Method, device, chip system and storage medium for a call

Abstract

The application provides a method, device, chip system and storage medium for a call. The method is applied to a terminal device, and the first information in a first RRC reconfiguration message received from a first cell and the first parameters in a first configuration item saved locally are checked, and when the corresponding values of the first parameters are abnormal, the abnormal values of the first parameters are ignored, so that the first RRC reconfiguration message is checked successfully, and the terminal device can complete RRC reconfiguration, and the probability of RRC reconfiguration failure is reduced.

Description

[0001] The present application is a divisional application, the original application is named Method, device, chip system and storage medium for call, the original application has an application number of 202310491058.X, an original application date of April 28, 2023, and the entire contents of the original application are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of communication, in particular to a method, device, chip system and storage medium for call. BACKGROUND

[0003] In the 5G, i.e. NR (New Radio) network, the RRC reconfiguration (Radio Resource Control Reconfiguration) initiated by the network side (referring to the 5G base station, such as gNB (gNodeB, the next Generation Node B)) to the terminal device (also known as: UE) aims to modify the RRC connection established between the UE and the network side, so as to better adapt to the actual business scenario.

[0004] However, there is currently a situation that the UE fails to check the RRC reconfiguration message, thereby causing the call to be interrupted. SUMMARY

[0005] In order to solve the above technical problems, the present application provides a method, device, chip system and storage medium for call, which aims to reduce call failure and improve user experience.

[0006] In a first aspect, the present application provides a method for call. The method is applied to a terminal device, comprising: receiving a first RRC reconfiguration message sent by a base station corresponding to a first cell during a call process in the first cell; wherein before receiving the first RRC reconfiguration message, a first configuration item is saved in the terminal device; the first configuration item includes a first parameter and a first value corresponding to the first parameter; checking the first RRC reconfiguration message and the first configuration item; wherein the first RRC reconfiguration message includes first information; checking the first RRC reconfiguration message and the first configuration item includes checking the first information, the first parameter and the first value corresponding to the first parameter; during the process of checking the first RRC reconfiguration message and the first configuration item, when the value corresponding to the first parameter is abnormal, ignoring the abnormal value corresponding to the first parameter, so that the first RRC reconfiguration message is checked successfully; wherein the value corresponding to the first parameter includes the first value.

[0007] The first cell is a cell in which a terminal device (UE) currently resides, for example, Cell A, Cell B, or Cell C described below. In the present application, the first cell is taken as an example of Cell B.

[0008] The RRC reconfiguration message is an RRCReconfiguration sent by a base station corresponding to the cell to the UE. In the present application, the first RRC reconfiguration message is taken as an example of RRCReconfiguration 3 or RRCReconfiguration 4 described below.

[0009] The first configuration item is a configuration item locally saved by the terminal device, which can include the first parameter and a value corresponding to the first parameter. In the present application, the value corresponding to the first parameter saved in the terminal device is taken as an example of a first value. However, in actual applications, the value corresponding to the first parameter is not limited to the first value, but can also be a second value, a third value, and the like described below.

[0010] The terminal device checks the first message, the first parameter, and the first value corresponding to the first parameter. Specifically, it can be checked whether the first message, the first parameter, and the first value corresponding to the first parameter match or are compatible.

[0011] Therefore, when the value corresponding to the first parameter is abnormal, the abnormal value corresponding to the first parameter is ignored, so that the first RRC reconfiguration message is checked successfully, thereby ensuring that the terminal device can complete the RRC reconfiguration and reducing the probability of RRC reconfiguration failure.

[0012] The ignoring of the abnormal value corresponding to the first parameter can be not considering the abnormal value corresponding to the first parameter (it can be understood that the abnormal value corresponding to the first parameter is ignored when determining the checking result of the first RRC reconfiguration message), or the abnormal value corresponding to the first parameter can be modified or deleted or not effective by updating the value corresponding to the first parameter. Further, when determining the checking result of the first RRC reconfiguration message, the first RRC reconfiguration message will not be checked as failed due to the abnormal value corresponding to the first parameter, thereby avoiding the abnormal call.

[0013] For example, the ignoring of the abnormal value corresponding to the first parameter refers to an implementation manner of updating the value corresponding to the first parameter. Specifically, the value corresponding to the first parameter can be updated in the manner 1 or the manner 2 described in the following embodiments.

[0014] For example, in some implementations, the operation of updating the value corresponding to the first parameter, or the value corresponding to the parameter with the abnormal parameter value, can be uniformly represented as updating the configuration item in which the parameter is located, i.e., updating the configuration item. Hereinafter, the updating of the configuration item is taken as an example for description.

[0015] It should be noted that, in actual applications, the updating of the configuration items according to the mode 1 or the mode 2 can be understood as the updating of the configuration of the configuration items, or can be understood as the updating of the values of the configuration items, or can be understood as the updating of the contents of the configuration items. The present application takes the updating of the value corresponding to the parameter with the abnormal parameter value in the configuration items as an example for description.

[0016] According to the first aspect, after the first RRC reconfiguration message is successfully checked, the method further includes performing RRC reconfiguration according to the first RRC reconfiguration message, and feeding back an RRC reconfiguration complete message after the RRC reconfiguration is completed.

[0017] The RRC reconfiguration complete message is, for example, the RRC Reconfiguration Complete mentioned below.

[0018] According to the first aspect, or any one of the implementation modes of the first aspect, the operation of ignoring the abnormal value corresponding to the first parameter includes updating the value corresponding to the first parameter.

[0019] According to the first aspect, or any one of the implementation modes of the first aspect, the value corresponding to the first parameter further includes a second value; the first RRC reconfiguration message carries a second configuration item about the first cell, the second configuration item includes the first parameter and the second value corresponding to the first parameter; and the operation of ignoring the abnormal value corresponding to the first parameter includes, in the case that the first value and the second value are different, ignoring the abnormal value corresponding to the first parameter.

[0020] According to the first aspect, or any one of the implementation modes of the first aspect, the operation of ignoring the abnormal value corresponding to the first parameter includes updating the first value corresponding to the first parameter to the second value.

[0021] That is, when the value corresponding to the same parameter received from the network side currently and the value corresponding to the parameter stored locally by the terminal device are different, the mode 2 mentioned below can be used to update the configuration item. Specifically, the value corresponding to the parameter with the abnormal parameter in the configuration item is updated to the value corresponding to the parameter received from the network side currently (see S409a in the embodiments described below). In this way, by updating the value corresponding to the parameter with the abnormal parameter in the configuration item, the first RRC reconfiguration message is successfully checked, and the terminal device can continue to camp on the first cell and normally perform a call.

[0022] According to the first aspect, or any one of the first aspect of the above-mentioned implementation manners, the first information comprises information of the second cell, the first RRC reconfiguration message is used to instruct the terminal device to switch from the first cell to the second cell; and when the value corresponding to the first parameter is abnormal, the abnormal value corresponding to the first parameter is ignored, comprising: when the value corresponding to the first parameter is incompatible with the information of the second cell, the abnormal value corresponding to the first parameter is ignored.

[0023] According to the first aspect, or any one of the first aspect of the above-mentioned implementation manners, the abnormal value corresponding to the first parameter is ignored, comprising: updating the value corresponding to the first parameter from the first value to a third value.

[0024] That is, for the case that the first RRC reconfiguration message is used to instruct the terminal device to switch from the first cell to the second cell, the first information usually comprises relevant information of the second cell, such as whether the first parameter is currently supported by the second cell and the first value corresponding to the first parameter. Therefore, when the first information is not matched or compatible with the first parameter and the first value corresponding to the first parameter, it can be determined that the value corresponding to the first parameter is incompatible with the information of the second cell. In this case, the updating of the configuration item can be performed in the following manner 1. Specifically, the value corresponding to the abnormal parameter in the configuration item is updated to a value indicating that the parameter is not effective, such as the third value mentioned above. In this way, by updating the value corresponding to the abnormal parameter in the configuration item to a value indicating that the parameter is not effective, the first RRC reconfiguration message is successfully verified, and the terminal device can camp on the second cell to realize normal communication in the second cell.

[0025] According to the first aspect, or any one of the first aspect of the above-mentioned implementation manners, the first cell is a cell of a TDD system, and the second cell is a cell of an FDD system.

[0026] For example, the first cell is a Cell B of a TDD system mentioned below, and the second cell is a Cell C of an FDD system.

[0027] According to the first aspect, or any one of the first aspect of the above-mentioned implementation manners, the first configuration item is a configuration item of SRS resources in an antenna switching mode.

[0028] For example, when the first configuration item is a configuration item of SRS resources in an antenna switching mode, the first parameter is, for example, srs_tx_switch mentioned below, and the first value corresponding to the first parameter is, for example, “1”.

[0029] According to the first aspect, or any one of the first aspect of the above-mentioned implementation manners, the first value is 1, and the third value is 0.

[0030] For example, when the first configuration item is the SRS resource in the antenna switching mode, the first parameter is, for example, srs_tx_switch, the first value corresponding to the first parameter is, for example, "1", and the third value is, for example, "0". In this case, the update of the first configuration item is, for example, srs_tx_switch = 1 is updated to srs_tx_switch = 0.

[0031] According to the first aspect or any one of the implementations of the first aspect, the ignoring the abnormal value corresponding to the first parameter comprises: when the first parameter is a negligible parameter, ignoring the abnormal value corresponding to the first parameter; and wherein the first parameter is the negligible parameter comprises: the first parameter is the same as any one of a plurality of parameters stored in the terminal device, and the plurality of parameters comprises at least one parameter, and each of the at least one parameter corresponds to a parameter value that can be ignored.

[0032] The parameter list stored in the terminal device is the same as the configuration item list described below. In the following embodiments, the updateable configuration item recorded in the configuration item list is the negligible parameter described here.

[0033] According to the first aspect or any one of the implementations of the first aspect, the plurality of parameters in the parameter list are determined according to an existing standard protocol and are stored in the terminal device in advance. In this way, the negligible parameters corresponding to each cell are determined according to the existing standard protocol, so that the terminal device can perform RRC reconfiguration between various cells.

