KR20220064862A - Electronic device performing emergency service and method for operating thereof - Google Patents

Abstract

The present invention relates to an electronic device for performing an emergency service, which performs a system fallback to perform an emergency service, and an operation method thereof. According to various embodiments of the present invention, the electronic device comprises at least one processor. The at least one processor is configured to check an event related to an emergency service when registered in a first communication system; transmit a service request corresponding to the event to a network on the basis of checking the event; start a timer having an expiration time shorter than an expiration time of a T3517 timer on the basis of transmitting the service request; search for and select a cell corresponding to a PLMN of a second communication system different from the first communication system on the basis of failure to receive a response corresponding to the service request until the timer expires; perform at least one operation for registration in the second communication system on the basis of the selected cell; and perform the emergency service corresponding to the event through the second communication system on the basis of registration with the second communication system.

Description

Electronic device performing emergency service and operating method thereof

Various embodiments relate to an electronic device performing an emergency service and an operating method thereof.

In order to support various application scenarios for obtaining emergency service, user equipment (UE) and ^5th generation core (5GC) direct the UE to E-UTRA connected to 5GC, using mobilityFromNRCommand A mechanism for handover or redirection using RRC release may be supported. For example, when a new radio (NR) does not support an emergency service, a radio access technology (RAT) fall back in which the UE is handed over or redirected toward E-UTRA connected to 5GC may be performed. . Alternatively, when 5GC does not support emergency service, a system fallback to E-UTRA connected to an evolved pack core (EPC) in which the UE is handed over or redirected toward an evolved packet system (EPS) may be performed. If 5 ^th generation system (5GS) does not indicate support for emergency service and indicates support of emergency service fallback, emergency service fallback may be used.

For example, when the AMF indicates support for emergency service fallback in a registration accept message, for emergency service initiation, a UE supporting a normally registered emergency service fallback sends a service request. can start. For example, the UE may transmit a service request to the AMF. The UE may receive a response (eg, an RRC release message, or a handover command) causing a system fallback, and thus may perform an emergency service in the fallback communication system.

The UE may perform a system fallback (eg, EPS fallback) based on a handover command or an RRC release message received from the network in response to the service request. However, there is a possibility that the UE cannot receive a response from the network according to the deterioration of the electric field situation or a temporary problem in the network. 3GPP ( ^3rd generation partnership project) of TS (technical specification) 24.501 proposes a T3517 timer. The UE may wait for a response after the transmission of the service request until the T3517 timer expires. Accordingly, the execution of the emergency service may be delayed according to a response failure until the T3517 timer expires. If the T3517 timer is 15 seconds, the emergency call may be delayed by 15 seconds.

An electronic device and an operating method thereof according to various embodiments of the present disclosure may perform an emergency service by performing a system fallback based on expiration of a timer having an expiration time shorter than that of the T3517 timer.

According to various embodiments, the electronic device includes at least one processor, wherein the at least one processor, in a state registered with the first communication system, identifies an event related to an emergency service, and based on the confirmation of the event to transmit a service request corresponding to the event to the network, and based on the transmission of the service request, start a timer having an expiration time shorter than the expiration time of the T3517 timer, and perform the service until the timer expires Based on the failure to receive a response corresponding to the request, searching for and selecting a cell corresponding to a PLMN of a second communication system different from the first communication system, and registering with the second communication system based on the selected cell It may be configured to perform at least one operation for performing at least one operation for, and to perform the emergency service corresponding to the event based on the second communication system based on registration with the second communication system.

According to various embodiments of the present disclosure, in a method of operating an electronic device, in a state registered in a first communication system, an operation of identifying an event related to an emergency service, and a network service request corresponding to the event based on the confirmation of the event , starting a timer having an expiration time shorter than that of the T3517 timer based on the transmission of the service request, and failure to receive a response corresponding to the service request until the timer expires based on , searching for and selecting a cell corresponding to a PLMN of a second communication system different from the first communication system, and performing at least one operation for registration in the second communication system based on the selected cell and performing the emergency service corresponding to the event based on the second communication system.

According to various embodiments, the electronic device includes at least one processor, wherein the at least one processor checks an event related to an emergency service in a state registered with the first communication system, Based on it is confirmed that the emergency service fallback indicator confirmed in the registration process is set to not support, in response to the event confirmation related to the emergency service, a second communication system different from the first communication system searches for and selects a cell corresponding to the PLMN of , performs at least one operation for registration in the second communication system based on the selected cell, It may be configured to perform the emergency service corresponding to the event based on the communication system.

According to various embodiments, an electronic device capable of performing an emergency service by performing a system fallback based on expiration of a timer having an expiration time shorter than the expiration time of the T3517 timer, and a method of operating the same may be provided. Accordingly, it is possible to prevent the emergency service from being delayed during the expiration time of the T3517 timer, which is a relatively long time according to the standard document.

1 is a block diagram of an electronic device in a network environment, according to various embodiments of the present disclosure;
2A and 2B are block diagrams of an electronic device for supporting legacy network communication and 5G network communication, according to various embodiments.
3A is a flowchart illustrating an emergency services fallback process of a user device according to various embodiments of the present disclosure;
3B shows a flowchart of a comparative example for comparison with various examples.
4 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;
5 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;
6 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;
7 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure.
8 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;
9 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;
10 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;
11 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;
12 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;
13 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;

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

The processor 120, for example, executes software (eg, a program 140) to execute at least one other component (eg, a hardware or software component) of the electronic device 101 connected to the processor 120 . It can control and perform various data processing or operations. According to one embodiment, as at least part of data processing or operation, the processor 120 converts commands or data received from other components (eg, the sensor module 176 or the communication module 190 ) to the volatile memory 132 . may be stored in the volatile memory 132 , and may process commands or data stored in the volatile memory 132 , and store the result data in the non-volatile memory 134 . According to an embodiment, the processor 120 is the main processor 121 (eg, a central processing unit or an application processor) or a secondary processor 123 (eg, a graphic processing unit, a neural network processing unit) a neural processing unit (NPU), an image signal processor, a sensor hub processor, or a communication processor). For example, when the electronic device 101 includes the main processor 121 and the sub-processor 123 , the sub-processor 123 may use less power than the main processor 121 or may be set to be specialized for a specified function. can The auxiliary processor 123 may be implemented separately from or as a part of the main processor 121 .

The auxiliary processor 123 is, for example, on behalf of the main processor 121 while the main processor 121 is in an inactive (eg, sleep) state, or the main processor 121 is active (eg, executing an application). ), together with the main processor 121, at least one of the components of the electronic device 101 (eg, the display module 160, the sensor module 176, or the communication module 190) It is possible to control at least some of the related functions or states. According to an embodiment, the co-processor 123 (eg, an image signal processor or a communication processor) may be implemented as part of another functionally related component (eg, the camera module 180 or the communication module 190). there is. According to an embodiment, the auxiliary processor 123 (eg, a neural network processing device) may include a hardware structure specialized for processing an artificial intelligence model. Artificial intelligence models can be created through machine learning. Such learning may be performed, for example, in the electronic device 101 itself on which artificial intelligence is performed, or may be performed through a separate server (eg, the server 108). The learning algorithm may include, for example, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning, but in the above example not limited The artificial intelligence model may include a plurality of artificial neural network layers. Artificial neural networks include deep neural networks (DNNs), convolutional neural networks (CNNs), recurrent neural networks (RNNs), restricted boltzmann machines (RBMs), deep belief networks (DBNs), bidirectional recurrent deep neural networks (BRDNNs), It may be one of deep Q-networks or a combination of two or more of the above, but is not limited to the above example. The artificial intelligence model may include, in addition to, or alternatively, a software structure in addition to the hardware structure.

The memory 130 may store various data used by at least one component of the electronic device 101 (eg, the processor 120 or the sensor module 176 ). The data may include, for example, input data or output data for software (eg, the program 140 ) and instructions related thereto. The memory 130 may include a volatile memory 132 or a non-volatile memory 134 .

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 .

The input module 150 may receive a command or data to be used in a component (eg, the processor 120 ) of the electronic device 101 from the outside (eg, a user) of the electronic device 101 . The input module 150 may include, for example, a microphone, a mouse, a keyboard, a key (eg, a button), or a digital pen (eg, a stylus pen).

The sound output module 155 may output a sound signal to the outside of the electronic device 101 . The sound output module 155 may 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 may be used to receive an incoming call. According to one embodiment, the receiver may be implemented separately from or as part of the speaker.

The display module 160 may visually provide information to the outside (eg, a user) of the electronic device 101 . The display module 160 may include, for example, a control circuit for controlling a display, a hologram device, or a projector and a corresponding device. According to an embodiment, the display module 160 may include a touch sensor configured to sense a touch or a pressure sensor configured to measure the intensity of a force generated by the touch.

