WO2023065343A1 - Method and apparatus for controlling emergency bearer - Google Patents

Abstract

Provided in the present application are a method and apparatus for controlling an emergency bearer. In the technical solution provided in the present application, the method comprises: a terminal determining an emergency bearer service capability of a target cell, wherein the emergency bearer service capability of the target cell comprises the target cell supporting an emergency bearer service and the target cell not supporting the emergency bearer service; and the terminal determining, according to the emergency bearer service capability of the target cell, whether to execute a suppression operation, wherein the suppression operation is used for suppressing an inter-RAT behavior, and the inter-RAT behavior comprises the terminal performing reselection or handover from the current cell having an emergency bearer to the target cell. In the technical solution provided in the present application, by means of the terminal executing the suppression operation, an unnecessary inter-RAT behavior may be avoided, thereby guaranteeing the continuity of the emergency bearer to the greatest extent.

Description

A method and device for controlling emergency bearing technical field

The present application relates to the field of communications, and more specifically, to a method and device for controlling emergency bearers.

Background technique

Currently, in long term evolution (LTE) and new radio (NR) systems, there are LTE network voice services (Voice over LTE, VoLTE) and NR network voice services (Voice over NR, VoNR). For VoLTE and VoNR emergency calls, users can establish dedicated bearers for emergency calls on LTE and NR networks, perform emergency registration, and initiate emergency calls. This solution is called Internet Protocol multimedia subsystem (IMS) emergency calls. Since IMS emergency calls are closely related to personal safety, user equipment (UE) is not allowed to actively release emergency services under normal circumstances, but how to do as much as possible when cell reselection, handover, and redirection to neighboring cells of different systems occur? Guaranteeing the continuity of emergency bearing is an urgent problem to be solved at present.

Contents of the invention

The embodiment of the present application provides a method for controlling the emergency bearer. When the terminal hangs up the emergency call and there is an emergency bearer in the current cell, the terminal suppresses the behavior of different systems as much as possible, so as to ensure the continuity of the emergency bearer.

In a first aspect, a method for controlling an emergency bearer is provided, including: a terminal determines the emergency bearer service capability of a target cell, and the emergency bearer service capability of the target cell includes that the target cell supports the emergency bearer service and that the target cell does not Support emergency bearer service; the terminal determines whether to perform a suppression operation according to the emergency bearer service capability of the target cell, and the suppression operation is used to suppress the behavior of different systems, and the behavior of different systems includes the terminal from the current emergency bearer service Cell reselection or handover to the target cell.

Optionally, when the terminal hangs up the emergency call in the current cell, the terminal has an emergency bearer in the current cell, and the emergency bearer is established after the terminal sends the emergency call. During the emergency bearer period, the terminal does not need to re-establish the emergency call again. bearer.

Optionally, when the RRC layer of the radio link of the terminal is in an idle state, the different system behavior is to reselect from the current cell to the target cell; when the RRC layer of the terminal is in a connected state, the different system behavior is Handover from the current cell to the target cell.

Based on this solution, the terminal judges the emergency bearer service capability of the target cell before determining whether to perform the suppression operation. The terminal determines whether to perform the suppression operation according to the emergency bearer service capability of the target cell. When the terminal judges the emergency bearer service capability of the target cell that the target cell does not support the emergency bearer service, or the emergency bearer service capability of the target cell is unknown, if the terminal switches or reselects from the current cell with emergency bearer services to such The target cell, the terminal will still try to initiate an emergency bearer in such a target cell, which may cause the emergency bearer to be released or fail to work normally. This type of handover or reselection is an unnecessary behavior of different systems. Necessary different system behavior determination When performing the suppression operation, it hinders the possible handover or reselection of the terminal, which can avoid unnecessary different system behavior and prevent the terminal from being reselected or handed over to a target cell that does not support emergency bearer services due to different systems , resulting in discontinuous emergency bearer, avoiding the release of emergency bearer or failure to work normally, and avoiding accidents closely related to personal safety. When the terminal judges the emergency bearer service capability of the target cell and the solution is that the target cell supports emergency bearer service, If the terminal switches or reselects to such a target cell from a current cell with an emergency bearer, the terminal does not need to establish an emergency bearer again when the terminal is in the target cell, and the emergency bearer of the terminal is still continuous.

With reference to the first aspect, in a possible implementation manner, the terminal determines whether to perform the suppression operation according to the emergency bearer service capability of the target cell, including: when the terminal hangs up the emergency call in the current cell Next, the terminal determines whether to perform the suppression operation according to the emergency bearer service capability of the target cell.

Based on this solution, after the terminal makes an emergency call in the current cell, the current cell establishes an emergency bearer, the terminal hangs up the call, and the current cell maintains the emergency bearer. That is, when the terminal hangs up the emergency call in the current cell where there is an emergency bearer, the terminal further determines the emergency bearer capability of the target cell, and when the terminal judges that the target cell does not support the emergency bearer service or is unknown to the emergency bearer service capability of the target cell, The terminal determines to execute the suppression operation, and avoids unnecessary different system behavior through the suppression operation of the terminal, so as to ensure the continuity of the emergency bearer as much as possible. The method for controlling the emergency bearer of the present application can keep the continuity of the emergency bearer of the terminal after the phone is hung up as much as possible, avoid the unnecessary behavior of the terminal in different systems, and avoid the release of the emergency bearer or failure of the terminal due to reselection or switching of different systems. To avoid accidents related to personal safety caused by the failure of the terminal to re-establish the emergency bearer in time after the emergency call is hung up.

With reference to the first aspect, in a possible implementation manner, the terminal determining the emergency bearer service capability of the target cell includes: the terminal determining the emergency bearer service capability of the target cell according to historical cell information, the The historical cell information includes the emergency bearer service capability of the cell where the terminal has camped.

Optionally, the historical cell information may include that the cell where the terminal has camped supports the emergency bearer service capability or the cell where the terminal has camped does not support the emergency bearer service capability. In another case, when the target cell is not the cell where the terminal has camped, the terminal does not know the emergency bearer service capability of the target cell, and the historical cell information does not include the emergency bearer service capability of the target cell, that is, the The historical cell information does not record the emergency bearer service capability of the target cell. Optionally, the historical cell information may also include an ID of a cell that has camped on, and the terminal may judge whether the target cell is a cell that has camped on or not according to the ID of a cell that has camped on.

Optionally, the historical cell information includes the emergency bearer service capability of the cell where the terminal has camped, and the emergency bearer service capability is the emergency bearer service capability in a normal service state.

The terminal records the information of the historical cell it once resided in, and stores the emergency bearer service capability of the cell, which is generally stable and does not change in the current network environment. Therefore, the terminal can judge the emergency bearer service capability of the target cell before inter-system reselection or handover according to the stored historical cell information of the cell where it once resided, and the terminal decides whether to perform the suppression operation according to the judgment result, thereby avoiding unnecessary Inter-system behavior, avoiding discontinuity of emergency bearer caused by reselection of different system or handover to a target cell that does not support emergency bearer service.

With reference to the first aspect, in a possible implementation manner, determining the emergency bearer service capability of the target cell by the terminal includes: receiving, by the terminal, a broadcast message sent by the target cell, where the broadcast message is used to indicate The emergency bearer service capability of the target cell; the terminal determines the emergency bearer service capability of the target cell according to the broadcast message.

The terminal knows the emergency bearer service capability of the target cell through the indication of the received broadcast message, and further decides whether to perform the suppression operation. The broadcast message can be sent by a cell that the terminal has never camped on, that is, the terminal cannot know the emergency bearer service capability of the target cell that has not camped on through the recorded historical cell information, but can know the emergency bearer service capability of the target cell through the broadcast message sent by the target cell. The emergency bearer service capability of the target cell.

Based on this solution, the terminal avoids unnecessary inter-system behavior before inter-system reselection or handover, and avoids discontinuity of emergency bearer due to inter-system reselection or handover of the terminal to a target cell that does not support emergency bearer services.

With reference to the first aspect, in a possible implementation manner, the terminal determines the emergency bearer service capability of the target cell according to the broadcast message, including: the broadcast message includes an Internet Protocol Multimedia Subsystem IMS emergency service support flag , the IMS emergency service support flag is used to indicate that the target cell supports the emergency bearer service.

Optionally, the broadcast message sent by the target cell includes SIB1, and if the SIB1 message carries an IMS emergency service support flag, it is considered that the target cell supports the emergency service in restricted state and normal service. Restricted state refers to scenarios where PS services cannot be provided, such as arrears, no card and other scenarios. In the normal service state, it is necessary to judge whether the target cell supports the emergency bearer service according to the emergency bearer services indicator (Emergency bearer services indicator) field in Attach and TAU.

Optionally, if the broadcast message received by the terminal before inter-system reselection or handover has an IMS emergency service support flag, it can be considered that the target cell sending the broadcast message supports emergency bearer services in a restricted state and supports normal business states Emergency Bearer Service under

Optionally, if the broadcast message received by the terminal does not include the IMS emergency service support flag, the terminal does not know the emergency bearer service capability of the target cell.

With reference to the first aspect, in a possible implementation manner, when the terminal hangs up the emergency call in the current cell, the state of the radio resource control RRC layer of the terminal includes an idle state or a connected state.

Based on this scheme, the terminal can adopt different specific suppression operations according to different states of the RRC, and try to suppress unnecessary different system behaviors.

With reference to the first aspect, in a possible implementation manner, the terminal determines whether to perform the suppression operation according to the emergency bearer service capability of the target cell, including: when the terminal determines that the target cell does not support the emergency bearer service or When the terminal does not record the emergency bearer service capability of the target cell, the terminal performs the suppression operation.

Optionally, the fact that the terminal has not recorded the emergency bearer service capability of the target cell includes that the emergency bearer service capability of the target cell has not been recorded in the historical cell information (that is, the terminal has not camped on the target cell) or in the broadcast message Emergency services support sign not recorded. Based on this solution, if the target cell does not support the emergency bearer service before the terminal reselects or switches to the different system, the terminal reselects or switches to the target cell, which will cause the emergency bearer to be released or fail to work normally; The emergency bearer capacity of the target cell is unknown, if the terminal reselects from another system or switches to the target cell, there is a risk that the emergency bearer will be released or fail to work normally, so the emergency bearer service is not supported in the target cell or the terminal does not record the target When the emergency bearer service capability of the cell is checked, the terminal performs a suppression operation to ensure the continuity of the emergency bearer as much as possible.

With reference to the first aspect, in a possible implementation manner, the terminal does not record the emergency bearer service capability of the target cell, including: the historical cell information does not record the emergency bearer service capability of the target cell or the The broadcast message does not record the IMS emergency services support flag.

Optionally, the fact that the historical cell information does not record the emergency bearer service capability of the target cell indicates that the target cell is not a cell where the terminal has camped, and the target cell has a risk of not supporting the emergency bearer service.

Optionally, the broadcast message does not record the IMS emergency support service flag, indicating that the target cell does not support at least the emergency bearer service in the restricted state, and it is unknown whether the target cell supports the emergency bearer service in the normal state. At this time, the terminal judges The target cell has the risk of not supporting the emergency bearer service in normal state.

Based on this solution, the terminal performs a suppression operation on the target cell that has the risk of not supporting the emergency bearer service, so as to ensure the continuity of the emergency bearer as much as possible.

With reference to the first aspect, in a possible implementation manner, before the terminal determines whether to perform the suppression operation according to the emergency bearer service capability of the target cell, the method further includes: when the RRC layer of the terminal is idle In the state, the terminal determines that the priority of the current cell is lower than the priority of the target cell.

Optionally, when the priority of the current cell is lower than the priority of the target cell, the condition of inter-system behavior is met, but at this time the terminal needs to further judge the emergency bearer service capability of the target cell according to the historical cell information, and Determines whether to perform a suppress operation.