[0034] According to the first aspect or any one of the implementations of the first aspect, when the first parameter is the negligible parameter, the ignoring the abnormal value corresponding to the first parameter comprises: when the first parameter is the negligible parameter and the terminal device supports a compatible function, ignoring the abnormal value corresponding to the first parameter; and wherein the terminal device supporting the compatible function means that the terminal device supports ignoring the abnormal value corresponding to the negligible parameter.

[0035] The terminal device supporting the compatible function is, for example, the UE enabling the compatible function described below. For judging whether the terminal device supports the compatible function, refer to the description of S313 or S405 below, which will not be repeated here. S313 or S405 can be optional steps, in which case the terminal device can support the compatible function by default.

[0036] According to the first aspect or any one of the implementations of the first aspect, the method further comprises: when the first parameter is the negligible parameter and the terminal device does not support the compatible function, replying to the base station corresponding to the first cell with an RRC connection reestablishment message.

[0037] The RRC connection re-establishment message is, for example, an RRC Connection re-establishment message as described below.

[0038] The terminal device does not support the compatibility function, for example, the compatibility function is not enabled.

[0039] The terminal device replies to the first cell with the RRC connection re-establishment message, and the RRC connection re-establishment procedure can be triggered, for example, by referring to the UE performing the RLF procedure, reselecting a cell to camp on, such as selecting the original cell or a new cell to camp on, for example, S113 to S115, or S213 to S220, or S314 to S316, and the like.

[0040] According to the first aspect, or any one of the implementations of the first aspect, the first configuration item is configuration received by the terminal device from a cell camped on before the terminal device camps on the first cell.

[0041] For example, when the first cell is a Cell B as described below, the cell camped on by the terminal device before the terminal device camps on the first cell can be, for example, a Cell A as described below.

[0042] Correspondingly, when the cell camped on before the first cell is a Cell A, the first configuration item is, for example, configuration carried in an RRC reconfiguration message sent by a base station corresponding to the Cell A to the terminal device. For example, through an RRC reconfiguration message 1 or an RRC reconfiguration message 2 as described below, and the like.

[0043] According to the first aspect, or any one of the implementations of the first aspect, when the first information is information for the first cell, the RRC reconfiguration is performed according to the first RRC reconfiguration message, and after the RRC reconfiguration is completed, an RRC reconfiguration completion message is fed back, including: performing the RRC reconfiguration according to the first RRC reconfiguration message, and after the RRC reconfiguration is completed, feeding back the RRC reconfiguration completion message to a base station corresponding to the first cell. For details, please refer to S409a and S409b in the following embodiment.

[0044] According to the first aspect, or any one of the implementations of the first aspect, when the first RRC reconfiguration message indicates that the terminal device is switched from the first cell to a second cell, the RRC reconfiguration is performed according to the first RRC reconfiguration message, and after the RRC reconfiguration is completed, an RRC reconfiguration completion message is fed back, including: performing the RRC reconfiguration according to the first RRC reconfiguration message, and after the RRC reconfiguration is completed, replying to a base station corresponding to the second cell with the RRC reconfiguration completion message after camping on the second cell. For details, please refer to S409c and S409d in the following embodiment.

[0045] The second cell is a cell to which the terminal device (UE) is to be handed over. In the present application, when the first cell is Cell B, the second cell can be Cell A or Cell C, in the case where the UE can be handed over to Cell A, Cell B, and Cell C. For the purpose of facilitating the method for making a call provided in the present application, the second cell is taken as Cell C in the following description.

[0046] In the scenario where the second cell is taken as Cell C in the present application, the first RRC reconfiguration message mentioned herein is, for example, the RRC reconfiguration message 4 mentioned below. In this scenario, the incompatible first configuration item is, for example, the SRS resource configuration item of the antenna switching mode configured in the RRC reconfiguration message 3 mentioned below.

[0047] In a second aspect, the present application provides a method for making a call. The method is applied to a terminal device and includes: receiving a first RRC reconfiguration message sent by a base station corresponding to a first cell during a process of making a call in the first cell; checking the first RRC reconfiguration message; and in the process of checking the first RRC reconfiguration message, ignoring an abnormal parameter value corresponding to a parameter that has an abnormal parameter value, so that the first RRC reconfiguration message is checked successfully.

[0048] The first cell is a cell in which the terminal device (UE) currently resides, for example, Cell A, Cell B, or Cell C mentioned below. In the present application, the first cell is taken as Cell B in the following description.

[0049] The RRC reconfiguration message is an RRCReconfiguration sent by the base station corresponding to the cell to the UE.

[0050] The checking of the first RRC reconfiguration message can include, for example, checking the content in the first RRC reconfiguration message sent by the first cell and checking the parameters included in the configuration item saved locally by the terminal device and the parameter values corresponding to the parameters.

[0051] Therefore, by ignoring the abnormal parameter value corresponding to the parameter that has an abnormal parameter value checked by the terminal device in the RRC reconfiguration process, the first RRC reconfiguration message can be checked successfully, so that the terminal device can complete the RRC reconfiguration and the probability of RRC reconfiguration failure can be reduced.

[0052] According to the second aspect, the ignoring of the abnormal parameter value corresponding to the parameter includes updating the parameter value corresponding to the parameter.

[0053] According to a second aspect, or any possible implementation mode of the second aspect, the parameter value of the abnormal parameter is ignored, including: when the parameter with the abnormal parameter value is the ignorable parameter, the parameter value of the abnormal parameter is ignored; wherein the parameter with the abnormal parameter value is the ignorable parameter, including: the parameter with the abnormal parameter value is the same as any one of the parameters in the parameter list stored in the terminal device, and the parameter list includes at least one parameter, and the parameter value of each of the at least one parameter can be ignored.

[0054] The parameter list stored in the terminal device is the same as the configuration item list described below. In the following embodiments, the updatable configuration item recorded in the configuration item list is the ignorable parameter herein.

[0055] According to the second aspect, or any possible implementation mode of the second aspect, the ignorable parameter in the parameter list is determined according to an existing standard protocol and is stored in the terminal device in advance. In this way, the ignorable parameter corresponding to each cell is determined according to the existing standard protocol, so that the terminal device can perform RRC reconfiguration between various cells.

[0056] According to the second aspect, or any possible implementation mode of the second aspect, when the first parameter is the ignorable parameter, the parameter value of the abnormal parameter is ignored, including: when the parameter with the abnormal parameter value is the ignorable parameter and the terminal device supports the compatibility function, the parameter value of the abnormal parameter is ignored; wherein the terminal device supporting the compatibility function means that the terminal device supports ignoring the abnormal value of the ignorable parameter.

[0057] The terminal device supports the compatibility function, for example, the UE enables the compatibility function as described below. For judging whether the terminal device supports the compatibility function, refer to the description of S313 or S405 below, which will not be repeated here. S313 or S405 can be an optional step, in which case the terminal device can support the compatibility function by default.

[0058] According to the second aspect, or any possible implementation mode of the second aspect, the method further includes: when the parameter with the abnormal parameter value is the ignorable parameter and the terminal device does not support the compatibility function, replying to the base station corresponding to the first cell with an RRC connection re-establishment message.

[0059] The RRC connection re-establishment message is, for example, the RRC Connection re-establishment described below.

[0060] The terminal device does not support the compatibility function, for example, the compatibility function is not enabled as described below.

[0061] As to the terminal device replying the RRC connection reestablishment message to the first cell, the triggering of the RRC connection reestablishment procedure can refer to the following UE executing the RLF procedure, reselecting the cell to camp on, such as the part of selecting the original cell or a new cell to camp on, such as S113 to S115, or S213 to S220, or S314 to S316, and the like.

[0062] In a third aspect, the present application provides a terminal device. The terminal device comprises a memory and a processor, the memory and the processor are coupled; the memory stores program instructions, the program instructions are executed by the processor to make the terminal device execute the method in the first aspect or any possible implementation manner of the first aspect.

[0063] The third aspect and any one of the implementation manners of the third aspect correspond to the first aspect and any one of the implementation manners of the first aspect respectively; or correspond to the second aspect and any one of the implementation manners of the second aspect respectively. The technical effects corresponding to the third aspect and any one of the implementation manners of the third aspect can refer to the technical effects corresponding to the first aspect and any one of the implementation manners of the first aspect, or the technical effects corresponding to the second aspect and any one of the implementation manners of the second aspect, which will not be described here.

[0064] In a fourth aspect, the present application provides a computer readable medium for storing a computer program, the computer program comprising instructions for executing the method in the first aspect or any possible implementation manner of the first aspect.

[0065] The fourth aspect and any one of the implementation manners of the fourth aspect correspond to the first aspect and any one of the implementation manners of the first aspect respectively; or correspond to the second aspect and any one of the implementation manners of the second aspect respectively. The technical effects corresponding to the fourth aspect and any one of the implementation manners of the fourth aspect can refer to the technical effects corresponding to the first aspect and any one of the implementation manners of the first aspect, or the technical effects corresponding to the second aspect and any one of the implementation manners of the second aspect, which will not be described here.

[0066] In a fifth aspect, the present application provides a computer program, the computer program comprising instructions for executing the method in the first aspect or any possible implementation manner of the first aspect.

[0067] The fifth aspect and any possible implementation of the fifth aspect correspond to the first aspect and any possible implementation of the first aspect respectively, or correspond to the second aspect and any possible implementation of the second aspect respectively. The technical effects of the fifth aspect and any possible implementation of the fifth aspect can refer to the technical effects of the first aspect and any possible implementation of the first aspect, or the technical effects of the second aspect and any possible implementation of the second aspect, which will not be described herein.

[0068] In a sixth aspect, a chip system is provided, which includes a processor. The processor is configured to support instructions of the method in the first aspect or any possible implementation of the first aspect.

[0069] According to the sixth aspect, the processor includes a modem.

[0070] Correspondingly, the processor is configured to support instructions of the method in the first aspect or any possible implementation of the first aspect, and specifically includes:

[0071] The modem is configured to support instructions of the method in the first aspect or any possible implementation of the first aspect.

