Electronic device for searching for base station, and operation method of electronic device

Abstract

This electronic device may comprise: a communication circuit that transmits and / or receives data through a cellular network; an application processor; and a communication processor. The application processor may: on the basis of receiving a message from the communication processor, activate an IP multimedia subsystem (IMS) establishment timer that detects whether or not an IMS establishment time, which is a time indicating the maximum time required for the electronic device to be connected to an IMS, has expired; transmit, to the cellular network by using the communication circuit, a message (a packet data network (PDN) connectivity request message) requesting a PDN connection between the IMS and the electronic device; upon reception of a message rejecting a connection to a PDN, compare a time of waiting to reattempting the connection to the PDN with the remaining time of the IMS establishment time; and on the basis of the result of the comparison, determine to attempt a connection to another cellular network rather than the cellular network.

Description

Electronic device for searching for a base station and method of operating the electronic device

[0001] This document relates to an electronic device, and for example, to an electronic device configured to transmit and receive IMS data and search for a base station to provide a voice call service in a communication environment (e.g., stand alone (SA), non-stand alone (NSA)).

[0002] The Internet Protocol Multimedia Subsystem (IMS) can refer to a system that provides multimedia services based on the Internet Protocol (IP). IMS can provide various multimedia services to user equipment (UEs), regardless of their location. IMS can provide multimedia services such as voice, audio, video, and data based on the Internet Protocol (IP).

[0003] SA (stand alone) or NSA (non-stand alone) provides voice call service using data, and it may be difficult to provide voice call service using CS (circuit switching) or CDMA.

[0004] Electronic devices can provide VoLTE-based voice call services by performing IMS (IP multimedia subsystem) registration. If IMS (IP multimedia subsystem) registration is not performed, electronic devices may have difficulty providing voice call services.

[0005] Electronic devices can process communication requests coming from the IP Multimedia Subsystem (IMS) network and provide multimedia services to users through the IMS registration process. The IMS registration process may be required whenever an electronic device connects to an IMS network for the first time or when the user's location or network connection changes.

[0006] To provide voice call services in a communication environment (e.g., stand-alone (SA) or non-stand-alone (NSA)), an electronic device may attempt IMS registration. If IMS registration is not successful within a time limit (e.g., IMS establishment time), the electronic device may search for other public land mobile networks (PLMNs) that provide voice call services.

[0007] If an IMS registration attempt is rejected or there is no response, the electronic device may wait until a specified time (e.g., IMS retry time, IMS throttle time) has expired before attempting to register again. However, there is a limitation that the electronic device will wait until all timeouts (e.g., IMS establishment time) have expired before switching to searching for another PLMN, even if the specified time (e.g., IMS retry time, IMS throttle time) for re-attempting registration exceeds the remaining timeout period (e.g., remaining IMS establishment time).

[0008] An electronic device may include a communication circuit for transmitting and / or receiving data via a cellular network, an application processor, and a communication processor. The application processor may activate an IMS establishment timer for detecting whether an IMS establishment time, which is a time indicating a maximum time required for the electronic device to connect to an IP Multimedia Subsystem (IMS), has expired based on receiving a message from the communication processor, transmit a message requesting a PDN (packet data network) connection between the IMS and the electronic device (PDN connectivity request message) to the cellular network using the communication circuit, and, upon receiving a message rejecting a connection to the PDN, compare a waiting time for retrying a connection to the PDN with a remaining time of the IMS establishment time, and, based on a result of the comparison, determine to attempt a connection to a cellular network other than the cellular network.

[0009] The electronic device includes a communication processor and an application processor, wherein the application processor receives, using the communication processor, a message indicating that establishment of a communication connection with a public land mobile network (PLMN) has failed or that there has been no response for a specified period of time, and based on receiving the message indicating that establishment of the communication connection has failed or there has been no response, receives, using the communication processor, information about an IP multimedia subsystem (IMS) retry time, and determines to change a PLMN (public land mobile network) to which a connection is to be attempted based on whether a size of the IMS retry time and a size of the remaining IMS establishment time satisfy specified conditions.

[0010] The method of operating an electronic device may include: an operation of activating an IMS establishment timer for detecting whether an IMS establishment time, which is a time indicating a maximum time required for the electronic device to connect to the IMS, has expired while starting a connection procedure with an IMS (IP Multimedia Subsystem) through a cellular network; an operation of controlling a communication circuit to transmit a message (PDN connectivity request message) requesting connection of a PDN (packet data network) between the IMS and the electronic device to the cellular network; an operation of receiving a message rejecting connection of the PDN from the cellular network; an operation of comparing a waiting time for retrying connection of the PDN and a remaining time of the IMS establishment time, based on a result of the comparison, to attempt connection with at least one other cellular network among the cellular network and other cellular networks.

[0011] An electronic device according to this document may decide to search for another PLMN immediately rather than waiting for the remaining timeouts (e.g. IMS establishment time) to expire, in a situation where the specified time for re-registration attempts (e.g. IMS retry time, IMS throttle time) is greater than the remaining timeouts (e.g. IMS establishment time).

[0012] An electronic device according to this document can increase the network switching speed by attempting to switch to another PLMN relatively quickly in situations where it is difficult to provide voice call service.

[0013] FIG. 1 is a block diagram of an electronic device within a network environment according to various embodiments.

[0014] FIG. 2 is a block diagram of an electronic device for supporting legacy network communication and 5G network communication according to various embodiments.

[0015] FIG. 3 is a diagram illustrating a protocol stack structure of a network (100) of legacy communication and / or 5G communication according to one embodiment.

[0016] FIGS. 4A and 4B are diagrams illustrating wireless communication systems providing a network of legacy communication and / or 5G communication according to various embodiments.

[0017] FIG. 5 is a diagram illustrating an electronic device and a cellular network according to one embodiment.

[0018] Figure 6 is a block diagram of an electronic device according to one embodiment.

[0019] FIGS. 7A and 7B are flowcharts illustrating a method of operating an electronic device according to one embodiment.

[0020] FIG. 8a illustrates a first embodiment of determining whether to attempt a transition to another PLMN based on an IMS throttle timer value and an IMS establishment timer value.

[0021] FIG. 8b illustrates a second embodiment in which a decision is made to attempt a transition to another PLMN based on the IMS registration retry timer value and the IMS establishment timer value.

[0022] FIG. 1 is a block diagram of an electronic device (101) within a network environment (100) according to various embodiments. Referring to FIG. 1, in the network environment (100), the electronic device (101) may communicate with the electronic device (102) via a first network (198) (e.g., a short-range wireless communication network), or may communicate with at least one of the electronic device (104) or the server (108) via a second network (199) (e.g., a long-range wireless communication network). In one embodiment, the electronic device (101) may communicate with the electronic device (104) via the server (108). According to one embodiment, the electronic device (101) may include a processor (120), a memory (130), an input module (150), an audio output module (155), a display module (160), an audio module (170), a sensor module (176), an interface (177), a connection terminal (178), a haptic module (179), a camera module (180), a power management module (188), a battery (189), a communication module (190), a subscriber identification module (196), or an antenna module (197). In some embodiments, the electronic device (101) may omit at least one of these components (e.g., the connection terminal (178)), or may have one or more other components added. In some embodiments, some of these components (e.g., the sensor module (176), the camera module (180), or the antenna module (197)) may be integrated into one component (e.g., the display module (160)).

[0023] The processor (120) may, for example, execute software (e.g., a program (140)) to control at least one other component (e.g., a hardware or software component) of the electronic device (101) connected to the processor (120) and perform various data processing or operations. According to one embodiment, as at least a part of the data processing or operations, the processor (120) may store commands or data received from other components (e.g., a sensor module (176) or a communication module (190)) in a volatile memory (132), process the commands or data stored in the volatile memory (132), and store result data in a non-volatile memory (134). According to one embodiment, the processor (120) may include a main processor (121) (e.g., a central processing unit or an application processor) or an auxiliary processor (123) (e.g., a graphics processing unit, a neural processing unit (NPU), an image signal processor, a sensor hub processor, or a communication processor) that can operate independently or together with the main processor (121). For example, when the electronic device (101) includes the main processor (121) and the auxiliary processor (123), the auxiliary processor (123) may be configured to use less power than the main processor (121) or to be specialized for a given function. The auxiliary processor (123) may be implemented separately from the main processor (121) or as a part thereof.

