KR20230016440A - Method for providing service using ims data channel and apparatus thereof - Google Patents

Abstract

An electronic device according to various embodiments of the present disclosure includes a transceiver and a control unit. The control unit may: establish an IP multimedia subsystem (IMS) data channel; confirm release of QoS flow assigned to the established IMS data channel; when release of the QoS flow is confirmed, set a retransmission timer; control the transceiver to transmit a reconnection request message for the QoS flow; receive a response message corresponding to the reconnection request message; when a reconnection completion message for the QoS flow is received, cancel the retransmission timer; and provide services using the IMS data channel. When a QoS flow is disconnected, reconnection can be made quickly.

Description

Method and device for providing service using IMS data channel

Various embodiments of the present disclosure relate to a method and apparatus for providing a service using an IMS data channel, for example, a method and apparatus for providing a service by reconnecting even if the IMS data channel is disconnected. .

Internet protocol (IP) multimedia subsystem (IMS) is a subsystem for providing multimedia services based on Internet Protocol (IP), and various multimedia services such as voice, audio, video and/or data can provide.

When an electronic device provides a multimedia service (eg, a video call and/or a voice call) in an IMS network environment, it may perform a negotiation operation to establish (or form) a session with a counterpart electronic device. During a negotiation operation, the electronic device may determine a parameter for controlling a quality of service (QoS) of a multimedia service and provide a multimedia service based on the determined QoS parameter.

In an IMS network environment, when an electronic device transmits/receives voice/video data and simultaneously transmits/receives other data, when the QoS flow allocated to the IMS data channel for transmitting/receiving other data is disconnected, the electronic device or/and P-CSCF (proxy -call session control function) The server detects or confirms that the connection of the QoS flow is disconnected, terminates the SIP (session initiation protocol) session, or terminates the service provided through the IMS data channel, so that the service is terminated even though the user did not want it. You may experience discomfort. Disconnection of the QoS flow may occur when handover occurs because the electronic device is moving, or when radio resources in the network are insufficient or when the radio condition is poor.

An electronic device according to various embodiments of the present disclosure includes a transceiver and a control unit, wherein the control unit establishes an IP multimedia subsystem (IMS) data channel, confirms release of a QoS flow allocated to the established IMS data channel, When release of the QoS flow is confirmed, a retransmission timer is set, a reconnection request message for the QoS flow is transmitted by controlling the transceiver, a response message corresponding to the reconnection request message is received, and the QoS flow When a reconnection completion message for is received, the retransmission timer may be released, and a service may be provided using the IMS data channel.

A P-CSCF (proxy-call session control function) server according to various embodiments of the present disclosure includes a transceiver and a control unit, and the control unit controls the transceiver to request a notification when a QoS flow disconnection and/or resource allocation event occurs. Sending a message, receiving a response message corresponding to the request message, receiving a QoS flow disconnection notification message, setting a retransmission timer, transmitting a reconnection request message for the QoS flow, and When a message including a reconnection complete message and/or resource information allocated to the QoS flow is received, the retransmission timer can be released and service can be provided using the IMS data channel to which the QoS flow is allocated.

An operating method of an electronic device according to various embodiments of the present disclosure includes establishing an IP multimedia subsystem (IMS) data channel, confirming release of a QoS flow assigned to the established IMS data channel, and releasing the QoS flow. If confirmed, an operation of setting a retransmission timer, an operation of transmitting a reconnection request message for the QoS flow, an operation of receiving a response message corresponding to the reconnection request message, and an operation of receiving a reconnection completion message for the QoS flow If it is, an operation of releasing the retransmission timer and an operation of providing a service using the IMS data channel may be included.

A method of operating a P-CSCF (proxy-call session control function) server according to various embodiments of the present disclosure includes an operation of transmitting a notification request message when a QoS flow connection release and/or resource allocation event occurs, and a response corresponding to the request message Receiving a message, receiving a QoS flow disconnection notification message, setting a retransmission timer, transmitting a reconnection request message for the QoS flow, a reconnection completion message for the QoS flow, and/or When a message including resource information allocated to the QoS flow is received, an operation of releasing the retransmission timer and an operation of providing a service using an IMS data channel to which the QoS flow is allocated may be included.

According to various embodiments of the present disclosure, while an electronic device transmits and receives voice/video data and simultaneously transmits and receives other data in an IMS network environment, even if a QoS flow allocated to an IMS data channel for transmitting and receiving other data is disconnected, the QoS flow By reconnecting, the service provided through the IMS data channel can continue to be provided.

According to various embodiments of the present disclosure, when the QoS flow is disconnected, both the electronic device and the P-CSCF server can attempt to reconnect the QoS flow, so the reconnection attempt time can be shortened, and reconnection can be achieved in a short time. It could be possible. The electronic device or/and the P-CSCF server may determine the QoS flow reconnection attempt time considering the type of service provided through the IMS data channel.

According to various embodiments of the present disclosure, QoS flow reconnection may be attempted even when a radio access technology (RAT) is changed.

1 is a block diagram of an electronic device in a network environment, according to various embodiments.
2 is a sequence diagram illustrating an operation of establishing an IMS data channel according to an embodiment of the present disclosure.
3 is a sequence diagram in which an electronic device reconnects a disconnected QoS flow according to an embodiment of the present disclosure.
4 is a flowchart for reconnecting a disconnected QoS flow by an electronic device according to an embodiment of the present disclosure.
5 is a sequence diagram in which a P-CSCF server reconnects a disconnected QoS flow according to an embodiment of the present disclosure.
6 is a flowchart for reconnecting a disconnected QoS flow by a P-CSCF server according to an embodiment of the present disclosure.
7 is a block diagram of an electronic device according to an embodiment of the present disclosure.
8 is a block diagram of a P-CSCF server, according to an embodiment of the present disclosure.