[0072] The sixth aspect and any possible implementation of the sixth aspect correspond to the first aspect and any possible implementation of the first aspect respectively, or correspond to the second aspect and any possible implementation of the second aspect respectively. The technical effects of the sixth aspect and any possible implementation of the sixth aspect can refer to the technical effects of the first aspect and any possible implementation of the first aspect, or the technical effects of the second aspect and any possible implementation of the second aspect, which will not be described herein. BRIEF DESCRIPTION OF DRAWINGS

[0073] Figure 1 A mobile communication architecture diagram is exemplarily shown;

[0074] Figure 2a An interaction diagram of a UE and a network side when RRC reconfiguration is successful is exemplarily shown;

[0075] Figure 2b An interaction diagram of a UE and a network side when RRC reconfiguration fails is exemplarily shown;

[0076] Figure 3 A diagram of cell handover failure in an RRC reconfiguration process is exemplarily shown;

[0077] Figure 4Fig. 6 is a schematic diagram of a cell handover failure in another exemplary RRC reconfiguration procedure;

[0078] Figure 5 Fig. 7 is a schematic diagram of implementing RRC reconfiguration in an exemplary method for a call provided by an embodiment of the present application;

[0079] Figure 6 Fig. 8 is a schematic diagram of implementing RRC reconfiguration in another exemplary method for a call provided by an embodiment of the present application;

[0080] Figure 7 Fig. 9 is a schematic diagram of a software structure and hardware of a terminal device;

[0081] Figure 8 Fig. 10 is a schematic diagram of a hardware structure of a terminal device. DETAILED DESCRIPTION

[0082] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0083] The term “and / or” in the present document is merely used to describe an association relationship of associated objects, and indicates that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone.

[0084] The terms “first” and “second” and the like in the description and claims of the embodiments of the present application are used to distinguish different objects, and are not used to describe a specific order of the objects. For example, the first target object and the second target object are used to distinguish different target objects, and are not used to describe a specific order of the target objects.

[0085] In the embodiments of the present application, the words “exemplary” or “for example” are used to mean serving as an example, instance, or illustration. Any embodiment or design presented as “exemplary” or “for example” in the embodiments of the present application should not be interpreted as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of “exemplary” or “for example” is intended to present concepts in a specific way.

[0086] In the description of the embodiments of the present application, unless otherwise specified, the meaning of “a plurality of” is two or more. For example, a plurality of processing units means two or more processing units; a plurality of systems means two or more systems.

[0087] Based on the above premise, the technical solutions provided by the embodiments of the present application are described below.

[0088] Specifically, the technical solutions provided by the embodiments of the present application are the processing logic when the RRC reconfiguration process is performed during the call process of the calling party and the called party. In order to better illustrate the technical solutions provided by the embodiments of the present application, first, the mobile communication architecture to which the method for calling provided by the embodiments of the present application is directed is described in conjunction with the drawings.

[0089] Referring to Figure 1 , a mobile communication architecture is exemplarily shown. In the mobile communication architecture, terminal devices, (wireless) access networks, core networks and IP multimedia subsystem networks (IMS networks) required to implement voice / audio / video call services are shown.

[0090] Continuing to refer to Figure 1 , exemplarily, the terminal devices can include a calling party (such as terminal A) initiating a call service and a called party (such as terminal B) responding to the call service; the access network can include a base station (such as base station A) corresponding to terminal A and a base station (such as base station B) corresponding to terminal B; the core network can include an operator room (such as room A) corresponding to base station A and an operator room (such as room B) corresponding to base station B; the IMS network can include a calling IMS domain (network) corresponding to terminal A and a called IMS domain (network).

[0091] Exemplarily, in some implementations, base station A and base station B can be the same, for example, in the scenario where terminal A and terminal B face the same operator and terminal A and terminal B access the same cell (Cell).

[0092] Exemplarily, in other implementations, base station A and base station B can be two different base stations, for example, in the scenario where terminal A and terminal B face different operators. Alternatively, in the scenario where terminal A and terminal B face the same operator, but terminal A is located in one city or cell, and terminal B is located in another city or cell.

[0093] Exemplarily, in the scenario where base station A and base station B are the same, room A and room B can be the same or two different rooms.

[0094] It should be understood that the above description is only an example for better understanding the technical solutions of the embodiments and is not the only limitation of the embodiments.

[0095] Based on Figure 1The mobile communication architecture shown, when terminal A initiates a call service to terminal B, a media session between the two is established, and in the process of the call described in the following embodiments and drawings, terminal A sends a SIP request message to the called IMS domain through base station A, the machine room A and the calling IMS domain. Then it is sent to terminal B through the called IMS domain, the machine room B and the base station B. Correspondingly, the SIP response message made by terminal B to the SIP request message initiated by terminal A is fed back to terminal A through base station B, machine room B, called IMS domain, calling IMS domain, machine room A and base station A. Thus, the establishment of the media session between terminal A and terminal B is realized.

[0096] It should be noted that the so-called SIP refers to Session initialization Protocol. SIP is a multimedia communication protocol developed by Internet Engineering Task Force (IETF). It is a text-based application layer control protocol used to create, modify and release a session of one or more participants.

[0097] For example, in the process of establishing a media session between terminal A and terminal B, the SIP request messages involved may include INVITE, ACK, PRACK, etc.; the SIP response messages involved may include 200 OK, and various response messages starting with "1", such as 100 Trying, 183 Session Progress, 180 Ringing, etc.

[0098] In addition, it should be noted that when terminal A or terminal B initiates the operation of hanging up the call, the SIP request message (e.g. BYE) involved will also be transmitted to the IMS domain, machine room and base station corresponding to terminal B through the base station, machine room and IMS domain corresponding to the terminal initiating the BYE, such as terminal A, and finally reach terminal B. Correspondingly, after terminal B receives the BYE sent by terminal A, it will make a 200 OK SIP response message and send it to terminal A through base station B, machine room B, called IMS domain, calling IMS domain, machine room A and base station A. Thus, the media session between terminal A and terminal B will be disconnected.

[0099] It should be understood that the above description is only an example for better understanding of the technical solution of the present embodiment and is not the only limitation of the present embodiment. For the specific process of establishing a media session between terminal A and terminal B, the specific process of ending a media session, and the meaning of each SIP request message and SIP response message involved, please refer to the existing protocol standard, which will not be described here.

[0100] In addition, it should also be understood that the normal progress of the call relies on the wireless network resources determined by the base station and the terminal equipment (hereinafter referred to as: UE (User Equipment)) based on RRC. With the development of communication technology, for example, 5G network, in order to ensure that the wireless network resources can better adapt to the actual business scenario during the call process, RRC reconfiguration is introduced to realize the modification of the RRC connection between the UE and the base station. For example, establishing / modifying / releasing RB (Resource Block), performing cell switching (base station switching), setting / modifying / releasing measurement report, etc.

[0101] In addition, it should also be understood that the RRC reconfiguration can also be realized in the 4G network. Specifically, in the 4G network, the RRC reconfiguration is referred to as RRC connection reconfiguration (RRC Reconfiguration). For ease of illustration, the present embodiment takes the RRC reconfiguration in the 5G network as an example for illustration.

[0102] Specifically, in the 5G network, the RRC reconfiguration is initiated by the network side (5G base station). That is, the base station actively sends the RRC reconfiguration message to the corresponding UE, such as Figure 2a “RRC Reconfiguration” in the.

[0103] For example, the RRC reconfiguration message can carry the measurement configuration indicating the UE to perform the measurement report operation, the configuration of the SRS resource of the antenna switching mode, the configuration of the encryption and decryption algorithm adopted by the data packet interacting with the base station, etc. Here, it will not be listed one by one, only the configurations involved in the scenarios listed in the subsequent embodiments will be taken as examples. For the specific content and format of the RRC reconfiguration message carrying different configurations, please refer to the existing standard protocol, which will not be described here.

[0104] For example, when the UE receives the RRC reconfiguration message (for example, carrying the measurement configuration indicating the UE to perform the measurement report operation) sent by the 5G base station (the base station corresponding to the current cell), the UE will perform the measurement report operation according to the measurement configuration, and will generate the measurement report and feed back to the 5G base station. The 5G base station will then issue the RRC reconfiguration message to the UE indicating the UE to switch to the target base station according to the measurement report, so that the UE switches from the currently accessed 5G base station to the target base station. And based on the provisions of the existing standard protocol, the UE completes the RRC reconfiguration according to the RRC reconfiguration message sent by the 5G base station, that is, after switching to the target base station, it will reply to the target base station with a message indicating the completion of the RRC reconfiguration, such as Figure 2a“RRC ReconfigurationComplete” shown in FIG. 1. Conversely, if the target base station cannot match or be compatible with the configuration in the RRC reconfiguration message sent by the 5G base station, the UE will not be able to switch to the target base station. Moreover, based on the existing standard protocol provisions, the UE will perform an RLF (Radio Link Failure, RLF) procedure, such as releasing the connection with the 5G base station of the current cell, and reselecting to perform cell selection, and then performing an RRC connection re-establishment procedure with the reselected 5G base station, such as Figure 2b “RRC Connection re-establishment” shown in FIG. 1. When the reselected 5G base station is the 5G base station that has just been disconnected, since the RRC between the UE and the 5G base station was originally normal, the 5G base station will consider that the current RRC connection is abnormal after performing the RRC Connection re-establishment with the UE. Based on the existing standard protocol provisions, the 5G base station will issue a BYE message to the UE to end the current call, and then hang up the current call.

[0105] Based on the above provisions of the existing standard protocol, if the RRC reconfiguration message issued by the 5G base station is configured strictly in accordance with the existing standard protocol, such as in the case where the target base station does not support certain configurations, these configurations will be cancelled in the RRC reconfiguration message indicating the UE to switch to the target base station, and the RRC Connection re-establishment procedure will not be triggered.

[0106] However, in actual application scenarios, it is found that there are currently some 5G base stations in some regions that do not fully generate RRC reconfiguration messages in accordance with the existing standard protocol. This results in the UE performing cell switching according to the RRC reconfiguration message, which will result in switching failure and thus call interruption.