[0024] The auxiliary processor (123) may control at least a portion of functions or states associated with at least one component (e.g., a display module (160), a sensor module (176), or a communication module (190)) of the electronic device (101), for example, on behalf of the main processor (121) while the main processor (121) is in an inactive (e.g., sleep) state, or together with the main processor (121) while the main processor (121) is in an active (e.g., application execution) state. In one embodiment, the auxiliary processor (123) (e.g., an image signal processor or a communication processor) may be implemented as a part of another functionally related component (e.g., a camera module (180) or a communication module (190)). In one embodiment, the auxiliary processor (123) (e.g., a neural network processing unit) may include a hardware structure specialized for processing artificial intelligence models. The artificial intelligence models may be generated through machine learning. This learning can be performed, for example, on the electronic device (101) itself where the artificial intelligence model is executed, or can be performed through a separate server (e.g., server (108)). The learning algorithm can include, for example, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning, but is not limited to the examples described above. The artificial intelligence model can include multiple artificial neural network layers.The artificial neural network may be one of a deep neural network (DNN), a convolutional neural network (CNN), a recurrent neural network (RNN), a restricted Boltzmann machine (RBM), a deep belief network (DBN), a bidirectional recurrent deep neural network (BRDNN), a deep Q-network, or a combination of two or more of the above, but is not limited to the examples described above. In addition to, or alternatively to, a hardware structure, an artificial intelligence model may include a software structure.

[0025] The memory (130) can store various data used by at least one component (e.g., processor (120) or sensor module (176)) of the electronic device (101). The data can include, for example, software (e.g., program (140)) and input data or output data for commands related thereto. The memory (130) can include volatile memory (132) or non-volatile memory (134).

[0026] The program (140) may be stored as software in the memory (130) and may include, for example, an operating system (142), middleware (144), or an application (146).

[0027] The input module (150) can receive commands or data to be used in a component of the electronic device (101) (e.g., a processor (120)) from an external source (e.g., a user) of the electronic device (101). The input module (150) can include, for example, a microphone, a mouse, a keyboard, a key (e.g., a button), or a digital pen (e.g., a stylus pen).

[0028] The audio output module (155) can output audio signals to the outside of the electronic device (101). The audio output module (155) can include, for example, a speaker or a receiver. The speaker can be used for general purposes, such as multimedia playback or recording playback. The receiver can be used to receive incoming calls. In one embodiment, the receiver can be implemented separately from the speaker or as part of the speaker.

[0029] The display module (160) can visually provide information to an external party (e.g., a user) of the electronic device (101). The display module (160) may include, for example, a display, a holographic device, or a projector and a control circuit for controlling the device. According to one embodiment, the display module (160) may include a touch sensor configured to detect a touch, or a pressure sensor configured to measure the intensity of a force generated by the touch.

[0030] The audio module (170) can convert sound into an electrical signal, or vice versa, convert an electrical signal into sound. According to one embodiment, the audio module (170) can acquire sound through the input module (150), output sound through the sound output module (155), or an external electronic device (e.g., electronic device (102)) (e.g., speaker or headphone) directly or wirelessly connected to the electronic device (101).

[0031] The sensor module (176) can detect the operating status (e.g., power or temperature) of the electronic device (101) or the external environmental status (e.g., user status) and generate an electrical signal or data value corresponding to the detected status. According to one embodiment, the sensor module (176) can include, for example, a gesture sensor, a gyro sensor, a barometric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an IR (infrared) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor.

[0032] The interface (177) may support one or more designated protocols that may be used to directly or wirelessly connect the electronic device (101) with an external electronic device (e.g., the electronic device (102)). In one embodiment, the interface (177) may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, or an audio interface.

[0033] The connection terminal (178) may include a connector through which the electronic device (101) may be physically connected to an external electronic device (e.g., electronic device (102)). According to one embodiment, the connection terminal (178) may include, for example, an HDMI connector, a USB connector, an SD card connector, or an audio connector (e.g., a headphone connector).

[0034] The haptic module (179) can convert electrical signals into mechanical stimuli (e.g., vibration or movement) or electrical stimuli that a user can perceive through tactile or kinesthetic sensations. According to one embodiment, the haptic module (179) can include, for example, a motor, a piezoelectric element, or an electrical stimulation device.

[0035] The camera module (180) can capture still images and moving images. According to one embodiment, the camera module (180) may include one or more lenses, image sensors, image signal processors, or flashes.

[0036] The power management module (188) can manage power supplied to the electronic device (101). According to one embodiment, the power management module (188) can be implemented as, for example, at least a part of a power management integrated circuit (PMIC).

[0037] A battery (189) may power at least one component of the electronic device (101). In one embodiment, the battery (189) may include, for example, a non-rechargeable primary battery, a rechargeable secondary battery, or a fuel cell.

[0038] The communication module (190) may support the establishment of a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device (101) and an external electronic device (e.g., electronic device (102), electronic device (104), or server (108)), and the performance of communication through the established communication channel. The communication module (190) may operate independently from the processor (120) (e.g., application processor) and may include one or more communication processors that support direct (e.g., wired) communication or wireless communication. According to one embodiment, the communication module (190) may include a wireless communication module (192) (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module (194) (e.g., a local area network (LAN) communication module, or a power line communication module). Among these communication modules, the corresponding communication module can communicate with an external electronic device (104) via a first network (198) (e.g., a short-range communication network such as Bluetooth, wireless fidelity (WiFi) direct, or infrared data association (IrDA)) or a second network (199) (e.g., a long-range communication network such as a legacy cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., a LAN or WAN)). These various types of communication modules can be integrated into a single component (e.g., a single chip) or implemented as multiple separate components (e.g., multiple chips). The wireless communication module (192) can verify or authenticate the electronic device (101) within a communication network such as the first network (198) or the second network (199) by using subscriber information (e.g., an international mobile subscriber identity (IMSI)) stored in the subscriber identification module (196).

[0039] The wireless communication module (192) can support 5G networks and next-generation communication technologies following the 4G network, such as NR access technology (new radio access technology). The NR access technology can support high-speed transmission of high-capacity data (eMBB (enhanced mobile broadband)), minimization of terminal power and connection of multiple terminals (mMTC (massive machine type communications)), or high reliability and low latency (URLLC (ultra-reliable and low-latency communications)). The wireless communication module (192) can support, for example, a high-frequency band (e.g., mmWave band) to achieve a high data transmission rate. The wireless communication module (192) can support various technologies for securing performance in a high-frequency band, such as beamforming, massive multiple-input and multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, or large scale antenna. The wireless communication module (192) can support various requirements specified in the electronic device (101), an external electronic device (e.g., the electronic device (104)), or a network system (e.g., the second network (199)). According to one embodiment, the wireless communication module (192) can support a peak data rate (e.g., 20 Gbps or more) for eMBB realization, a loss coverage (e.g., 164 dB or less) for mMTC realization, or a U-plane latency (e.g., 0.5 ms or less for downlink (DL) and uplink (UL), or 1 ms or less for round trip) for URLLC realization.

[0040] The antenna module (197) can transmit or receive signals or power to or from an external device (e.g., an external electronic device). In one embodiment, the antenna module (197) may include an antenna including a radiator formed of a conductor or a conductive pattern formed on a substrate (e.g., a PCB). In one embodiment, the antenna module (197) may include a plurality of antennas (e.g., an array antenna). In this case, at least one antenna suitable for a communication method used in a communication network, such as the first network (198) or the second network (199), may be selected from the plurality of antennas, for example, by the communication module (190). A signal or power may be transmitted or received between the communication module (190) and an external electronic device via the at least one selected antenna. In some embodiments, in addition to the radiator, another component (e.g., a radio frequency integrated circuit (RFIC)) may be additionally formed as a part of the antenna module (197).