1 is a block diagram of an electronic device 101 within 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 through a second network 199. It may communicate with at least one of 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, an audio output module 155, a display module 160, an audio module 170, 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 the antenna module 197 may be included. In some embodiments, in the electronic device 101, at least one of these components (eg, the connection terminal 178) may be omitted or one or more other components may be added. In some embodiments, some of these components (eg, sensor module 176, camera module 180, or antenna module 197) are integrated into a single component (eg, display module 160). It can be.

The processor 120, for example, executes software (eg, the program 140) to cause at least one other component (eg, hardware or software component) of the electronic device 101 connected to the processor 120. It can control and perform various data processing or calculations. According to one embodiment, as at least part of data processing or operation, processor 120 transfers instructions or data received from other components (e.g., sensor module 176 or communication module 190) to volatile memory 132. , processing commands or data stored in the volatile memory 132 , and storing resultant data in the non-volatile memory 134 . According to one embodiment, the processor 120 includes a 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 ( NPU: neural processing unit (NPU), image signal processor, sensor hub processor, or communication processor). For example, when the electronic device 101 includes the main processor 121 and the auxiliary processor 123, the auxiliary processor 123 may use less power than the main processor 121 or be set to be specialized for a designated function. can The secondary processor 123 may be implemented separately from or as part of the main processor 121 .

The secondary processor 123 may, for example, take the place 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, running an application). ) state, 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 one embodiment, the auxiliary processor 123 (eg, an image signal processor or a communication processor) may be implemented as part of other functionally related components (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. AI models can be created through machine learning. Such learning may be performed, for example, in the electronic device 101 itself where the artificial intelligence model 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 foregoing, but is not limited to the foregoing examples. The artificial intelligence model may include, in addition or alternatively, software structures in addition to hardware structures.

The memory 130 may store various data used by at least one component (eg, the processor 120 or the sensor module 176) of the electronic device 101 . The data may include, for example, input data or output data for software (eg, program 140) and commands related thereto. The memory 130 may include volatile memory 132 or 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 by a component (eg, the processor 120) of the electronic device 101 from the outside of the electronic device 101 (eg, a user). 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 sound signals 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. A receiver may be used to receive an incoming call. According to one embodiment, the receiver may be implemented separately from the speaker or as part of it.

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

The audio module 170 may convert sound into an electrical signal or vice versa. According to an embodiment, the audio module 170 acquires sound through the input module 150, the sound output module 155, or an external electronic device connected directly or wirelessly to the electronic device 101 (eg: Sound may be output through the electronic device 102 (eg, a speaker or a headphone).

The sensor module 176 detects an operating state (eg, power or temperature) of the electronic device 101 or an external environmental state (eg, a user state), and generates an electrical signal or data value corresponding to the detected state. can do. According to one embodiment, the sensor module 176 may include, for example, a gesture sensor, a gyro sensor, an air pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a bio sensor, It may include a temperature sensor, humidity sensor, or light sensor.

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

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

The haptic module 179 may convert electrical signals into mechanical stimuli (eg, vibration or motion) or electrical stimuli that a user may perceive through tactile or kinesthetic senses. According to one 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 one 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 one embodiment, the power management module 188 may be implemented as at least part of a power management integrated circuit (PMIC), for example.

The battery 189 may supply power to at least one component of the electronic device 101 . According to one embodiment, the 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). Establishment and communication through the established communication channel may be supported. 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 be a wireless communication module 192 (eg, a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module 194 (eg, a : a local area network (LAN) communication module or a power line communication module). Among these communication modules, a corresponding communication module 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 telecommunications network such as a computer network (eg, a LAN or a WAN). These various types of communication modules may be integrated as one component (eg, a single chip) or implemented as a plurality of separate components (eg, multiple chips). The wireless communication module 192 uses subscriber information (eg, International Mobile Subscriber Identifier (IMSI)) stored in the subscriber identification module 196 within a communication network such as the first network 198 or the second network 199. The electronic device 101 may be identified or authenticated.

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

The antenna module 197 may transmit or receive signals or power to the outside (eg, an external electronic device). According to an embodiment, the antenna module 197 may include an antenna including a radiator formed of a conductor or a conductive pattern formed on a substrate (eg, PCB). According to one 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 selected from the plurality of antennas by the communication module 190, for example. can be chosen 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)) may be additionally formed as a part of the antenna module 197 in addition to the radiator.

According to various embodiments, the antenna module 197 may form a mmWave antenna module. According to one embodiment, the mmWave antenna module includes a printed circuit board, an RFIC disposed on or adjacent to a first surface (eg, a lower surface) of the printed circuit board and capable of supporting a designated high frequency band (eg, mmWave band); and a plurality of antennas (eg, array antennas) disposed on or adjacent to a second surface (eg, a top surface or a side surface) 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 signal ( e.g. commands or data) can be exchanged with each other.

According to an embodiment, commands 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 part of operations executed in the electronic device 101 may be executed in one or more external electronic devices among the external electronic devices 102 , 104 , or 108 . For example, when the electronic device 101 needs to perform a certain function or service automatically or in response to a request from a user or another device, the electronic device 101 instead of executing the function or service by itself. Alternatively or additionally, one or more external electronic devices may be requested to perform the function or at least part of the service. One or more external electronic devices receiving 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 deliver the execution result to the electronic device 101 . The electronic device 101 may provide the result as at least part of a response to the request as it is or additionally processed. To this end, 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 one embodiment, the external electronic device 104 or server 108 may be included in the second network 199 . The electronic device 101 may be applied to intelligent services (eg, smart home, smart city, smart car, or health care) based on 5G communication technology and IoT-related technology.