[0107] In order to better understand, the following describes two specific cases that cause RRC reconfiguration failure in combination with Figure 3 and Figure 4 .

[0108] Before describing the two specific cases that cause RRC reconfiguration failure, some descriptions involved in the following embodiments are described.

[0109] Specifically, in the embodiments of the present application, the verification operation performed by the UE when receiving the RRC reconfiguration message issued by the network side includes verification of the information in the RRC reconfiguration message currently received from the network side, and verification of the content of the configuration items saved locally by the UE, such as parameters and values corresponding to the parameters. Specifically, it can be understood that the UE will perform set operation on the information in the RRC reconfiguration message issued by the network side and the content of the configuration items saved locally, and then verify all the obtained content, such as whether the content is matched or compatible. In order to facilitate description, the present application directly describes the verification of the RRC reconfiguration message in the drawings and the embodiment part.

[0110] Referring to Figure 3 , for example, it is assumed that the base stations corresponding to Cell A, Cell B and Cell C are all 5G base stations, i.e., all support issuing RRC reconfiguration messages.

[0111] Continuing to refer to Figure 3 , for example, in the scenario shown in Figure 3 , the frequency band corresponding to Cell B is in Time Division Duplexing (TDD) mode, for example, n78 cell with frequency in n78 frequency range; the frequency band corresponding to Cell C is in Frequency Division Duplexing (FDD) mode, for example, n1 cell with frequency in n1 frequency range.

[0112] Continuing to refer to Figure 3 , for example, when the UE establishes a media session with the called party through the base station corresponding to Cell A, the core network, the IMS domain, the IMS domain corresponding to the called party, the core network and the base station, i.e., in the process of calling (S101) in Cell A, Cell A can perform RRC Reconfiguration process (S102) with the UE.

[0113] Continuing to refer to Figure 3 , for example, the RRC Reconfiguration process of S102 can include S102a, S102b and S102c.

[0114] For example, S102a is a step of issuing an RRC reconfiguration message by the base station in Cell A (hereinafter directly described as cell) to the UE. In the present embodiment, the RRC reconfiguration message issued by Cell A to the UE is an RRC reconfiguration message carrying measurement configuration (hereinafter referred to as: RRC reconfiguration message 1).

[0115] For example, S102b is a step of checking the content in the RRC reconfiguration message 1 by the UE. Specifically, the UE checks whether the information (information elements) configured for Cell A in the RRC reconfiguration message 1 is reasonable according to the existing standard protocol and the properties of Cell A.

[0116] For example, if the UE passes the checking of the RRC reconfiguration message 1, i.e., there is no abnormal information element (or configuration item) in the RRC reconfiguration message 1, the UE performs RRC reconfiguration according to the RRC reconfiguration message 1, and performs S102c after completing the RRC reconfiguration. That is, the UE sends an RRC Reconfiguration Complete to Cell A to indicate that the RRC reconfiguration performed by Cell A for the RRC reconfiguration message 1 is completed.

[0117] For example, if the UE fails to pass the checking of the RRC reconfiguration message 1, the UE performs RLF and releases the connection with Cell A, and then reselects a cell for camping. In this case, the UE can select the original cell, i.e., the currently accessed cell, for camping, or select a new cell for camping. The specific processing after the checking fails, such as S113 to S115, is not described here.

[0118] For example, the embodiment takes the case that the checking of the content in the RRC reconfiguration message 1 in S102b is successful, i.e., the UE performs S102c.

[0119] Continuing to refer to Figure 3 For example, since the RRC reconfiguration message 1 carries the measurement configuration, after the UE completes the RRC reconfiguration according to the RRC reconfiguration message 1, the UE performs the measurement operation.

[0120] Understandably, the RRC reconfiguration is to ensure that the wireless network resources can better adapt to the actual business scenario during the call. Therefore, it is necessary to ensure that the signal of the cell to be switched to is stronger than the signal of the currently accessed cell. Therefore, the measurement configuration carried in the RRC reconfiguration message can be the measurement configuration for triggering the UE to perform the A3 event (the measurement configuration carried in the subsequent other RRC reconfiguration messages is also for triggering the UE to perform the A3 event).

[0121] Based on this, the UE performs S103 according to the measurement configuration, i.e., the UE generates an A3 measurement report (A3 MR) when the signal of Cell A gradually weakens and the signal of Cell B gradually strengthens during the movement from Cell A to Cell B.

[0122] Continuing to refer to Figure 3For example, after the UE generates the A3 MR, the UE sends the A3 MR to the Cell A, i.e., S104 is performed.

[0123] Continuing to refer to Figure 3 For example, after the Cell A receives the A3 MR sent by the UE, the Cell A sends the UE an RRC reconfiguration message 2 indicating that the UE is switched to the Cell B, i.e., S105 is performed.

[0124] Understandably, the A3 MR generated by the UE can contain address information of the Cell B whose signal gradually becomes strong, and therefore the RRC reconfiguration message 2 sent by the Cell A to the UE can carry the address information of the Cell B to be switched to, so that the UE switches to the Cell B according to the address information of the Cell B.

[0125] In addition, the RRC reconfiguration message 2 can also carry relevant information of the Cell B, such as attributes, configuration items currently configured, etc., which are not listed here and are not limited by the present application.

[0126] Understandably, the UE needs to perform a verification operation when receiving any RRC reconfiguration message sent by the network side. Therefore, after receiving the RRC reconfiguration message 2 sent by the Cell A, the UE also needs to verify the content in the RRC reconfiguration message 2.

[0127] For example, if the UE verifies the RRC reconfiguration message 2 successfully, the UE switches to the Cell B according to the address information of the Cell B carried in the RRC reconfiguration message 2, and stays in the Cell B before receiving the next instruction to switch to a cell.

[0128] It should be understood that when the UE stays in the Cell B, the current media session will continue in the Cell B without hanging up the phone, i.e., the call between the UE and the Cell A in S101 will be performed between the UE and the Cell B.

[0129] For example, if the UE verifies the RRC reconfiguration message 2 unsuccessfully, the UE performs an RLF process, such as releasing the connection with the current cell and then reselecting a cell to stay in. When reselecting a cell to stay in, the UE can also select the original cell to stay in or select a new cell to stay in. The specific processing after the verification fails, such as S113 to S115, is not specifically described here.

[0130] For example, the present embodiment takes the verification of the UE on the content in the RRC reconfiguration message 2 as an example of successful verification, i.e., the UE receives the RRC reconfiguration message 2 sent by the Cell A and performs S106.

[0131] Since the result of S106 is that the UE's check on the content in RRC Reconfiguration message 2 is successful, after camping on Cell B, the UE will also send RRC Reconfiguration Complete to Cell A, informing Cell A that the RRC reconfiguration (switching to Cell B) for RRC Reconfiguration message 2 has been completed, i.e. S107 is performed.

[0132] Continuing to refer to Figure 3 , for example, if the conversation continues between the UE and Cell B, Cell B performs RRC Reconfiguration process with the UE (S108).

[0133] Continuing to refer to Figure 3 , for example, the RRC Reconfiguration process of S108 can include S108a, S108b, S108c and S108d.

[0134] For example, S108a is the step of the base station in Cell B (hereinafter directly described as a cell) issuing an RRC reconfiguration message to the UE. In this embodiment, taking the RRC reconfiguration message issued by Cell B to the UE as an example, the RRC reconfiguration message (hereinafter referred to as RRC reconfiguration message 3) carrying the configuration of the SRS resource of the antenna switching mode.

[0135] Regarding the above-mentioned SRS (Sounding Reference Signal), it is a signal used to detect the channel quality of the uplink frequency band. In actual application, the configuration of the SRS resource for the UE to periodically send SRS can be informed to the UE through the SIB (System Information Blocks) message, or the RRC Connection Setup (RRC connection establishment) message, or the above-mentioned RRC reconfiguration message sent by the network side.

[0136] Among them, the SRS resource configuration sent by the SIB corresponds to the Cell Specific SRS (cell-specific SRS); the SRS resource configuration sent by the RRC connection establishment message or the RRC reconfiguration message corresponds to the Dedicated SRS (UE-specific SRS).

[0137] Among them, the SRS resource configuration can support four modes of beam management, codebook, non-codebook, and antenna switching (antennaSwitching).

[0138] For beam management mode, there is no need for base station feedback associated with SSB (Synchronization Signal / PBCH Block) beam management.

[0139] For codebook mode, the base station gets SRI (SRS resource indicator), TPMI (Transmitted Precoding Matrix Indicator), and RI (Rank Indicator) information by measuring SRS, and then feeds back the three to the UE as needed based on the codebook case.

[0140] For non-codebook mode, the base station gets SRI, TPMI, and RI information by measuring SRS, feeds back SRI to the UE, and selects the same precoding matrix for PUSCH (Physical Uplink Shared CHannel) as SRS (the SRI corresponds to SRS, and the precoding matrix selection may come from CSI-RS (Channel State Information-Reference Signal) measurement).

[0141] For antenna switching mode, SRS is used to measure downlink CSI (channel state information) when downlink CSI cannot be obtained. Because the UE transmitting antennas are generally less, the UE needs to traverse all antennas through antenna switching to measure uplink CSI, so that the base station obtains downlink CSI based on the reciprocity of uplink and downlink channels, which does not need base station feedback. However, according to the existing standard protocol, TDD cells (i.e. cells corresponding to frequency bands belonging to TDD mode frequency bands) support the configuration of SRS resources in antenna switching mode, but FDD cells (i.e. cells corresponding to frequency bands belonging to FDD mode frequency bands) do not support the configuration of SRS resources in antenna switching mode. The specific reasons are as follows: for a TDD system, uplink and downlink share one spectrum resource, and time is divided into uplink and downlink. In most cases, for a given UE, we can consider that the uplink and downlink experienced by the UE are the same path, i.e. the spatial characteristics are approximately the same, which is also called uplink and downlink channel reciprocity. Therefore, the TDD system can use the uplink SRS to obtain the downlink channel CSI by using the uplink and downlink channel reciprocity. Further, in order to obtain the downlink CSI information of each channel, the base station can make the UE switch to different antenna ports to send SRS in turn, so as to obtain the CSI of each downlink channel through the uplink SRS of each uplink channel. For the FDD system, the downlink and uplink are two independent spectrum resources, and the uplink and downlink channel reciprocity cannot be used. Therefore, SRS cannot be used to evaluate the downlink channel quality in FDD mode, and the FDD system does not support the configuration of SRS resources in antenna switching mode.