The audio module 170 may convert a sound into an electric signal or, conversely, convert an electric signal into a sound. According to an embodiment, the audio module 170 acquires a sound through the input module 150 , or an external electronic device (eg, a sound output module 155 ) connected directly or wirelessly with the electronic device 101 . A sound may be output through the electronic device 102 (eg, a speaker or headphones).

The sensor module 176 detects an operating state (eg, power or temperature) of the electronic device 101 or an external environmental state (eg, user state), and generates an electrical signal or data value corresponding to the sensed state. can do. According to an embodiment, the sensor module 176 may 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, It may include a temperature sensor, a humidity sensor, or an illuminance sensor.

The interface 177 may support one or more designated protocols that may be used by the electronic device 101 to directly or wirelessly connect with an external electronic device (eg, the electronic device 102 ). According to an 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.

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

The haptic module 179 may convert an electrical signal into a mechanical stimulus (eg, vibration or movement) or an electrical stimulus that the user can perceive through tactile or kinesthetic sense. According to an embodiment, the haptic module 179 may include, for example, a motor, a piezoelectric element, or an electrical stimulation device.

The camera module 180 may capture still images and moving images. According to an embodiment, the camera module 180 may include one or more lenses, image sensors, image signal processors, or flashes.

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

The battery 189 may supply power to at least one component of the electronic device 101 . According to one embodiment, battery 189 may include, for example, a non-rechargeable primary cell, a rechargeable secondary cell, or a fuel cell.

The communication module 190 is a direct (eg, wired) communication channel or a wireless communication channel between the electronic device 101 and an external electronic device (eg, the electronic device 102, the electronic device 104, or the server 108). It can support establishment and communication performance through the established communication channel. The communication module 190 may include one or more communication processors that operate independently of the processor 120 (eg, an application processor) and support direct (eg, wired) communication or wireless communication. According to one embodiment, the communication module 190 may include a communication module 192 (eg, a cellular communication module, a short-range communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module 194 (eg, a LAN). (local area network) communication module, or a power line communication module). A corresponding communication module among these communication modules is a first network 198 (eg, a short-range communication network such as Bluetooth, wireless fidelity (WiFi) direct, or infrared data association (IrDA)) or a second network 199 (eg, legacy It may communicate with the external electronic device 104 through a cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (eg, a telecommunication network such as a LAN or a WAN). These various types of communication modules may be integrated into one component (eg, a single chip) or may be implemented as a plurality of components (eg, multiple chips) separate from each other. The communication module 192 uses subscriber information (eg, International Mobile Subscriber Identifier (IMSI)) stored in the subscriber identification module 196 to communicate electronically within a communication network, such as the first network 198 or the second network 199 . Device 101 may be identified or authenticated.

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

The antenna module 197 may transmit or receive a signal or power to the outside (eg, an external electronic device). According to an embodiment, the antenna module 197 may include an antenna including a conductor formed on a substrate (eg, a PCB) or a radiator formed of a conductive pattern. According to an embodiment, the antenna module 197 may include a plurality of antennas (eg, 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 is connected from the plurality of antennas by, for example, the communication module 190 . can be selected. A signal or power may be transmitted or received between the communication module 190 and an external electronic device through the selected at least one antenna. According to some embodiments, other components (eg, a radio frequency integrated circuit (RFIC)) other than the radiator may be additionally formed as a part of the antenna module 197 .

According to various embodiments, the antenna module 197 may form a mmWave antenna module. According to one embodiment, the mmWave antenna module comprises a printed circuit board, an RFIC disposed on or adjacent to a first side (eg, bottom side) of the printed circuit board and capable of supporting a designated high frequency band (eg, mmWave band); and a plurality of antennas (eg, an array antenna) disposed on or adjacent to a second side (eg, top or side) of the printed circuit board and capable of transmitting or receiving signals of the designated high frequency band. can do.

At least some of the components are connected to each other through a communication method between peripheral devices (eg, a bus, general purpose input and output (GPIO), serial peripheral interface (SPI), or mobile industry processor interface (MIPI)) and a signal (eg : commands or data) can be exchanged with each other.

According to an embodiment, the command or data may be transmitted or received between the electronic device 101 and the external electronic device 104 through the server 108 connected to the second network 199 . Each of the external electronic devices 102 or 104 may be the same as or different from the electronic device 101 . According to an embodiment, all or a part of operations executed in the electronic device 101 may be executed in one or more external electronic devices 102 , 104 , or 108 . For example, when the electronic device 101 is to perform a function or service automatically or in response to a request from a user or other device, the electronic device 101 may perform the function or service itself instead of executing the function or service itself. Alternatively or additionally, one or more external electronic devices may be requested to perform at least a part of the function or the service. One or more external electronic devices that have received the request may execute at least a part of the requested function or service, or an additional function or service related to the request, and transmit a result of the execution to the electronic device 101 . The electronic device 101 may process the result as it is or additionally and provide it as at least a part of a response to the request. For this, for example, cloud computing, distributed computing, mobile edge computing (MEC), or client-server computing technology may be used. The electronic device 101 may provide an ultra-low latency service using, for example, distributed computing or mobile edge computing. In another embodiment, the external electronic device 104 may include an Internet of things (IoT) device. Server 108 may be an intelligent server using machine learning and/or neural networks. According to an embodiment, the external electronic device 104 or the server 108 may be included in the second network 199 . The electronic device 101 may be applied to an intelligent service (eg, smart home, smart city, smart car, or health care) based on 5G communication technology and IoT-related technology.

2A 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. 2A , the electronic device 101 includes a first communication processor 212 , a second communication processor 214 , a first radio frequency integrated circuit (RFIC) 222 , a second RFIC 224 , and a third RFIC 226 , fourth RFIC 228 , first radio frequency front end (RFFE) 232 , second RFFE 234 , first antenna module 242 , second antenna module 244 , third An antenna module 246 and antennas 248 may be included. The electronic device 101 may further include a processor 120 and a memory 130 . The second network 199 may include a first cellular network 292 and a second cellular network 294 . According to another embodiment, the electronic device 101 may further include at least one component among the components illustrated in FIG. 1 , and the second network 199 may further include at least one other network. According to an embodiment, a first communication processor 212 , a second communication processor 214 , a first RFIC 222 , a second RFIC 224 , a fourth RFIC 228 , a first RFFE 232 , and the second RFFE 234 may form at least a part of the communication module 192 . According to another embodiment, the fourth RFIC 228 may be omitted or may be included as a part of the third RFIC 226 .

The first communication processor 212 may support establishment of a communication channel of a band to be used for wireless communication with the first cellular network 292 and legacy network communication through the established communication channel. According to various embodiments, the first cellular network may be a legacy network including a second generation (2G), 3G, 4G, or long term evolution (LTE) network. The second communication processor 214 establishes a communication channel corresponding to a designated band (eg, about 6 GHz to about 60 GHz) among bands to be used for wireless communication with the second cellular network 294 , and a 5G network through the established communication channel communication can be supported. According to various embodiments, the second cellular network 294 may be a 5G network defined by 3GPP. Additionally, according to an embodiment, the first communication processor 212 or the second communication processor 214 corresponds to another designated band (eg, about 6 GHz or less) among bands to be used for wireless communication with the second cellular network 294 . It is possible to support the establishment of a communication channel, and 5G network communication through the established communication channel.

The first communication processor 212 may transmit/receive data to and from the second communication processor 214 . For example, data classified to be transmitted over the second cellular network 294 may be changed to be transmitted over the first cellular network 292 . In this case, the first communication processor 212 may receive transmission data from the second communication processor 214 . For example, the first communication processor 212 may transmit/receive data through the second communication processor 214 and the interprocessor interface 213 . The interprocessor interface 213 may be implemented as, for example, a universal asynchronous receiver/transmitter (UART) (eg, high speed-UART (HS-UART) or peripheral component interconnect bus express (PCIe) interface). Alternatively, the first communication processor 212 and the second communication processor 214 may exchange control information and packet data information using, for example, a shared memory. The communication processor 212 may transmit/receive various information to and from the second communication processor 214 , such as sensing information, information on output strength, and resource block (RB) allocation information.

Depending on the implementation, the first communication processor 212 may not be directly connected to the second communication processor 214 . In this case, the first communication processor 212 may transmit and receive data through the second communication processor 214 and the processor 120 (eg, an application processor). For example, the first communication processor 212 and the second communication processor 214 may transmit and receive data with the processor 120 (eg, an application processor) through the HS-UART interface or the PCIe interface, but There is no restriction on the type. Alternatively, the first communication processor 212 and the second communication processor 214 may exchange control information and packet data information using a shared memory with the processor 120 (eg, an application processor). .

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 co-processor 123 , or the communication module 190 . there is. For example, as shown in FIG. 2B , the unified communication processor 260 may support both functions for communication with the first cellular network 292 and the second cellular network 294 .