A designated application that can be executed in the IMS network environment may request transmission and reception of other data while transmitting and receiving voice/video data between electronic devices. Data other than voice/video data may be data for providing a real-time interactive service, and may require QoS guarantee. For example, an application capable of controlling a drone may request transmission of data for controlling a drone while receiving video/sound data from the drone, and an application capable of controlling a car may transmit data to the front/rear of the car. While receiving an image received through an attached camera and a sound received through a microphone, transmission of data for controlling a vehicle may be requested. In an IMS network environment, an electronic device may separately establish an IMS data channel capable of transmitting and receiving other data (eg, data for controlling drones and automobiles) in addition to channels for transmitting and receiving voice/video data. The IMS data channel may be allocated a QoS flow of an IMS protocol data unit (PDU) session that can guarantee 5G QoS. 5G QoS can be set differently depending on the type of data transmitted and received using the IMS data channel. The IMS data channel can be either a dedicated guaranteed bit rate (GBR) bearer, a dedicated non-GBR bearer, or a default non-GBR bearer, and can be a QoS class identifier (QCI)/5G QoS identifier (5QI) ) may be selected from among 71, 72, 73, 74, 76, or 9 in consideration of characteristics of data transmitted and received through the IMS data channel. <Table 1> below shows QoS characteristics according to 5QI.

5QI value Resource type Default priority level Packet delay budget Packet Error Rate Default Averaging Window Example Services 71 GBR 56 150ms ^10-6 2000ms “Live” uplink streaming 72 56 300ms 10 ^-4 2000ms “Live” uplink streaming 73 56 300ms ^10-8 2000ms “Live” uplink streaming 74 56 500m ^10-8 2000ms “Live” uplink streaming 76 56 500ms 10 ^-4 2000ms “Live” uplink streaming 9 Non-GBR 90 300ms ^10-6 N/A Video (Buffered Streaming) TCP-based (e.g. www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)

For example, if a designated application requires “live” uplink streaming, 5QI indicates the possible delay of data transmitted through live uplink streaming (eg Packet delay budget) and the degree of error (eg Packet Error Rate). An IMS data channel (or QoS flow) of one of 71, 72, 73, 74, 76 or 9 may be established based on.

According to an embodiment, the IMS data channel includes a remote health service, a remote control service, a remote surgery service, a drone steering service, and a collaboration service using VR (virtual reality). , and / or AR (augmented reality) can be used to provide a control service.

2 is a sequence diagram illustrating an operation of establishing an IMS data channel according to an embodiment of the present disclosure.

Referring to FIG. 2 , the first electronic device 201 (eg, the electronic device 101 of FIG. 1 ) may, in operation 210, access a connectable network. The first electronic device 201 may access the network according to procedures defined in standards. The first electronic device 201 may be connected to a 5G network, for example. The first electronic device 201 may access a 5G core (5GC) 207 through a radio access network (RAN) 205 . In FIG. 2 , the first electronic device 201 is described as connected to a 5G network, but may also be connected to a long term evolution (LTE) network or a wireless fidelity (WiFi) network.

In operation 215, the first electronic device 201 may connect to the IMS core 209 and register with the IMS server. The first electronic device 201 may use, for example, Session Initiation Protocol (SIP) to register with the IMS server.

In operation 220, the first electronic device 201 may request transmission/reception of voice data with the second electronic device 203 to the IMS core 209. Voice data may be, for example, a voice call.

In operation 225, the IMS core 209 may request the second electronic device 203 to transmit/receive voice data with the first electronic device 201 through the network connected by the second electronic device 203.

The RAN 205, the 5G core (5GC) 207, and the IMS core 209, in operation 230, may change the session for security of resources allocated to voice data.

In operation 235, a path for transmitting and receiving voice data may be created between the first electronic device 201 and the second electronic device 203.

In operation 240, the first electronic device 201 may request an IMS session update to add an IMS data channel to the IMS core 209 with the second electronic device 203.

The IMS core 209 may request an IMS session update from the second electronic device 203 in operation 245 .

The RAN 205, the 5G core (5GC) 207, and the IMS core 209 may change the session in operation 250 to secure resources allocated to the IMS data channel.

In operation 255, an IMS data channel for transmitting and receiving data between the first electronic device 201 and the second electronic device 203 may be created.

Meanwhile, the IMS data channel (or QoS flow) established as shown in FIG. 2 may be disconnected between network entities (e.g., eNB, MME, gNB) or disconnected according to the network environment and resource status. When the QoS flow is disconnected, the electronic device or/and the P-CSCF server can detect or confirm that the QoS flow is disconnected, and the electronic device terminates the SIP session or maintains the SIP session and provides it as a QoS flow. provision of services may be terminated.

Hereinafter, a method for reconnecting a disconnected QoS flow by an electronic device or/and a P-CSCF server according to various embodiments of the present disclosure will be described.

3 is a sequence diagram in which an electronic device reconnects a disconnected QoS flow according to an embodiment of the present disclosure.

Referring to FIG. 3, the electronic device 301 (eg, the electronic device 101 of FIG. 1), the 5G network 303, and the P-CSCF server 305, in operation 310, establish an IMS data channel. can A QoS flow may be allocated to the established IMS data channel, and when the allocated QoS flow is disconnected, the IMS data channel may also be disconnected.

According to one embodiment, the 5G network 303 may include a gNB, an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), and a policy control function (PCF).

Then, when the QoS flow (or IMS data channel) is disconnected, in operation 315, the 5G network 303 may notify the electronic device 301 that the QoS flow is disconnected. The 5G network 303 may notify the electronic device 301 that the connection of the QoS flow is released using a message related to a radio resource control (RRC) connection.