[0142] The specific implementation of SRS round transmission can be referred to the existing protocol, which will not be described here.

[0143] For example, S108b is a step of checking the content of the RRC reconfiguration message 3 by the UE. Specifically, the UE will check whether the information (information element) configured for Cell B in the RRC reconfiguration message 3 is reasonable according to the existing standard protocol and the properties of Cell B.

[0144] From the above description, it can be known that Cell B is a TDD system, and the TDD system supports the configuration of SRS resources in antenna switching mode. Therefore, it is reasonable to carry the configuration of SRS resources in antenna switching mode in the RRC reconfiguration message 3, and thus the UE successfully checks the content of the RRC reconfiguration message 3. The UE will perform RRC reconfiguration according to the RRC reconfiguration message 3, for example, configure SRS resources in antenna switching mode, i.e. perform S108c.

[0145] Continue to refer toFigure 3 For example, after completing the RRC reconfiguration according to the RRC reconfiguration message 3, the UE will perform S108d. That is, the UE sends an RRC Reconfiguration Complete to the Cell B, indicating that the RRC reconfiguration performed by the Cell B for the RRC reconfiguration message 3 has been completed.

[0146] Continuing to refer to Figure 3 For example, in some implementations, the Cell B can also issue an RRC reconfiguration message carrying a measurement configuration to the UE.

[0147] For example, in some other implementations, the measurement configuration instructing the UE to perform a measurement report can also be directly carried in the RRC reconfiguration message 3.

[0148] For the processing of the RRC reconfiguration message by the UE, please refer to S102a to S102c, which will not be described in detail here.

[0149] For the purpose of illustration, this embodiment still takes the case of successful verification as an example. That is, the UE will perform a measurement report according to the measurement configuration, that is, perform S109. Specifically, in S109, the UE will generate an A3 measurement report (A3 MR) when the signal of the Cell B gradually weakens and the signal of the Cell C gradually strengthens during the process of moving from the Cell B to the Cell C.

[0150] Continuing to refer to Figure 3 For example, after the UE generates the A3 MR, the UE will send the A3 MR to the Cell B, that is, perform S110.

[0151] Continuing to refer to Figure 3 For example, after the Cell B receives the A3 MR sent by the UE, the Cell B issues an RRC reconfiguration message 4 to the UE, instructing the UE to switch to the Cell C, that is, perform S111. For example, in this embodiment, the configuration of the SRS resource in the antenna switching mode is not removed in the RRC reconfiguration message 4, that is, the configuration of the SRS resource in the antenna switching mode is still retained. After the UE receives the RRC reconfiguration message 4 issued by the Cell B, the UE will also verify the content in the RRC reconfiguration message 4, that is, perform S112.

[0152] As described above, Cell C is an FDD system, and FDD systems do not support the configuration of SRS resources in antenna switching mode. Therefore, according to existing standard protocols, Cell B should send an RRC reconfiguration message to the UE before RRC reconfiguration message 4, instructing the UE to release the already configured SRS resources for antenna switching mode. Alternatively, the information for removing the configuration of SRS resources for antenna switching mode can be directly included in RRC reconfiguration message 4.

[0153] However, in Figure 3 In the scenario shown, when Cell B sends RRC reconfiguration message 4 to the UE, it does not include the configuration information for removing the SRS resources used for the antenna switching mode. However, the UE configures the SRS resources for the antenna switching mode in S108d. A configuration of a parameter previously received in Cell B and saved in the UE has not been deleted by the network according to the protocol. When the UE applies this previously saved configuration of the parameter in Cell B to the Cell C it is switching to, the configuration of that parameter in the UE will be incompatible or mismatched with Cell C because Cell C does not support it, leading to RRC reconfiguration message verification failure. It should be understood that, in some practical scenarios, the verification of an RRC reconfiguration message discussed in this paper involves the terminal device combining the information carried in the RRC reconfiguration message (or the content of the message) with the configuration information already saved in the terminal device (which may come from one or more previous RRC reconfiguration messages) to obtain the verification result of the RRC reconfiguration message. Therefore, when the UE verifies the RRC reconfiguration message 4 (which may include relevant information about Cell C), the verification result for the RRC reconfiguration message 4 fails because Cell C does not support the configuration of SRS resources for antenna switching modes already saved in the terminal device.

[0154] See also Figure 4 For example, when the UE fails to verify the RRC reconfiguration message 4, the UE will execute the RLF procedure (including releasing the connection with Cell B), and then reselect the cell and camp on the newly selected cell.

[0155] Regarding the operations performed by the UE in the event of an RRC reconfiguration message verification failure, existing standard protocols can be referenced. This embodiment takes the selection of the original cell as an example, that is, after the UE fails to verify RRC reconfiguration message 4, the UE executes S113 as an example.

[0156] See also Figure 3For example, if the UE chooses to camp on the original cell (i.e., the Cell B on which the UE camped before the handover), the UE will send an RRC Connection re-establishment Request message to Cell B carrying the reason value of the RRC reconfiguration failure (such as Reconfiguration failure). For example, sending an RRC Connection re-establishment Request carrying Reconfiguration failure to Cell B will enable Cell B and the UE to perform the RRC connection re-establishment procedure, i.e., execute S114.

[0157] For example, after receiving the RRC Connection re-establishment Request, Cell B will reply to the UE with an RRC Connection Setup message indicating the radio bearer and serving cell group, so that the UE and Cell B can re-establish the RRC connection.

[0158] For details on the specific implementation process of RRC connection re-establishment between the UE and the base station, please refer to the existing standard protocols, which will not be elaborated here.

[0159] For example, since the RRC Connection re-establishment Request carries the "Reconfiguration failure" message, after the RRC connection between the UE and Cell B is successfully re-established, Cell B will immediately send the reason for the RRC reconfiguration failure to the UE. Because the RRC connection between Cell B and the UE was normal before the RRC connection re-establishment, in a scenario where the UE reselects the original cell, the original cell, i.e., Cell B, will consider the RRC connection with the UE to be abnormal. In this case, Cell B will immediately send a BYE message to the UE. The BYE message's reason field will carry the message that Cell B determined the handover from Cell B to Cell C failed due to insufficient bearer resource, corresponding to error code 503, i.e., S115.

[0160] Because Cell B sent a BYE message to release the current call, the call between the UE and Cell B will be interrupted.

[0161] The analysis finds that the reason why the UE fails to handover from an n78 cell (the n78 frequency band belongs to a TDD mode frequency band) to an n1 cell (the n1 frequency band belongs to an FDD mode frequency band) during a call is that the network (here, the network specifically refers to a base station corresponding to the n78 cell) configures an antenna switching mode SRS resource for the UE on the n78 cell, and before the handover to a cell that does not support the configuration of the antenna switching mode SRS resource, the network (here, the network specifically refers to the base station corresponding to the n78 cell) does not instruct the UE to remove the configuration (in this case, according to the provisions of the standard protocol process, the base station corresponding to the n78 cell should send an RRC Reconfiguration message carrying the removal of the configuration of the antenna switching mode SRS resource to the UE to instruct the UE to release the SRS resource on the UE side before instructing the UE to handover to another cell (the cell does not support the configuration of the antenna switching mode SRS resource)), and the n1 cell cannot support the configuration of the antenna switching mode SRS resource, so when the UE hands over to the n1 cell, SRS based on the SRS resource configured by the network for the UE on the n78 cell will fail to handover.

[0162] Therefore, as known from the above description, the UE does not handover from the Cell B to the Cell C not because of insufficient bearer resources, but because there is a configuration incompatible with the Cell C in the RRC Reconfiguration message 4, such as the configuration of the antenna switching mode SRS resource incompatible with the Cell C as mentioned above.

[0163] It should be understood that the above description is only an example for better understanding the technical solutions of the embodiments and is not the only limitation of the embodiments.

[0164] Referring to Figure 3 , exemplary scenarios are taken when the UE selects a new cell to camp in after the RRC Reconfiguration message check fails.

[0165] In the embodiments, the limitations of the Cell A, the Cell B, and the Cell C in Figure 4 are still taken as examples, and the specific implementation of S201 to S207 can be referred to S101 to S107 in Figure 4 , which will not be described herein. The following describes the specific processing involved when the UE selects a new cell (such as the Cell A, which is a new cell relative to the Cell B from which the UE has just released the connection and the Cell C to which the UE attempts to handover) to camp in after the RRC Reconfiguration message 4 check fails, in combination with S208 to S220 shown in Figure 4 .

[0166] S208: UE performs RRC Reconfiguration procedure with Cell B.

[0167] Referring to Figure 4 , the RRC Reconfiguration procedure of S208 may include S208a, S208b, S208c and S208d.

[0168] S208a is an example of a step in which Cell B sends an RRC Reconfiguration message to UE. In this embodiment, the RRC Reconfiguration message 3 sent by Cell B to UE is an example of an RRC Reconfiguration message carrying the configuration of SRS resources in antenna switching mode and the configuration of starting ROHC algorithm. It should be understood that in actual applications, the configuration of SRS resources in antenna switching mode and the configuration of starting ROHC algorithm can be sent to UE by the same RRC Reconfiguration message or by different RRC Reconfiguration messages, and the present embodiment does not limit this.

[0169] S208b is an example of a step in which UE checks the content in the RRC Reconfiguration message 3. Specifically, UE checks whether the information (information elements) configured for Cell B in the RRC Reconfiguration message 3 is reasonable according to existing standard protocols and the properties of Cell B.

[0170] It can be understood that base stations and UEs generally have the ability to use the ROHC algorithm (a widely recognized algorithm for data header compression and decompression on a wireless link). By default, the UE can be configured to turn off the ROHC algorithm (i.e., the UE does not use the ROHC algorithm), and when the UE receives the RRC Reconfiguration message sent by the base station and the RRC Reconfiguration message carries the configuration of starting the ROHC algorithm, the UE starts the ROHC algorithm.