The first RFIC 222, when transmitting, transmits a baseband signal generated by the first communication processor 212 from about 700 MHz to about 700 MHz used for the first cellular network 292 (eg, a legacy network). It can be converted to a radio frequency (RF) signal of 3 GHz. Upon reception, an RF signal is obtained from a first network 292 (eg, a legacy network) via an antenna (eg, a first antenna module 242 ), and via an RFFE (eg, a first RFFE 232 ). It may be preprocessed. The first RFIC 222 may convert the preprocessed RF signal into a baseband signal to be processed by the first communication processor 212 .

The second RFIC 224, when transmitting, uses the baseband signal generated by the first communication processor 212 or the second communication processor 214 to the second cellular network 294 (eg, a 5G network). It can be converted into an RF signal (hereinafter, 5G Sub6 RF signal) of the Sub6 band (eg, about 6 GHz or less). Upon reception, a 5G Sub6 RF signal is obtained from a second cellular network 294 (eg, 5G network) via an antenna (eg, second antenna module 244 ), and an RFFE (eg, second RFFE 234 ) ) can be preprocessed. The second RFIC 224 may convert the preprocessed 5G Sub6 RF signal into a baseband signal to be processed by a corresponding one of the first communication processor 212 or the second communication processor 214 .

The third RFIC 226 transmits the baseband signal generated by the second communication processor 214 to the 5G Above6 band (eg, about 6 GHz to about 60 GHz) to be used in the second cellular network 294 (eg, 5G network). It can be converted into an RF signal (hereinafter referred to as 5G Above6 RF signal). Upon reception, a 5G Above6 RF signal may be obtained from the second cellular network 294 (eg, 5G network) via an antenna (eg, antenna 248 ) and pre-processed via a third RFFE 236 . The third RFIC 226 may convert the preprocessed 5G Above6 RF signal into a baseband signal to be processed by the second communication processor 214 . According to one embodiment, the third RFFE 236 may be formed as part of the third RFIC 226 .

According to an embodiment, the electronic device 101 may include the fourth RFIC 228 separately from or as at least a part of the third RFIC 226 . In this case, the fourth RFIC 228 converts the baseband signal generated by the second communication processor 214 into an RF signal (hereinafter, IF signal) of an intermediate frequency band (eg, about 9 GHz to about 11 GHz). After conversion, the IF signal may be transmitted to the third RFIC 226 . The third RFIC 226 may convert the IF signal into a 5G Above6 RF signal. Upon reception, a 5G Above6 RF signal may be received from the second cellular network 294 (eg, 5G network) via an antenna (eg, antenna 248 ) and converted to an IF signal by a third RFIC 226 . there is. The fourth RFIC 228 may convert the IF signal into a baseband signal for processing by the second communication processor 214 .

According to an embodiment, the first RFIC 222 and the second RFIC 224 may be implemented as at least a part of a single chip or a single package. According to various embodiments, when the first RFIC 222 and the second RFIC 224 in FIG. 2A or 2B are implemented as a single chip or a single package, they may be implemented as an integrated RFIC. In this case, the integrated RFIC is connected to the first RFFE 232 and the second RFFE 234 to convert a baseband signal into a signal of a band supported by the first RFFE 232 and/or the second RFFE 234 and , the converted signal may be transmitted to one of the first RFFE 232 and the second RFFE 234 . According to an embodiment, the first RFFE 232 and the second RFFE 234 may be implemented as at least a part of a single chip or a single package. According to an example, at least one antenna module of the first antenna module 242 or the second antenna module 244 may be omitted or may be combined with another antenna module to process RF signals of a plurality of corresponding bands.

According to an embodiment, the third RFIC 226 and the antenna 248 may be disposed on the same substrate to form the third antenna module 246 . For example, the communication module 192 or the processor 120 may be disposed on the first substrate (eg, main PCB). In this case, the third RFIC 226 is located in a partial area (eg, the bottom surface) of the second substrate (eg, sub PCB) separate from the first substrate, and the antenna 248 is located in another partial region (eg, the top surface). is disposed, the third antenna module 246 may be formed. 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, for example, can reduce loss (eg, attenuation) of a signal in a high-frequency band (eg, about 6 GHz to about 60 GHz) used for 5G network communication by the transmission line. Accordingly, the electronic device 101 may improve the quality or speed of communication with the second network 294 (eg, a 5G network).

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, for example, as a part of the third RFFE 236 , a plurality of phase shifters 238 corresponding to the plurality of antenna elements. During transmission, each of the plurality of phase shifters 238 may transform the phase of a 5G Above6 RF signal to be transmitted to the outside of the electronic device 101 (eg, a base station of a 5G network) through a corresponding antenna element. . Upon reception, each of the plurality of phase shifters 238 may convert the phase of the 5G Above6 RF signal received from the outside through a corresponding antenna element into the same or substantially the same phase. This enables transmission or reception through beamforming between the electronic device 101 and the outside.

The second cellular network 294 (eg, 5G network) may be operated independently (eg, Stand-Alone (SA)) or connected to the first cellular network 292 (eg, legacy network). Example: Non-Stand Alone (NSA)). For example, the 5G network may have only an access network (eg, a 5G radio access network (RAN) or a next generation RAN (NG RAN)), and may not have a core network (eg, a next generation core (NGC)). In this case, after accessing the access network of the 5G network, the electronic device 101 may access an external network (eg, the Internet) under the control of a core network (eg, evolved packed core (EPC)) of the legacy network. Protocol information for communication with a legacy network (eg, LTE protocol information) or protocol information for communication with a 5G network (eg, New Radio (NR) protocol information) is stored in the memory 230, and other components (eg, a processor 120 , the first communication processor 212 , or the second communication processor 214 ).

3A is a flowchart illustrating an emergency services fallback process of a user device according to various embodiments of the present disclosure;

According to various embodiments, the UE 300 (eg, the electronic device 101 ), in operation 311 , a next generation-radio access network (NG-RAN) 301 , an access and mobility management function (AMF) 302 , and a user plane function (UPF) 303 may be used to camp on 5 ^th generation system (5 GS). For example, the UE 300 may camp on a universal mobile telecommunications system (UMTS) terrestrial radio access (E-UTRA) cell or a new radio (NR) cell within 5GS. For example, when 5GS supports an emergency service, support may be delivered to the UE 300 through a registration accept message, for example, to be performed based on TA and RAT. can

According to various embodiments, the UE 300 may, in operation 313 , confirm that it is required to create an emergency session. For example, it may have a pending IMS emergency session request (eg, voice) from upper layers. In operation 315 , the UE 300 may send a service request to the AMF 302 . When the AMF 302 indicates in a registration accept message that it supports emergency services fallback, in order to initiate an emergency service, in general, support emergency services fallback The general UE 300 may transmit a service request that sets the service type to an emergency service fallback, which is, for example, 3GPP ( ^3rd generation project partnership) TS (technical specification) 23.502 may be followed, but there are no restrictions.

According to various embodiments, the AMF 302 may provide an N2 request for an emergency fallback to the NG-RAN 301 in operation 317 . After receiving the service request for emergency service, AMF 302, based on factors such as N26 availability, network configuration, and raid conditions, to either E-UTRA/5GC or E-UTRAN/EPC, An N2 procedure that causes either IDLE state mobility (redirection) or CONNECTED state mobility (handover procedure) may be triggered. The 5GC may request an emergency service fallback by executing an NG-AP procedure indicating to the NR-RAN 301 that it is a fallback for an emergency service. The AMF 302 may inform the target core network for the RAN node to recognize that an inter-RAT fallback or an inter-system fallback is executed, based on the support of the emergency service within the evolved packet core (EPC) or 5GC. When the AMF 302 initiates a redirect for the UE 300 for which authentication was successful, the AMF 302 may include a security context in the request of the trigger fallback towards the NG-RNA 301. .

According to various embodiments, in operation 319 , inter-RAT handover or RRC redirection to E-UTRA connected to 5GC may be performed. The AMF 302 may redirect the UE 300 to the appropriate RAT/system using a service type indication in the service request. For example, when the UE 300 currently camps on the NR cell, either one of the following two procedures may be performed.

- EPS (evolved packet system) 304 to the handover (handover) or redirection (redirection)

- Handover or redirection to universal mobile telecommunications system (UMTS) terrestrial radio access (E-UTRA) connected to 5 ^th generation core (5GC)

In operation 321 , the NG-RAN 301 may initiate a redirect or handover to the E-UTRAN connected to the EPS 304 . The NG-RAN 301 may use the security context provided by the AMF 302 . If the redirection procedure is used in either operation 319 or 321, it may be provided to the UE 300 so that the target core network can perform an appropriate NAS procedure.

After handover to the target cell, in operation 323 , the UE 300 may establish a PDU session/PDN connection for the IMS emergency service. The UE 300 may, for example, perform an IMS procedure for establishing an IMS emergency session according to a scheme based on 3GPP TS 23.617.