In operation 320, the electronic device 301, the 5G network 303, and the P-CSCF server 305 terminate the service provided using the IMS data channel, and the electronic device 301 reconnects the QoS flow as follows. you can try like

In operation 325, the electronic device 301 may set a retransmission timer. The electronic device 301 may start the retransmission timer even when the retransmission timer expires or a handover in which a radio access technology (RAT) is changed occurs. Change of RAT may include, for example, a change from a 5G network to a long term evolution (LTE), a change from an LTE network or a 5G network to WiFi, or a change conversely.

According to one embodiment, the value of the retransmission timer may be determined by referring to loss and/or latency values in the SDP. Loss and latency can be provided by the 3gpp-qos-hint attribute of the SDP offer message. Here, loss represents how much packet loss is allowed in the service provided using the IMS data channel, and latency represents how much packet transmission delay time is allowed in the service provided using the IMS data channel. there is. As the loss value is smaller, the service provided using the IMS data channel is a service that processes data that is strict on loss, and for example, a service that supports remote surgery may correspond to this. As the Latency value is smaller, the service provided using the IMS data channel is a service that processes real-time data, and may correspond to, for example, an autonomous driving service. A value of the retransmission timer may be set to a smaller value so that the QoS flow is quickly reconnected as the loss value and/or latency value are smaller.

According to an embodiment, <Equation 1> below may determine a value of a retransmission timer, for example.

<Equation 1>

Rt = C * L * 1/|log(PI)| ² * ^2RC

Here, Rt may represent a retransmission timer value, C is a constant (default: 32), RC is the number of retransmissions, L is latency (ms), and PI may represent packet loss. According to <Equation 1>, the value of the retransmission timer may be proportional to latency and 1/|log(PI)|. C, which is a constant, can be set differently according to the requirements of the business operator. In order to prevent too frequent reconnection attempts, the value of the retransmission timer may be increased by the power of 2 of RC using RC.

For example, in the case of an IMS data channel that transmits vital information of an emergency patient, since it is important data, when loss is set to 10 ^-8 and latency is set to 500 ms, the value of the retransmission timer is as follows according to Equation 1 It can be set as in <Table 2>.

number of retransmissions One 2 3 4 5 6 value of retransmit timer 500ms 1000ms 2000ms 4000ms 8000ms 16000ms

As another example, in the case of an IMS data channel that transmits game information, when the loss representing the importance of data is relatively low at 10 ^-4 and the latency is set at 200 ms, the value of the retransmission timer is shown in Table 3 below according to Equation 1. > can be set as

number of retransmissions One 2 3 4 5 6 value of retransmit timer 800ms 1600ms 3200ms 6400ms 12800ms 25600ms

In operation 330, the electronic device 301 may transmit a QoS flow reconnection request message to the P-CSCF server 305. The reconnection request message of the QoS flow may be, for example, a SIP Invite message. The electronic device 301 may transmit the precondition for resource reservation to the P-CSCF server 305 together with the SIP Invite message. The electronic device 301 may transmit a SIP Invite message to check whether reconnection of the QoS flow is possible.

When receiving the SIP Invite message, the P-CSCF server 305 may transmit 183 session progress as a response thereto, in operation 335. The P-CSCF server 305 may agree on the reservation of resources included in the precondition transmitted by the electronic device 301 and may transmit 183 session progress to notify the electronic device 301 of this.

In operation 340, the P-CSCF server 305 may request the 5G network 303 to reconnect the QoS flow. The P-CSCF server 305 checks the SDP (session description protocol) negotiated between the SIP Invite message and the 183 session progress message transmitted by the electronic device 301 to reconnect (or allocate) the QoS flow to the 5G network ( 303) can be requested.

The 5G network 303 may check whether reconnection of the requested QoS flow is possible in operation 340. In operation 345, the 5G network 303 may reconnect the QoS flow if reconnection of the QoS flow is possible.

When the QoS flow is reconnected, the 5G network 303 may notify the electronic device 301 that the QoS flow is reconnected in operation 350 .

In operation 355, the electronic device 301 may transmit an update message to the P-CSCF server 305 to renegotiate session parameters.

In operation 360, the P-CSCF server 305 may transmit a 200 OK message to the electronic device 301 in response to the update message.

In operation 365, the electronic device 301 may release the retransmission timer and provide a service using the reconnected IMS data channel.

In a state where reconnection of the QoS flow is not completed, the retransmission timer of the electronic device 301 may expire (operation 370).

When the retransmission timer expires, the electronic device 301 may transmit a cancellation message to the P-CSCF server 305 in operation 375. The cancellation message may be, for example, an SIP Cancel message. The cancellation message may be a message for canceling a reconnection request message previously requested by the electronic device 301 .

In operation 380, the P-CSCF server 305 may transmit a response message to the Cancel message. The response message may be, for example, a 200 OK message of SIP. The P-CSCF server 305 may transmit a response message to the electronic device 301.

In operation 385, the P-CSCF server 305 may transmit a 487 request terminated message to the electronic device 301 in response to the canceled SIP Invite message.

The electronic device 301 may return to operation 325 to start a retransmission timer in order to reconnect the QoS flow.

4 is a flowchart for reconnecting a disconnected QoS flow by an electronic device according to an embodiment of the present disclosure.

According to an embodiment, the electronic device (eg, the electronic device 101 of FIG. 1 ) may establish an IMS data channel with the 5G network and the IMS core in operation 410 . The IMS data channel may be a channel created to transmit/receive data other than voice/video data in an IMS network. A QoS flow may be allocated to the IMS data channel. An IMS data channel can be created by an application.

According to an embodiment, the electronic device 101 may confirm that the QoS flow (or IMS data channel) is disconnected through an RRC connection-related message transmitted from the network in operation 420. When the connection of the QoS flow is disconnected, the connection of the IMS data channel may also be disconnected.

According to an embodiment, the electronic device 101 may set a retransmission timer in operation 430. The electronic device 101 may set the value of the retransmission timer in consideration of the loss and/or latency values in the SDP. The method for determining the value of the retransmission timer is described in operation 325 of FIG. 3, and detailed descriptions here may be omitted to avoid redundancy.