[0171] In addition, it should be understood that when the base station informs the UE to start the ROHC algorithm, the base station itself will also start the ROHC algorithm. In this way, when the UE camps on the cell of the base station, the two can use the ROHC algorithm to compress the data packets sent and decompress the data packets received.

[0172] In addition, Cell B in this embodiment is a TDD system, and the TDD system supports the configuration of SRS resources in antenna switching mode. Therefore, it is reasonable to carry the configuration of SRS resources in antenna switching mode in the RRC Reconfiguration message 3, and therefore the UE checks the content in the RRC Reconfiguration message 3 successfully. The UE will perform RRC Reconfiguration according to the RRC Reconfiguration message 3, for example, configure SRS resources in antenna switching mode and start the ROHC algorithm, i.e., perform S208c.

[0173] With reference to Figure 4 , exemplary, after completing the RRC reconfiguration according to the RRC reconfiguration message 3, the UE will perform S208d. Namely, sending the RRC Reconfiguration Complete to the Cell B, to inform the Cell B that the RRC reconfiguration performed by the Cell B for the RRC reconfiguration message 3 has been completed.

[0174] With reference to Figure 4 , exemplary, in some implementations, the Cell B can also issue the RRC reconfiguration message carrying the measurement configuration to the UE.

[0175] Exemplary, in some other implementations, the measurement configuration instructing the UE to perform the measurement reporting operation can also be directly carried in the RRC reconfiguration message 3.

[0176] As to the processing of the UE for the RRC reconfiguration message, please refer to S102a to S102c, which will not be repeated here.

[0177] For the convenience of description, this embodiment still takes the successful verification as an example, namely, the UE will perform the measurement reporting operation according to the measurement configuration, namely, performing S209.

[0178] S209: When the signal of the Cell B gradually weakens and the signal of the Cell C gradually strengthens during the process of the UE moving from the Cell B to the Cell C, the UE will generate an A3 measurement report (A3 MR).

[0179] S210: The UE sends the A3 MR to the Cell B.

[0180] S211: The Cell B sends the RRC reconfiguration message 4 instructing the UE to switch to the Cell C to the UE.

[0181] This embodiment still takes the configuration of the SRS resource in the antenna switching mode which is not removed / eliminated in the RRC reconfiguration message 4 as an example.

[0182] S212: The UE verifies the RRC reconfiguration message 4.

[0183] Understandably, the Cell B has performed the data interaction with the Cell C according to the A3 MR reported by the UE in S210 when issuing the RRC reconfiguration message 4 to the UE. Assuming that the Cell C also starts the ROHC algorithm, therefore, the configuration of closing the ROHC algorithm does not need to be carried in the RRC reconfiguration message 4. Therefore, the UE will not close the ROHC algorithm.

[0184] In addition, as to the processing logic of the S212 verification process, please refer to S112 in the above embodiments, which will not be repeated here.

[0185] S213: Perform RLF procedure, select new cell (Cell A) to camp on.

[0186] The specific operations involved in performing RLF can refer to existing standard protocols.

[0187] Continuing to refer to Figure 3 , for example, if the UE selects to camp on the new cell (Cell A) after performing the RLF procedure, the UE sends an RRC Connection re-establishment Request carrying Reconfiguration failure to Cell A, so that Cell A and the UE can perform an RRC connection re-establishment procedure, i.e., perform S214.

[0188] S214: RRC connection re-establishment procedure of camping on the new cell.

[0189] Specifically, since Cell A is a new cell, Cell A can send an RRC reconfiguration message 5 to the UE. The UE can send an RRC Reconfiguration Complete to Cell A after successfully verifying the RRC reconfiguration message 5, to inform Cell A that the RRC reconfiguration performed by Cell A on the RRC reconfiguration message 5 is complete. Thus, the establishment of the RRC connection between the UE and Cell A is achieved.

[0190] Continuing to refer to Figure 4 , for example, in S208c, the UE starts the ROHC algorithm according to the configuration for starting the ROHC algorithm carried in the RRC reconfiguration message 3 after successfully verifying the RRC reconfiguration message 3. However, before camping on Cell A, the UE has not received the RRC reconfiguration message for Cell B to issue a configuration for closing the ROHC algorithm. Therefore, after camping on Cell A, the UE still starts the ROHC algorithm.

[0191] Based on this, if Cell A does not start the ROHC algorithm. After the RRC connection between the UE and Cell A is established, the UE will continue to compress and decompress data packets based on the ROHC algorithm, i.e., perform S215. Cell A will compress and decompress data packets using a non-ROHC algorithm, i.e., perform S216.

[0192] S215: Compress and decompress data packets based on the ROHC algorithm.

[0193] That is, the UE will compress the uplink RTP sent to Cell A based on the ROHC algorithm, and decompress the downlink RTP packet received from Cell A based on the ROHC algorithm.

[0194] S216: The base station corresponding to Cell A does not start the ROHC algorithm, and uses a non-ROHC algorithm for data packet compression and decompression processing.

[0195] That is, Cell A will compress the uplink RTP sent to the UE using a non-ROHC algorithm, and decompress the downlink RTP packet received from the UE using a non-ROHC algorithm.

[0196] S217: Uplink RTP packet / downlink RTP packet.

[0197] Understandably, for the UE, the uplink RTP in S217 is the RTP packet sent by the UE to Cell A, and the downlink RTP packet is the RTP packet sent by Cell A to the UE. For Cell A, the uplink RTP in S217 is the RTP packet sent by Cell A to the UE, and the downlink RTP packet is the RTP packet sent by the UE to Cell A.

[0198] S218: Decompression failure, discard.

[0199] Understandably, since the UE decompresses the received RTP packet based on the ROHC algorithm after receiving the RTP packet sent by Cell A, and Cell A does not compress the RTP to be sent to the UE using the ROHC algorithm. Therefore, the UE will not be able to decompress the RTP packet sent by Cell A, i.e., decompression failure will occur. For the decompressed RTP packet, the UE will discard it directly.

[0200] S219: Decompression failure, discard.

[0201] Understandably, since Cell A does not decompress the received RTP packet based on the ROHC algorithm after receiving the RTP packet sent by the UE, and the UE compresses the RTP to be sent to Cell A using the ROHC algorithm. Therefore, Cell A will not be able to decompress the RTP packet sent by the UE, i.e., decompression failure will occur. For the decompressed RTP packet, Cell A will also discard it directly.

[0202] In this way, the UE and the Cell A will not directly receive the RTP packets sent by each other and related to the current call. According to the existing standard protocol, the UE will determine that the current call has an RTP or RTCP (Real-time Transport Control Protocol) resource timeout when the UE does not receive the RTP packets related to the current call within a certain time. In this case, the UE will send a BYE message to the Cell A. The reason field of the BYE message carries the RTP / RTCP timeout resource, and the corresponding error code is 2, i.e., S220.

[0203] S220: BYE message (reason field: cause=2; text="RTP / RTCP timeout Resource").

[0204] Since the UE sends the BYE message for releasing the current call, the call between the UE and the Cell A will be disconnected. The reason that the UE and the Cell A cannot receive the RTP packets sent by each other is not that the UE and the Cell A do not send the RTP packets within a set time, but that the configurations of the UE and the Cell A do not match, for example, one of the UE and the Cell A starts the ROHC algorithm, and the other does not start the ROHC algorithm.

[0205] It should be understood that the above description is only an example for better understanding the technical solution of the embodiment and is not the only limitation of the embodiment.

[0206] Through the above description Figure 3 and Figure 4According to the description of the scenarios, the call drop problem that occurs after the UE performs the RLF procedure and reselects to camp on a cell is caused by the UE failing to verify the RRC reconfiguration message sent by the network side. For example, in one scenario, during the verification of the RRC reconfiguration message, the RRC reconfiguration message indicates that the UE switches to a specified cell C, and the RRC reconfiguration message does not carry a configuration item (such as information for deleting the configuration of the SRS resource of the antenna switching mode) of a certain parameter of the cell C, but the UE has the configuration of the SRS resource of the antenna switching mode that is incompatible with the cell C, which causes the RRC reconfiguration message to fail to be verified. Therefore, some embodiments of the present application provide a method for a call, which aims to enable the terminal device to update the abnormal configuration item (the parameter in the configuration item is abnormal, such as the current corresponding value being incompatible with or not matching the cell to be camped on) in the case that the network side does not completely control the configuration of certain parameters according to the existing standard protocol, so that the RRC reconfiguration message for indicating the UE to switch to the specified cell is verified successfully, and then the UE can successfully switch from the original cell to the specified cell, thereby reducing the problem of switching failure, so that the UE does not cause the call to have a problem even if the cell is switched during the call, reducing the call failure and improving the user experience. Alternatively, for example, in another scenario, during the verification of the RRC reconfiguration message, the RRC reconfiguration message carries a certain configuration item (the certain configuration item can also be referred to as the configuration of a certain parameter) corresponding to the current cell B, but the configuration item carried by the RRC reconfiguration message is incompatible or does not match the corresponding configuration item previously saved in the UE and corresponding to the current cell B (it can be understood that the value of the certain parameter carried by the RRC reconfiguration message and corresponding to the current cell B is incompatible or does not match the value of the parameter previously saved in the UE and corresponding to the current cell B), which causes the subsequent procedure to fail or fail, and then causes the call to have an abnormality. In this scenario, some embodiments of the present application provide a method for a call, which aims to enable the terminal device to update the abnormal configuration item in the case that the network side does not completely control the configuration of certain parameters according to the existing standard protocol, so that the RRC reconfiguration message is verified successfully, and then the call can continue smoothly.