Based on this solution, the possibility of suppressing unnecessary behavior of different systems is further improved, the continuity of emergency bearer is guaranteed as much as possible, and the release of emergency bearer or failure to work normally caused by the behavior of different systems is avoided.

With reference to the first aspect, in a possible implementation manner, performing the suppression operation by the terminal includes: setting, by the terminal, the priority of the current cell to the highest priority.

Optionally, the priority of the current cell is set to the highest priority by default, and the priority of the target cell is lower than the priority of the current priority by default to ensure the use of high priority reselection rules. At this time, the terminal does not meet the reselection conditions and can Try to avoid unnecessary different system behaviors to ensure the continuity of emergency bearer.

With reference to the first aspect, in a possible implementation manner, the terminal performing the suppression operation includes:

The terminal reduces the camping standard of the current cell or increases the camping standard of the target cell.

Optionally, by modifying the serving cell reselection threshold (threshServingLow) broadcast in the current cell SIB3, thereby reducing the residence standard of the current cell; or by increasing the high priority reselection threshold of the target cell, for example: in the NR neighboring cell SIB24 Broadcast NR frequency low priority reselection threshold (threshX-High-r15), thus increasing the difficulty of reselecting to the target cell, suppressing unnecessary behavior of different systems as much as possible, and ensuring the continuity of emergency bearer

With reference to the first aspect, in a possible implementation manner, the terminal performing the suppression operation includes: when the RRC layer of the terminal is in a connected state, the terminal suppresses reporting of the B1 measurement report.

Optionally, the B1 event is an event in which the signal quality of a neighboring cell of a different system becomes higher than a corresponding threshold, and the entry condition and exit condition of the B1 event are different depending on whether the current cell is in NR or LTE. After receiving the measurement configuration information, the terminal performs measurement according to the instructions and meets the reporting conditions. The terminal will report the measurement report, and the measurement report reported first will first execute the target cell judgment. The RSRP information of the target cell mainly exists in the measurement report, and the terminal can ensure the continuity of the emergency bearer by suppressing the suppression operation reported in the measurement report.

With reference to the first aspect, in a possible implementation manner, the terminal determines whether to perform the suppression operation according to the emergency bearer service capability of the target cell, including: when the terminal determines that the target cell supports the emergency bearer service, The terminal is prohibited from performing the suppression operation.

Optionally, when the terminal determines that the target cell supports the emergency bearer service capability according to the historical cell information, the terminal is prohibited from performing the suppression operation.

Optionally, the terminal determines that the target cell supports the emergency bearer service capability according to the broadcast message, that is, when the IMS emergency service support flag in the broadcast message indicates that the target cell supports the emergency bearer service, the terminal is prohibited from performing the suppression operation.

Based on this solution, the terminal knows that the target cell supports the emergency bearer service before inter-system reselection or handover occurs, and if the terminal inter-system reselects or switches to the target cell, the emergency bearer will not be released or fail to work normally. When the target cell supports the emergency bearer service, the terminal is prohibited from performing the suppression operation, and the emergency bearer is continuous.

With reference to the first aspect, in a possible implementation manner, before the terminal determines whether to perform the suppression operation according to the emergency bearer service capability of the target cell, the method further includes: when the RRC layer of the terminal is idle In the state, the terminal determines that the priority of the current cell is higher than the priority of the target cell; the terminal is prohibited from performing the suppression operation.

Optionally, when the priority of the current cell is equal to or higher than the priority of the target cell, the terminal does not need to further judge the emergency bearing capacity of the target cell according to the historical cell information, and can determine that the terminal is prohibited from performing the suppression operation , so as to improve the efficiency of controlling emergency load

With reference to the first aspect, in a possible implementation manner, the method further includes: the terminal starts an inter-system suppression timer when there is an emergency bearer in the current cell; when the terminal determines that the target cell supports the emergency bearer When serving, the terminal stops the different system suppression timer; or when the terminal determines that the target cell does not support the emergency bearer service or the terminal does not record the emergency bearer service capability of the target cell, the terminal The emergency bearer is released when the inter-system suppression timer expires.

Optionally, if the emergency bearer exists and the current cell is available, the timer for suppressing different systems is started. During the operation of the timer for suppressing different systems, the terminal should suppress the second radio access technology from the current radio access technology network in a specified scenario. reselection, switching, and redirection. When the timer for suppressing different systems is enabled, the timer for suppressing different systems protects the emergency bearer, and when the timer for suppressing different systems expires, the emergency bearer is no longer protected. The flexible protection of emergency bearers can be realized by suppressing the different system timers.

In a second aspect, a terminal is provided, including: a judging module, configured to determine the emergency bearer service capability of a target cell, where the emergency bearer service capability of the target cell includes that the target cell supports the emergency bearer service and that the target cell does not Supporting emergency bearer services; an execution module, configured to determine whether to perform a suppression operation according to the emergency bearer service capability of the target cell, the suppression operation is used to suppress behaviors of different systems, and the behaviors of different systems include The current cell reselects or switches to the target cell.

With reference to the second aspect, in a possible implementation manner, when the terminal hangs up the emergency call in the current cell, the execution module determines whether to perform the suppression operation according to the emergency bearer service capability of the target cell .

With reference to the second aspect, in a possible implementation manner, the judging module includes: a first judging unit, configured to determine the emergency bearer service capability of the target cell according to historical cell information, where the historical cell information includes the The emergency bearer service capability of the cell where the terminal has camped.

With reference to the second aspect, in a possible implementation manner, the judging module includes: a second judging unit, configured to determine the emergency bearer service capability of the target cell according to a broadcast message, where the broadcast message is used to indicate the The emergency bearer service capability of the target cell.

With reference to the second aspect, in a possible implementation manner, the broadcast message includes an IMS emergency service support flag; the second judging unit determines that the target cell supports the emergency bearer service according to the IMS emergency service support flag.

With reference to the second aspect, in a possible implementation manner, when the terminal hangs up the emergency call in the current cell, the state of the RRC layer of the terminal includes an idle state or a connected state.

With reference to the second aspect, in a possible implementation manner, when the judgment module determines that the target cell does not support the emergency bearer service capability or the judgment module does not record the emergency bearer service capability of the target cell, the An execution module executes the suppression operation.

With reference to the second aspect, in a possible implementation manner, the judging module not recording the emergency bearer service capability of the target cell includes: the historical cell information in the first judging unit does not record the emergency bearer service capability of the target cell. The bearer service capability or the broadcast message in the second judging unit does not record the IMS emergency service support flag.

With reference to the second aspect, in a possible implementation manner, the judging module further includes: a third judging unit, configured to determine the priority of the current cell; when the RRC layer of the terminal is in an idle state, the The third judging unit is configured to determine that the priority of the current cell is lower than the priority of the target cell.

With reference to the second aspect, in a possible implementation manner, the execution module includes: a first execution unit configured to set the priority of the current cell to the highest priority.

With reference to the second aspect, in a possible implementation manner, the execution module includes: a second execution unit configured to decrease the camping standard of the current cell or increase the camping standard of the target cell.

With reference to the second aspect, in a possible implementation manner, the execution module includes: a third execution unit configured to suppress the reporting of the B1 measurement report; when the RRC layer of the terminal is in a connected state, the third execution unit The execution unit suppresses reporting of the B1 measurement report.

With reference to the second aspect, in a possible implementation manner, when the judgment module determines that the target cell supports the emergency bearer service, the execution module prohibits execution of the suppression operation.

With reference to the second aspect, in a possible implementation manner, the judging module further includes: a third judging unit, configured to determine the priority of the current cell; when the RRC layer of the terminal is in an idle state, the The third judging unit is configured to determine that the priority of the current cell is higher than the priority of the target cell; and the execution unit prohibits execution of the suppression operation.

With reference to the second aspect, in a possible implementation manner, the terminal further includes: suppressing the different system timer; the terminal starts the suppressing different system timer when there is an emergency bearer in the current cell; when the judging unit When it is determined that the target cell supports the emergency bearer service, the terminal stops the inter-system suppression timer; or when the judging unit determines that the target cell does not support the emergency bearer service or the judging unit does not record the target cell When the emergency bearer service capability is available, the terminal releases the emergency bearer when the inter-system suppression timer expires.

In a third aspect, a terminal is provided, and the terminal includes a processor, a memory, and a transceiver; the transceiver is used to receive signals and send signals; the memory is used to store program codes; the processor is used to obtain from the The memory invokes the program code to execute the first aspect or any possible implementation manner of the first aspect.

In a fourth aspect, a terminal is provided. The terminal includes a processor. When the processor invokes a computer program in a memory, the first aspect or any possible implementation manner of the first aspect is executed.

In a fifth aspect, a terminal is provided, the terminal includes a memory and a processor; the memory is used to store a computer program, and when the processor invokes the computer program in the memory, the terminal executes the first Aspect or any possible implementation of the first aspect.

According to a sixth aspect, a computer-readable storage medium is provided, the computer-readable storage medium includes computer programs or instructions, and when the computer programs or instructions are run on a computer, the computer executes the computer according to the first aspect or the first any possible implementation of the aspect.

In a seventh aspect, a computer program product is provided, the computer program product includes a computer program or an instruction, and when the computer program or instruction is run on a computer, the computer executes any one of the first aspect or the first aspect. a possible implementation.

Description of drawings

FIG. 1 is a schematic diagram of an emergency call hangup provided by an embodiment of the present application;

FIG. 2 is a schematic flowchart of a method for controlling emergency bearer provided by an embodiment of the present application;

FIG. 3 is a structural diagram of an IMS emergency call provided by an embodiment of the present application;

Figure 4 is a schematic diagram of the emergency registration process provided by the embodiment of the present application;

FIG. 5 is a schematic diagram of an emergency call flow provided by an embodiment of the present application;

FIG. 6 is a schematic flowchart of a method for controlling emergency bearer provided by another embodiment of the present application;

FIG. 7 is a TAU flowchart in the IDLE state provided by the embodiment of the present application;

FIG. 8 is a TAU flowchart in the CONNECTED state provided by the embodiment of the present application;

Fig. 9 is the Attach flow chart provided by the embodiment of the present application;

Fig. 10 is a basic flowchart of handover provided by the embodiment of the present application;

Figure 11 is a flow chart of handover strategies from E-UTRAN to NR and from NR to E-UTRAN provided by the embodiment of the present application;

Fig. 12 is a flow chart of the delivery of measurement control events provided by the embodiment of the present application;

FIG. 13 is a flow chart of redirecting E-UTRAN to NG-RAN provided by the embodiment of the present application;

FIG. 14 is a flow chart of switching from NG-RAN to E-UTRAN provided by the embodiment of the present application;

FIG. 15 is a schematic flowchart of a method for controlling emergency bearers provided by another embodiment of the present application;

Fig. 16 is a flow chart of reselection between different systems from E-UTRAN to NG-RAN provided by the embodiment of the present application;

FIG. 17 is a flow chart of reselection from NG-RAN to E-UTRAN different systems provided by the embodiment of the present application;

Fig. 18 is a schematic flowchart of a method for controlling emergency bearers provided by another embodiment of the present application;

FIG. 19 is a schematic flowchart of a method for controlling emergency bearers provided by another embodiment of the present application;

Fig. 20 is a schematic flowchart of a method for controlling emergency bearers provided by another embodiment of the present application;

Fig. 21 is a schematic flowchart of a method for controlling emergency bearers provided by another embodiment of the present application;

Fig. 22 is a schematic diagram of the execution terminal provided by the embodiment of the present application;

Fig. 23 is a schematic diagram of a terminal provided by an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

The technical solution of the embodiment of the present application can be applied to various communication systems, such as: Global System of Mobile communication (Global System of Mobile communication, GSM) system, code division multiple access (Code Division Multiple Access, CDMA) system, broadband code division multiple access (Wideband Code Division Multiple Access, WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, the future fifth generation (5th Generation, 5G) system or New Radio (New Radio, NR), etc.