[0041] According to various embodiments, the antenna module (197) may form a mmWave antenna module. In one embodiment, the mmWave antenna module may include a printed circuit board, an RFIC disposed on or adjacent a first side (e.g., a bottom side) of the printed circuit board and capable of supporting a designated high-frequency band (e.g., a mmWave band), and a plurality of antennas (e.g., an array antenna) disposed on or adjacent a second side (e.g., a top side or a side side) of the printed circuit board and capable of transmitting or receiving signals in the designated high-frequency band.

[0042] At least some of the above components can be interconnected and exchange signals (e.g., commands or data) with each other via a communication method between peripheral devices (e.g., a bus, GPIO (general purpose input and output), SPI (serial peripheral interface), or MIPI (mobile industry processor interface)).

[0043] According to one embodiment, commands or data may be transmitted or received between the electronic device (101) and an external electronic device (104) via a server (108) connected to a second network (199). Each of the external electronic devices (102 or 104) may be the same or a different type of device as the electronic device (101). According to one embodiment, all or part of the operations executed in the electronic device (101) may be executed in one or more of the external electronic devices (102, 104, or 108). For example, when the electronic device (101) is to perform a certain function or service automatically or in response to a request from a user or another device, the electronic device (101) may, instead of or in addition to executing the function or service itself, request one or more external electronic devices to perform the function or at least a part of the service. One or more external electronic devices that receive the request may execute at least a portion of the requested function or service, or an additional function or service related to the request, and transmit the result of the execution to the electronic device (101). The electronic device (101) may process the result as is or additionally and provide it as at least a portion of a response to the request. For this purpose, cloud computing, distributed computing, mobile edge computing (MEC), or client-server computing technology may be used, for example. The electronic device (101) may provide an ultra-low latency service by using distributed computing or mobile edge computing, for example. In another embodiment, the external electronic device (104) may include an Internet of Things (IoT) device. The server (108) may be an intelligent server utilizing machine learning and / or a neural network. According to one embodiment, the external electronic device (104) or the server (108) may be included in the second network (199).The electronic device (101) can be applied to intelligent services (e.g., smart home, smart city, smart car, or healthcare) based on 5G communication technology and IoT-related technology.

[0044] Electronic devices according to the various embodiments disclosed in this document may take various forms. Electronic devices may include, for example, portable communication devices (e.g., smartphones), computer devices, portable multimedia devices, portable medical devices, cameras, wearable devices, or home appliances. Electronic devices according to the embodiments of this document are not limited to the aforementioned devices.

[0045] The various embodiments of this document and the terminology used therein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various modifications, equivalents, or substitutes of the embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of the items, unless the context clearly indicates otherwise. In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can include any one of the items listed together in the corresponding phrase among those phrases, or all possible combinations thereof. Terms such as "first," "second," or "first" or "second" may be used merely to distinguish one component from another, and do not limit the components in any other respect (e.g., importance or order). When a component (e.g., a first component) is referred to as "coupled" or "connected" to another (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0046] The term "module" used in various embodiments of this document may include a unit implemented in hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit. A module may be an integral component, or a minimum unit or part of such a component that performs one or more functions. For example, according to one embodiment, a module may be implemented in the form of an application-specific integrated circuit (ASIC).

[0047] Various embodiments of the present document may be implemented as software (e.g., a program (140)) including one or more instructions stored in a storage medium (e.g., an internal memory (136) or an external memory (138)) readable by a machine (e.g., an electronic device (101)). For example, a processor (e.g., a processor (120)) of the machine (e.g., an electronic device (101)) may call at least one instruction among the one or more instructions stored from the storage medium and execute it. This enables the machine to operate to perform at least one function according to the at least one called instruction. The one or more instructions may include code generated by a compiler or code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-transitory' simply means that the storage medium is a tangible device and does not contain signals (e.g., electromagnetic waves), and the term does not distinguish between cases where data is stored semi-permanently or temporarily on the storage medium.

[0048] According to one embodiment, the method according to various embodiments disclosed in this document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store (e.g., Play Store™) or directly between two user devices (e.g., smart phones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0049] According to various embodiments, each component (e.g., a module or a program) of the above-described components may include one or more entities, and some of the entities may be separated and placed in other components. According to various embodiments, one or more components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to various embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0050] FIG. 2 is a block diagram (200) of an electronic device (101) for supporting legacy network communication and 5G network communication according to various embodiments. Referring to FIG. 2, the electronic device (101) may include a first communication processor (212), a second communication processor (214), a first radio frequency integrated circuit (RFIC) (222), a second RFIC (224), a third RFIC (226), a fourth RFIC (228), a first radio frequency front end (RFFE) (232), a second RFFE (234), a first antenna module (242), a second antenna module (244), and an antenna (248). The electronic device (101) may further include a processor (120) and a memory (130). The network (199) may include a first network (292) and a second network (294). In another embodiment, the electronic device (101) may further include at least one of the components described in FIG. 1, and the network (199) may further include at least one other network. In one embodiment, the first communication processor (212), the second communication processor (214), the first RFIC (222), the second RFIC (224), the fourth RFIC (228), the first RFFE (232), and the second RFFE (234) may form at least a portion of the wireless communication module (192). In another embodiment, the fourth RFIC (228) may be omitted or may be included as a portion of the third RFIC (226).

[0051] The first communication processor (212) may establish a communication channel in a band to be used for wireless communication with the first network (292), and may support legacy network communication through the established communication channel. According to various embodiments, the first network may be a legacy network including a second generation (2G), 3G, 4G, or long term evolution (LTE) network. The second communication processor (214) may establish a communication channel corresponding to a designated band (e.g., about 6 GHz to about 60 GHz) among the bands to be used for wireless communication with the second network (294), and may support 5G network communication through the established communication channel. According to various embodiments, the second network (294) may be a 5G network defined by 3GPP. Additionally, according to one embodiment, the first communication processor (212) or the second communication processor (214) may establish a communication channel corresponding to another designated band (e.g., about 6 GHz or less) among the bands to be used for wireless communication with the second network (294), and support 5G network communication through the established communication channel. According to one embodiment, the first communication processor (212) and the second communication processor (214) may be implemented in a single chip or a single package. According to various embodiments, the first communication processor (212) or the second communication processor (214) may be formed in a single chip or a single package with the processor (120), the auxiliary processor (123), or the communication module (190).

[0052] The first RFIC (222) may, upon transmission, convert a baseband signal generated by the first communication processor (212) into a radio frequency (RF) signal of about 700 MHz to about 3 GHz used in the first network (292) (e.g., a legacy network). Upon reception, the RF signal may be acquired from the first network (292) (e.g., a legacy network) via an antenna (e.g., the first antenna module (242)) and preprocessed via an RFFE (e.g., the first RFFE (232)). The first RFIC (222) may convert the preprocessed RF signal into a baseband signal so that it may be processed by the first communication processor (212).

[0053] The second RFIC (224) may, upon transmission, convert a baseband signal generated by the first communication processor (212) or the second communication processor (214) into an RF signal (hereinafter, a 5G Sub6 RF signal) of a Sub6 band (e.g., about 6 GHz or less) used in the second network (294) (e.g., a 5G network). Upon reception, the 5G Sub6 RF signal may be acquired from the second network (294) (e.g., a 5G network) via an antenna (e.g., the second antenna module (244)) and preprocessed via an RFFE (e.g., the second RFFE (234)). The second RFIC (224) may convert the preprocessed 5G Sub6 RF signal into a baseband signal so that the preprocessed 5G Sub6 RF signal may be processed by a corresponding communication processor among the first communication processor (212) or the second communication processor (214).