[0207] Specifically, in the method for call provided by some embodiments of the present application, a way of updating the configuration item with exception is introduced, and a way of part of configuration items in the RRC reconfiguration message, that is, when the UE checks the RRC reconfiguration issued by the currently accessed base station and carrying the configuration of switching to the target base station, the UE detects whether the function of allowing updating of incompatible configuration items (hereinafter referred to as: compatible function) is enabled. Further, in the case where it is determined that the function is enabled, and the configuration items in the RRC reconfiguration message that do not match / incompatible with the target base station (hereinafter referred to as: configuration items with exception) are the configuration items in the preset configuration item list, the configuration items with exception are updated, such as by invalidating the configuration of the configuration items with exception (hereinafter referred to as: mode 1, for mode 1, the value corresponding to the configuration item with exception can be modified from "1" (which can represent that the configuration item has corresponding configuration) to "0" (which can represent that the configuration corresponding to the configuration item is removed), so that the configuration of the configuration item with exception can be invalidated (which can also be understood as removing the configuration corresponding to the configuration item with exception), so as to ignore the configuration item with exception. The configuration of the configuration item with exception can be understood as ignoring the configuration item with exception.), or by updating the content configured in the UE for the configuration item with exception to the content of the configuration item configured in the RRC reconfiguration message (hereinafter referred to as: mode 2), so as to make the RRC reconfiguration message pass the check, and further realize switching from the current base station to the target base station.

[0208] It should be noted that the configuration items in the preset configuration item list in the present application are specifically the configuration items allowed to be updated according to the above-mentioned mode 1 or mode 2 based on the existing standard protocol and the attributes of the target base station to be switched to, and updating the configuration items in the preset configuration item list will not affect the RRC reconfiguration.

[0209] In order to better understand the method for call provided by the present application, the method for call provided by the embodiments of the present application is introduced based on the scenarios shown in Figure 5 and Figure 5 The specific implementation scenarios are described in combination with Figure 4

[0210] Before the method for call provided by the embodiments of the present application is described, some descriptions involved in the following embodiments are described.

[0211] Specifically, in the embodiments of the present application, the preset configuration item list is the parameter configuration list pre-stored in the terminal device as described above.

[0212] Correspondingly, the updatable configuration item is the ignorable parameter as described above.

[0213] ​Furthermore, in the embodiments of this application, the configuration item with an abnormality is the configuration item whose value corresponding to the parameter mentioned above is abnormal. For example, when the value corresponding to the first parameter is abnormal, the first configuration item including the first parameter is the configuration item with an abnormality.

[0214] Based on this premise, in the following embodiments and the corresponding accompanying drawings, determining whether an abnormal configuration item is a configuration item in a preset configuration item list (e.g., S404) essentially means that when the value corresponding to the first parameter is abnormal, it is determined whether the first parameter is the same as any parameter in the parameter list stored in the terminal device. Since the parameter value corresponding to each parameter included in the parameter list can be updated, when it is determined that the first parameter is the same as any parameter in the parameter list stored in the terminal device, the first parameter can be determined to be an ignoreable parameter. That is, the abnormal configuration item mentioned in the following embodiments is an updatable configuration item.

[0215] Accordingly, when a configuration item includes parameters and corresponding parameter values, updating the configuration item is essentially updating the values ​​corresponding to the parameters in the configuration item.

[0216] See Figure 5 S301 to S311 and Figure 5 The implementations of S201 to S211 in the above embodiments are similar, and the specific implementation details are detailed in the description of S201 to S211, which will not be repeated here. Among them, S312 to S319 are the processing logic performed by the UE and the network side after introducing the method for making calls provided in this application.

[0217] See also Figure 5 For example, after receiving the RRC reconfiguration message 4 from Cell B, when verifying the RRC reconfiguration message 4, the UE will check whether the Cell C to which it is required to switch is an FDD system, and whether the UE has configured the antenna switching mode based on the RRC reconfiguration message previously received from the network side.

[0218] As described in the above embodiments, when the target base station to be switched to is an FDD system, i.e., it does not support the configuration of SRS resources in antenna switching mode, but the UE has configured SRS resources in antenna switching mode, the UE will result in an RRC reconfiguration message verification failure. Therefore, after introducing the method for making calls provided in this application, the UE needs to determine through S312 whether it is currently in an FDD system in Cell C and whether the UE has configured SRS resources in antenna switching mode.

[0219] Accordingly, when the above situation is determined, based on the user call method provided in this application, the UE will further detect whether the compatibility function is activated, that is, execute S313.

[0220] According to the existing standard protocol, for FDD system, the configuration of SRS resource in antenna switching mode is not supported, so when the target base station to be switched to is FDD system, the UE can not check the configuration of SRS resource in antenna switching mode, and make the RRC reconfiguration message 4 check successful in the case of compatible configuration.

[0221] For example, in some implementations, the configuration of SRS resource in antenna switching mode can be agreed, such as srs_tx_switch = 1 indicating that the SRS resource in antenna switching mode is configured. In the case of starting the compatible function, in S317, the UE can modify the configuration of SRS resource in antenna switching mode from "1" to "0" locally, that is, modify srs_tx_switch = 1 to srs_tx_switch = 0.

[0222] The starting of the compatible function can be understood as the enabling of the updating of the abnormal configuration item, which can be enabled by default by the UE or enabled by the user on the UE.

[0223] Continuing to refer to Figure 3 For example, after completing S317, since the configuration item in RRC reconfiguration message 4, such as the configuration of SRS resource in antenna switching mode, which does not conform to the existing standard protocol for FDD system Cell C, has been updated to srs_tx_switch = 0 in the UE, that is, the UE has removed the SRS resource in antenna switching mode, the UE checks the result of RRC reconfiguration message 4 as check success. In this way, the UE can switch to Cell C according to the address information corresponding to Cell C in RRC reconfiguration message 4, and will reside in Cell C before receiving the next instruction to switch cells, that is, execute S318.

[0224] As described above, after the UE completes RRC reconfiguration, it will send RRCReconfiguration Complete to the network side to inform the network side that the UE has completed RRC reconfiguration. Based on this, after the UE resides in Cell C, the UE will also send RRC Reconfiguration Complete to Cell C to inform Cell C that the RRC reconfiguration (switching to Cell C) performed by Cell C for RRC reconfiguration message 4 has been completed, that is, execute S319.

[0225] For example, when the UE resides in Cell C, the current media session will continue in Cell C without hanging up the phone, that is, the call is between the UE and Cell C.

[0226] For example, if it is determined in S313 that the UE does not start the compatible function, in this case, the UE can be set to perform the existing reselection cell process according to the existing standard protocol.

[0227] With reference to Figure 4 For example, in the case where the UE does not start the compatible function, the embodiment takes the scenario that the UE selects the original cell for camping as an example. The S314 to S316 involved in camping into the original cell are similar to the implementation of the S113 to S115 in the embodiment shown in Figure 5 The specific implementation details are described in the S113 to S115, which will not be repeated here.

[0228] For example, in another implementation, for example, in the scenario that the UE selects a new cell, such as Cell A, for camping in the case where the UE does not start the compatible function, the processing involved in camping into the new cell can be referred to the description of the S213 to S220 in the embodiment shown in Figure 6 The specific implementation details are described in the S113 to S115, which will not be repeated here.

[0229] It should be understood that the above description is only an example for better understanding the technical solution of the embodiment and is not the only limitation of the embodiment.

[0230] In addition, it should be noted that the starting of the compatible function (the name of the function can also be other names) can be started by the terminal manufacturer according to the customization requirements before the UE is factory-finished, and the compatible function switch of the UE put into a certain region or a certain type of UE is started. In this way, for the region or the type of UE, the configuration item that exists abnormally can be updated according to the method for user call provided by the embodiment of the application, so that the RRC reconfiguration message is checked successfully, thereby ensuring that the call will not be abnormal, for example, the UE updates the configuration item of the SRS resource of the antenna switching mode according to the above-mentioned mode 1, thereby ensuring that the UE can be successfully switched from the cell of the TDD system to the cell of the FDD system, reducing the problem of switching failure, and protecting the call from being hung up.

[0231] For example, in another implementation, all UEs generated by the terminal manufacturer can be set to start the compatible function by default. For this implementation, in the case where Cell C is determined to be the FDD system and the UE is configured with the antenna switching mode, S313 to S316 can be directly skipped and S317 can be performed.

[0232] For example, in another implementation, an entry can be provided in the UE for user operation, and the user can decide whether to start the compatible function according to the needs.

[0233] It should be understood that the above description is only an example for better understanding the technical solutions of the embodiments and is not the only limitation of the embodiments.

[0234] Because Figure 6 The embodiments are mainly aimed at the problem scenarios caused by the configuration of the SRS resource of the antenna switching mode, so the updated abnormal configuration items are mainly the configuration items of the SRS resource of the antenna switching mode. However, in actual application scenarios, for scenarios that do not involve the configuration of the SRS resource of the antenna switching mode, there will also be a problem of cell switching failure caused by the incompatibility of the configuration items. Therefore, the embodiments of the present application propose another method for a call, which determines the configuration items that can be updated by the UE (the configuration items that can be updated by the UE can also be understood as the configuration items that can be corrected by the UE) in different scenarios according to the existing standard protocol in advance, and can configure these configuration items that can be updated by the UE in the UE in advance, such as configuring the above-mentioned preset configuration item list in the UE. In this way, when the UE checks the content in the RRC reconfiguration message from the network side, it directly determines whether the configuration item that causes the check failure can be updated according to the above-mentioned mode 1 or mode 2 according to the pre-configured configuration item that can be updated, and then updates (which can also be understood as correcting) the configuration item that causes the abnormality according to the above-mentioned mode 1 or mode 2 when the configuration item that causes the abnormality can be updated, so that the UE can be not affected by the abnormal configuration item and normally switched to the target cell. Regarding this implementation, the following will be specifically described in combination with Figure 6 .

[0235] Referring to Figure 6 , for example, when the UE is in a call process in the first cell (S401), if a first RRC reconfiguration message issued by the first cell is received (S402), the UE will check the first RRC reconfiguration message (S403).

[0236] Regarding the process of establishing a media session between the UE and the first cell, please refer to S101 in the above-mentioned embodiments, which will not be described here.

[0237] Regarding the above-mentioned first cell, for example, it can be Cell A, or Cell B, or Cell C in the above-mentioned embodiments. For ease of understanding, the first cell in the embodiments is taken as Cell B.