The terminal equipment in the embodiment of the present application may refer to user equipment, access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. The terminal equipment can also be a cellular phone, a cordless phone, a Session Initiation Protocol (Session Initiation Protocol, SIP) phone, a wireless local loop (Wireless Local Loop, WLL) station, a personal digital processing (Personal Digital Assistant, PDA), a wireless communication Functional handheld devices, computing devices or other processing devices connected to wireless modems, vehicle-mounted devices, wearable devices, terminal devices in the future 5G network or future evolution of the public land mobile network (Public Land Mobile Network, PLMN) The terminal device and the like are not limited in this embodiment of the present application.

The network device in the embodiment of the present application may be a device for communicating with a terminal device, and the network device may be a Global System of Mobile communication (GSM) system or a code division multiple access (Code Division Multiple Access, CDMA) The base station (Base Transceiver Station, BTS) in the wideband code division multiple access (Wideband Code Division Multiple Access, WCDMA) system (NodeB, NB) can also be the evolved base station (Evolutionary Base Station) in the LTE system NodeB, eNB or eNodeB), it can also be a wireless controller in the cloud radio access network (Cloud Radio Access Network, CRAN) scenario, or the network device can be a relay station, access point, vehicle equipment, wearable device and future The embodiment of the present application does not limit the network equipment in the 5G network or the network equipment in the future evolved PLMN network.

The technical solution provided by this application can be applied to an emergency call scenario. FIG. 1 shows a schematic diagram of an emergency call hangup. As shown in Figure 1, the terminal makes an emergency call in the current cell and establishes an emergency bearer with the current cell. After the emergency call is hung up, if the signal quality of the current cell or the priority of the current cell does not meet the service conditions, the terminal may The behavior of different system reselection or handover, when the terminal undergoes different system reselection or handover, if the target cell of reselection or handover does not have the condition to support the emergency bearer service capability, the emergency bearer will be released or cannot work normally. If the terminal needs to make an emergency call again, since there is no emergency bearer, the emergency bearer needs to be re-established. At the same time, the call back from the emergency call center cannot be received, and the location of the emergency call will also be affected. Emergency calls are closely related to personal safety. If emergency calls cannot be served normally, serious accidents will occur.

Therefore, in order to solve the above problems, this application provides a method for controlling emergency bearers. After the emergency call is hung up, and there are emergency bearers in the current cell, try to suppress the unnecessary behavior of different systems of the terminal and ensure the continuity of emergency bearers as much as possible. sex.

Fig. 2 is a schematic flowchart of a method for controlling emergency bearers provided by the present application. Through the method 200, the terminal can determine whether to perform a suppression operation, so as to suppress unnecessary behavior of the different system of the terminal. Referring to Fig. 2, the method may include S210 and S220, each step will be described below.

S210, the terminal determines the emergency bearer service capability of the target cell.

The method for the terminal to determine the emergency bearer service capability of the target cell includes: the terminal stores the historical cell information of the cell where it once resided, and there may be information about the emergency bearer service capability of the target cell in the historical cell message; the terminal receives the broadcast message sent by the target cell, The broadcast message may carry information about the emergency bearer service capability of the target cell.

S220, the terminal determines whether to perform a suppression operation.

The terminal determines whether to perform a suppression operation according to the emergency bearer service capability of the target cell. The suppression operation is used to suppress the behavior of the different system, and the behavior of the different system includes reselection or handover of the terminal from the current cell with the emergency bearer to the target cell. That is, the terminal may perform the suppression operation according to the emergency bearer service capability of the target cell, and may also be prohibited from performing the suppression operation.

It should be understood that, when the terminal hangs up the emergency call in the current cell, the terminal determines whether to perform the suppression operation according to the emergency bearing capacity of the target cell.

It should be understood that when the terminal hangs up the emergency call in the current cell, the emergency bearer still exists in the current cell.

It should be understood that when the terminal hangs up the emergency call in the current cell, the radio resource control RRC layer of the terminal can be in the idle state or in the connected state; when the RRC layer of the terminal releases the wireless link, the RRC is in the idle state, and the RRC layer of the terminal When the radio link is not released by the layer, RRC is in the connected state.

It should be understood that when the RRC layer of the terminal is in the idle state, the inter-system behavior of the terminal is reselection; when the RRC layer of the terminal is in the connected state, the inter-system behavior of the terminal is switching. Depending on the state of the RRC layer of the terminal, the different system behavior of the terminal is different, and the suppression operation is also different accordingly.

It should be understood that the emergency bearer in the current cell requires the terminal to establish an emergency bearer in the current cell, that is, the terminal determines whether to perform suppression before the method in this embodiment includes the terminal establishing an emergency bearer in the current cell, as shown in Figure 3-5. The relevant process of bearing is described in detail.

It should be understood that the establishment of the emergency bearer firstly requires the terminal to make an emergency call in the current cell. An emergency call means that when a user dials an emergency number (such as 110, 119, 120, etc.), the network side connects the call to the nearest emergency call center. Usually, the priority of emergency calls is higher than that of ordinary calls. Even if the user is not registered or in arrears, or is a terminal without a card, the network side should try to ensure that the emergency call is connected as much as possible. For LTE network voice services (Voice over LTE, VoLTE) and NR network voice services (Voice over NR, VoNR) emergency calls, users can establish dedicated bearers for emergency calls on LTE and NR networks, perform emergency registration, and initiate emergency calls. This scheme is called Internet Protocol Multimedia Subsystem IMS emergency call.

To better understand the IMS emergency call, Figure 3 shows the IMS emergency call architecture. As shown in Figure 3, the emergency call architecture includes proxy-call session control function (proxy-call session control function, P-CSCF), emergency call session control function (emergency call session control function, E-CSCF), emergency Access conversion function (emergency access transfer function, EATF), mobility management entity (mobility management entity, MME), media gateway control function (media gateway control function, MGCF), serving gateway (serving gateway, S-GW), PDN Gateway (PDN gateway, P-GW), policy and charging rules function (policy and charging rules function, PCRF), packet switched domain (packet switched, PS), service type session control function (serving-call session control function, S-CSCF), interrogating-call session control function (interrogating-call session control function, I-CSCF) and other network elements. Wherein, the P-CSCF identifies the emergency registration, routes the registration request to the S-CSCF in the home domain, identifies the emergency call, and routes the emergency call to the E-CSCF. The E-CSCF selects the nearest emergency call center according to the user's current location information. If the emergency call center is in the IMS domain, it will be routed to the I-CSCF. If it is in the circuit switched domain (circuit switched, CS), it will be routed to the MGCF. EATF performs session continuity service processing of emergency calls, provides session anchoring function and session switching function from LTE network to 2G/3G network. The MME encapsulates the locally configured emergency number list in the Attach Accept message, and sends it to the UE to select an emergency access point name (Access Point Name, APN) according to the emergency call identifier of the UE. The MGCF is responsible for routing to the emergency call center. S-GW is a single access point and acts as a proxy for multiple services. A service gateway enables transformation, routing, and common processing across all services. As a connection point, P-GW provides transmission between UE and Public Data Network (PDN). One UE can access multiple PDNs through multiple P-GWs at the same time. P-GW realizes the implementation of control strategies, Packet filtering, billing, lawful interception and packet filtering for users. Another key role of the P-GW is as an anchor point for mobility management between 3GPP and non-3GPP networks. PCRF is the framework defined in the 3GPP standard, and it is the fusion of PDF and CRF. It completes dynamic quality of service (Quality of service, QoS) policy control and dynamic flow-based charging control functions, and also provides authorization based on user subscription information. control function. The PS domain provides users with "packet data services".

It should be understood that emergency registration is first required for the terminal to implement an IMS emergency call. As described above, the P-CSCF identifies the emergency registration request and routes the emergency registration request to the S-CSCF in the home domain. Figure 4 shows a schematic diagram of the emergency registration process, as shown in Figure 4. 4, the steps in the emergency registration process are described below:

S410, the UE requests emergency registration.

The UE first reads the Universal Subscriber Identity Module (USIM) card information to obtain the International Mobile Subscriber Identity (IMSI), and then derives the Internet Protocol Multimedia Private Identity (IMPI) from the IMSI. ) and Internet Protocol Multimedia Public Identity (Temp-Internet Protocol Multimedia Public Identity, T-IMPU), UE sends a message to the IMS visited network entrance P-CSCF to request emergency registration. The uniform resource identifier (Uniform Resource Identifier, URI) parameter of the contact (Contact) header field in the request message carries the "sos" identifier, indicating emergency registration. This parameter also carries an emergency registration address, which is the address of the terminal allocated by the P-GW during the establishment of the emergency call default bearer.

The P-CSCF forwards the UE's request for emergency registration to the I-CSCF. P-CSCF queries the Domain Name Server (DNS) server according to the domain name in the Request-URI (Request-URI) (sip:ims.mnc101.mcc732.3gppnetwork.org) header field, and obtains the home domain network Ingress I-CSCF network element address, forwards a registration request (REGISTER) message to I-CSCF.

S420. The I-CSCF sends a User Authorization Request (UAR) message to the Internet Protocol multimedia subsystem-Home Subscriber Server (IMS-HSS).

After the I-CSCF receives the REGISTER message, the I-CSCF obtains the address or host name of the P-CSCF from the via (Via) header field, and checks whether the address or host name of the P-CSCF is in the trust domain or the local domain, and obtains the IMS- The Internet Protocol (IP) address of the HSS network element sends a UAR message to the IMS-HSS to request the address or capability set of the S-CSCF.

S430, the IMS-HSS returns a User Authorization Answer (UAA) message to the I-CSCF.

The IMS-HSS queries the local database information and determines that the user has opened an account, then returns a UAA message, and returns the address or capability set of the S-CSCF. The I-CSCF forwards the emergency registration request message to the S-CSCF according to the S-CSCF address returned by the integrated IMS-HSS.

S440. The S-CSCF sends a Multimedia Authentication Request (MAR) message to the IMS-HSS. Request to get the authentication vector (Authorization Vector, AV).

S450. The IMS-HSS returns a multimedia authentication answer (Multimedia Authentication Answer, MAA) to the S-CSCF.

S460, the S-CSCF returns a 401 response.

The S-CSCF saves the expected authentication response parameter Expected response (Expected response, XRES) for subsequent verification of the user's authentication response. The UE calculates the RES (Response) based on the shared key and random number (Random number, RAND), reconstructs the emergency registration request message, carries the RES, and sends it to the P-CSCF according to the path of the initial emergency registration request message, and the same steps will not be repeated. .

S470. The S-CSCF sends a Server Assignment Request (Server Assignment Request, SAR) message to the IMS-HSS. Request to download the user's subscription data.

S480. The IMS-HSS returns a server assignment response (Server Assignment Request, SAA) to the S-CSCF. Carry the user's subscription data.

S490, the S-CSCF returns a 200 OK response to the UE side, indicating that the initial registration is successful. The URI parameter of the Contact header field in the message carries the "sos" identifier, and only carries the address for emergency registration, not the address for normal registration.

It should be understood that part of the process of emergency registration is similar to ordinary user registration, and the only difference with ordinary user registration is that emergency registration will not trigger the access stratum (AS) layer.

Fig. 5 shows a schematic diagram of an emergency call flow, as shown in Fig. 5, and each step will be described below.

S501, UE sends an emergency session request. The UE initiates an emergency call session request on the emergency call APN. The Request-URI header field in the emergency session request message carries the emergency call number.

S502, the P-CSCF returns a call progress response 100 Trying to the UE. 100Trying indicates that the request message has been received and is being processed. The P-CSCF identifies the call as an emergency call according to the called number.

S503. The P-CSCF sends an Authentication Authorization Request (AAR) message to the policy and charging rules function (Policy and charging rules function, PCRF), requesting to establish a dedicated bearer for the emergency call.