[0054] The third RFIC (226) can convert a baseband signal generated by the second communication processor (214) into an RF signal (hereinafter, 5G Above6 RF signal) of a 5G Above6 band (e.g., about 6 GHz to about 60 GHz) to be used in the second network (294) (e.g., 5G network). Upon reception, the 5G Above6 RF signal can be acquired from the second network (294) (e.g., 5G network) via an antenna (e.g., antenna (248)) and preprocessed via the third RFFE (236). The third RFIC (226) can convert the preprocessed 5G Above6 RF signal into a baseband signal so that it can be processed by the second communication processor (214). According to one embodiment, the third RFFE (236) can be formed as a part of the third RFIC (226).

[0055] The electronic device (101) may, according to one embodiment, include a fourth RFIC (228) separately from or at least as a part of the third RFIC (226). In this case, the fourth RFIC (228) may convert a baseband signal generated by the second communication processor (214) into an RF signal (hereinafter, referred to as an IF signal) of an intermediate frequency band (e.g., about 9 GHz to about 11 GHz) and then transmit the IF signal to the third RFIC (226). The third RFIC (226) may convert the IF signal into a 5G Above6 RF signal. Upon reception, the 5G Above6 RF signal may be received from the second network (294) (e.g., a 5G network) via an antenna (e.g., antenna (248)) and converted into an IF signal by the third RFIC (226). The fourth RFIC (228) can convert the IF signal into a baseband signal so that the second communication processor (214) can process it.

[0056] According to an embodiment, the first RFIC (222) and the second RFIC (224) may be implemented as a single chip or at least a portion of a single package. According to an embodiment, the first RFFE (232) and the second RFFE (234) may be implemented as a single chip or at least a portion of a single package. According to an embodiment, at least one antenna module among the first antenna module (242) or the second antenna module (244) may be omitted or combined with another antenna module to process RF signals of a corresponding plurality of bands.

[0057] According to one embodiment, the third RFIC (226) and the antenna (248) may be disposed on the same substrate to form a third antenna module (246). For example, the wireless communication module (192) or the processor (120) may be disposed on the first substrate (e.g., the main PCB). In this case, the third RFIC (226) may be disposed on a portion (e.g., the lower surface) of a second substrate (e.g., the sub PCB) separate from the first substrate, and the antenna (248) may be disposed on another portion (e.g., the upper surface) to form the third antenna module (246). By disposing the third RFIC (226) and the antenna (248) on the same substrate, it is possible to reduce the length of the transmission line therebetween. This can reduce, for example, the loss (e.g., attenuation) of signals in the high-frequency band (e.g., about 6 GHz to about 60 GHz) used in 5G network communications due to transmission line transmission. As a result, the electronic device (101) can improve the quality or speed of communication with the second network (294) (e.g., the 5G network).

[0058] According to an example, the antenna (248) may be formed as an antenna array including a plurality of antenna elements that may be used for beamforming. In this case, the third RFIC (226) may include a plurality of phase shifters (238) corresponding to the plurality of antenna elements, for example, as part of the third RFFE (236). Upon transmission, each of the plurality of phase shifters (238) may shift the phase of a 5G Above6 RF signal to be transmitted to an external source (e.g., a base station of a 5G network) of the electronic device (101) via its corresponding antenna element. Upon reception, each of the plurality of phase shifters (238) may shift the phase of a 5G Above6 RF signal received from the external source via its corresponding antenna element to the same or substantially the same phase. This enables transmission or reception via beamforming between the electronic device (101) and the external source.

[0059] The second network (294) (e.g., a 5G network) may operate independently (e.g., Stand-Alone (SA)) or connected to (e.g., Non-Stand Alone (NSA)) the first network (292) (e.g., a legacy network). For example, the 5G network may only have an access network (e.g., a 5G radio access network (RAN) or next generation RAN (NG RAN)) and no core network (e.g., next generation core (NGC)). In this case, the electronic device (101) may access an external network (e.g., the Internet) under the control of the core network (e.g., evolved packed core (EPC)) of the legacy network after accessing the access network of the 5G network. Protocol information for communication with a legacy network (e.g., LTE protocol information) or protocol information for communication with a 5G network (e.g., New Radio (NR) protocol information) may be stored in the memory (230) and accessed by other components (e.g., the processor (120), the first communication processor (212), or the second communication processor (214)).

[0060] FIG. 3 is a diagram illustrating a protocol stack structure of a network (100) of legacy communication and / or 5G communication according to one embodiment.

[0061] Referring to FIG. 3, a network (100) according to the illustrated embodiment may include an electronic device (101), a legacy network (392), a 5G network (394), and a server (108).

[0062] The electronic device (101) may include an Internet protocol (312), a first communication protocol stack (314), and a second communication protocol stack (316). The electronic device (101) may communicate with a server (108) via a legacy network (392) and / or a 5G network (394).

[0063] According to one embodiment, the electronic device (101) can perform Internet communication associated with a server (108) using an Internet protocol (312) (e.g., TCP, UDP, IP). The Internet protocol (312) can be executed, for example, in a main processor included in the electronic device (101) (e.g., the main processor (121) of FIG. 1).

[0064] In another embodiment, the electronic device (101) may wirelessly communicate with a legacy network (392) using a first communication protocol stack (314). In another embodiment, the electronic device (101) may wirelessly communicate with a 5G network (394) using a second communication protocol stack (316). The first communication protocol stack (314) and the second communication protocol stack (316) may be executed, for example, in one or more communication processors included in the electronic device (101) (e.g., the wireless communication module (192) of FIG. 1).

[0065] The server (108) may include an Internet protocol (322). The server (108) may transmit and receive data related to the Internet protocol (322) with the electronic device (101) via a legacy network (392) and / or a 5G network (394). According to one embodiment, the server (108) may include a cloud computing server that exists outside the legacy network (392) or the 5G network (394). In another embodiment, the server (108) may include an edge computing server (or a mobile edge computing (MEC) server) located within at least one of the legacy network or the 5G network (394).

[0066] The legacy network (392) may include an LTE base station (340) and an EPC (342). The LTE base station (340) may include an LTE communication protocol stack (344). The EPC (342) may include a legacy NAS protocol (346). The legacy network (392) may perform LTE wireless communication with an electronic device (101) using the LTE communication protocol stack (344) and the legacy NAS protocol (346).

[0067] The above 5G network (394) may include an NR base station (350) and a 5GC (352). The NR base station (350) may include an NR communication protocol stack (354). The 5GC (352) may include a 5G NAS protocol (356). The 5G network (394) may perform NR wireless communication with the electronic device (101) using the NR communication protocol stack (354) and the 5G NAS protocol (356).

[0068] According to one embodiment, the first communication protocol stack (314), the second communication protocol stack (316), the LTE communication protocol stack (344), and the NR communication protocol stack (354) may include a control plane protocol for transmitting and receiving control messages and a user plane protocol for transmitting and receiving user data. The control messages may include, for example, messages related to at least one of security control, bearer establishment, authentication, registration, or mobility management. The user data may include, for example, data remaining excluding the control messages.

[0069] According to one embodiment, the control plane protocol and the user plane protocol may include physical (PHY), medium access control (MAC), radio link control (RLC), or packet data convergence protocol (PDCP) layers. The PHY layer may, for example, channel code and modulate data received from a higher layer (e.g., MAC layer) and transmit it over a wireless channel, and demodulate and decode data received over a wireless channel and transmit it to the higher layer. The PHY layer included in the second communication protocol stack (316) and the NR communication protocol stack (354) may further perform operations related to beam forming. The MAC layer may, for example, logically / physically map data to a wireless channel to be transmitted and received, and perform hybrid automatic repeat request (HARQ) for error correction. The RLC layer may, for example, concatenate, segment, or reassemble data, and perform data ordering, reordering, or duplication checking. The PDCP layer may perform operations related to, for example, ciphering and data integrity of control messages and user data. The second communication protocol stack (316) and the NR communication protocol stack (354) may further include a service data adaptation protocol (SDAP). The SDAP may, for example, manage radio bearer allocation based on the quality of service (QoS) of user data.