3B shows a flowchart of a comparative example for comparison with various examples. At least some of the operations of the electronic device 101 according to the comparative example may be performed by the electronic device 101 according to various embodiments.

In operation 331 , the UE 300 (eg, the electronic device 101 ) transmits, to the network 306 , a service request in which the service type is set as emergency service fallback to the network 306 in operation 331 . can The UE 300 sends a handover command (eg, mobilityFromNRCommand) or an RRC release message (eg, E-UTRA) that causes a redirect from the network 306 , as described with respect to FIG. 3A , as described in connection with FIG. 3A . RRCConnectionrelease message of , or RRCRelease message of NR) can be expected. Based on the transmission of the service request, the UE 300 may start a T3517 timer in operation 333 . The T3517 timer may be defined, for example, in 3GPP TS 24.501, and may have an expiration time of, for example, 15 seconds, but there is no limitation. The T3517 timer may be started based on the transmission of the service request message. The T3517 timer may be stopped, for example, based on receipt of a message in response to a service request.

In one example, the network 306 may transmit a message in response to the service request, at operation 335 . However, depending on the electric field conditions, the UE 300 may fail to receive the message from the network 306 . Alternatively, although not shown, in another example, the network 306 may fail to receive the service request from the UE 300 , in which case the network 306 does not send a message in response to the service request. it may not be In another example, the network 306 may have received the service request from the UE 300 but not send a message in response to the service request, depending on an internal error of the network 306 . According to the various examples described above, the UE 300 may fail to receive a message from the network 306 during the expiration time of the T3517 timer. In operation 337 , the UE 300 may confirm expiration of the T3517 timer. If the T3517 timer has expired, the UE 300 may abort the emergency service procedure. For example, if the service type of the service request message is set to "emergency service fallback" and the service request procedure is initiated in 5GMM-IDLE mode, the 5GMM sublayer stops the service request procedure, and the The resource may be released and the failure of the service request procedure may be notified to upper layers. Alternatively, if the service type of the service request message is set to "emergency service fallback" and the service request procedure is initiated in the 5GMM-CONNECTED mode, the 5GMM sublayer stops the service request procedure and stays in the 5GMM-CONNECTED mode. , it is possible to notify the failure of the service request procedure to the upper layers.

On the other hand, if the expiration time of the T3517 timer is 15 seconds as in 3GPP TS 24.501, the UE 300 displays a screen indicating that an emergency service, for example, an emergency call, is trying to connect for 15 seconds. can Accordingly, there is a problem in that the standby time of the emergency service becomes long despite the emergency situation.

4 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;

According to various embodiments, the electronic device 101 (eg, at least one of the processor 120 , the first communication processor 212 , the second communication processor 214 , or the unified communication processor 260 ) includes: In operation 401 , an event related to an emergency service may be checked while registered in the first communication system. For example, it is assumed that the electronic device 101 is registered in 5GS (or 5GC). The electronic device 101 may receive a request for emergency service fallback from the upperlayer in 5GMM-IDLE mode, 5GMM-CONNECTED mode through 3GPP access, or 5GMM-CONNECTED mode of RRC inactive indication. . The electronic device 101 may be registered in 5GS based on, for example, the RAT of E-UTRA or NR, and there is no limit to the RAT. Meanwhile, in the present embodiment, it is assumed that the electronic device 101 is initially registered in 5GS (or 5GC), but there is no limitation in the communication system (or core network) in which the electronic device 101 is registered. For example, the electronic device 101 may acquire an emergency call request, and may identify the acquired emergency call request as an event related to an emergency service. On the other hand, the type of emergency service is not limited.

According to various embodiments, in operation 403 , the electronic device 101 may transmit a service request message corresponding to the event to the network. For example, the electronic device 101 may set the service type of the service request message to “emergency service fallback”. The purpose of the service type element is to specify the purpose of the service request procedure. The service type is a Type 1 information element, and may conform to, for example, 3GPP TS 24.501, but there is no limitation. For example, the electronic device 101 may set the service type to “emergency service fallback” by setting a service type value of “0100”.

According to various embodiments, the electronic device 101 may start a timer in operation 405 based on the transmission of the service request message. For example, the electronic device 101 may start a timer having an expiration time shorter than the expiration time of the T3517 timer. For example, the expiration time of the timer may be set based on a time required for the electronic device 101 to transmit a service request message to the network and to receive a response message from the network. For example, the network operator may set a maximum period for responding to the service request message, and a time equal to or longer than the maximum period may be set as the expiration time of the timer, but there is no limitation on the setting method. For example, the expiration time of the timer may be set to 1 second, which is shorter than 15 seconds of the T3517 timer. On the other hand, since there may be a time difference between the transmission time of the service request message and the reception time of the response message for each network operator, the expiration time of the timer may be specific to the network operator, and may be changed according to the network conditions according to implementation. may be

According to various embodiments, in operation 407 , the electronic device 101 may search and select a cell corresponding to the PLMN of the second communication system, for example, EPS, based on failure to receive a response until the timer expires. there is. For example, the electronic device 101 may preferentially search for and/or select a registered PLMN (RPLMN) and/or a home PLMN (HPLMN) of the second communication system, but there is no limitation. The electronic device 101 may search for at least one cell corresponding to the selected PLMN. For example, the electronic device 101 may search for a cell or perform a full scan based on stored information. The electronic device 101 may select one cell from among the at least one identified cell based on the cell search result. For example, the electronic device 101 may select a cell that satisfies a cell selection criterion, but there is no limitation on a cell selection method. As will be described later, the electronic device 101 may identify a cell confirmed to support the second communication system.

According to various embodiments, when a cell is selected, the electronic device 101 may perform at least one operation for registration with the second communication system in operation 409 . For example, the electronic device 101 may perform a RACH procedure with the selected cell. The electronic device 101 performs a tracking area update (TAU) procedure in a second communication system (EPS) or a core network (eg, EPC) of the second communication system using the RRC connection established based on the RACH procedure. can be done Alternatively, the electronic device 101 may perform an Attach procedure to the core network of the second communication system.

In one example, the electronic device 101 may select a cell supporting the second communication system (or connected to the second communication system) among cells corresponding to the PLMN of the second communication system. For example, the electronic device 101 may identify the type of a communication system (eg, a core network) supported by the cell based on system information (eg, SIB 1) from the cell. Table 1 is an example of SIB 1 (eg, SystemInformationBlockType1).

- TS 36.331: 6.2.2 Message definitions
- SystemInformationBlockType1
PLMN-IdentityInfo ::= SEQUENCE {
plmn-Identity PLMN-Identity, <<<<<
cellReservedForOperatorUse ENUMERATED {reserved, notReserved}
}

PLMN-IdentityInfo-r15 ::= SEQUENCE {
plmn-Identity-5GC-r15 CHOICE{
plmn-Identity-r15 PLMN-Identity,
plmn-Index-r15 INTEGER (1..maxPLMN-r11)
},

In SIB 1 in Table 1, “PLMN-IdentityInfo” including “plmn-Identity” and/or “PLMN-IdentityInfo-r15” including “plmn-Identity-5GC-r15” may be included. For example, when “PLMN-IdentityInfo” is included in SIB 1, it may mean that the cell corresponding to SIB 1 supports EPC. For example, when “PLMN-IdentityInfo-r15” is included in SIB 1, it may mean that the cell corresponding to SIB 1 supports 5GC. The electronic device 101 may select a cell supporting the second communication system based on the information included in SIB 1 described above. If the electronic device 101 needs to fall back to EPS, the electronic device 101 selects a cell that has transmitted SIB 1 including “plmn-Identity” to select a cell supporting EPS. it might be

According to various embodiments, based on registration with the second communication system, the electronic device 101 may perform a service corresponding to an event in operation 411 . For example, the electronic device 101 may perform at least one procedure for establishing an IMS emergency session. At least one procedure for establishing an IMS emergency session may follow, for example, 3GPP TS 23.167, but there is no limitation.

As described above, the establishment of the IMS emergency session may be started in the network of the newly registered second communication system (eg, EPS) after the emergency service fallback operation is completed. Accordingly, even if the electronic device 101 falls back the communication system to the second communication system without receiving the response message before the expiration of the T3517 timer, since the establishment of the IMS emergency session is performed thereafter, the emergency service is not provided. It is highly probable that it will work normally. Accordingly, the emergency service can be performed after the expiration time of a relatively short timer (eg, 1 second) without waiting for 15 seconds, which is the expiration time of the standard T3517.

5 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;

According to various embodiments, the electronic device 101 (eg, at least one of the processor 120 , the first communication processor 212 , the second communication processor 214 , or the unified communication processor 260 ) includes: In operation 501 , an event related to an emergency service may be checked while registered in the first communication system. In operation 503 , the electronic device 101 may transmit a service request message corresponding to the event to the network and start a timer. As described above, the electronic device 101 may transmit a service request message in which the service type is set to “emergency service fallback”. The timer started in operation 503 may have an expiration time shorter than that of the T3517 timer, for example.