S504, the PCRF sends a random access response (RACH response, RAR) message to the P-GW.

S505. The P-GW returns a re-authentication response (Re-Auth Answer, RAA) message to the PCRF, and then establishes a dedicated voice bearer for the emergency call.

S506. The PCRF returns a successful authentication authorization accounting (authentication authorization accounting, AAA) message to the P-CSCF, which carries the user location information returned by the PCRF. The P-CSCF identifies the call as an emergency call according to the called number, and then routes the call to the E-CSCF. According to the called number and UE location information, the E-CSCF searches the local routing table to determine the address of the emergency call center, and routes the emergency call to the appropriate emergency call center. The same steps will not be repeated.

S507, the emergency call between the UE and the PSAP is successfully established.

S508, the emergency call between the UE and the PSAP is hung up. The UE sends a BYE message to the PSAP to end the session.

S509. The P-CSCF sends a string (String, STR) message to the PCRF to release the bearer session.

After receiving the STR message, the PCRF deletes the relevant flow information, and sends a RAR instruction to the P-GW to delete the dedicated bearer. After receiving the RAR, the P-GW deletes the dedicated bearer and returns the RAA message to the Unified Policy and Accounting Control System (Unified Policy and Charging Controller, UPCC). UPCC receives the RAA response and returns a session termination answer (STA) response message. The process of deleting the dedicated bearer of the voice stream is completed. The PSAP returns a BYE message, and the subsequent steps repeat S504, S505, S507 and S508, and the same steps will not be repeated.

It should be understood that after the terminal initiates an emergency call session request, an emergency bearer is established, and after the call ends, the network actively releases the bearer session, and the emergency bearer is released.

It should be understood that it is stipulated in the 3GPP protocol that the UE cannot actively cancel its emergency public user identity. This is because IMS emergency calls are closely related to personal safety. In order to ensure that emergency calls and their accompanying functions can continue correctly, the emergency bearer is actively released by the network, and the UE is not allowed to actively log out of emergency services under normal circumstances. Only after the emergency registration times out, the UE's emergency registration will be canceled in time. When the emergency bearer exists, the network can use the emergency bearer to perform emergency Call Back and locate the emergency call. If the UE needs to initiate an emergency call again in a short period of time, it does not need to rebuild the emergency bearer.

The 3GPP protocol describes whether the current base station and the corresponding core network support the emergency bearer: provide an IMS emergency call support indication to notify the UE of supporting the emergency bearer service. In the normal service state, the UE is notified whether its PLMN supports the emergency service through the emergency service support indicator in the attach (Attach) and tracking area update (Tracking area update, TAU) process. In the restricted service state, for emergency services other than the emergency call (Emergency call, eCall) on the IMS, the UE learns from the broadcast indication (ims-Emergency Support) whether the cell supports the emergency service on the NG-RAN. The broadcast indicator is set to "supported" if any access and mobility management function (AMF) in a non-shared environment or at least one PLMN in a shared environment supports the IMS emergency bearer service. Among them, the restricted state pointed out in the agreement refers to the scenarios where PS services cannot be provided, such as arrears, no card and other scenarios. According to the ims-EmergencySupport flag carried in the System Information Block Type 1 (System Information Block Type1, SIB1) message, Determine whether to support restricted state emergency calls. In the normal service state, it is necessary to judge whether the currently camped base station supports emergency bearer services according to the emergency bearer services indicator (Emergency bearer services indicator) field in the ATTACH and TAU.

Fig. 6 is a schematic flowchart of a method for controlling emergency bearers according to another embodiment of the present application. Through the method 600, the terminal can determine the emergency bearer service capability of the target cell according to the historical cell information, so as to suppress unnecessary behavior of the terminal in different systems. Referring to FIG. 6 , the method may include S610 , S620 , S630 and S640 and each step will be described below.

It should be understood that, for example, the method 600 is a schematic flow of a method for controlling an emergency bearer when the terminal is in an RRC layer connected state.

S610, the terminal judges whether the historical cell information records the emergency bearing capacity of the target cell.

It should be understood that the historical cell information includes the emergency bearer service capability of the cell where the terminal has camped and the ID of the cell where the terminal has camped. When the historical cell information does not record the emergency bearer service capability of the target cell, it means that the terminal has never camped in the target cell, that is to say, the emergency bearer service capability of the terminal is unknown at this time, and the target cell may support The emergency bearer service may also not support the emergency bearer service, and the target cell may not support the emergency bearer service. When the historical cell information records the emergency bearer service capability of the target cell, the terminal needs to further determine whether the target cell recorded in the historical cell information supports the emergency bearer service.

It should be understood that whether the historical cell records the emergency bearer service capability of the target cell includes the emergency bearer service capability in the normal service state. In the normal service state, it is necessary to judge whether the currently camped base station supports the emergency bearer service according to the Emergency bearer services indicator field in Attach and TAU. The following is a detailed description of the Attach and TAU processes in the 3GPP protocol:

In the LTE system, the location of the terminal is located in the tracking area (Tracking Area, TA), and the location update of the terminal is called TAU. Simply put, after the terminal changes its TA, it needs to inform the network of its new TA through the TAU process. The UE may initiate a TAU process in an idle (IDLE) or connected (CONNECTED) state, and TAU includes regular TAU and periodic TAU. The purpose of the conventional TAU process is to notify the network of the registration tracking area information of the UE and the bearer status of the evolved packet system (EPS), and the network synchronizes local parameters according to the reported TA information and EPS bearer status, and decides whether to allocate a new location area Identification list (TAI LIST). The periodic TAU is controlled by the T3412 protocol timer. When the UE enters the IDLE state from the CONNECTED state, the T3412 timer is started. The duration of the timer is configurable through the MME and is carried in the Attach Accept (ATTACH ACCEPT) or Tracking Area Update Accept (TAU ACCEPT) message. The purpose of the periodic TAU is that the UE periodically informs the MME that the UE is still in the tracking area list (TA LIST) and hopes to continue to receive services. Otherwise, after a period of time (reachable timer, four minutes greater than T3412), if the MME does not receive the The periodic TAU message of the UE considers that the UE has left the TA LIST, or the UE is abnormally shut down, etc., thereby releasing the relevant resources occupied by the UE. The scenarios where TAU occurs mainly include:

1. The TA changes in the registration state (after reselection or switching, the new TA is not in the original TAI LIST);

2. Periodic TAU timer T3412 expires;

3. After the coverage area is lost in the registration state, the UE's local EPS bearer is deactivated and re-enters the coverage area;

4. When UE network capability parameters or discontinuous reception (Discontinuous Transmission, DRX) parameters change;

5. Different system reselection occurs, and user plane data is not cached;

6. The reason for the release of the RRC connection is: the TAU process needs to be loaded.

Figure 7 and Figure 8 show the TAU process in IDLE state and CONNECTED state respectively, and Figure 9 shows the process of Attach, detailed steps can be found in Figure 7, Figure 8 and Figure 9.

S620. The terminal suppresses reporting of the B1 measurement report.

It should be understood that when the terminal judges that the historical cell information does not record the emergency bearer service capability of the target cell, the terminal does not know the emergency bearer service capability of the target cell. The cell does not support the emergency bearer service, and the terminal cannot re-establish the emergency bearer in the target cell or the emergency bearer cannot be continued normally, so that the terminal cannot realize the emergency call and the incidental functions related to the emergency call.

It should be understood that the B1 event is an event in which the signal quality of a neighboring cell of a different system becomes higher than a corresponding threshold, and the entry condition and exit condition of the B1 event are different depending on whether the current cell is in NR or LTE. After receiving the measurement configuration information, the terminal performs measurement according to the instructions and meets the reporting conditions. The terminal will report the measurement report, and the measurement report reported first will first execute the target cell judgment. The RSRP information of the target cell mainly exists in the measurement report, and the terminal can ensure the continuity of the emergency bearer by suppressing the suppression operation reported in the measurement report.

S630, the terminal judges whether the target cell supports the emergency bearer service.

It should be understood that after the emergency bearer service capability of the target cell is recorded in the historical cell information, the terminal needs to further determine whether the target cell supports the emergency bearer service according to the recorded historical cell information.

It should be understood that when the historical cell information records that the target cell does not support the emergency bearer service, the terminal executes step S620, that is, the terminal suppresses the reporting of the B1 measurement report; when the historical cell information records that the target cell supports the emergency bearer service, even if the terminal has a different system behavior , and the continuity of the emergency bearer will not be destroyed, and the terminal does not need to perform suppression operations at this time.

S640. The terminal prohibits execution of the suppression operation.

It should be understood that when the historical cell information records that the target cell supports the emergency bearer service, the terminal is prohibited from performing suppression operations. At this time, the terminal includes but is not limited to prohibiting the reporting of the B1 measurement report.

It should be understood that when the RRC layer of the terminal is in the connected state, service movement between systems in the connected state includes handover. The prohibition of the terminal from performing the suppression operation means that the terminal does not suppress the inter-system handover process when the RRC layer of the terminal is in the connected state. To further understand the handover process, FIG. 10 shows the basic flow of handover, and FIG. 11 shows the handover strategy flow from evolved universal terrestrial radio access network (evolved universal terrestrial radio access network, E-UTRAN) to NR and NR to E-UTRAN , the detailed steps can be seen in the specific description of Fig. 10 and Fig. 11 .

It should be understood that based on the basic handover process, it further involves service mobility between E-UTRAN and coverage-based NG radio access network (NG Radio Access Network, NG-RAN) systems and coverage-based NG-RAN to E-UTRAN Inter-system service mobility. Exemplarily, the method for controlling emergency bearer in this application may include service mobility between E-UTRAN and NG-RAN systems. Among them, service mobility between coverage-based E-UTRAN and NG-RAN systems, that is, the function of coverage-based E-UTRAN redirection to NG-RAN is relatively basic in terms of measurement control delivery, target cell or target frequency point judgment , There are differences in the switching execution phase. Among them, the evolved Node B (Evolved Node B, eNodeB) will generate a list of target cells or target frequency points according to the reported B1 event measurement report, which will carry the RSRP value of the cell, and select the cell with the best signal quality according to the RSRP to perform redirection. At this time, handover execution only supports E-UTRAN to NR redirection. FIG. 12 shows the process of delivering measurement control events, and detailed steps can be found in the specific description of FIG. 12 . Figure 13 shows the flow of redirection from E-UTRAN to NG-RAN, detailed steps can be seen in the specific description of Figure 13 .

It should be understood that the above-mentioned another coverage-based NG-RAN to E-UTRAN intersystem service mobility, that is, the function of coverage-based NG-RAN handover to E-UTRAN, compared with the basic Or there is a difference in the stage of determining the target frequency point. The next-generation base station (generation Node B, gNodeB) will generate a list of target cells or target frequency points according to the reported B1/B2 event (controlled by the parameter NRInterRatHoParam.InterRatHoTriggerEventType) measurement report, and select the cell with the best signal quality to perform redirection. Fig. 14 shows the process of switching from NG-RAN to E-UTRAN, and the detailed steps can be seen in the specific description of Fig. 14 .

In this embodiment, when it comes to judging the emergency bearer service capability in the normal service state of the target cell, it needs to be judged through the Attach and TAU processes. As shown in FIG. 7, the detailed steps of the TAU process in the idle state are as follows:

S710, UE network attached storage (Network Attached Storage, NAS) triggers RRC to initiate an access procedure.

S720, the MME receives the tracking area update request (TAU Request, TAU REQ) of the UE. The public procedure may be triggered after the MME receives the TAU request message.

S730, the MME sends a TAU acceptance message.

S740, if the Globally Unique Temporary UE Identity (GUTI) information element is included in the TAU Accept message, the UE will send a Tracking Area Update Complete (TAU COMPLETE) message to the MME; if the TAU is not due to handover trigger or TAU When there is no need to recreate the bearer for the activated Evolved packet system (EPS) bearer during the process, after the TAU is completed, the MME will release the signaling connection with the UE.