[0070] According to various embodiments, the control plane protocol may include a radio resource control (RRC) layer and a non-access stratum (NAS) layer. The RRC layer may process control data related to, for example, radio bearer establishment, paging, or mobility management. The NAS may process control messages related to, for example, authentication, registration, and mobility management.

[0071] FIGS. 4A and 4B are diagrams illustrating wireless communication systems that provide a network for legacy communication and / or 5G communication according to various embodiments. Referring to FIGS. 4A and 4B , a network environment (100A to 100B) may include at least one of a legacy network and a 5G network. The legacy network may include, for example, a 4G or LTE base station (e.g., an eNodeB (eNB)) of the 3GPP standard that supports wireless connection with an electronic device (101) and an evolved packet core (EPC) that manages 4G communication. The 5G network may include, for example, a New Radio (NR) base station (450) (e.g., a gNodeB (gNB)) that supports wireless connection with an electronic device (101) and a 5GC (452) (5th generation core) that manages 5G communication of the electronic device (101).

[0072] According to various embodiments, the electronic device (101) may transmit and receive control messages and user data via legacy communication and / or 5G communication. The control messages may include, for example, messages related to at least one of security control, bearer setup, authentication, registration, or mobility management of the electronic device (101). The user data may refer to, for example, user data excluding control messages transmitted and received between the electronic device (101) and the core network (430).

[0073] Referring to FIG. 4A, an electronic device (101) according to one embodiment can transmit and receive at least one of a control message or user data to and from at least a portion of a 5G network (e.g., an NR base station (450), a 5GC (452)) using at least a portion of a legacy network.

[0074] According to various embodiments, in an MR-DC environment, one of the LTE base stations or the NR base station may operate as a master node (MN) (410) and the other may operate as a secondary node (SN) (420). The MN (410) may be connected to a core network (430) and may transmit and receive control messages. The MN (410) and the SN (420) may be connected via a network interface and may transmit and receive messages related to management of radio resources (e.g., communication channels) to each other.

[0075] Referring to FIG. 4b, according to various embodiments, the 5G network can transmit and receive control messages and user data independently from the electronic device (101).

[0076] FIG. 5 is a diagram illustrating an electronic device and a cellular network according to one embodiment.

[0077] Referring to FIG. 5, the legacy network and the 5G network according to various embodiments can independently provide data transmission and reception. For example, the electronic device (101) and the EPC (542) can transmit and receive control messages and user data via the LTE base station (540). As another example, the electronic device (101) and the 5GC (552) can transmit and receive control messages and user data via the NR base station (550).

[0078] According to various embodiments, the electronic device (101) may be registered with at least one of the EPC (542) or the 5GC (552) to transmit and receive control messages.

[0079] According to various embodiments, the EPC (542) or the 5GC (552) may interwork to manage communication of the electronic device (101). For example, movement information of the electronic device (101) may be transmitted and received through an interface between the EPC (542) and the 5GC (552).

[0080] FIG. 6 is a diagram illustrating an electronic device according to one embodiment.

[0081] Referring to FIG. 6, an electronic device (e.g., electronic device (101) of FIG. 1) may include a communication circuit (610), a communication processor (e.g., first communication processor (212) of FIG. 2 and / or second communication processor (242) of FIG. 2) (620), and / or an application processor (e.g., processor (120) of FIG. 1) (630).

[0082] The application processor (630) can control various components of the electronic device (101). Specific operations will be described later.

[0083] The communication processor (620) can perform data transmission and / or reception via the first cellular communication and / or the second cellular communication. The communication processor (640) can be connected to a first node (e.g., a master node (MN) (410) of FIG. 4A) via the first cellular communication, or can be connected to a second node (e.g., a secondary node (SN) (420) of FIG. 4A) via the second cellular communication. The communication processor (620) can transmit user data received from the application processor (630) via the first cellular communication and / or the second cellular communication, and can transmit user data received via the first cellular communication and / or the second cellular communication to the application processor (620).

[0084] The first cellular communication may refer to any one of various cellular communication methods that the electronic device (101) can support, for example, a communication method on the second cellular network (294) of FIG. 2. For example, the first cellular communication may be a communication method using a 5th generation mobile communication method (e.g., stand alone (SA)).

[0085] The second cellular communication may refer to any one of various cellular communication methods that an electronic device (e.g., the electronic device (101) of FIG. 1) can support, for example, a communication method on the first cellular network (292) of FIG. 2. For example, the second cellular communication may be a communication method using a 4th generation mobile communication method (e.g., NSA (non-stand alone)).

[0086] An electronic device (101) can process communication requests coming from an IP Multimedia Subsystem (IMS) network and provide multimedia services to a user through an IMS registration process. The IMS registration process may be required whenever the electronic device (101) is first connected to an IMS network or when the user's location or network connection changes.

[0087] The electronic device (101) may activate an IMS throttle timer when a connection failure occurs during a process of requesting a PDN (packet data network) connection for IMS registration. The IMS throttle timer may include a back-off timer that operates when an IMS PDU (protocol data unit) is rejected in a stand-alone (SA) or non-stand-alone (NSA) mode. The back-off timer is mentioned in TS 24.501 section 6.4.1.4. The electronic device (101) may attempt to set up an IMS PDU again after the IMS throttle time has elapsed.

[0088] The electronic device (101) may receive information about an IMS (IP multimedia subsystem) retry time using the communication processor (620) based on receiving a message indicating that a communication connection establishment has failed or there has been no response. The electronic device (101) may determine to change a public land mobile network (PLMN) to which to attempt a connection based on whether the size of the IMS retry time and the size of the remaining IMS establishment time meet specified conditions under the control of the application processor (630).

[0089] According to one embodiment, the electronic device (101) can receive information about the size of the IMS (IP multimedia subsystem) throttle time using the communication processor (620) under the control of the application processor (630). The application processor (630) can determine to change the public land mobile network (PLMN) to which to attempt connection based on whether the size of the IMS throttle time and the size of the remaining IMS establishment time satisfy specified conditions. The IMS throttle time can include a waiting time to make another IMS PDU connection request when an IMS PDU connection request is rejected. According to one embodiment, the electronic device (101) can request IMS registration again only after the IMS throttle time has elapsed when a PDN connection is rejected after an IMS registration request.

[0090] According to one embodiment, the IMS establishment time may include a time during which IMS registration can be attempted. The IMS establishment timer may refer to a timer for limiting the IMS registration attempt time. If the electronic device (101) fails to successfully register with the IMS within the IMS establishment time, it may attempt to switch to another network capable of voice call service. The IMS establishment time is referred to as a 'manufacturer-determined period of time' in 3GPP standard TS 24.501 section 4.3.2. The IMS establishment time may be, for example, between 2 and 12 minutes and may vary by operator.

[0091] According to one embodiment, a condition related to an operation of changing a public land mobile network (PLMN) to which a connection is attempted may include a condition in which the size of the IMS throttle time exceeds the size of the remaining IMS establishment time. If the size of the IMS throttle time is relatively larger than the size of the remaining IMS establishment time, the electronic device (101) may attempt to switch to another PLMN because it cannot make an IMS PDU connection during the remaining IMS establishment time. The electronic device (101) may change the public land mobile network (PLMN) to which a connection is attempted even if there is remaining IMS establishment time.

[0092] In one embodiment, the conditions associated with the operation of changing the public land mobile network (PLMN) to which a connection is attempted may include a condition that the difference between the size of the IMS throttle time and the size of the remaining IMS establishment time is less than a specified level.

[0093] The application processor (630) may transmit a message to the communication processor (620) instructing the change of the PLMN to which the connection is to be attempted based on a determination to change the PLMN to which the connection is to be attempted. The communication processor (620) may receive priority information about the PLMN and determine whether voice call service can be provided starting from a PLMN with a relatively high priority.

[0094] The communication processor (620) may attempt to establish a communication connection with the searched PLMN based on the search for a PLMN capable of providing voice call services.