According to various embodiments, the electronic device 101 may check whether a response is received from the network in operation 505 . If a response is received from the network (505 - Yes), the electronic device 101 performs an operation for fallback in operation 507 to perform a system fallback, and performs a service corresponding to the event in the fallback system. can do. For example, when the electronic device 101 receives an RRC release message causing redirection from the network, the electronic device 101 may perform an operation for redirection. The electronic device 101 may perform a cell search based on reception of the RRC release message, and may select a cell based on the search result. The electronic device 101 may perform a RACH procedure with the selected cell. The electronic device 101 may perform registration (eg, TAU procedure or Attach procedure) with the second communication system based on the RRC connection established based on the result of performing the RACH procedure. For example, when the electronic device 101 receives a handover command from the network, the electronic device 101 may perform an operation for handover to a target cell designated in the handover command. At least one operation for redirection from the first communication system to the second communication system and/or at least one operation for handover may conform to, for example, 3GPP TS 23.502, but there is no limitation.

According to various embodiments, when a response is not received from the network (505 - No), the electronic device 101 may check whether the timer expires in operation 509 . Before the timer expires (509-No), the electronic device 101 may monitor whether a response is received from the network. When the timer expires (509-Yes), the electronic device 101 performs at least one operation for selection of a cell corresponding to the PLMN of the second communication system and registration with the second communication system in operation 511 . can When the timer expires, the electronic device 101 may search and/or select a cell corresponding to the PLMN of the second communication system even if a message is not received from the network. The electronic device 101 performs a RACH procedure with any one of the cells corresponding to the selected PLMN, and performs a TAU procedure or an Attach procedure to the second communication system based on the established RRC connection, whereby the second communication system can be registered in In operation 513 , the electronic device 101 may perform a service corresponding to an event based on registration with the second communication system. The electronic device 101 may, for example, perform an emergency call based on the second communication system.

6 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;

According to various embodiments, the electronic device 101 (eg, at least one of the processor 120 , the first communication processor 212 , the second communication processor 214 , or the unified communication processor 260 ) includes: In operation 601 , an event related to an emergency service may be checked while registered in the first communication system. In operation 603 , the electronic device 101 may transmit a service request message corresponding to the event to the network and start a timer. As described above, the electronic device 101 may transmit a service request message in which the service type is set to “emergency service fallback”. The timer started in operation 603 may have an expiration time shorter than that of the T3517 timer, for example. In operation 605 , the electronic device 101 may receive a response from the network before the timer expires. For example, the electronic device 101 may receive an RRC release message requesting redirection to the cell of the second communication system or a handover command instructing handover to the cell of the second communication system. The electronic device 101 may stop the timer based on the reception of the message from the network.

According to various embodiments, in operation 607 , the electronic device 101 may determine whether a cell of the second communication system is discovered. If a cell of the second communication system is discovered (607-Yes), the electronic device 101 may perform a TAU procedure based on one of the discovered cells in operation 609 . For example, when the electronic device 101 is connected to a second communication system (eg, EPS), the electronic device 101 performs at least one operation for handover from 5GS to EPS, or N26 At least one operation for inter-system redirection of the interface to the EPS may be performed. In both cases, the electronic device 101 may perform the TAU procedure, for example, the 3GPP TS 23.502 procedure may be performed, but there is no limitation. After performing the TAU procedure, the electronic device 101 may perform an IMS-based emergency service in operation 611 . For example, the electronic device 101 may perform at least one procedure for establishing an IMS emergency session, and may perform an emergency service (eg, an emergency call) based on the IMS emergency session. If the cell of the second communication system is not discovered (607-No), the electronic device 101 registers as a third communication system (eg, UTMS or GSM) in operation 613 to provide a CS-based service. can also be done

According to various embodiments, the electronic device 101 may check information on the core network designated in the RRC release message. As described above, the network may transmit an RRC release message designating the second core network for fallback to the second communication system (eg, the second core network). For example, Table 2 is an example of an RRCRelease message defined in 3GPP TS 38.331.

- TS 38.331: RRCRelease (NR/5GC → E-UTRA/EPC or E-UTRA/5GC)

RedirectedCarrierInfo ::= CHOICE {
nr CarrierInfoNR,
eutra RedirectedCarrierInfo-EUTRA,
...
}

RedirectedCarrierInfo-EUTRA ::= SEQUENCE {
eutraFrequency ARFCN-ValueEUTRA,
cnType ENUMERATED {epc,fiveGC} OPTIONAL -- Need N
}

As shown in Table 2, the RRCRelease message may include a frequency to be redirected (eg, eutraFrequency ARFCN-ValueEUTRA) and a core network to be redirected (eg, cnType ENUMERATED {epc,fiveGC}). If the network transmits an RRCRelease message having a cnType of “epc”, the electronic device 101 must camp on a cell supporting EPC to perform an emergency service. Accordingly, the electronic device 101 may be configured to select a cell supporting the core network specified in the RRC release message.

For example, the electronic device 101 may check system information corresponding to each of at least one cell identified during discovery, for example, system information block (SIB) 1 . The electronic device 101 may identify a core network supported by each of at least one cell based on system information, for example, information included in SIB 1 . As described above, the electronic device 101, based on whether or not “PLMN-IdentityInfo” and/or “PLMN-IdentityInfo-r15” is included in SIB 1, the corresponding cell EPC (or EPS), and/or Alternatively, it can be checked whether 5GC (or 5GS) is supported. The electronic device 101 may select a cell corresponding to the core network designated in the RRC release message, based on SIB 1.

According to various embodiments, the electronic device 101 camps on a cell supporting the core network specified in the RRC release message and performs a subsequent procedure, whereby an emergency service may be performed.

7 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure.

According to various embodiments, the electronic device 101 (eg, at least one of the processor 120 , the first communication processor 212 , the second communication processor 214 , or the unified communication processor 260 ) includes: In operation 701 , an event related to an emergency service may be checked while registered in the first communication system. In operation 703 , the electronic device 101 may transmit a service request message corresponding to the event to the network and start a timer. As described above, the electronic device 101 may transmit a service request message in which the service type is set to “emergency service fallback”. The timer started in operation 703 may have an expiration time shorter than that of the T3517 timer, for example. The electronic device 101 may fail to check the response from the network during the expiration time of the timer, and in operation 705 , check the expiration of the timer.

According to various embodiments, the electronic device 101 may select a PLMN corresponding to the second communication system in operation 707 . The electronic device 101 may confirm that the PLMN to be searched for corresponds to the second communication system based on the confirmation of the event related to the emergency service and/or the service type being “emergency service fallback”. Accordingly, the electronic device 101 may refrain from selecting a PLMN corresponding to only the first communication system. In operation 709 , the electronic device 101 may determine whether a cell corresponding to the selected PLMN is searched for. In one example, the electronic device 101 may select a cell supporting (or connected to) the second communication system. For example, the electronic device 101 may camp on by selecting a suitable cell based on a cell search result, but there is no limitation on the cell to camp on. The electronic device 101 may perform a cell search based on stored information or may perform a full scan. In one example, the electronic device 101 may determine whether a specific cell supports the second communication system based on SIB 1 confirmed as a result of the cell search. The electronic device 101 may camp on by selecting a cell confirmed to support the second communication system. For example, if the reception strength of the synchronization signal from the first cell is greater than the reception strength of the synchronization signal from the second cell according to the cell search result, the first cell does not support the second communication system and the second cell If it is confirmed that the second communication system is supported, the second cell may be selected and camped on.

According to various embodiments, the electronic device 101 may select a cell, perform a RACH procedure, and perform a TAU procedure (or an Attach procedure) in operation 711 . After being registered with the second communication system, the electronic device 101 may perform an IMS-based emergency service in operation 713 . For example, the electronic device 101 may perform at least one procedure for establishing an IMS emergency session, and may perform an emergency service (eg, an emergency call) based on the IMS emergency session. If the cell of the second communication system is not discovered (709-No), the electronic device 101 registers with the third communication system (eg, UTMS or GSM) in operation 715 to provide a CS-based service. can also be done

8 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;

According to various embodiments, the electronic device 101 (eg, at least one of the processor 120 , the first communication processor 212 , the second communication processor 214 , or the unified communication processor 260 ) includes: In operation 801, an IMS-based emergency service may be performed using the second communication system. For example, the electronic device 101 may identify an event related to an emergency service while registered in the first communication system. The electronic device 101 may transmit a service request message of a service type of “emergency service fallback” to the network. In one example, the electronic device 101 may receive a message in response to the service request message from the network, and may perform redirection or handover to the second communication system. In another example, the electronic device 101 may perform PLMN selection and registration of the second communication system based on expiration of a timer with an expiration time shorter than that of the T3517 timer. The electronic device 101 may perform an emergency service based on registration with the second communication system. The electronic device 101 may end emergency service performance in operation 803 . The electronic device 101 may maintain a state registered with the second communication system even after the emergency service is finished.