As shown in Figure 8, the TAU process in the connected state, the TAU process in the connected state is different from the TAU process in the idle state in the following ways:

S810, the MME receives the TAU request. The TAU request is sent to the MME through an uplink direct transmission message.

If the user wants to obtain the service he wants from the network side, he can only receive the service from the network after the successful attachment. Through the initial attachment process of Evolved Packet Core (EPC), end users can complete a series of processes such as registration to the 4G network, EPS initial bearer establishment, etc. The attach process can occur in the following scenarios:

1. 4G users who have just opened an account turn on the phone for the first time within the coverage area of LTE;

2.4G users turn off and on again. It may be connected to 2G/3G network before shutting down;

3. Switch from Non-3Gpp network to 3Gpp network.

Other steps will not be described in detail. It should be understood that the RRC layer of the terminal in this embodiment is in the connected state, so the corresponding TAU flow should be the TAU flow in the connected state shown in FIG. 8 .

As shown in Figure 9, the detailed steps of the Attach process are as follows:

S901. The UE sends an Attach registration request. The UE initiates an attach request (Attach request). The Attach Request message is encapsulated in the RRC Connect message and sent to the eNB together.

S902, the MME sends an authentication request.

S903, the MME receives the returned authentication request. The ME can query the IP address of the old mobility management entity (old MME) at the DNS according to the mobility management entity identity (MME Identity, MMEI) part of the old globally unique temporary UE identity (old GUTI), and then Obtain the UE's International Mobile Subscriber Identification (IMSI) from the old MME. But sometimes the old mobility management entity has deleted the UE data (eg. the UE has been out of contact for too long), and the MME cannot obtain the IMSI information from the old mobility management entity.

S904, the MME sends an ID request.

S905, the MME receives the ID return message fed back by the UE.

S906, the UE sends an encryption option request. If the ciphered options transfer flag carried in the Attach registration message in step 1 is set, the ciphered options request must be completed.

S907, the MME sends a deletion request. If there are UE active bearer contexts in the new MME, the new MME deletes these contexts.

S908, the MME sends an update request.

S909, the HSS sends a cancel location message.

S910, the HSS receives a session deletion request.

S911, the HSS returns an update message. The HSS completes the location registration of the user, and the HSS returns an update unknown response (update location answer) message for confirmation.

S912, the MME requests to establish a default bearer. The MME sends a message to the selected SGW, requesting to establish a default bearer.

S913, the S-GW sends a conference establishment message. According to the P-GW address provided by the MME, the S-GW sends a create session request (create session request) message to the PGW, requesting to establish a default bearer.

S914, the P-GW and the PCRF establish a default bearer rule. The PCRF can formulate corresponding EPS rules for establishing the EPS default bearer according to the local policy database and some external auxiliary databases. Return a control credit answer (control credit answer) message to the PGW.

S915, the P-GW returns a conference establishment request message. So far, the core network part of EPS default bearer has been established.

S916, the MME sends an Attach acceptance message. The MME sends an attach accept message to the eNB, and requests the eNB to allocate radio resources to establish a radio access bearer (Evolved radio access bearer, ERAB). The initial context setup request (initial context setup request) message includes the ERAB bearer list that needs to be established, parameters such as QoS required for establishing the ERAB.

S917, RRC connection reconfiguration. The eNB sends an RRC connection reconfiguration message to the UE, which includes transparently transmitted attach accept and other messages, and allocates resources to establish an air interface bearer. The UE replies the RRC connection reconfiguration completion message to the eNB. At this time, the RRC connection is completed and confirmed. According to the understanding of the state, the UE state has changed from the idle state to the connected state.

S918, the eNB sends a setup reply message. The eNB returns an initial context setup response message to the MME.

S919, the Attach is completed. The UE sends an Attach completion message, encapsulates it into an air interface direct transmission message, and sends it to the eNB.

S920, the MME sends a bearer modification request. The MME sends a modify bearer request message to the S-GW.

S921, the MME receives a bearer modification request response. The S-GW replies a bearer modification response message to the MME.

S922, the MME sends a modification request. After the MME receives the bearer update response message, if the bearer is established and the subscription data shows that the user can switch to a non-3GPP network, if the MME selects a P-GW different from the PDN subscription context specified in the subscription data in the HSS, then the MME will The APN should be sent to the HSS together with the P-GW ID (to prepare for handover and movement between non-3GPP).

S923, the MME receives a modification request response.

In this embodiment, the RRC layer of the terminal is in the connected state, so the behavior of different systems is specifically shown as switching, as shown in Figure 10, which is the basic switching process, and the detailed steps are as follows:

S1001. Switching function start judgment. For different handover functions, the conditions for whether the UE needs to initiate handover in the current serving cell are completely different, mainly including: switching of the handover function, whether adjacent frequency points are configured, signal quality of the serving cell, and signal quality of adjacent cells.

S1002, processing mode selection. According to whether to measure neighboring cells before the handover, the handover processing mode can be divided into a measurement mode and a blind mode.

S1003, switching the measurement mode. The measurement mode is the process of measuring the signal quality of candidate target cells and generating a list of target cells according to the measurement report.

S1004, blind mode switching. The blind mode is a process of directly generating a list of target cells or target frequency points according to the configuration of relevant priority parameters without measuring the signal quality of candidate target cells. When this method is adopted, the UE has a high risk of access failure in the neighboring cell, so it is generally not used, and it is only used when a handover must be initiated as soon as possible.

S1005, delivering measurement control. After the UE establishes a radio bearer, the eNodeB/gNodeB will send measurement configuration information to the UE through RRC Connection Reconfiguration/RRC Reconfiguration respectively according to the configuration of the handover function. After the UE is in the connected state or completes the handover, if the measurement configuration information is updated, the eNodeB/gNodeB will send the updated measurement configuration information through the RRC Connection Reconfiguration/RRC Reconfiguration message.

The measurement object of the measurement task is mainly composed of attributes such as measurement system, measurement frequency point, or measurement cell. Instruct the UE on which cells or frequency points to measure the signal quality. The report configuration of the measurement task mainly includes the measurement event information, the trigger quantity and reporting quantity of event reporting, and other information of the measurement report. Instruct the UE under what conditions to report the measurement report, and according to what standard to report the measurement report. In addition, the measurement task also includes other configurations, such as measuring GAP, measuring filtering, and so on. Measurement events include A1, A2, B1, B2. For different switching functions, the specific measurement events used are different. Table 1 shows the definitions of measurement events. The trigger volume of eNB/gNB in SRAN15.1 only supports RSRP. For eNB, if the parameter InterRatHoComm.InterRatHoA1A2TrigQuan is configured as Reference Signal Received Quality (RSRQ) or, RSRP and RSRQ, RSRP-based inter-system measurement is still issued at this time.

Table 1 Definition of measurement events

The specific meanings of the relevant scalars in the conditional formulas in the above table are: Ms and Mn respectively represent the measurement results of the serving cell and neighboring cells; Hys represents the amplitude hysteresis of the measurement results; , Thresh1, and Thresh2 represent the threshold values; Ofs and Ofn represent the frequency offsets of the serving cell and the neighboring cell, respectively; Ocn represent the cell-specific offset CIO (Cell Individual Offset) of the E-UTRAN neighboring cell, respectively.

Events A1 and A2 are used in the judgment stage of starting the handover function to measure the signal quality of the serving cell. Events B1 and B2 are used in the judgment phase of the target cell or target frequency to measure the signal quality of neighboring cells. The measurement control delivery and measurement reporting mechanisms of each event (A1, A2, B1, B2) are the same.

S1006, reporting the measurement report. After receiving the measurement configuration information delivered by the eNB/gNB, the UE performs measurement according to the instructions. When the reporting conditions are met, the UE reports the measurement report to the eNB/gNB.

S1007. Determine the target cell or target frequency point. The target cell or target frequency point judgment is controlled and executed by eNB/gNB. Each handover function mainly refers to information such as handover mode, measurement report, and handover strategy to evaluate and make decisions on candidate cells or frequency points. It mainly includes the following aspects: the processing of the measurement report, which is only involved in the switching of the measurement mode; the determination of the switching strategy; the generation of the target cell or target frequency point list.

The eNB/gNB processes the measurement report according to the first-in-first-out method, that is, the measurement report reported first executes the target cell judgment first.

The handover strategy refers to the procedure in which the eNB/gNB changes the UE from the current serving cell to a new serving cell. The basic handover strategy involved is defined as follows: handover is to change the service from the PS domain of the original serving cell to the PS domain of the target cell , the process of ensuring service continuity; redirection is the process in which the eNB/gNB directly releases the UE and instructs the UE to select a cell to access at a certain frequency point.

The target cell or the target frequency point filters out the cells whose PLMN is not in the PLMN list in the neighbor cell list, and filters out the relevant cells that are prohibited by the cell handover restriction list/movement restriction list indicated in the context establishment request message sent by the MME/AMF, so as to generate the target cell or target frequency point list.

S1008, switching execution.

This embodiment mainly involves the service flow between E-UTRAN and NG-RAN systems. As shown in FIG. 11, the detailed steps of the handover strategy process from E-UTRAN to NR and from NR to E-UTRAN are as follows:

S1110, inter-system mobility management.

S1120, processing mode selection, can select measurement mode or blind mode.

S1130, after the measurement mode is selected, it is necessary to further determine whether the switching condition is met.

S1140. Perform switching when the switching condition is met; perform redirection when the switching condition is not satisfied.

S1150. After the blind mode is selected, directly perform blind redirection.

It should be understood that in the handover process of service mobility between coverage-based E-UTRAN to NR-RAN systems, there are differences between the measurement control delivery steps and the basic functions. As shown in Figure 12, in the handover process, the measurement control time delivery Schematic diagram of the process, the detailed process is as follows:

S1201. Determine whether the sub-switch "ReduceInvalidA1A2RptSigSwitch" in eNodeBAlgoSwitch.HoSignalingOptSwitch is turned on.

When the value of InterRatHoA1A2TringQuan is RSRP, RSRQ or BOTH, it is further judged whether the sub-switch is turned on, and the delivery sequence of event A1 relative to event A2 in the coverage-based inter-system handover can be controlled by the sub-switch "ReduceInvalidA1A2RptSigSwitch" in eNodeBAlgoSwitch.HoSignalingOptSwitch . If the switch is turned on, when the UE establishes a connection, the eNB first sends event A2, and after receiving the report of event A2, it sends event A1 to reduce invalid event A1 reports; if the switch is turned off, when the UE establishes a connection, the eNB Send event A2 and event A1 at the same time.

S1202, when the sub-switch is not turned on, simultaneously execute the event measurement control of the different system A1A2 based on RSRP.

S1203, receiving an A2 event measurement report.

S1204, the value of InterRatHoEventType is B1 or B2.

S1205, only start the different system B1 event measurement.

S1206. Receive the different system A1 event measurement report.

S1207, stop the different system B1 measurement.

S1208, when the sub-switch is turned on, only deliver the RSRP-based A2 event measurement control of the different system.

S1209, receiving the A2 event measurement report.

S1210, the value of InterRatHoEventType is B1 or B2.

S1211, only start the different system B1 event measurement.

S1212, delivering the measurement control of the different system A1 event.

S1213, receiving the different system A1 event measurement report.

S1214, stop the different system B1 measurement.

When the UE receives the different system A2 event measurement report, the coverage-based measurement mode switching function starts, and if it receives the different system A1 event measurement report during the measurement process, the function stops.

Exemplarily, as shown in Figure 13, the process of redirecting E-UTRAN to NR-RAN, the detailed steps are stated as follows:

S1301. The UE sends an RRC connection request. The UE initiates an RRC connection request (RRC Connection Request).

S1302, the eNB initiates RRC connection establishment. The eNB initiates RRC connection setup.