[0095] According to one embodiment, the electronic device (101) may receive, using the communication processor (620), a message indicating that an attempt to establish a communication connection with a public land mobile network (PLMN) has failed or that there has been no response for a specified period of time. Based on receiving the message indicating that the attempt to establish a communication connection has failed or that there has been no response, the electronic device (101) may receive, using the communication processor (620), information about an IP multimedia subsystem (IMS) retry time. The electronic device (101) may determine to change a public land mobile network (PLMN) to which to attempt a connection based on whether the size of the IMS retry time and the size of the remaining IMS establishment time satisfy specified conditions under the control of the application processor (630).

[0096] In one embodiment, the specified condition may include a condition where the size of the IMS retry time exceeds the size of the remaining IMS establishment time.

[0097] According to one embodiment, the condition may include that the difference between the size of the IMS retry time and the size of the remaining IMS establishment time is less than a specified level.

[0098] The IMS retry time may include the time to wait for a registration request to be re-attempted when a registration request for a session initiation protocol (SIP) is rejected or remains unanswered while connected to an IP multimedia subsystem (IMS) protocol data unit (PDU). The IMS establishment time may include the time during which an IMS registration attempt may be attempted.

[0099] FIGS. 7A and 7B are flowcharts illustrating a method of operating an electronic device according to one embodiment.

[0100] The operations described through FIGS. 7a and 7b may be implemented based on instructions that may be stored in a computer recording medium or memory (e.g., memory (130) of FIG. 1). The illustrated method may be executed by the electronic device described above through FIGS. 1 to 6 (e.g., electronic device (101) of FIG. 6), and the technical features described above will be omitted below. The order of each operation of FIGS. 7a and 7b may be changed, some operations may be omitted, and some operations may be performed simultaneously.

[0101] In operation 710 of FIG. 7a, the electronic device (101) may receive information about the size of an IMS (IP multimedia subsystem) throttle time using a communication processor (e.g., communication processor (620) of FIG. 6).

[0102] An electronic device (101) can process communication requests coming from an IP Multimedia Subsystem (IMS) network and provide multimedia services to a user through an IMS registration process. The IMS registration process may be required whenever the electronic device (101) is first connected to an IMS network or when the user's location or network connection changes.

[0103] The electronic device (101) may activate an IMS throttle timer when a connection failure occurs during a process of requesting a PDN (packet data network) connection for IMS registration. The IMS throttle timer may include a back-off timer that operates when an IMS PDU (protocol data unit) is rejected in SA (stand alone) or NSA (non-stand alone). The back-off timer is mentioned in TS 24.501 section 6.4.1.4. The electronic device (101) may attempt IMS PDU setup again after the IMS throttle time has elapsed. The IMS throttle time may include a waiting time for making another IMS PDU connection request when an IMS PDU connection request is rejected. According to one embodiment, the electronic device (101) may request IMS registration again only after the IMS throttle time has elapsed when a PDN connection is rejected after an IMS registration request.

[0104] In operation 712, the electronic device (101) may determine to change the public land mobile network (PLMN) to which it will attempt to connect under the control of an application processor (e.g., the application processor (630) of FIG. 6). The application processor (630) may determine to change the public land mobile network (PLMN) to which it will attempt to connect based on whether the size of the IMS throttle time and the size of the remaining IMS establishment time meet specified conditions. The IMS establishment timer may refer to a timer for limiting the IMS registration attempt time. If the electronic device (101) fails to successfully complete IMS registration within the IMS establishment time, it may attempt to switch to another network capable of providing voice call service. The IMS establishment time is referred to as a 'manufacturer-determined period of time' in 3GPP standard TS 24.501 section 4.3.2. The IMS establishment time may be, for example, between 2 and 12 minutes and may vary by operator.

[0105] The specified condition may include, for example, a condition in which the size of the IMS throttle time exceeds the size of the remaining IMS establishment time. The electronic device (101) may decide to change the public land mobile network (PLMN) to which it will attempt to connect based on whether the size of the IMS throttle time exceeds the size of the remaining IMS establishment time. For example, if the size of the IMS throttle time is 10 minutes and the size of the remaining IMS establishment time is 5 minutes, the electronic device (101) may not transmit a message requesting a PDN connection to the base station (805) again until 10 minutes, which is the IMS throttle time, have passed. However, if the remaining IMS establishment time is 5 minutes, the electronic device (101) may have to attempt to switch to another PLMN after 5 minutes have passed. If the electronic device (101) according to this document determines that the size of the IMS throttle time exceeds the size of the remaining IMS establishment time, it may attempt to switch to another PLMN instead of waiting for the size of the remaining IMS establishment time and then attempting to switch to another PLMN. The electronic device (101) according to this document can increase the network switching speed by attempting to switch to another PLMN relatively quickly in situations where it is difficult to provide voice call services. The electronic device (101) can initialize the IMS throttle time, IMS establishment time, and IMS retry time based on the completion of the switch to another PLMN.

[0106] The specified conditions may include, for example, a condition where the difference between the size of the IMS throttle time and the size of the remaining IMS establishment time is less than a specified level.

[0107] The electronic device (101) may determine to change the public land mobile network (PLMN) to which it will attempt to connect if the difference between the size of the IMS throttle time and the size of the remaining IMS establishment time is less than a specified level (e.g., 1 minute). For example, in a situation where the size of the IMS throttle time is 10 minutes and the size of the remaining IMS establishment time is 10 minutes and 30 seconds, the electronic device (101) may determine to change the public land mobile network (PLMN) to which it will attempt to connect based on the difference between the size of the IMS throttle time and the size of the remaining IMS establishment time being less than a specified level (e.g., 1 minute). The electronic device (101) may initialize all of the IMS throttle time, the IMS establishment time, and the IMS retry time based on the completion of the transition to another PLMN.

[0108] According to one embodiment, the electronic device (101) may control the communication circuit (610) to initiate a connection procedure with an IP Multimedia Subsystem (IMS) through a cellular network using a communication processor (620), activate an IMS establishment timer that detects whether an IMS establishment time, which is a time indicating a maximum time required for the electronic device to connect to the IMS, has expired, and transmit a message (e.g., a PDN connectivity request message) requesting a PDN (packet data network) connection between the IMS and the electronic device to the cellular network. The message requesting a PDN (packet data network) connection between the IMS and the electronic device (101) may include a PDN Connectivity Request in the case of NSA (non-stand alone) and may include a PDU SESSION ESTABLISHMENT REQUEST in the case of SA (stand alone). The electronic device (101) may receive a message rejecting a PDN connection from the cellular network and transmit the message to the application processor (630). A message rejecting a connection to a PDN may include PDN Connectivity Reject in the case of NSA (non-stand alone) and PDU SESSION ESTABLISHMENT REJECT in the case of SA (stand alone). Under the control of the application processor (630), upon receipt of a message rejecting a connection to a PDN, the electronic device (101) compares a waiting time for retrying a connection to the PDN with the remaining time of the IMS establishment time, and based on the comparison result, attempts to connect to a cellular network other than the cellular network with which a connection is currently established (e.g., another PLMN).

[0109] According to one embodiment, the application processor (630) may attempt to connect to a cellular network other than the cellular network if the time it waits to retry the connection to the PDN is greater than the remaining time of the IMS establishment time.

[0110] According to one embodiment, if the time to wait for retrying connection to the PDN is greater than the remaining time of the IMS establishment time, the application processor (630) may not retry connection to the PDN and may attempt connection to a cellular network other than the cellular network.

[0111] According to one embodiment, as part of attempting to connect a cellular network to another cellular network, the communication processor (620) may select one of the plurality of other cellular networks based on a priority of each of the plurality of other cellular networks, and determine whether the selected cellular network is capable of providing the specified service.

[0112] In one embodiment, the designated service may include a voice call service.

