMS failure is temporary, temporarily disabling the RAT for the UE.

Abstract: Systems and methods of enabling access for non-emergency voice calls are described. A UE operates in a network supporting voice services via a multitude of RATs. The UE attempts to access the network via a first RAT offering voice services and data services. If the UE does not receive a response from the network within a first time period, the UE re-attempts the access to the network via the first RAT. If the number of access attempts for which the UE does not receive a response is at least a threshold value, the UE refrains during a second time period from further access attempts via the first RAT for the purpose of receiving data services, and continues to attempt access via the first or second RAT for the purpose of receiving voice services.