In a state of being registered in the second communication system to perform the emergency service, according to various embodiments, the electronic device 101 requests redirection of the first communication system from the network in operation 805 after the emergency service is terminated. message, for example, an RRC release message may be received. For example, after performing an emergency service based on a cell supporting E-UTRA registered in EPC, the electronic device 101 may end execution of the emergency service. The electronic device 101 may receive an RRCConnectionRelease message instructing a redirect to 5GC from the network. The RRCConnectionRelease message may include a core network to be redirected (eg, cn-Type-r15 ENUMERATED {epc,fivegc}). When cn-Type-r15 ENUMERATED is designated as fivegc, the electronic device 101 may identify a core network to be redirected to as 5GC. The network according to various embodiments may induce the electronic device 101 to redirect the electronic device 101 to the communication system prior to the fallback based on it is confirmed that the emergency service has been terminated.

According to various embodiments, the electronic device 101 may camp on a cell of the first communication system in operation 807 . For example, the electronic device 101 may camp on a cell supporting the first communication system. If the electronic device 101 receives the RRC release message causing redirection to 5GC, the electronic device 101 may select one of the cells supporting 5GC and camp on. For example, the electronic device 101 may check the type of the core network supported by the cell based on SIB 1 identified as a result of the search. In operation 809 , the electronic device 101 may perform a RACH procedure with respect to a cell. In operation 811 , the electronic device 101 may perform registration (eg, a TAU procedure or an attach procedure) with the first communication system. As described above, after the emergency service is terminated, the electronic device 101 may return to the first communication system before the fallback.

9 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;

According to various embodiments, the electronic device 101 (eg, at least one of the processor 120 , the first communication processor 212 , the second communication processor 214 , or the unified communication processor 260 ) includes: In operation 901, an IMS-based emergency service may be performed using the second communication system. As described with reference to FIG. 8 , the electronic device 101 may transmit a service request message corresponding to an emergency service, and may be registered with the second communication system based on a response from a network or expiration of a timer. . The electronic device 101 may perform an emergency service based on registration with the second communication system. The electronic device 101 may end emergency service performance in operation 903 . The electronic device 101 may maintain a state registered with the second communication system even after the emergency service is finished.

According to various embodiments, in operation 905 , the electronic device 101 may receive an RRC reconfiguration message including the MO associated with the first communication system from the serving cell. The RRC reconfiguration message may be either an RRCConnectionReconfiguraiton message of 3GPP TS 36.331 or an RRCReconfiguraiton message of 3GPP TS 38.331. The MO may include information associated with a frequency (or cell) on which a user equipment (UE) should perform measurement. The cell-related information may include at least one of a frequency channel number, cell identification information (eg, physical cell identifier: PCI), a black list, and an offset value for each cell. The RRC reconfiguration message may include a reporting configuration, for example, a reporting condition for performing a measurement report (MR). The RRC reconfiguration message may include at least one of a measurement ID for identifying the MO, a quantity configuration indicating a value to be measured by the UE, or a measurement gap associated with a measurement period. The electronic device 101 may perform measurement based on information in the received RRC Reconfiguration message.

According to various embodiments, in operation 907 , the electronic device 101 may confirm that the MO-based measurement result (eg, a layer 3 filtered value) satisfies the reporting condition. For example, at the measurement timing of a signal (eg, a synchronization signal and/or a reference signal) from a cell based on the first communication system, reference signal received power (RSRP), reference signal received quality (RSRQ), SINR ( It can be confirmed that signal to interference noise ratio), received signal strength indicator (RSSI), and/or signal-to-noise ratio (SNR) satisfies the reporting condition. In operation 909 , the electronic device 101 may perform a measurement report (MR) based on the satisfaction of the report condition. Based on the received MR, the network may transmit a handover command indicating a target cell supporting (or connected to) the first communication system to the electronic device 101 . The electronic device 101 may receive a handover command in operation 911. The electronic device 101 may be registered as the first communication system based on the target cell supporting the first communication system by performing a handover in operation 913 based on the received handover command.

10 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;

According to various embodiments, the electronic device 101 (eg, at least one of the processor 120 , the first communication processor 212 , the second communication processor 214 , or the unified communication processor 260 ) includes: In operation 1001, an IMS-based emergency service may be performed using the second communication system. As described with reference to FIG. 8 , the electronic device 101 may transmit a service request message corresponding to an emergency service, and may be registered with the second communication system based on a response from a network or expiration of a timer. . The electronic device 101 may perform an emergency service based on registration with the second communication system. The electronic device 101 may end emergency service execution in operation 1003 . The electronic device 101 may maintain a state registered with the second communication system even after the emergency service is finished. The electronic device 101 may enter the IDLE state in operation 1005 in a state registered with the second communication system.

According to various embodiments, the electronic device 101 may receive SIB 24 from a serving cell (eg, eNB). In 3GPP TS 36.331, SIB 24 is described as an IE (information element) of systeminformationblcoktype 24. SIB 24 may include information related only to NR neighbor cell and inter-RAT cell reselection for cell reselection, for example, information on NR frequencies supporting the SA mode of 5G. SIB 24 may include a common cell reselection parameter with respect to frequency. SIB 24 may include, for example, frequency information (eg, ARFCN) of NR supporting SA mode. Frequency information of NR supporting SA mode may mean supporting 5GC (or 5GS). While camp-on to a cell associated with the second communication system (eg, EPC), the electronic device 101 provides cell information of NR supporting the SA mode of the first communication system (eg, 5GC) around the cell, eg For example, you can check cell information that supports 5GC. The electronic device 101 according to various embodiments may identify a frequency supporting the SA mode of the first communication system (eg, 5GS) in the vicinity based on information included in SIB 24 .

In operation 1007 , the electronic device 101 according to various embodiments may measure a frequency associated with the identified first communication system based on SIB 24 . In operation 1009 , the electronic device 101 may confirm satisfaction of a cell reselection criterion as a result of the measurement. Based on the satisfaction of the cell reselection condition, the electronic device 101 may perform cell reselection in operation 1011 . The electronic device 101 may camp on the reselected cell, and thus return to the first communication system (eg, 5GS).

11 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure.

According to various embodiments, the electronic device 101 (eg, at least one of the processor 120 , the first communication processor 212 , the second communication processor 214 , or the unified communication processor 260 ) includes: In operation 1101, an IMS-based emergency service may be performed using the second communication system. As described with reference to FIG. 8 , the electronic device 101 may transmit a service request message corresponding to an emergency service, and may be registered with the second communication system based on a response from a network or expiration of a timer. . The electronic device 101 may perform an emergency service based on registration with the second communication system. The electronic device 101 may end emergency service execution in operation 1103 . The electronic device 101 may maintain a state registered with the second communication system even after the emergency service is finished. In operation 1105 , the electronic device 101 may check the lapse of a specified time. The electronic device 101 may, for example, confirm that registration with the fallback second communication system is maintained until a specified time elapses.

According to various embodiments, based on registration with the fallback second communication system being maintained until a specified time elapses, the electronic device 101 may scan a frequency associated with the first communication system stored in advance in operation 1107 . there is. For example, the electronic device 101 may store and manage information on a frequency supporting the SA mode of the first communication system in advance. For example, the electronic device 101 may store a frequency when it is registered (or connected) to the first communication system in the SA mode. In operation 1109 , the electronic device 101 may confirm that the measurement result of the specific frequency confirms that the cell reselection condition is satisfied. Based on the satisfaction of the cell reselection condition, the electronic device 101 may perform cell reselection in operation 1111 .

12 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;

According to various embodiments, the electronic device 101 (eg, at least one of the processor 120 , the first communication processor 212 , the second communication processor 214 , or the unified communication processor 260 ) includes: In operation 1201 , an event related to an emergency service may be checked while registered in the first communication system. For example, the electronic device 101 may identify an event related to an emergency service while being registered with 5GS (or 5GC). For example, the electronic device 101 may acquire an emergency call request, and may identify the acquired emergency call request as an event related to an emergency service. On the other hand, the type of emergency service is not limited. In operation 1203 , the electronic device 101 may transmit a service request message corresponding to the event to the network. For example, the electronic device 101 may set the service type of the service request message to “emergency service fallback”.

