Apple Inc.

Intel Corporation

Nitin Kuppelur

Karthik Anantharaman

Deepak Kumar Dash

Deepak Dash

Krisztian Kiss

Sridhar Prakasam

Nirlesh Koshta

Kavya B Ravikumar

Shashanka Totadamane Ramappa

Robert Zaus

Xiangpeng Jing

Nitin Gowda Basavarajappa

Anish George

Vijay Venkataraman

Vivek G Gupta

Alosious Pradeep Prabhakar

Rohit R Matolia

Qi He

Roland Gruber

Pradeep Pangi

Gurunadha Rao Kota

Rajkumar Krishnaperumal

Madhusudhan Cheripally

Lester K Chan

Lester Chan

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.

Voice over internet protocol multimedia subsystem

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.

Handling PLMN prioritization

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).

Steering of roaming check during mobility registration

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.

Apparatuses, systems, and methods for SoR list management and PLMN selection based on an SoR list. A UE may receive an SoR container which may include a list of OPLMNs. The UE may store a prior list of OPLMNs stored on a USIM of the UE on a memory of the UE. The UE replace the prior list of OPLMNs stored on the USIM with the list of OPLMNs included in the SoR container. The UE may consider the prior list of OPLMNs as a lower priority list as compared to the list of OPLMNs stored on the USIM. Additionally, in response to determining to move from a current PLMN, the UE may scan for a new PLMN based on the list of OPLMNs stored on the USIM.

Steering of roaming PLMN list update and management

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.

User equipment devices (UEs) and methods are described for performing single network slice selection assistance information (S-NSSAI)-aware public land mobile network (PLMN) selection in a roaming scenario. A mapping list is received that includes a mapping of a plurality of public land mobile networks (PLMNs) to corresponding S-NSSAI values. The mapping list is received from a home PLMN (HPLMN) of the UE over non-3rd generation partnership (non-3GPP) access, from a server, or from a Universal Mobile Telecommunications Service (UMTS) subscriber identity module (USIM) of the UE. An available PLMN is determined that is mapped to a preferred S-NSSAI value of the UE based on the mapping list. A connection is established with the available PLMN.

Enhanced network slicing for public land mobile network selection while roaming

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.

Enhanced internet protocol multimedia subsystem call handling

Apparatuses and computer-readable storage media for handling timers for mobile terminated circuit-switched fallback (MT CSFB) calls. An apparatus for a user equipment (UE) includes processing circuitry operably coupled to a data storage device. The data storage device is configured to store a value of an extended service request for mobile terminated services (EXT-MT) timer. The value of the EXT-MT timer is less than a value of a guard timer of a Visitor Location Register (VLR). The processing circuitry is configured to start the EXT-MT timer and generate an extended service request message to be transmitted to a Mobility Management Entity (MME) responsive to a paging for an MT CSFB call, and attempt to select a radio access technology of a different type of network if the EXT-MT timer expires before the UE successfully performs inter system change and a circuit switched fallback cancellation request was not received from a subscriber.

Handling of timer expiry for MT CSFB

This disclosure relates to a mobile device, comprising: a receiver configured to receive a radio signal comprising transmissions from a plurality of radio cells; and a processor configured to derive second information from the received radio signal, the second information indicating at least one neighboring radio cell, wherein the processor is configured to initiate a radio cell selection based on the second information if the second information indicates at least one neighboring radio cell configured for the first RAT.

Device and method for radio cell selection

Delay in IMS call establishment and other time critical data transfers may be reduced by seeking alternative transmission methods for time critical data, when a transmission cannot be completed or the Radio Access Technology is otherwise unavailable. A Critical Service Manager ('CSM') receives and evaluates priority information about a given data transfer. By evaluating this priority information, the CSM can identify priority data, or latency intolerant data, such as IMS calls or emergency calls. Where network rejects a connection request and issues a wait timer, the CSM may lower the retransmission count to hasten a permanent transmission failure. Upon a permanent transmission failure, the CSM can determine an alternative protocol for transmission of the priority data, such as transmitting data through circuit switch fallback, via Wi-Fi, or through another legacy RAT.

Growing community of inventors

Bengaluru, India

Nitin Kuppelur