According to an embodiment, the electronic device 101 may transmit a reconnection request message for QoS flow in operation 440. The reconnection request message for the QoS flow may be, for example, a SIP Invite message. The electronic device 101 may transmit the SIP Invite message to the P-CSCF server. According to an embodiment, the electronic device 101 may transmit a precondition including information on a resource to be used together with a SIP Invite message.

According to an embodiment, the electronic device 101 may receive a response message to the reconnection request message for QoS flow transmitted in operation 450 . The response message may be, for example, 183 session progress.

According to an embodiment, the electronic device 101 may receive a reconnection completion message for QoS flow in operation 460 . The reconnection completion message for the QoS flow may be, for example, an RRC connection related message.

According to an embodiment, when the electronic device 101 receives the reconnection completion message for the QoS flow, in operation 460, the electronic device 101 may cancel the set retransmission timer.

According to an embodiment, in operation 470, the electronic device 101 may provide a service using an IMS data channel.

5 is a sequence diagram in which a P-CSCF server reconnects a disconnected QoS flow according to an embodiment of the present disclosure.

Referring to FIG. 5 , the electronic device 501, the 5G network 503, the policy control function (PCF) 505, and the P-CSCF server 507 may establish an IMS data channel in operation 510. A QoS flow may be allocated to the established IMS data channel, and when the allocated QoS flow is disconnected, the IMS data channel may also be disconnected. According to an embodiment, the PCF 505 is a component of the 5G network 503, which manages an integrated policy for the entire operation of the 5G network and transmits the policy to another control plane NF (network function). can do.

In FIG. 5, it is described that the 5G network is connected to the RAT, but the LTE network may be connected. When the LTE network is connected to the RAT, the 5G network 503 in FIG. 5 may be replaced with the LTE network and the PCF 505 may be replaced with a policy and charging rule function (PCRF).

In operation 515, the P-CSCF server 507 may request the PCF 505 to notify the PCF 505 of a QoS flow disconnection related event or/and a resource allocation related event. According to one embodiment, the PCF 505 and the P-CSCF server 507 may be connected through an N5 interface. The PCF 505 and the P-CSCF server 507 may request and respond to necessary information using an HTTP method. The P-CSCF server 507 may request notification when an event related to disconnection of QoS flow and/or an event related to resource allocation occurs using PUT among HTTP methods. Here, the HTTP method may be a message.

The PCF 505 may transmit a response message to the request to the P-CSCF server 507 at operation 520 . The response message may be, for example, 204 no content.

When the QoS flow is disconnected, the 5G network 503 may notify the PCF 505 and the electronic device 501 of the QoS flow disconnection in operations 525-1 and 525-2.

In operation 530, the PCF 505 may notify the P-CSCF server 507 of disconnection of the QoS flow. Notification of disconnection of QoS flow can use POST of HTTP method.

In operation 535, the P-CSCF server 507 may transmit a response message to the notification of disconnection of the QoS flow to the PCF 505. The response message may be, for example, 204 no content.

In operation 540, the electronic device 501, the 5G network 503, the PCF 505, and the P-CSCF server 507 terminate the service provided using the IMS data channel, and the P-CSCF server 507 performs the QoS You can try to reconnect the flow as follows.

The P-CSCF server 507, in operation 545, may set a retransmission timer. A method of setting the retransmission timer by the P-CSCF server 507 may be the same as or similar to the method of setting the retransmission timer by the electronic device in operation 325 of FIG. 3 . According to an embodiment, the value of the retransmission timer may be set in consideration of at least one of an allowable packet loss and an allowable packet transmission delay time in a service provided using the IMS data channel. The value of the retransmission timer may be determined by considering the number of retransmissions in addition to the allowable packet loss and the allowable packet transmission delay time. Here, detailed descriptions may be omitted to avoid repetition of descriptions.

In operation 550, the P-CSCF server 507 may transmit a QoS flow reconnection request message to the PCF 505. The P-CSCF server 507 may request reconnection of the QoS flow using PUT among HTTP methods.

The PCF 505 may transmit a QoS flow reconnection request message to the 5G network 503 in operation 555 .

The 5G network 503 may allocate resources to be used for reconnection of the QoS flow, and transmit a message including information on the allocated resources to the PCF 505 in operation 560 .

The PCF 505 may transmit information about allocated resources or/and a QoS flow reconnection completion message to the P-CSCF server 507 in operation 565 . Information on allocated resources may be included in an HTTP POST message and transmitted. The QoS flow reconnection completion message may be an HTTP POST message.

P-CSCF server 507 may send a response message to PCF 505 in operation 570 . The response message may be, for example, a 204 no content message.

The 5G network 503 may transmit a QoS flow reconnection completion message to the electronic device 501 in operation 575 .

Upon receiving the QoS flow reconnection complete message, the electronic device 501 may, in operation 580, transmit a service re-request message using the IMS data channel to the P-CSCF server 507. The service re-request message may be, for example, a SIP Invite message.

Thereafter, the electronic device 501, the 5G network 503, the PCF 505, and the P-CSCF server 507 may provide a service using the IMS data channel in operation 585.

According to an embodiment, the P-CSCF server 507, in operation 590, when the retransmission timer expires before receiving the reconnection completion message for the QoS flow and/or the message including resource information allocated to the QoS flow. You can reset the retransmission timer.

6 is a flowchart for reconnecting a disconnected QoS flow by a P-CSCF server according to an embodiment of the present disclosure.

According to an embodiment, the P-CSCF server (eg, the P-CSCF server 507 in FIG. 5) is an electronic device (eg, the electronic device 501 in FIG. 5), a 5G network (eg, the 5G network in FIG. 5) 503) and a PCF (eg, PCF 505 in FIG. 5) and an IMS data channel may be established.