According to various embodiments, the electronic device 101 may select and search the PLMN of the second communication system, for example, EPS, based on the transmission of the service request message in operation 1205 . For example, the electronic device 101 may preferentially select and search a registered PLMN (RPLMN) and/or a home PLMN (HPLMN) of the second communication system, but there is no limitation. In operation 1207 , the electronic device 101 may determine whether a cell corresponding to the selected PLMN is searched for. For example, the electronic device 101 may perform a search for a cell associated with the second communication system corresponding to the selected PLMN, for example, may perform a stored information-based search and/or a full scan, There are no restrictions on the search method. In contrast to the embodiment of FIG. 4 , the electronic device 101 may select a PLMN of the second communication system and search for a cell without waiting for the timer to expire after transmission of the service request message.

If a cell corresponding to the selected PLMN is identified (1207-Yes), the electronic device 101 may select a cell in operation 1209 and perform a RACH procedure and a TAU procedure (or an Attach procedure). Accordingly, the electronic device 101 may be registered in the second communication system. The electronic device 101 may perform an IMS-based emergency service in operation 1211 in a state registered with the second communication system. After completing the emergency service, the electronic device 101 may return to the first communication system according to, for example, a method based on FIGS. 8 , 9 , 10 , or 11 . If a cell corresponding to the selected PLMN is not identified (1207 - NO), the electronic device 101 may perform a CS-based service by registering as a third communication system in operation 1213 . As described above, it is possible to prevent delay in the execution of the emergency service due to an error in the electric field or the network.

13 is a flowchart illustrating a method of operating an electronic device according to various embodiments of the present disclosure;

According to various embodiments, the electronic device 101 (eg, at least one of the processor 120 , the first communication processor 212 , the second communication processor 214 , or the unified communication processor 260 ) includes: In operation 1301, in the state registered in the first communication system, an event related to the emergency service may be checked. For example, the electronic device 101 may identify an event related to an emergency service while being registered with 5GS (or 5GC). For example, the electronic device 101 may acquire an emergency call request, and may identify the acquired emergency call request as an event related to an emergency service. On the other hand, the type of emergency service is not limited.

According to various embodiments, the electronic device 101 may select the PLMN of the second communication system, for example, EPS, based on the confirmation of the event related to the emergency service in operation 1303 . For example, the electronic device 101 may preferentially search for and select a registered PLMN (RPLMN) and/or a home PLMN (HPLMN) of the second communication system, but there is no limitation. In operation 1305 , the electronic device 101 may determine whether a cell corresponding to the selected PLMN is identified. For example, the electronic device 101 may perform a search for a cell associated with the second communication system corresponding to the selected PLMN, for example, may perform a stored information-based search and/or a full scan, There are no restrictions on the search method. In contrast to the embodiment of FIG. 4 , the electronic device 101 may select a PLMN of the second communication system and search for a cell in response to an event confirmation related to an emergency service without transmitting a service request message. For example, when it is confirmed that an emergency service fallback indicator does not support the electronic device 101 in the registration process of the first communication system, the electronic device 101 sends a service request Without sending a message, in response to the event confirmation, a search for a cell corresponding to the second communication system may be performed.

If a cell corresponding to the selected PLMN is identified (1305-Yes), the electronic device 101 may select a cell in operation 1307 and perform a RACH procedure and a TAU procedure (or an Attach procedure). Accordingly, the electronic device 101 may be registered in the second communication system. The electronic device 101 may perform an IMS-based emergency service in operation 1309 in a state registered with the second communication system. After completing the emergency service, the electronic device 101 may return to the first communication system according to, for example, a method based on FIGS. 8 , 9 , 10 , or 11 . If the cell corresponding to the selected PLMN is not identified (1205-No), the electronic device 101 may perform a CS-based service by registering as a third communication system in operation 1311 . As described above, it is possible to prevent delay in the execution of the emergency service due to an error in the electric field or the network.

According to various embodiments, the electronic device includes at least one processor, wherein the at least one processor, in a state registered with the first communication system, identifies an event related to an emergency service, and based on the confirmation of the event to transmit a service request corresponding to the event to the network, and based on the transmission of the service request, start a timer having an expiration time shorter than the expiration time of the T3517 timer, and perform the service until the timer expires Based on the failure to receive a response corresponding to the request, searching for and selecting a cell corresponding to a PLMN of a second communication system different from the first communication system, and registering with the second communication system based on the selected cell It may be configured to perform at least one operation for performing at least one operation for, and to perform the emergency service corresponding to the event based on the second communication system based on registration with the second communication system.

According to various embodiments, the at least one processor is configured to transmit, as at least part of an operation of transmitting the service request corresponding to the event to the network, the service request including a service type of emergency service fallback to the network. can be set.

According to various embodiments, the at least one processor performs a RACH procedure with the selected cell as at least part of an operation of performing the at least one operation for registration with the second communication system based on the selected cell, , may be configured to perform a procedure for registration in the second communication system based on an RRC connection established based on the RACH procedure.

According to various embodiments, the at least one processor, as at least part of the operation of selecting the cell, based on information included in SIB 1 from the cell, based on the cell supporting the second communication system, , can be set to select the cell.

According to various embodiments, the at least one processor may be configured to perform at least one procedure for establishing an IMS emergency session as at least a part of the operation of performing the emergency service corresponding to the event.

According to various embodiments, the at least one processor receives an RRC release message requesting redirection from the network before the timer expires, and based on the reception of the RRC release message, designated in the RRC release message. It may be further configured to perform a redirection procedure to the second communication system.

According to various embodiments, the at least one processor receives a handover command from the network before the timer expires, and, based on the handover command, transmits the second communication system designated in the handover command. It may be further configured to perform a handover procedure to a supported target cell.

According to various embodiments, the at least one processor checks frequency information supporting the SA mode of the first communication system confirmed by SIB 24 received from a serving cell, and after performing the emergency service, the It may be further configured to identify another cell supporting the SA mode of the first communication system based on the checked frequency information, and reselect the other cell based on the cell reselection condition being satisfied by the other cell.

According to various embodiments, the at least one processor checks frequency information for supporting the SA mode of the first communication system stored in the electronic device, and based on the lapse of a specified time after performing the emergency service, It may be further configured to identify another cell supporting the SA mode of the first communication system based on the identified frequency information, and reselect the other cell based on the other cell satisfying a cell reselection condition. .

According to various embodiments, the at least one processor, after performing the emergency service, receives an RRC release message requesting redirection to the first communication system, and receives the first RRC release message specified in the received RRC release message. and may be further configured to perform a redirection procedure to a communication system.

According to various embodiments, the at least one processor, after performing the emergency service, receives an RRC reset message including a measurement object, and based on a measurement result based on the measurement object satisfying a reporting condition, It may be further configured to perform a handover procedure to a target cell designated in the handover command based on a report and receiving a handover command in response to the measurement report.

According to various embodiments of the present disclosure, in a method of operating an electronic device, in a state registered in a first communication system, an operation of identifying an event related to an emergency service, and a network service request corresponding to the event based on the confirmation of the event , starting a timer having an expiration time shorter than that of the T3517 timer based on the transmission of the service request, and failure to receive a response corresponding to the service request until the timer expires based on , searching for and selecting a cell corresponding to a PLMN of a second communication system different from the first communication system, and performing at least one operation for registration in the second communication system based on the selected cell operation, and performing the emergency service corresponding to the event based on the second communication system based on registration with the second communication system.

According to various embodiments, the transmitting of the service request corresponding to the event to the network may include transmitting the service request including a service type of emergency service fallback to the network.

According to various embodiments, the performing of the at least one operation for registration in the second communication system based on the selected cell may include performing a RACH procedure with the selected cell, and based on the RACH procedure, It may include performing a procedure for registration in the second communication system based on the established RRC connection.

According to various embodiments, the operation of selecting the cell may select the cell based on information included in SIB 1 from the cell, and based on the cell supporting the second communication system.

According to various embodiments, the operation of performing the emergency service corresponding to the event may perform at least one procedure for establishing an IMS emergency session.

According to various embodiments, the method of operating an electronic device includes receiving an RRC release message requesting redirection from the network before the timer expires, and based on the reception of the RRC release message, the RRC release message The method may further include performing a redirection procedure to the designated second communication system.

According to various embodiments of the present disclosure, in a method of operating an electronic device, receiving a handover command from the network before the timer expires, and based on the handover command, the second communication specified in the handover command The method may further include performing a handover procedure to a target cell supporting the system.

According to various embodiments of the present disclosure, a method of operating an electronic device includes checking frequency information supporting the SA mode of the first communication system, which is confirmed by SIB 24 received from a serving cell, after performing the emergency service, an operation of identifying another cell supporting the SA mode of the first communication system based on the identified frequency information, and an operation of reselecting the other cell based on the satisfaction of the cell reselection condition of the other cell may include

According to various embodiments, the electronic device includes at least one processor, wherein the at least one processor checks an event related to an emergency service in a state registered with the first communication system, Based on it is confirmed that the emergency service fallback indicator confirmed in the registration process is set to not support, in response to the event confirmation related to the emergency service, a second communication system different from the first communication system searches for and selects a cell corresponding to the PLMN of , performs at least one operation for registration in the second communication system based on the selected cell, It may be configured to perform the emergency service corresponding to the event based on the communication system.