S1303, the UE replies that the RRC connection is established.

S1304, the eNB sends an initial UE message. The eNB sends an initial context establishment request message to the EPC.

S1305. The EPC sends an initial context establishment request message. The EPC sends an initial context establishment request message to the eNB, and the eNB establishes the UE context after receiving the message.

S1306, the eNB sends a security mode command.

S1307, the UE replies that the security mode command is completed.

S1308, the eNB initiates a UE capability query.

S1309, the UE reports its own NR capability.

S1310, the eNB initiates RRC connection reconfiguration. The eNB initiates RRC Connection Reconfiguration (RRC Connection Reconfiguration) to establish SRB2.

S1311, the UE replies with an RRC connection reconfiguration message.

S1312, the eNB replies to the EPC. The UE context is established.

If it is satisfied: UE carries the SupportedBandList NR-SA cell; when the service mobility switch and NR redirection switch between E-UTRAN and NG-RAN systems are turned on at the same time, the eNB actively queries the UE NR capability, and the subsequent process is as in S1308 and S1309. I won't repeat them here. If the above conditions are not met, this process ends. S1313, the eNB delivers the A2 event measurement configuration.

The UE replies with the RRC connection reconfiguration message, as described in S1311, which will not be repeated here.

S1314, the UE reports an A2 time measurement report.

S1315, the eNB issues B1 event measurement. The eNB receives the A2 event measurement report, sends the A1 event measurement and sends the different system B1 event measurement according to the NR frequency point priority from high to low.

The UE replies with the RRC connection reconfiguration message, as described in S1311, which will not be repeated here.

S1316, the UE reports a B1 or A1 event. If the UE reports the B1 event measurement report, go to the next step. If the UE reports the A1 event measurement report, it means that the signal of the serving cell is good, and inter-system redirection does not need to be triggered. The eNB deletes the A1/B1 event measurement, the UE continues to perform the A2 event measurement, and the UE replies that the RRC connection reconfiguration is complete.

S1317, the eNB makes a redirection decision.

S1318, the eNB sends an RRC connection release message. According to the redirection decision, the eNB sends an RRC connection release message to the UE, carrying the frequency point information of the target NG-RAN cell.

S1319, the UE performs random access. The UE performs random access to the target NG-RAN cell according to information such as the target frequency point.

S1320, the UE receives a random access response.

Exemplarily, as shown in Figure 14, it is a flow chart of coverage-based NR handover to E-UTRAN, and the detailed process is stated as follows:

S1401. The UE sends an RRC connection request.

S1402, the gNB initiates RRC connection establishment. gNB initiates RRC Setup to establish SRB1.

S1403, the UE replies that the establishment of the RRC connection is completed.

S1404, the gNB sends an initial UE message. The gNB transparently transmits through the initial UE message.

S1405. The 5G core network (5G Core Network, 5GC) sends an initial context establishment request. 5GC initiates an initial context establishment request to gNB.

S1406, the gNB sends a security mode command. The gNB initiates a security mode command at the AS layer.

S1407, the UE replies that the security mode command is completed.

S1408, the gNB sends a UE capability query.

S1409, the UE reports its own NR capability.

S1410, the gNB sends an RRC connection reconfiguration message. The gNB initiates RRC connection reconfiguration to establish SRB2.

S1411. The UE replies with a connection reconfiguration message. The reconfiguration is complete.

S1412, the gNB sends a context establishment complete message. The gNB replies to the 5GC that the UE context is established.

S1413, the gNB issues A2 event measurement control.

S1414, the UE replies that the measurement control is completed.

S1415, the UE reports the A2 event measurement report.

S1416, the gNB issues B1 or B2 event measurement. The gNB receives the A2 event measurement report, sends the different system A1 event measurement, and sends the different system B1 or B2 event measurement according to the trigger event type of the different system handover.

S1417, the UE reports the B1 or B2 event measurement.

S1418, the gNB sends a handover request. After receiving the B1 or B2 event measurement report, the gNB generates a target cell list based on the cell signal quality reported in the measurement report, selects the cell with the best signal quality as the target E-UTRAN cell, and sends a handover request to the 5GC.

S1419 The target E-UTRAN cell completes the handover preparation process.

S1420, the 5GC notifies handover preparation.

5GC notifies gNB to complete the handover preparation,

S1421, the gNB sends handover control. S1422, the eNB notifies the EPC that the handover is completed.

S1423, the EPC notifies the 5GC that the data forwarding tunnel has been established.

S1424, the gNB receives the UE context release message, and releases the UE context.

S1425, the 5GC feeds back to the EPC that data forwarding has been completed.

Fig. 15 is a schematic flowchart of a method for controlling emergency bearers according to another embodiment of the present application. Through the method 1500, when the RRC layer of the terminal is in an idle state, the terminal can determine the emergency bearer service capability of the target cell according to the historical cell information, so as to suppress unnecessary inter-system behavior of the terminal. Referring to Fig. 15, the method may include S1510, S1520, S1530 and S1540, each step will be described below.

It should be understood that, for example, the method 1500 is a schematic flow of a method for controlling emergency bearer when the RRC layer of the terminal is idle, and when the RRC layer of the terminal is idle, the different system behavior of the terminal is reselection.

S1510, the terminal judges whether the historical cell information records the emergency bearer service capability of the target cell.

It should be understood that the method for the terminal to determine whether the historical cell information records the emergency bearer service capability of the target cell in S1510 is the same as that in S610 above, and will not be repeated here.

S1520. The terminal sets the current cell priority as the highest priority.

It should be understood that when the terminal judges that the emergency bearer service capability of the target cell is not recorded in the historical cell information, the terminal does not know the emergency bearer service capability of the target cell, and the target cell may or may not support the emergency bearer service. The target cell is at risk of not supporting emergency bearer services. In order to prevent the terminal from reselecting to a target cell that does not support the emergency bearer service in a different system, the terminal performs a suppression operation. Exemplarily, the suppression operation performed by the terminal includes setting the current cell priority as the highest priority. That is, the terminal compares the priority of the current cell with the target cell, and when the priority of the current cell is set to the highest priority by default, the priority of the target cell is lower than the priority of the current cell, and it is guaranteed to use the high priority cell reselection According to the rules, only when the signal quality of the current cell does not meet the service conditions, it will reselect to the target cell.

S1530, the terminal judges whether the target cell supports the emergency bearer service.

It should be understood that when the terminal determines that the historical cell information records the emergency bearer service capability of the target cell, the terminal needs to further determine whether the target cell supports the emergency bearer service. When the target cell does not support the emergency bearer service, the terminal performs a suppression operation. For example, the terminal sets the priority of the current cell as the highest priority. The re-election behavior ensures the continuity of emergency bearers. When the target cell supports the emergency bearer service, the continuity of the emergency bearer will not be destroyed even if the terminal reselects to the target cell from a different system.

S1540, the terminal prohibits execution of the suppression operation.

It should be understood that when the target cell supports the emergency bearer service, the terminal is prohibited from performing the suppression operation. Exemplarily, the terminal is prohibited from setting the current cell as the highest priority. At this time, the terminal may reselect from another system. According to the current 3GPP scheme, the behavior of inter-system reselection or handover is only related to the cell priority and the measurement behavior of the RRC layer of the terminal, and has nothing to do with the state of the emergency bearer.

It should be understood that after the terminal selects a PLMN, it will select a cell in the PLMN to camp on. After camping in the cell, the terminal monitors system messages and measures the current cell and neighboring cells according to neighboring cell measurement rules and cell reselection rules to select a cell with better signal quality to camp on.

Exemplarily, FIG. 16 shows the reselection process from E-UTRAN to NG-RAN, and the detailed steps are as follows:

S1610, the eNB sends a system broadcast message. The UE reads system broadcast messages in an idle state. The cell reselection rules of the system broadcast message include: service frequency low priority reselection threshold, reselection timer duration, high priority reselection threshold of adjacent cell frequencies, low priority reselection of adjacent cell frequencies Threshold, priority of neighboring cells, minimum access level of serving cell, maximum allowable transmit power of UE, etc.

S1620, a cell reselection registration process. The UE performs cell reselection according to the high and low priority reselection rules. If the priority of the adjacent frequency point is higher than that of the serving cell, the cell of the adjacent frequency point will be measured all the time. When the high priority cell reselection rule is met, the high priority adjacent cell is reselected: E-UTRAN frequency point The priority is configured via CellResel.CellReselPriority. The NR adjacent frequency priority on E-UTRAN is configured through the parameter NrNFreq.NrFreqReselPriority. If the priority of adjacent frequency points is lower than that of the serving cell, and the level value Srxlev calculated during the reselection process of the serving cell is less than or equal to the start measurement threshold S _{nonIntraSearchP} of inter-frequency or inter-system cells, the low priority is enabled cell frequency point measurement. When the low priority cell reselection rules are met, reselect to a low priority neighboring cell.

The high-priority cell reselection rules are as follows: For the E-UTRAN system, when the following conditions are met at the same time, the high-priority NG-RAN cell will be selected for cell reselection.

1. The UE stays in the current serving cell for more than 1s.

2. During the NR neighbor cell reselection time broadcast by the eNB in SIB24 (configured by CellReselToNr.NrCellReselectionTimer), the Srxlev of the evaluated neighbor cell is continuously greater than the threshX-High-r15 broadcast in SIB24 (configured by the parameter NrNFreq.NrFreqHighPriReselThld).

The low-priority cell reselection rules are as follows: For the E-UTRAN system, when the following conditions are met at the same time, the cell reselection will select a low-priority NG-RAN cell.

1. The conditions for high-priority cell reselection are not met.

2. The UE stays in the current serving cell for more than 1s.

3. During the inter-system neighbor reselection time broadcast by the eNB in SIB24 (configured by CellReselToNr.NrCellReselectionTimer), the Srxlev value of the serving cell is continuously smaller than the serving cell reselection threshold (threshServingLow) broadcast in SIB3 (configured by the parameter CellResel.ThrshServLow ), and the Srxlev of the evaluated neighboring cell is continuously greater than the NR frequency point low priority reselection threshold threshX-Low-r15 broadcast in SIB24 (configured through the parameter NrNFreq.NrFreqLowPriReselThld.).

Exemplarily, FIG. 17 shows the reselection process from NG-RAN to E-UTRAN, and the detailed steps are as follows:

S1710, the gNB sends a system broadcast message. The UE reads system broadcast messages in an idle state. The cell reselection rules of the system broadcast message include: service frequency low priority reselection threshold, reselection timer duration, high priority reselection threshold of adjacent cell frequencies, low priority reselection of adjacent cell frequencies Threshold, priority of neighboring cells, minimum access level of serving cell, maximum allowable transmit power of UE, etc.

S1710, TAU process. As detailed in the TAU process above.

If the priority of the adjacent frequency point is higher than that of the serving cell, the cell of the adjacent frequency point will be measured all the time. When the high priority cell reselection rule is met, the high priority adjacent cell is reselected: NG-RAN frequency point The priority is configured through NRCellReselConfig.CellReselPriority; the priority of adjacent frequency points from NG-RAN to E-UTRAN is configured through NRCellEutranNFreq.EutranFreqReselPriority.

If the priority of the adjacent frequency points is lower than that of the serving cell, and the Srxlev of the serving cell is less than or equal to S _{nonIntraSearchP} , the low priority cell frequency point measurement is enabled. When the low priority cell reselection rules are met, reselect to a low priority neighboring cell.

The high-priority reselection rules are as follows: For NG-RAN systems, when the following conditions are met at the same time, the cell reselection will select a high-priority E-UTRAN cell.

1. The UE stays in the current serving cell for more than 1s.

2. During the E-UTRAN neighbor cell reselection time broadcast by gNB in SIB5 (configured by NRCellReselConfig.EutranCellReselTimer), the Srxlev of the evaluated neighbor cell is continuously greater than the reselection to high priority frequency point threshold broadcast in SIB5 (threshX-High ) (configured by the parameter NRCellEutranNFreq.EutranFreqHighPriReselThld).