According to one embodiment, the P-CSCF server 507, in operation 610, may transmit a message requesting notification to the PCF when a disconnection event and/or a resource allocation event of a QoS flow assigned to an IMS data channel occurs. . The P-CSCF server and PCF are connected through the N5 interface and can transmit and receive messages.

In operation 620, the P-CSCF server 507 may receive a response message to a message requesting notification when a disconnection event and/or a resource allocation event of a QoS flow allocated to an IMS data channel occurs. The response message may be, for example, 204 NO content.

Thereafter, the P-CSCF server 507 may receive a QoS flow connection release notification message in operation 630.

In operation 640, the P-CSCF server 507 may set a retransmission timer to reconnect the QoS flow. A method of setting the value of the retransmission timer by the P-CSCF server 507 may be the same as a method of setting the value of the retransmission timer by the electronic device 501 . Here, detailed descriptions may be omitted to avoid repetition of descriptions.

In operation 650, the P-CSCF server 507 may transmit a QoS flow reconnection request message to the PCF 505. The PCF 505 may transmit a QoS flow reconnection request message to the 5G network. The 5G network may attempt QoS flow reconnection. The 5G network 503 may transmit resource information allocated to the QoS flow to the PCF 505 when the QoS flow is reconnected.

The P-CSCF server 507, in operation 660, upon receiving a reconnection completion message for a QoS flow and/or a message including resource information allocated to the QoS flow, may cancel the previously set retransmission timer.

In operation 670, the P-CSCF server 507 may provide a service using an IMS data channel to which a QoS flow is allocated.

7 is a block diagram of an electronic device according to an embodiment of the present disclosure.

According to an embodiment, the electronic device 700 (eg, the electronic device 101 of FIG. 1 ) includes a control unit 710 (eg, the processor 120 of FIG. 1 ) and a transceiver 720 (eg, the electronic device 101 of FIG. 1 ). of the communication module 190).

According to an embodiment, the controller 710 may control the transceiver 720 to transmit/receive messages with other devices or networks. The controller 710 may establish an IMS data channel, confirm release of the QoS flow assigned to the established IMS data channel, and set a retransmission timer when release of the QoS flow is confirmed. The controller 710 may control the transceiver 720 to transmit a reconnection request message for QoS flow and receive a response message corresponding to the reconnection request message. When receiving the reconnection complete message for the QoS flow, the control unit 710 can release the retransmission timer and provide service using the IMS data channel. According to an embodiment, if the retransmission timer expires before the QoS flow reconnection completion message is received or the RAT is changed, the control unit 710 may reset the retransmission timer and attempt QoS flow reconnection. .

According to an embodiment, the value of the retransmission timer may be set in consideration of at least one of an allowable packet loss and an allowable packet transmission delay time in a service provided using the IMS data channel. The controller 710 may determine the value of the retransmission timer using the allowable packet loss and the allowable packet transmission delay included in the SDP offer message. The value of the retransmission timer may be determined by considering the number of retransmissions in addition to the allowable packet loss and the allowable packet transmission delay time.

According to an embodiment, the transceiver 720 is electrically connected to the control unit 710 and may operate under the control of the control unit 710 .

In FIG. 7 , the electronic device 700 includes only the control unit 710 and the transmission/reception unit 720 , but may further include other components of FIG. 1 . In addition, the control unit 710 and the transmission and reception unit 720 may be configured by being combined into one or configured to be further separated.

8 is a block diagram of a P-CSCF server, according to an embodiment of the present disclosure.

According to an embodiment, the P-CSCF server 800 (eg, the P-CSCF server 507 of FIG. 5) may include a controller 810 and a transceiver 820. The P-CSCF server 800 is connected to a PCF (eg, PCF 505 in FIG. 5) through an N5 interface to transmit and receive messages.

According to an embodiment, the control unit 810 may control the transmission/reception unit 820 to transmit/receive messages with other devices or networks. The controller 810 may control the transceiver 820 to transmit a notification request message when a QoS flow connection release and/or resource allocation event occurs, and to receive a response message corresponding to the request message. When the QoS flow connection is released, the control unit 810 may receive a QoS flow connection release notification message. Upon receiving the QoS flow connection release notification message, the controller 810 may set a retransmission timer and transmit a reconnection request message for the QoS flow. When receiving a reconnection completion message for a QoS flow and/or a message including resource information allocated to the QoS flow, the control unit 810 releases the retransmission timer and provides service using the IMS data channel to which the QoS flow is allocated. can do. According to an embodiment, if the retransmission timer expires before the QoS flow reconnection complete message is received, the controller 810 may reset the retransmission timer and attempt QoS flow reconnection.

According to an embodiment, the value of the retransmission timer may be set in consideration of at least one of an allowable packet loss and an allowable packet transmission delay time in a service provided using the IMS data channel. The value of the retransmission timer may be determined by considering the number of retransmissions in addition to the allowable packet loss and the allowable packet transmission delay time.

According to an embodiment, the transceiver 820 may be electrically connected to the control unit 810 and operate under the control of the control unit 810 .

8, the P-CSCF server 800 includes a controller 810 and a transceiver 820, but may further include an antenna (not shown). In addition, the control unit 810 and the transmission and reception unit 820 may be configured by being combined into one or configured to be further separated.

An electronic device according to various embodiments of the present disclosure includes a transceiver and a control unit, wherein the control unit establishes an IP multimedia subsystem (IMS) data channel, confirms release of a QoS flow allocated to the established IMS data channel, When release of the QoS flow is confirmed, a retransmission timer is set, a reconnection request message for the QoS flow is transmitted by controlling the transceiver, a response message corresponding to the reconnection request message is received, and the QoS flow When a reconnection completion message for is received, the retransmission timer may be released, and a service may be provided using the IMS data channel.