The electronic device according to various embodiments disclosed in this document may have various types of devices. The electronic device may include, for example, a portable communication device (eg, a smart phone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, or a home appliance device. The electronic device according to the embodiment of the present document is not limited to the above-described devices.

The various embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments, but it should be understood to include various modifications, equivalents, or substitutions of the embodiments. In connection with the description of the drawings, like reference numerals may be used for similar or related components. The singular form of the noun corresponding to the item may include one or more of the item, unless the relevant context clearly dictates otherwise. As used herein, "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 "A , B, or C" each may include any one of, or all possible combinations of, items listed together in the corresponding one of the phrases. Terms such as "first", "second", or "first" or "second" may be used simply to distinguish an element from other elements in question, and may refer elements to other aspects (e.g., importance or order) is not limited. It is said that one (eg, first) component is "coupled" or "connected" to another (eg, second) component, with or without the terms "functionally" or "communicatively". When referenced, it means that one component can be connected to the other component directly (eg by wire), wirelessly, or through a third component.

The term “module” used in various embodiments of this document may include a unit implemented in hardware, software, or firmware, and is interchangeable with terms such as, for example, logic, logic block, component, or circuit. can be used as A module may be an integrally formed part or a minimum unit or a part of the part that performs one or more functions. For example, according to an embodiment, the module may be implemented in the form of an application-specific integrated circuit (ASIC).

According to various embodiments of the present document, one or more instructions stored in a storage medium (eg, internal memory 136 or external memory 138) readable by a machine (eg, electronic device 101) may be implemented as software (eg, the program 140) including For example, the processor (eg, the processor 120 ) of the device (eg, the electronic device 101 ) may call at least one command among one or more commands stored from a storage medium and execute it. This makes it possible for the device to be operated to perform at least one function according to the called at least one command. The one or more instructions may include code generated by a compiler or code executable by an interpreter. The device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-transitory' only means that the storage medium is a tangible device and does not contain a signal (eg, electromagnetic wave), and this term refers to the case where data is semi-permanently stored in the storage medium and It does not distinguish between temporary storage cases.

According to one embodiment, the method according to various embodiments disclosed in this document may be provided as included in a computer program product. Computer program products may be traded between sellers and buyers as commodities. The computer program product is distributed in the form of a machine-readable storage medium (eg compact disc read only memory (CD-ROM)), or via an application store (eg Play Store™) or on two user devices ( It can be distributed (eg downloaded or uploaded) directly between smartphones (eg: smartphones) and online. In the case of online distribution, at least a part of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium such as a memory of a server of a manufacturer, a server of an application store, or a relay server.

According to various embodiments, each component (eg, module or program) of the above-described components may include a singular or a plurality of entities, and some of the plurality of entities may be separately disposed in other components. there is. According to various embodiments, one or more components or operations among the above-described corresponding components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (eg, a module or a program) may be integrated into one component. In this case, the integrated component may perform one or more functions of each component 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, operations performed by a module, program, or other component are executed sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations are executed in a different order, or omitted. or one or more other operations may be added.

Claims (20)

In an electronic device,
at least one processor;
The at least one processor comprises:
In the state registered in the first communication system, check the event related to the emergency service,
based on the confirmation of the event, sending a service request corresponding to the event to the network;
based on the transmission of the service request, starting a timer having an expiration time shorter than that of the T3517 timer;
Searching for and selecting a cell corresponding to a PLMN of a second communication system different from the first communication system based on the failure to receive a response corresponding to the service request until the timer expires;
performing at least one operation for registration in the second communication system based on the selected cell;
The electronic device is configured to perform the emergency service corresponding to the event based on the second communication system based on registration with the second communication system. The method of claim 1,
The at least one processor is configured to transmit the service request including a service type of emergency service fallback to the network as at least part of an operation of transmitting the service request corresponding to the event to the network. The method of claim 1,
The at least one processor, as at least part of the operation of performing the at least one operation for registration in the second communication system based on the selected cell,
performing the RACH procedure with the selected cell,
An electronic device configured to perform a procedure for registration in the second communication system based on an RRC connection established based on the RACH procedure. 4. The method of claim 3,
The at least one processor is configured to, as at least part of the operation of selecting the cell, select the cell based on the cell supporting the second communication system, based on information included in SIB 1 from the cell. set electronics. The method of claim 1,
The at least one processor is configured to perform at least one procedure for establishing an IMS emergency session as at least a part of the operation of performing the emergency service corresponding to the event. The method of claim 1,
The at least one processor,
Receiving an RRC release message requesting redirection from the network before the timer expires,
The electronic device further configured to perform a redirection procedure to the second communication system specified in the RRC release message based on the reception of the RRC release message. The method of claim 1,
The at least one processor,
receiving a handover command from the network before the timer expires;
The electronic device is further configured to perform a handover procedure to a target cell supporting the second communication system specified in the handover command, based on the handover command. The method of claim 1,
The at least one processor,
Checking the frequency information supporting the SA mode of the first communication system confirmed by SIB 24 received from the serving cell,
After performing the emergency service, check another cell supporting the SA mode of the first communication system based on the confirmed frequency information,
The electronic device is further configured to reselect the other cell based on the satisfaction of the cell reselection condition. The method of claim 1,
The at least one processor,
Checking frequency information supporting the SA mode of the first communication system stored in the electronic device,
Based on the lapse of a specified time after performing the emergency service, check another cell supporting the SA mode of the first communication system based on the checked frequency information,
The electronic device is further configured to reselect the other cell based on the satisfaction of the cell reselection condition. The method of claim 1,
The at least one processor,
After performing the emergency service, receiving an RRC release message requesting redirection to the first communication system,
The electronic device further configured to perform a redirection procedure to the first communication system specified in the received RRC release message. The method of claim 1,
The at least one processor,
After performing the emergency service, receiving an RRC reset message including a measurement object,
Based on that the measurement result based on the measurement object satisfies a reporting condition, a measurement report is performed,
The electronic device further configured to perform a handover procedure to a target cell designated in the handover command based on receiving a handover command in response to the measurement report. A method of operating an electronic device, comprising:
checking an event related to an emergency service in a state registered in the first communication system;
transmitting a service request corresponding to the event to a network based on the confirmation of the event;
starting a timer having an expiration time shorter than an expiration time of a T3517 timer based on the transmission of the service request;
searching for and selecting a cell corresponding to a PLMN of a second communication system different from the first communication system based on failure to receive a response corresponding to the service request until the timer expires;
performing at least one operation for registration in the second communication system based on the selected cell, and
performing the emergency service corresponding to the event based on the second communication system based on registration with the second communication system
A method of operating an electronic device comprising a. 13. The method of claim 12,
The transmitting of the service request corresponding to the event to the network includes transmitting the service request including a service type of emergency service fallback to the network. 13. The method of claim 12,
The operation of performing the at least one operation for registration in the second communication system based on the selected cell includes:
performing a RACH procedure with the selected cell, and
performing a procedure for registration in the second communication system based on the RRC connection established based on the RACH procedure
A method of operating an electronic device comprising a. 15. The method of claim 14,
The operation of selecting the cell includes selecting the cell based on information included in SIB 1 from the cell and the cell supporting the second communication system. 13. The method of claim 12,
The operation of performing the emergency service corresponding to the event includes performing at least one procedure for establishing an IMS emergency session. 13. The method of claim 12,
Receiving an RRC release message requesting redirection from the network before the timer expires, and
Based on the reception of the RRC release message, performing a redirection procedure to the second communication system specified in the RRC release message
The method of operating an electronic device further comprising a. 13. The method of claim 12,
receiving a handover command from the network before the timer expires; and
performing a handover procedure to a target cell supporting the second communication system specified in the handover command based on the handover command
The method of operating an electronic device further comprising a. 13. The method of claim 12,
checking frequency information supporting the SA mode of the first communication system, which is confirmed by SIB 24 received from a serving cell;
After performing the emergency service, the operation of identifying another cell supporting the SA mode of the first communication system based on the confirmed frequency information, and
Reselecting the other cell based on the satisfaction of the cell reselection condition of the other cell
The method of operating an electronic device further comprising a. In an electronic device,
at least one processor;
The at least one processor comprises:
In the state registered in the first communication system, check the event related to the emergency service,
Based on it is confirmed that the emergency service fallback indicator confirmed in the registration process of the first communication system is set to not support, in response to the confirmation of the event related to the emergency service, the first communication system Search and select a cell corresponding to the PLMN of the second communication system different from the
performing at least one operation for registration in the second communication system based on the selected cell;
The electronic device is configured to perform the emergency service corresponding to the event based on the second communication system based on registration with the second communication system.

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