The low priority reselection rules are as follows:

For the NG-RAN system, when the following conditions are met, the cell reselection will select a low-priority E-UTRAN cell.

1. The conditions for high-priority cell reselection are not met.

2. The UE stays in the current serving cell for more than 1s.

3. During the E-UTRAN neighbor cell reselection time broadcast by gNB in SIB5 (configured by NRCellReselConfig.EutranCellReselTimer), the Srxlev of the serving cell is continuously smaller than the threshServingLowP broadcast in SIB2 (configured by the parameter NRCellReselConfig.ServFreqLowPriRsrpReselThd), and the neighbor cell is evaluated Srxlev is continuously greater than the threshX-Low broadcast in SIB5 (configured through the parameter NRCellEutranNFreq.EutranFreqLowPriReselThld).

Fig. 18 is a schematic flowchart of a method for controlling emergency bearers according to another embodiment of the present application. Through the method 1800, when the RRC layer of the terminal is in an idle state, the terminal can determine the emergency bearer service capability of the target cell according to the historical cell information, so as to suppress unnecessary behavior of the terminal in different systems. Referring to FIG. 18, the method may include S1810, S1820, S1830, and S1840, and each step will be described below.

It should be understood that, for example, the method 1800 is a schematic flow of a method for controlling emergency bearer when the RRC layer of the terminal is idle, and when the RRC layer of the terminal is idle, the different system behavior of the terminal is reselection.

S1810, the terminal judges whether the historical cell information records the emergency bearer service capability of the target cell.

It should be understood that the method of S1810 for the terminal to determine whether the historical cell information records the emergency bearer service capability of the target cell is the same as that of S610 above, and will not be repeated here.

S1820. The terminal modifies the resident standard.

It should be understood that when the terminal judges that the historical cell information does not record the emergency bearer service capability of the target cell, there is a risk that the target cell does not support the emergency bearer service, and the terminal performs a suppression operation at this time. Exemplarily, the modification of the camping standard by the terminal includes that the terminal lowers the camping standard of the current cell or increases the camping standard of the target cell. The terminal can modify threshServingLow in the SIB3 broadcast of the current cell, thereby lowering the residence standard of the current cell; or increase the high-priority cell reselection threshold of the target cell, such as threshX-High-r15 broadcast in the SIB24 of the target cell, thereby The difficulty of reselecting to the target cell is increased, that is, the residence standard of the target cell is improved.

It should be understood that the purpose of the terminal to lower the residence standard of the current cell or increase the residence standard of the target cell is to increase the difficulty of reselection of the terminal from different systems, to minimize the difficulty of reselection of the terminal to the target cell from different systems, and to ensure the emergency bearer capacity as much as possible. continuity.

S1830. The terminal judges whether the target cell supports the emergency bearer service.

It should be understood that after the terminal determines the emergency bearer service capability of the target cell recorded in the historical cell information, the terminal needs to further determine whether the target cell supports the emergency bearer service according to the historical cell information. When the target cell does not support the emergency bearer service, the terminal performs a suppression operation. For example, the terminal may lower the camping standard of the current cell or increase the camping standard of the target cell. When the target cell supports the emergency bearer service, the terminal does not need to perform suppression operations.

S1840. The terminal prohibits execution of the suppression operation.

It should be understood that when the target cell supports the emergency bearer service, the terminal is prohibited from performing the suppression operation. Even if the terminal reselects to the target cell from a different system, the continuity of the emergency bearer will not be destroyed, and the terminal does not need to perform the suppression operation.

Fig. 19 is a schematic flowchart of a method for controlling emergency bearers according to another embodiment of the present application. Through the method 1900, when the RRC layer of the terminal is in an idle state, the terminal can determine the emergency bearer service capability of the target cell according to the historical cell information, so as to suppress unnecessary behavior of the terminal in different systems. Referring to Fig. 19, the method may include S1910, S1920, S1930, S1940 and S1950, each step will be described below.

It should be understood that, for example, the method 1900 is a schematic flow of a method for controlling emergency bearer when the RRC layer of the terminal is idle, and when the RRC layer of the terminal is idle, the different system behavior of the terminal is reselection.

S1910, the terminal judges whether the priority of the current cell is the highest priority.

It should be understood that before the terminal determines whether the historical cell information records the emergency bearer service capability of the target cell, the terminal first determines the priority of the current cell. The terminal compares the priority of the current cell with the priority of the target cell. When the priority of the current cell is the highest priority, the terminal does not meet the reselection conditions of different systems. At this time, the terminal does not need to perform suppression operations and no different system will occur. Reselection; when the priority of the current cell is not the highest priority, that is, when the priority of the target cell is higher than the priority of the current cell, the terminal may reselect the different system, and the terminal may need to perform suppression operations to suppress the different system Re-election, try to ensure the continuity of emergency bearer.

S1920, the terminal judges whether the historical cell information records the emergency bearer service capability of the target cell.

It should be understood that when the terminal determines that the priority of the current cell is not the highest priority, the terminal needs to further determine whether the historical cell information records the emergency bearer service capability of the target cell. For details, see S610, which will not be repeated here.

S1930, the terminal modifies the priority of the current cell to be the highest priority or modifies the camping standard.

It should be understood that when the terminal judges that the historical cell information does not record the emergency bearer service capability of the target cell, the terminal performs a suppression operation. For example, the terminal can modify the priority of the current cell to the highest priority or modify the camping standard. The standard can be understood as lowering the residence standard of the current cell or increasing the residence standard of the target cell.

S1940, the terminal judges whether the target cell supports the emergency bearer service.

It should be understood that when the terminal determines the emergency bearer service capability of the target cell recorded in the historical cell information, the terminal needs to further determine whether the target cell supports the emergency bearer. When the target cell does not support the emergency bearer service, the terminal performs a suppression operation to try to suppress unnecessary inter-system reselection; when the target cell supports the emergency bearer service, the terminal does not need to perform the suppression operation.

S1950, the terminal prohibits execution of the suppression operation.

It should be understood that when the priority of the current cell is the highest, or when the target cell supports the emergency bearer service, the terminal is prohibited from performing the suppression operation. At this time, if the terminal reselects from the current cell to the target cell, the continuity of the emergency bearer will not be destroyed, so there is no need to suppress the behavior of different systems.

Fig. 20 is a schematic flowchart of a method for controlling emergency bearers according to another embodiment of the present application. Through the method 2000, the terminal can determine the emergency bearer service capability of the target cell according to the received broadcast message, and determine whether unnecessary inter-system behavior of the terminal needs to be suppressed. Referring to Fig. 20, the method may include S2020, S2020 and S2030, each step will be described below.

S2010, the terminal judges whether the target cell carries an IMS emergency service support flag.

It should be understood that the terminal receives a broadcast message sent by the target cell, the broadcast message is used to indicate the emergency bearer service capability of the target cell, and the broadcast message may carry an IMS emergency bearer service support flag. The terminal needs to judge the content of the received broadcast message, and judge whether the target cell supports the emergency bearer service according to the flag carried in the broadcast message.

S2020, the terminal performs a suppression operation.

It should be understood that when the terminal judges that the broadcast message does not carry the IMS emergency service support flag, the emergency bearer service capability of the terminal to the target cell is unknown. Perform suppression operations.

S2030, the terminal prohibits execution of the suppression operation.

It should be understood that when the terminal judges that the IMS emergency service support flag is carried in the broadcast message, the flag is used to indicate that the target cell supports the emergency bearer service. The emergency bearer continuity is broken, and the terminal is prohibited from performing suppression operations.

Fig. 21 is a schematic flowchart of a method for controlling emergency bearers according to another embodiment of the present application. Through the method 2100, according to different states of the RRC layer of the terminal, different suppression operations can be used to suppress unnecessary behavior of different systems of the terminal. Referring to Fig. 21, the method may include S2101, S2102, S2103, S2104, S2105, S2106 and S2107, each step will be described below.

S2101. The terminal sends an Attach/TAU request. The specific steps are shown in FIG. 7-9 and will not be repeated here.

S2102. The network sends an Attach/TAU message.

It should be understood that the terminal locally records the ID and emergency service capability of the current cell according to the information carried in the Attach or TAU. For example, the terminal may record the history information of multiple resident cells.

S2103. The terminal initiates an emergency call.

It should be understood that when the RRC layer of the terminal is in the connected state, the terminal initiates an emergency call. The specific flow of the emergency call is shown in FIG. 5 and will not be repeated here.

S2104, the network establishes an emergency bearer.

It should be understood that after the terminal makes an emergency call in the current cell, the terminal establishes an emergency bearer with the current cell through an emergency registration procedure, and the terminal maintains the emergency bearer in the current cell.

S2105, hang up the terminal call.

S2106. The terminal starts a timer for suppressing different systems.

It should be understood that after the terminal hangs up the emergency call, there is an emergency bearer in the current cell and the current cell is available, the terminal starts the suppression different system timer, and during the start of the suppression different system timer, the terminal's different system behavior is suppressed; the suppression different system timing After the device is stopped, the inter-system behavior of the terminal is not suppressed, and the terminal can freely perform inter-system behavior from the current cell to the target cell.

It should be understood that at this time, the RRC layer of the terminal is in a connected state, and the terminal performs suppression operations including suppressing reporting of the B1 measurement report.

S2107, the RRC layer of the terminal is released.

It should be understood that when the RRC layer of the terminal is released, the RRC is in an idle state. For example, when the RRC layer of the terminal is in an idle state, the suppression operation performed by the terminal includes modifying the priority of the current cell to the highest priority or lowering the priority of the current cell. The residence standard of the cell or improve the residence standard of the target cell.

Exemplarily, the method for controlling an emergency bearer in the embodiment of the present application may be executed by the terminal shown in FIG. 22 . It should be understood that the terminal shown in FIG. 22 is only an example, and the implementation subject of the embodiment of the present application may also include other modules or units, or include modules with functions similar to those of the modules in FIG. 22 , or do not need to include the all modules. Each module and unit in Fig. 22 is described below,

The judging module 2210 is configured to determine the emergency bearer service capability of the target cell. The emergency bearer service capability of the target cell includes that the target cell supports the emergency bearer service and the target cell does not support the emergency bearer service.

Optionally, the judging module 2210 may also include a first judging unit 2211, configured to determine the emergency bearer service capability of the target cell according to historical cell information.

Optionally, the judging module 2210 may further include a second judging unit 2212, configured to determine the emergency bearer service capability of the target cell according to the broadcast message.

Optionally, the judging module 2210 may also include a third judging unit 2213, which is used to determine the priority of the current cell before the judging module determines the emergency bearer service capability of the target cell, including determining that the priority of the current cell is lower than the target cell. The priority of the cell or the priority of the current cell is higher than the priority of the target cell.

Executing module 2220, configured to determine whether to perform a suppression operation according to the emergency bearer service capability of the target cell, the suppression operation is used to suppress the behavior of the different system, and the behavior of the different system includes the reselection or handover of the terminal from the current cell with the emergency bearer to the target cell .

Optionally, the execution module 2220 may also include a first execution unit 2221, configured to set the priority of the current cell to the highest priority when the RRC layer of the terminal is in an idle state.

Optionally, the execution module 2220 may further include a second execution unit 2222, configured to reduce the camping standard of the current cell or increase the camping standard of the target cell when the RRC layer of the terminal is in an idle state.

Optionally, the execution module 2220 may further include a third execution unit 2223, configured to suppress the reporting of the B1 measurement report when the RRC layer of the terminal is in the connected state.