In the electronic device according to various embodiments of the present disclosure, the value of the retransmission timer may be determined in consideration of at least one of an allowable packet loss and an allowable packet transmission delay time in a service provided using the IMS data channel.

In an electronic device according to various embodiments of the present disclosure, the allowable packet loss and/or the allowable packet transmission delay time may be included in a session description protocol (SDP) offer message.

In an electronic device according to various embodiments of the present disclosure, the value of the retransmission timer may increase in proportion to the number of retransmissions.

In an electronic device according to various embodiments of the present disclosure, the reconnection request message may be a session initiation protocol (SIP) invite message, and the response message may be a 183 session progress message.

The control unit of the electronic device according to various embodiments of the present disclosure may reset the retransmission timer when the retransmission timer expires before the QoS flow reconnection completion message is received or a radio access technology (RAT) change occurs. can

A P-CSCF (proxy-call session control function) server according to various embodiments of the present disclosure includes a transceiver and a control unit, and the control unit controls the transceiver to request a notification when a QoS flow disconnection and/or resource allocation event occurs. Sending a message, receiving a response message corresponding to the request message, receiving a QoS flow disconnection notification message, setting a retransmission timer, transmitting a reconnection request message for the QoS flow, and When a message including a reconnection complete message and/or resource information allocated to the QoS flow is received, the retransmission timer can be released and service can be provided using the IMS data channel to which the QoS flow is allocated.

In the P-CSCF server according to various embodiments of the present disclosure, the value of the retransmission timer may be determined in consideration of at least one of an allowable packet loss and an allowable packet transmission delay time in a service provided using the IMS data channel. .

The control unit of the P-CSCF server according to various embodiments of the present disclosure may transmit a notification request message to a policy control function (PCF) when the QoS flow connection release and/or resource allocation event occurs using HTTP PUT.

When the retransmission timer expires before the control unit of the P-CSCF server according to various embodiments of the present disclosure receives a reconnection completion message for the QoS flow and/or a message including resource information allocated to the QoS flow, , the retransmission timer may be reset.

An operating method of an electronic device according to various embodiments of the present disclosure includes establishing an IP multimedia subsystem (IMS) data channel, confirming release of a QoS flow assigned to the established IMS data channel, and releasing the QoS flow. If confirmed, an operation of setting a retransmission timer, an operation of transmitting a reconnection request message for the QoS flow, an operation of receiving a response message corresponding to the reconnection request message, and an operation of receiving a reconnection completion message for the QoS flow If it is, an operation of releasing the retransmission timer and an operation of providing a service using the IMS data channel may be included.

In the operating method of the electronic device according to various embodiments of the present disclosure, the value of the retransmission timer may be determined in consideration of at least one of an allowable packet loss and an allowable packet transmission delay time in a service provided using the IMS data channel. there is.

In the operating method of an electronic device according to various embodiments of the present disclosure, the allowable packet loss and/or the allowable packet transmission delay time may be included in a session description protocol (SDP) offer message.

In the operating method of an electronic device according to various embodiments of the present disclosure, the value of the retransmission timer may increase in proportion to the number of retransmissions.

In the operating method of an electronic device according to various embodiments of the present disclosure, the reconnection request message may be a Session Initiation Protocol (SIP) Invite message, and the response message may be a 183 session progress message.

In the operating method of an electronic device according to various embodiments of the present disclosure, if the retransmission timer expires before the reconnection completion message of the QoS flow is received or a radio access technology (RAT) change occurs, the retransmission timer is reset. It may further include an operation to do.

A method of operating a P-CSCF (proxy-call session control function) server according to various embodiments of the present disclosure includes an operation of transmitting a notification request message when a QoS flow connection release and/or resource allocation event occurs, and a response corresponding to the request message Receiving a message, receiving a QoS flow disconnection notification message, setting a retransmission timer, transmitting a reconnection request message for the QoS flow, a reconnection completion message for the QoS flow, and/or When a message including resource information allocated to the QoS flow is received, an operation of releasing the retransmission timer and an operation of providing a service using an IMS data channel to which the QoS flow is allocated may be included.

In the operating method of the P-CSCF server according to various embodiments of the present disclosure, the value of the retransmission timer is determined by considering at least one of allowable packet loss and allowable packet transmission delay time in the service provided using the IMS data channel. can be determined

In the operation method of the P-CSCF server according to various embodiments of the present disclosure, the operation of transmitting a notification request message when the QoS flow disconnection and / or resource allocation event occurs is transmitted to a policy control function (PCF) using HTTP PUT It can work.

In the method of operation of the P-CSCF server according to various embodiments of the present disclosure, if the retransmission timer expires before the reconnection complete message for the QoS flow and/or the message including resource information allocated to the QoS flow is received , may further include an operation of resetting the retransmission timer.

Electronic devices according to various embodiments disclosed in this document may be devices of various types. 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. An electronic device according to an embodiment of the present document is not limited to the aforementioned devices.

Various embodiments of this document and terms used therein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various modifications, equivalents, or substitutes of the embodiments. In connection with the description of the drawings, like reference numbers may be used for like or related elements. The singular form of a noun corresponding to an item may include one item or a plurality of items, unless the relevant context clearly dictates otherwise. In this document, "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 Each of the phrases such as "at least one of , B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first", "second", or "first" or "secondary" may simply be used to distinguish a given component from other corresponding components, and may be used to refer to a given component in another aspect (eg, importance or order) is not limited. A (e.g., first) component is said to be "coupled" or "connected" to another (e.g., second) component, with or without the terms "functionally" or "communicatively." When mentioned, it means that the certain component may 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, logical blocks, parts, or circuits. can be used as A module may be an integrally constructed component or a minimal unit of components or a portion thereof that performs one or more functions. For example, according to one embodiment, the module may be implemented in the form of an application-specific integrated circuit (ASIC).