[0113] In operation 720 of FIG. 7b, the electronic device (101) may receive a message indicating that a communication connection with a public land mobile network (PLMN) has failed to be established from a base station (e.g., server (108) of FIG. 3) using the communication processor (620) or a message indicating that there has been no response for a specified period of time.

[0114] In operation 722, the electronic device (101) may receive information about an IMS (IP multimedia subsystem) retry time using the communication processor (620). The electronic device (101) may operate an IMS registration retry timer based on receiving a message indicating that an error has occurred for SIP (session initiation protocol) registration or determining that there is no response. The IMS registration retry timer may be used to measure the IMS retry time. The IMS retry time may include a time to wait for a registration request again when a registration request for SIP (session initiation protocol) is rejected or there is no response while connected to an IMS (IP multimedia subsystem) PDU (protocol data unit).

[0115] At operation 724, the electronic device (101) may determine to change the public land mobile network (PLMN) to which to attempt connection based on whether the size of the IMS retry time and the size of the remaining IMS establishment time meet specified conditions under the control of the application processor (630).

[0116] The specified conditions may include a condition where the size of the IMS retry time exceeds the size of the remaining IMS establishment time. The specified conditions may include a condition where the difference between the size of the IMS retry time and the size of the remaining IMS establishment time is less than a specified level.

[0117] For example, if the IMS retry time is 10 minutes and the remaining IMS establishment time is 5 minutes, the electronic device (101) can transmit a message requesting a PDN connection to the base station (805) again only after the IMS retry time of 10 minutes has passed. However, if the remaining IMS establishment time is 5 minutes, the electronic device (101) may have to attempt to switch to another PLMN after 5 minutes have passed. The electronic device (101) according to this document may attempt to switch to another PLMN immediately, rather than waiting for the remaining IMS establishment time and then attempting to switch to another PLMN in a situation where the IMS retry time exceeds the remaining IMS establishment time. The electronic device (101) according to this document may attempt to switch to another PLMN relatively quickly in a situation where it is difficult to provide a voice call service, thereby increasing the network switching speed.

[0118] The electronic device (101) may determine to change the public land mobile network (PLMN) to which it will attempt to connect if the difference in the size of the IMS retry time and the size of the remaining IMS establishment time is less than a specified level (e.g., 1 minute). For example, in a situation where the size of the IMS retry time is 10 minutes and the size of the remaining IMS establishment time is 10 minutes and 30 seconds, the electronic device (101) may determine to change the public land mobile network (PLMN) to which it will attempt to connect based on the difference in the size of the IMS retry time and the size of the remaining IMS establishment time being less than a specified level (e.g., 1 minute).

[0119] The electronic device (101) can initialize the IMS throttle time, the IMS establishment time, and the IMS retry time based on the completion of the transition to another PLMN.

[0120] FIG. 8a illustrates a first embodiment of determining whether to attempt a transition to another PLMN based on an IMS throttle timer value and an IMS establishment timer value.

[0121] FIG. 8b illustrates a second embodiment in which a decision is made to attempt a transition to another PLMN based on the IMS registration retry timer value and the IMS establishment timer value.

[0122] The operations described through FIGS. 8A and 8B can be implemented based on instructions that can be stored in a computer recording medium or memory (e.g., memory (130) of FIG. 1). The illustrated method can be executed by the electronic device described above through FIGS. 1 to 6 (e.g., electronic device (101) of FIG. 6), and the technical features described above will be omitted below. The order of each operation of FIGS. 8A and 8B can be changed, some operations can be omitted, and some operations can be performed simultaneously.

[0123] In FIG. 8A, the electronic device (101) can establish an RRC (radio resource control) connection with a base station (805). RRC (radio resource control) may refer to a protocol used when a user's terminal communicates with a wireless base station. The base station (805) may include, for example, an LTE base station (540) and an NR base station (550) of FIG. 5.

[0124] In operation 810, the electronic device (101) may start an IMS establishment timer based on the establishment of an RRC connection with the base station (805). The IMS establishment time may refer to a time limit within which IMS registration may be attempted. The electronic device (101) may attempt to switch to another PLMN based on failure to successfully complete IMS registration within a preset IMS establishment time.

[0125] In operation 812, the electronic device (101) may transmit a message requesting a packet data network (PDN) connection to the base station (805). A packet data network (PDN) may include a network used for data communication in a mobile communication system. The electronic device (101) may use the PDN to access online services including at least one of a mobile app, email, social media, or streaming service. The electronic device (101) may use the PDN to perform data communication with a mobile communication network. The electronic device (101) may use the PDN to exchange data packets with the base station (805).

[0126] At operation 814, the electronic device (101) may receive a message from the base station (805) indicating that the PDN connection has been rejected.

[0127] At step 816, the electronic device (101) may operate an IMS PDU throttle timer based on receiving a message indicating that a PDN connection has been rejected. The IMS PDU throttle timer may be used to measure the IMS throttle time. The IMS throttle time may refer to the time to wait before making another IMS PDU connection request when an IMS PDU connection request is rejected. The IMS throttle time may increase together with the number of rejections of the IMS PDU connection request. For example, the IMS throttle time may increase to 5 minutes when the number of rejections of the IMS PDU connection request is 1, 10 minutes when the number of rejections is 2, and 30 minutes when the number of rejections is 3. This is only an example, and the IMS throttle time may vary depending on the configuration.

[0128] In operation 818, the electronic device (101) may determine to change the public land mobile network (PLMN) to which to attempt connection based on whether the size of the IMS throttle time and the size of the IMS establishment time meet specified conditions under the control of an application processor (e.g., the application processor (630) of FIG. 6).

[0129] The specified condition may include, for example, a condition in which the size of the IMS throttle time exceeds the size of the remaining IMS establishment time. The electronic device (101) may decide to change the public land mobile network (PLMN) to which it will attempt to connect based on the size of the IMS throttle time exceeding the size of the IMS establishment time. For example, if the size of the IMS throttle time is 10 minutes and the size of the remaining IMS establishment time is 5 minutes, the electronic device (101) may not transmit a message requesting a PDN connection to the base station (805) again until 10 minutes, which is the IMS throttle time, have passed. However, if the remaining IMS establishment time is 5 minutes, the electronic device (101) may have to attempt to switch to another PLMN after 5 minutes have passed. The electronic device (101) according to this document may attempt to switch to another PLMN immediately in a situation in which the size of the IMS throttle time exceeds the size of the remaining IMS establishment time, rather than waiting for the size of the remaining IMS establishment time and then attempting to switch to another PLMN. The electronic device (101) according to this document can increase the network switching speed by attempting to switch to another PLMN relatively quickly in a situation where it is difficult to provide voice call service.

[0130] The specified conditions may include, for example, a condition where the difference between the size of the IMS throttle time and the size of the remaining IMS establishment time is less than a specified level.

[0131] The electronic device (101) may determine to change the public land mobile network (PLMN) to which it will attempt to connect if the difference between the size of the IMS throttle time and the size of the remaining IMS establishment time is less than a specified level (e.g., 1 minute). For example, in a situation where the size of the IMS throttle time is 10 minutes and the size of the remaining IMS establishment time is 10 minutes and 30 seconds, the electronic device (101) may determine to change the public land mobile network (PLMN) to which it will attempt to connect based on the difference between the size of the IMS throttle time and the size of the remaining IMS establishment time being less than a specified level (e.g., 1 minute).

[0132] The electronic device (101) can initialize the IMS throttle time, the IMS establishment time, and the IMS retry time based on the completion of the transition to another PLMN.

[0133] FIG. 8b illustrates a second embodiment in which a decision is made to attempt a transition to another PLMN based on the IMS registration retry timer value and the IMS establishment timer value.

[0134] In FIG. 8B, the electronic device (101) can establish an RRC (radio resource control) connection with a base station (805). RRC (radio resource control) may include a protocol used when a user's terminal communicates with a wireless base station. The base station (805) may include, for example, an LTE base station (540) and an NR base station (550) of FIG. 5.