Suppress the different system timer 2230, the terminal starts the suppress different system timer when there is an emergency bearer in the current cell; when the judging unit determines that the target cell supports the emergency bearer service, the terminal stops suppressing the different system timer; or when the judging unit determines that the target cell does not When the emergency bearer service is supported or the judging unit does not record the emergency bearer service capability of the target cell, the terminal releases the emergency bearer when the inter-system suppression timer expires.

As shown in Figure 23, the embodiment of this application also proposes a terminal 2300, which can be the terminal 2200 in Figure 22, and the terminal can adopt the hardware structure shown in Figure 23, which can be used to perform the same The content corresponding to the embodiment method. The terminal may include: a processor 2310 and a transceiver 2320. Optionally, the terminal may further include a memory 2330. The processor 2310, the transceiver 2320, and the memory 2330 communicate with each other through an internal connection path.

It should be understood that, in the embodiment of the present application, the processor 2310 may be a central processing unit (Central Processing Unit, referred to as "CPU"), a microprocessor, an application-specific integrated circuit (application-specific integrated circuit, ASIC), A dedicated processor, or one or more integrated circuits for implementing the technical solutions of the embodiments of the present application. Alternatively, a processor may refer to one or more devices, circuits, and/or processing cores for processing data (eg, computer program instructions). For example, it may be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control communication devices (such as base stations, terminals, or chips, etc.), execute software programs, and process data of software programs.

Optionally, the processor 2310 may include one or more processors, such as one or more central processing units (central processing unit, CPU). In the case where the processor is a CPU, the CPU may be a single Core CPU, also can be multi-core CPU.

The transceiver 2320 is used to transmit and receive data and/or signals, and to receive data and/or signals. The transceiver may include a transmitter for transmitting data and/or signals and a receiver for receiving data and/or signals.

The memory 2330 includes, but is not limited to, random access memory (random access memory, RAM), read-only memory (read-only memory, ROM), erasable programmable memory (erasable programmable read only memory, EPROM), read-only CD-ROM (compact disc read-only memory, CD-ROM), the memory 1030 is used to store related instructions and data. The memory 2330 is used to store program codes and data of the network device, and may be a separate device or integrated in the processor 2310 .

Specifically, the processor 2310 is configured to control the transceiver and the terminal to perform information transmission. For details, refer to the description in the method embodiments, and details are not repeated here.

It can be understood that Fig. 23 only shows a simplified design of the terminal. In practical applications, the device can also include other necessary components, including but not limited to any number of transceivers, processors, controllers, memories, etc., and all terminals that can implement this application are within the protection scope of this application within.

Embodiments of the present application also provide a computer-readable storage medium, which stores one or more programs or instructions, and when the programs or instructions run on a computer, the computer executes the above-mentioned embodiment. method.

The embodiment of the present application also proposes a computer program, the computer program includes a program or an instruction, and when the computer program or instruction is executed by a computer, the computer can execute the corresponding procedure of the method in the foregoing embodiment.

In this application, "at least one" means one or more, and "multiple" means two or more. "And/or" describes the association relationship of associated objects, indicating that there may be three types of relationships, for example, A and/or B, which can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A, B can be singular or plural. The character "/" generally indicates that the contextual objects are an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one item (piece) of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c can be single or multiple .

It should be understood that reference throughout the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the present application. Thus, appearances of "in one embodiment" or "in an embodiment" in various places throughout the specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present application, the size of the sequence numbers of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its functions and internal logic, and should not be used in the embodiments of the present application. The implementation process constitutes any limitation.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.

Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working process of the devices, modules and units described above can refer to the corresponding process in the foregoing method embodiments, and details are not repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods may be implemented in other ways. For example, the terminal device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined Or it can be integrated into another system, or some features can be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit.

The above is only a specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application. Should be covered within the protection scope of this application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims (35)

A method for controlling emergency bearing, comprising: The terminal determines the emergency bearer service capability of the target cell, where the emergency bearer service capability of the target cell includes that the target cell supports the emergency bearer service and that the target cell does not support the emergency bearer service; The terminal determines whether to perform a suppression operation according to the emergency bearer service capability of the target cell, the suppression operation is used to suppress the behavior of the different system, and the behavior of the different system includes the reselection or handover of the terminal from the current cell with the emergency bearer to the target cell. The method according to claim 1, wherein the terminal determines whether to perform a suppression operation according to the emergency bearer service capability of the target cell, comprising: When the terminal hangs up the emergency call in the current cell, the terminal determines whether to perform a suppression operation according to the emergency bearer service capability of the target cell. The method according to claim 1 or 2, wherein the terminal determining the emergency bearer service capability of the target cell comprises: The terminal determines the emergency bearer service capability of the target cell according to the historical cell information, where the historical cell information includes the emergency bearer service capability of the cell where the terminal has camped. The method according to claim 1 or 2, wherein the terminal determining the emergency bearer service capability of the target cell comprises: The terminal receives a broadcast message sent by the target cell, where the broadcast message is used to indicate the emergency bearer service capability of the target cell; The terminal determines the emergency bearer service capability of the target cell according to the broadcast message. The method according to claim 4, wherein the terminal determines the emergency bearer service capability of the target cell according to the broadcast message, comprising: The broadcast message includes an Internet Protocol Multimedia Subsystem IMS emergency service support flag, and the IMS emergency service support flag is used to indicate that the target cell supports the emergency bearer service. The method according to any one of claims 1-5, wherein when the terminal hangs up the emergency call in the current cell, the state of the radio resource control RRC layer of the terminal includes idle state or connected state. The method according to any one of claims 1-6, wherein the terminal determines whether to perform a suppression operation according to the emergency bearer service capability of the target cell, including: When the terminal determines that the target cell does not support the emergency bearer service or the terminal does not record the emergency bearer service capability of the target cell, the terminal performs the suppression operation. The method according to claim 7, wherein the terminal does not record the emergency bearer service capability of the target cell, comprising: The historical cell information does not record the emergency bearer service capability of the target cell or the broadcast message does not record the IMS emergency service support flag. The method according to claim 7, wherein before the terminal determines whether to perform the suppression operation according to the emergency bearer service capability of the target cell, the method further comprises: When the RRC layer of the terminal is in an idle state, the terminal determines that the priority of the current cell is lower than the priority of the target cell. The method according to claim 9, wherein the terminal performing the suppression operation comprises: The terminal sets the priority of the current cell as the highest priority. The method according to claim 9, wherein the terminal performing the suppression operation comprises: The terminal reduces the camping standard of the current cell or increases the camping standard of the target cell. The method according to claim 7, wherein the terminal performing the suppression operation comprises: When the RRC layer of the terminal is in the connected state, the terminal suppresses the reporting of the B1 measurement report. The method according to any one of claims 1-6, wherein the terminal determines whether to perform a suppression operation according to the emergency bearer service capability of the target cell, including: When the terminal determines that the target cell supports the emergency bearer service, the terminal is prohibited from performing the suppression operation. The method according to any one of claims 1-6, wherein before the terminal determines whether to perform a suppression operation according to the emergency bearer service capability of the target cell, the method further comprises: When the RRC layer of the terminal is in an idle state, the terminal determines that the priority of the current cell is higher than the priority of the target cell; The terminal is prohibited from performing the suppression operation. The method according to any one of claims 1-14, further comprising: The terminal starts a timer for suppressing different systems when there is an emergency bearer in the current cell; When the terminal determines that the target cell supports emergency bearer services, the terminal stops the different system suppression timer; or When the terminal determines that the target cell does not support the emergency bearer service or the terminal does not record the emergency bearer service capability of the target cell, the terminal releases the emergency bearer when the different system suppression timer expires. A terminal, characterized in that, comprising: A judging module, configured to determine the emergency bearer service capability of the target cell, where the emergency bearer service capability of the target cell includes that the target cell supports the emergency bearer service and that the target cell does not support the emergency bearer service; An execution module, configured to determine whether to perform a suppression operation according to the emergency bearer service capability of the target cell, the suppression operation is used to suppress the behavior of the different system, and the behavior of the different system includes the reselection of the terminal from the current cell with the emergency bearer Or switch to the target cell. The terminal according to claim 16, wherein when the terminal hangs up the emergency call in the current cell, the execution module determines whether to execute the suppression operation according to the emergency bearer service capability of the target cell. The terminal according to claim 16 or 17, wherein the judging module comprises: The first judging unit is configured to determine the emergency bearer service capability of the target cell according to historical cell information, where the historical cell information includes the emergency bearer service capability of the cell where the terminal has camped. The terminal according to claim 16 or 17, wherein the judging module comprises: The second judging unit is configured to determine the emergency bearer service capability of the target cell according to a broadcast message, where the broadcast message is used to indicate the emergency bearer service capability of the target cell. The terminal according to claim 19, wherein the broadcast message includes an IMS emergency service support flag; The second judging unit determines that the target cell supports the emergency bearer service according to the IMS emergency service support flag. The terminal according to any one of claims 16-20, wherein when the terminal hangs up the emergency call in the current cell, the state of the RRC layer of the terminal includes an idle state or a connected state. The terminal according to any one of claims 16-21, wherein when the judging module determines that the target cell does not support the emergency bearer service capability or the judging module does not record the emergency bearer service of the target cell When capable, the execution module executes the suppression operation. The terminal according to claim 22, wherein the judging module does not record the emergency bearer service capability of the target cell comprises: The historical cell information in the first judgment unit does not record the emergency bearer service capability of the target cell or the broadcast message in the second judgment unit does not record the IMS emergency service support flag. The terminal according to claim 22, wherein the judging module further comprises: a third judging unit, configured to determine the priority of the current cell; When the RRC layer of the terminal is in an idle state, the third judging unit is configured to determine that the priority of the current cell is lower than the priority of the target cell. The terminal according to claim 24, wherein the execution module comprises: The first execution unit is configured to set the priority of the current cell as the highest priority. The terminal according to claim 24, wherein the execution module comprises: The second executing unit is configured to lower the camping standard of the current cell or increase the camping standard of the target cell. The terminal according to claim 22, wherein the execution module comprises: a third execution unit, configured to suppress the reporting of the B1 measurement report; When the RRC layer of the terminal is in the connected state, the third execution unit suppresses reporting of the B1 measurement report. The terminal according to any one of claims 16-21, wherein when the judging module determines that the target cell supports the emergency bearer service, the executing module forbids executing the suppressing operation. The terminal according to any one of claims 16-21, wherein the judging module further includes: a third judging unit, configured to determine the priority of the current cell; When the RRC layer of the terminal is in an idle state, the third judging unit is configured to determine that the priority of the current cell is higher than the priority of the target cell; The execution unit prohibits execution of the suppress operation. The terminal according to any one of claims 16-29, further comprising: suppressing different system timers; The terminal starts a timer for suppressing different systems when there is an emergency bearer in the current cell; When the judging unit determines that the target cell supports emergency bearer services, the terminal stops the different system suppression timer; or When the judging unit determines that the target cell does not support the emergency bearer service or the judging unit does not record the emergency bearer service capability of the target cell, the terminal releases the emergency bearer service when the different system suppression timer expires. bearer. A terminal, characterized in that it includes: a processor, a memory, and a transceiver; The transceiver is used to receive signals and send signals; The memory is used to store program codes; The processor is configured to call the program code from the memory to execute the method according to any one of claims 1-15. A terminal, characterized by comprising: a processor, and when the processor invokes a computer program in a memory, the method according to any one of claims 1-15 is executed. A terminal, characterized by comprising: a memory and a processor; the memory is used to store a computer program, and when the processor invokes the computer program in the memory, the terminal executes the method described in claims 1-15 any one of the methods described. A computer-readable storage medium, characterized in that the computer-readable storage medium includes a computer program or an instruction, and when the computer program or instruction is run on a computer, the computer executes any one of claims 1-15. method described in the item. A computer program product, characterized in that the computer program product includes a computer program or an instruction, and when the computer program or instruction is run on a computer, the computer executes the computer program described in any one of claims 1-15. method.

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