Various embodiments of this document provide 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). It may be implemented as software (eg, the program 140) including them. For example, a processor (eg, the processor 120 ) of a device (eg, the electronic device 101 ) may call at least one command among one or more instructions stored from a storage medium and execute it. This enables the device to be operated to perform at least one function according to the at least one command invoked. 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-temporary' only means that the storage medium is a tangible device and does not contain a signal (e.g. electromagnetic wave), and this term refers to the case where data is stored semi-permanently in the storage medium. It does not discriminate when it is temporarily stored.

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

According to various embodiments, each component (eg, module or program) of the above-described components may include a single object 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 aforementioned corresponding components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (eg modules or programs) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by a corresponding component among the plurality of components prior to the integration. . According to various embodiments, the actions performed by a module, program, or other component are executed sequentially, in parallel, iteratively, or heuristically, or one or more of the actions are executed in a different order, or omitted. or one or more other actions may be added.

Claims (20)

In electronic devices,
transceiver; and
including a control unit;
The control unit,
Establish an IP multimedia subsystem (IMS) data channel;
Check release of the QoS flow allocated to the established IMS data channel;
When the release of the QoS flow is confirmed, a retransmission timer is set,
Controls the transceiver to transmit a reconnection request message for the QoS flow;
Receiving a response message corresponding to the reconnection request message;
When the reconnection completion message for the QoS flow is received, the retransmission timer is released, and
An electronic device that provides a service using the IMS data channel. According to claim 1,
The electronic device of claim 1 , wherein the value of the retransmission timer is determined in consideration of at least one of an allowable packet loss and an allowable packet transmission delay time in a service provided using the IMS data channel. According to claim 2,
The electronic device, characterized in that the allowable packet loss and / or the allowable packet transmission delay time is included in a session description protocol (SDP) offer message. According to claim 1,
The value of the retransmission timer increases in proportion to the number of retransmissions. According to claim 1,
The reconnection request message is a session initiation protocol (SIP) Invite message,
The response message is a 183 session progress message, the electronic device. The method of claim 1, wherein the control unit,
If the retransmission timer expires before the reconnection completion message of the QoS flow is received or a radio access technology (RAT) change occurs, the electronic device resets the retransmission timer. In the P-CSCF (proxy-call session control function) server,
transceiver; and
including a control unit;
The control unit,
Controls the transceiver to transmit a notification request message when a QoS flow disconnection and / or resource allocation event occurs,
Receiving a response message corresponding to the request message;
Receive a QoS flow disconnection notification message,
set a retransmission timer,
Sending a reconnection request message for the QoS flow,
When a reconnection complete message for the QoS flow and/or a message including resource information allocated to the QoS flow is received, the retransmission timer is released,
A P-CSCF server that provides a service using an IMS data channel to which the QoS flow is allocated. According to claim 7,
The value of the retransmission timer is determined in consideration of at least one of an allowable packet loss and an allowable packet transmission delay time in the service provided using the IMS data channel. The method of claim 7, wherein the control unit,
A P-CSCF server that transmits a notification request message to a policy control function (PCF) when the QoS flow connection release and/or resource allocation event occurs using HTTP PUT. The method of claim 7, wherein the control unit,
If the retransmission timer expires before a reconnection completion message for the QoS flow and/or a message including resource information allocated to the QoS flow is received, the P-CSCF server resets the retransmission timer. In the operating method of the electronic device,
establishing an IP multimedia subsystem (IMS) data channel;
confirming release of the QoS flow allocated to the established IMS data channel;
setting a retransmission timer when release of the QoS flow is confirmed;
Transmitting a reconnection request message for the QoS flow;
receiving a response message corresponding to the reconnection request message;
releasing the retransmission timer when a reconnection complete message for the QoS flow is received; and
A method of operating an electronic device comprising providing a service using the IMS data channel. According to claim 11,
The method of claim 1 , wherein the value of the retransmission timer is determined in consideration of at least one of an allowable packet loss and an allowable packet transmission delay time in a service provided using the IMS data channel. According to claim 12,
The allowable packet loss and/or the allowable packet transmission delay time are included in a session description protocol (SDP) offer message. According to claim 11,
The method of operating the electronic device, wherein the value of the retransmission timer increases in proportion to the number of retransmissions. According to claim 11,
The reconnection request message is a session initiation protocol (SIP) Invite message,
The response message is a 183 session progress message, the operating method of the electronic device. According to claim 11,
If the retransmission timer expires before the reconnection completion message of the QoS flow is received or a radio access technology (RAT) is changed, resetting the retransmission timer. In the operation method of the P-CSCF (proxy-call session control function) server,
Transmitting a notification request message when a QoS flow disconnection and/or resource allocation event occurs;
receiving a response message corresponding to the request message;
Receiving a QoS flow connection release notification message;
setting a retransmission timer;
Transmitting a reconnection request message for the QoS flow;
releasing the retransmission timer when a reconnection completion message for the QoS flow and/or a message including resource information allocated to the QoS flow is received; and
A method of operating a P-CSCF server including an operation of providing a service using an IMS data channel to which the QoS flow is allocated. According to claim 17,
Wherein the value of the retransmission timer is determined in consideration of at least one of an allowable packet loss and an allowable packet transmission delay time in a service provided using the IMS data channel. The method of claim 17, wherein the operation of transmitting a notification request message when the QoS flow connection release and/or resource allocation event occurs,
An operation method of a P-CSCF server, which is an operation of transmitting to PCF (policy control function) using HTTP PUT. According to claim 17,
If the retransmission timer expires before the reconnection completion message for the QoS flow and/or the message including resource information allocated to the QoS flow is received, the P-CSCF further comprises an operation of resetting the retransmission timer. How the server works.

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