[0135] In operation 820, the electronic device (101) may operate an IMS establishment timer based on the establishment of an RRC connection with the base station (805). The IMS establishment timer may be used to measure the IMS establishment time. The IMS establishment time may indicate a time limit within which IMS registration may be attempted. The electronic device (101) may attempt to switch to another network based on failure to successfully complete IMS registration within a preset IMS establishment time.

[0136] An electronic device (101) can establish a packet data network (PDN) connection with a base station (805). A packet data network (PDN) may include a network used for data communication in a mobile communication system. The electronic device (101) can use an online service, including at least one of a mobile app, email, social media, or streaming service, using the PDN. The electronic device (101) can perform data communication with a mobile communication network using the PDN. The electronic device (101) can exchange data packets with the base station (805) using the PDN.

[0137] In operation 822, the electronic device (101) may transmit a message requesting SIP (session initiation protocol) registration to the base station (805).

[0138] In operation 824, the electronic device (101) may receive a message from the base station (805) indicating that an error has occurred in the SIP (session initiation protocol) registration. Alternatively, the electronic device (101) may determine that it is in a non-responsive state based on not receiving a response to a message requesting SIP (session initiation protocol) registration within a specified time from the base station (805).

[0139] In operation 826, the electronic device (101) may receive a message indicating that an error has occurred for SIP (session initiation protocol) registration or may operate an IMS registration retry timer based on determining that there is no response. The IMS registration retry time may be used to measure an IMS retry time. The IMS retry time may include a time to wait for a registration request again when a registration request for SIP (session initiation protocol) is rejected or there is no response while connected to an IMS (IP multimedia subsystem) PDU (protocol data unit).

[0140] In operation 828, the electronic device (101) may determine to change the public land mobile network (PLMN) to which to attempt connection based on whether the size of the IMS retry time and the size of the remaining IMS establishment time meet specified conditions. The specified conditions may include a condition in which the size of the IMS retry time exceeds the size of the remaining IMS establishment time. The specified conditions may include a condition in which the difference between the size of the IMS retry time and the size of the remaining IMS establishment time is less than a specified level.

[0141] For example, if the IMS retry time is 10 minutes and the remaining IMS establishment time is 5 minutes, the electronic device (101) can transmit a message requesting a PDN connection to the base station (805) again only after the IMS retry time of 10 minutes has passed. However, if the remaining IMS establishment time is 5 minutes, the electronic device (101) may have to attempt to switch to another PLMN after 5 minutes have passed. The electronic device (101) according to this document may attempt to switch to another PLMN immediately, rather than waiting for the remaining IMS establishment time and then attempting to switch to another PLMN in a situation where the IMS retry time exceeds the remaining IMS establishment time. The electronic device (101) according to this document may attempt to switch to another PLMN relatively quickly in a situation where it is difficult to provide a voice call service, thereby increasing the network switching speed.

[0142] The electronic device (101) may determine to change the public land mobile network (PLMN) to which it will attempt to connect if the difference in the size of the IMS retry time and the size of the remaining IMS establishment time is less than a specified level (e.g., 1 minute). For example, in a situation where the size of the IMS retry time is 10 minutes and the size of the remaining IMS establishment time is 10 minutes and 30 seconds, the electronic device (101) may determine to change the public land mobile network (PLMN) to which it will attempt to connect based on the difference in the size of the IMS retry time and the size of the remaining IMS establishment time being less than a specified level (e.g., 1 minute).

[0143] The electronic device (101) can initialize the IMS throttle time, the IMS establishment time, and the IMS retry time based on the completion of the transition to another PLMN.

Claims

1. In an electronic device (101), Communication circuitry (610) for transmitting and / or receiving data via a cellular network; application processor (630); and Contains a communication processor (620), The above application processor Activate an IMS establishment timer to detect whether the IMS establishment time, which is a time indicating the maximum time required for the electronic device to connect to the IMS (IP Multimedia Subsystem), has expired based on receiving a message from the communication processor; Using the above communication circuit, a message requesting a PDN (packet data network) connection between the IMS and the electronic device (PDN connectivity request message) is transmitted to the cellular network, Upon receipt of a message rejecting the connection to the PDN, compare the waiting time to retry the connection to the PDN with the remaining time of the IMS establishment time, An electronic device that determines, based on the results of the above comparison, to attempt to connect to a cellular network other than the above cellular network.

2. In paragraph 1, The above application processor An electronic device configured to attempt to connect to a cellular network other than the cellular network if the time it waits to retry connecting to the PDN is greater than the remaining time of the IMS establishment time.

3. In paragraph 1, The above application processor An electronic device configured to attempt connection to a cellular network other than the cellular network without retrying connection to the PDN if the waiting time for retrying connection to the PDN is greater than the remaining time of the IMS establishment time.

4. In paragraph 1, The above communication processor As part of attempting to connect to said cellular network and another cellular network, selecting one of said plurality of other cellular networks based on a priority of each of said plurality of other cellular networks; An electronic device configured to determine whether the selected cellular network is capable of providing a specified service.

5. In paragraph 4, The above specified services Electronic devices including voice calling services 6. In the electronic device (101), Communication processor (620); Includes an application processor (630), The above application processor Receive a message indicating that a communication connection with a public land mobile network (PLMN) has failed to be established using the above communication processor or a message indicating that there has been no response for a specified period of time; Receive information about an IMS (IP multimedia subsystem) retry time using the communication processor based on receiving a message indicating that a communication connection establishment has failed or there has been no response; An electronic device that determines which public land mobile network (PLMN) to attempt connection to based on whether the size of the IMS retry time and the size of the remaining IMS establishment time meet specified conditions.

7. In paragraph 6, The conditions specified above are An electronic device including a condition where the size of the above IMS retry time exceeds the size of the remaining IMS establishment time.

8. In paragraph 6, The conditions specified above are An electronic device including a condition in which a difference between the size of the IMS retry time and the size of the remaining IMS establishment time is less than a specified level.

9. In paragraph 6, The above processor An electronic device that searches for a PLMN that can provide voice call service based on a decision to change the public land mobile network (PLMN) to which it attempts to connect.

10. In paragraph 6, The above processor An electronic device that attempts to establish a communication connection with a searched PLMN using the communication processor based on the search for a PLMN capable of providing voice call services.

11. In paragraph 6, The above IMS retry time includes the time to wait for a re-registration request when a registration request for SIP (session initiation protocol) is rejected or unresponsive while connected to an IMS (IP multimedia subsystem) PDU (protocol data unit). The above IMS establishment time is an electronic device that includes the time at which IMS registration can be attempted.

12. In the operating method of an electronic device (101), An action of activating an IMS establishment timer to detect whether an IMS establishment time, which is a time indicating the maximum time required for the electronic device to connect to the IMS, has expired while starting a connection procedure with the IMS (IP Multimedia Subsystem) through a cellular network; and An operation of controlling a communication circuit (610) to transmit a message (PDN connectivity request message) requesting a connection of a packet data network (PDN) between the IMS and the electronic device to the cellular network; An action of receiving a message from said cellular network rejecting a connection to said PDN; Upon receipt of a message rejecting a connection to the PDN, comparing the waiting time to retry a connection to the PDN with the remaining time of the IMS establishment time; and A method comprising, based on the results of the comparison, an action of determining to attempt a connection with at least one other cellular network among the cellular network and other cellular networks.

13. In paragraph 12, A method further comprising: setting the cellular network to attempt connection with a cellular network other than the cellular network if the waiting time for retrying connection to the PDN is greater than the remaining time of the IMS establishment time.

14. In paragraph 12, The conditions specified above are A method further comprising: attempting to connect to a cellular network other than the cellular network without retrying the connection to the PDN if the waiting time for retrying the connection to the PDN is greater than the remaining time of the IMS establishment time.

15. In paragraph 12, As part of attempting to connect to said cellular network and another cellular network, selecting one of said plurality of other cellular networks based on a priority of each of said plurality of other cellular networks; A method further comprising the action of determining whether the selected cellular network is capable of providing the specified service.

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