[0238] When the first cell is Cell B, the first RRC reconfiguration message can be, for example, the RRC reconfiguration message 3 or the RRC reconfiguration message 4 sent by Cell B to the UE in the above-mentioned embodiments.

[0239] As to the checking logic of the UE to the first RRC reconfiguration message, please refer to S108b, or S112, or S208b, or S212, or S308b, etc. in the above embodiments, which will not be repeated here.

[0240] Continuing to refer to Figure 6 , for example, if the checking determines that there is no abnormal configuration item (or incompatible configuration item) in the first RRC reconfiguration message, it can be considered that the checking to the RRC reconfiguration message 4 is successful, and the UE can perform S410; otherwise, if there is an abnormal configuration item, it can be considered that the checking to the RRC reconfiguration message 4 fails, and the UE can perform S405.

[0241] It should be noted that the configuration carried by the first RRC reconfiguration message can be for the first cell or can indicate switching to the second cell (for example, Cell C). Therefore, in S410, the UE can perform specific operations according to the cell to which the first RRC reconfiguration message is directed.

[0242] Continuing to refer to Figure 6 , for example, when the first RRC reconfiguration message indicates switching to the second cell, the UE performs the operation of camping on the second cell according to the first RRC reconfiguration message, that is, S410a is performed. Accordingly, after the UE camps on the second cell, the UE sends an RRC Reconfiguration Complete to the second cell, that is, S410b is performed. The ongoing call of the UE will continue in the second cell.

[0243] Continuing to refer to Figure 6 , for example, when the first RRC reconfiguration message carries the configuration for the first cell (such as the RRC reconfiguration message 3 in the above embodiments), the UE performs the operation of configuring according to the configuration carried in the first RRC reconfiguration message, that is, S410c is performed. In this case, after the UE configures according to the first RRC reconfiguration information, the UE still camps on the first cell, so the UE sends an RRC Reconfiguration Complete to the first cell, that is, S410d is performed. The ongoing call of the UE will continue in the first cell.

[0244] Continuing to refer to Figure 6 , for example, after the checking to the first RRC reconfiguration message fails, the UE can perform S404 to determine whether the abnormal configuration item is a configuration item (updatable configuration item) in the preset configuration item list.

[0245] Exemplarily, if there is an abnormal configuration item (all) that is a preset updatable configuration item, the UE can further detect whether the compatible function is enabled, i.e., perform S405. Accordingly, if the compatible function is enabled, S409 can be performed. Conversely, if the compatible function is not enabled, in this case, the UE can be configured to perform the existing RLF procedure and the procedure of reselecting a cell for camping according to the existing standard protocol. The embodiment takes camping to the original cell as an example, i.e., the UE performs S406-S408 in the case where the compatible function is not enabled. For the specific implementation procedure of S406-S408, refer to S113-S115 or S314-S316 in the above embodiment, which will not be repeated here.

[0246] In actual application, in the case where the compatible function is not enabled, the UE can also camp to the new cell, i.e., perform S213-S220 in the above embodiment, which will not be repeated here.

[0247] It should be noted that the configuration carried in the first RRC reconfiguration message can be for the first cell or can be for indicating switching to the second cell (taking Cell C as an example). Therefore, in S409, the UE can perform different operations according to the different cells to which the first RRC reconfiguration message is for, which will be described in detail as follows.

[0248] Continuing to refer to Figure 7 Exemplarily, when the first RRC reconfiguration message carries the configuration for the first cell (such as the RRC reconfiguration message 3 in the above embodiment), the UE can update the abnormal configuration item to the corresponding configuration in the first RRC reconfiguration message in the above-mentioned manner 1, i.e., perform S409a. Specifically, when the first RRC reconfiguration message carries the second configuration item (which can also be understood as the first configuration item corresponding to the first configuration item saved in the UE, with the same name but different corresponding values) for the first cell, before receiving the first RRC reconfiguration message, the terminal device saves the first configuration item, the first configuration item and the second configuration item are for the same parameter but have different parameter values, and then the UE finds that the first configuration item is abnormal (which can be understood as the configuration corresponding to the parameter is abnormal) in the process of checking the first RRC reconfiguration message. In this case, after the UE updates the value of the first configuration item according to the first RRC reconfiguration message, it still camps in the first cell, so the UE sends the RRCReconfiguration complete message to the first cell, i.e., perform S409b. The ongoing call of the UE will continue in the first cell.

[0249] For example, for the scenario of updating the abnormal configuration item in mode 2, for example, when the UE switches from the above-mentioned Cell A to Cell B, the UE is configured according to the configuration of Cell B sent by Cell A, and after camping on Cell B, Cell B modifies the already configured configuration and carries it in the first RRC reconfiguration message sent to the UE, which causes the problem that some configuration items of Cell B configured in the UE are incompatible with the configuration carried in the first RRC reconfiguration message. For this case, the UE essentially operates according to the configuration in the last received RRC reconfiguration message. Therefore, the abnormal configuration item needs to be updated to the configuration in the last received RRC reconfiguration message.

[0250] It should be understood that the above description is only an example for better understanding the technical solutions of the embodiments and is not the only limitation of the embodiments.

[0251] Continuing to refer to Figure 7 , for example, when the first RRC reconfiguration message indicates switching to the second cell, the operation of the UE is to invalidate the abnormal configuration item, such as updating the abnormal configuration item in the above-mentioned mode 1, making the first RRC reconfiguration message pass the check, and then camping on the second cell according to the first RRC reconfiguration message, i.e., performing S409c. Correspondingly, after the UE camps on the second cell, it will send an RRC Reconfiguration Complete to the second cell, i.e., performing S409d. The current call of the UE will continue in the second cell.

[0252] For example, taking the above-mentioned configuration item of the SRS resource of the antenna switching mode as an example, in S409c, the UE can update the configuration item srs_tx_switch=1 of the SRS resource of the antenna switching mode to srs_tx_switch=0, so as to invalidate the configuration of the SRS resource of the antenna switching mode (which can also be understood as removing the configuration of the SRS resource of the antenna switching mode), and then the UE can pass the check of the first RRC reconfiguration message. It can be understood that when srs_tx_switch=1, the UE preliminarily checks that the check item is abnormal (i.e., the configuration item does not match Cell C) when checking the first RRC reconfiguration message, and the UE can modify the value of the configuration item to invalidate the configuration item, so that the first RRC reconfiguration message can finally be checked successfully by the UE.

[0253] It should be understood that the above description is only an example for better understanding the technical solutions of the embodiments and is not the only limitation of the embodiments.

[0254] In addition, it also needs to be explained that, based on the method for call provided in the present application, whether the configuration item with an abnormality is a preset updateable configuration item is determined, and when it is determined that all the configuration items with an abnormality are updateable configuration items, the operation of detecting whether the compatible function is enabled can occur when the UE receives any RRC reconfiguration message. The above description is only an example for better understanding the technical solution of the embodiment and is not the only limitation of the embodiment.

[0255] In addition, it should also be understood that, in the description of the method for call provided in the embodiment of the present application, only the 5G network is taken as an example, and the method is also applicable to the 4G network. Moreover, with the development of communication technology in the future, in the next generation communication technology such as 6G, if these networks can realize RRC reconfiguration based on the existing standard protocol, the method for call provided in the embodiment of the present application is also applicable.

[0256] In addition, it should also be understood that, in order to realize the above functions, the terminal device comprises hardware and / or software modules corresponding to each function. The algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed by hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application in combination with the embodiments, but such implementation should not be considered beyond the scope of the present application.

[0257] In order to better understand the technical solutions provided in the embodiments of the present application, taking a mobile phone as an example, based on the relationship between the software structure and the hardware of the mobile phone, the function modules, hardware involved in the method for call provided in the embodiments of the present application, and the interaction between the function modules and the hardware are described.

[0258] Before describing the software structure of the mobile phone, first, the architecture that can be used by the software system of the mobile phone is described.

[0259] Specifically, in actual application, the software system of the mobile phone can use layered architecture, event-driven architecture, microkernel architecture, microservice architecture, or cloud architecture.

[0260] In addition, it can be understood that the software system currently used by mainstream terminal devices includes but is not limited to Windows system, Android system and iOS system. In order to facilitate the description, the embodiments of the present application take the Android system with layered architecture as an example to exemplarily describe the software structure of the mobile phone. The technical solutions for call provided in the embodiments of the present application are also applicable to other systems in the specific implementation.

[0261] Further, it should also be understood that the current layered architecture of a mobile phone divides software into several layers, each of which has a clear role and division of labor. Layers communicate with each other through software interfaces. These layers may, for example, include an application layer, an application framework layer, an Android runtime and system library, a hardware abstraction layer, a kernel layer, and the like. The following will only take the layer in which the functional modules involved in the method for a call provided in the embodiments of the present application are located as an example for description.

[0262] Referring to Figure 7 , a schematic diagram of the software structure of the mobile phone of the embodiments of the present application and the hardware involved is shown. In Figure 1 , from top to bottom, there are an application layer, an application framework layer, a kernel layer, and hardware.

[0263] The application layer may, for example, include a series of application packages. The application framework layer provides application programming interfaces (APIs) and programming frameworks for the applications of the application layer. In some implementations, these programming interfaces and programming frameworks may be described as functions.

[0264] Continuing to refer to Figure 1 , in the technical solutions provided in the embodiments of the present application, the application layer may include a phone application, a settings application, a compatibility function enabling application, and the like.

[0265] The phone application may, for example, be used by a user to initiate a call service operation.

[0266] Correspondingly, the mobile phone may, in response to this operation behavior, establish a media session with a called party based on the mobile communication architecture shown in Figure 7 . As for the establishment of a media session, reference may be made to the description of the establishment of a media session by the terminal A and the terminal B based on the mobile communication architecture shown in Figure 7 . Details will not be described here.

[0267] The compatibility function enabling application may, for example, provide an entry for enabling a compatibility function.

[0268] For example, in the case where the compatibility function described in the above embodiments may be enabled by a user, the user may enable the compatibility function through the entry provided by the compatibility function enabling application that is specially used to enable the compatibility function, so that the mobile phone can, when the configuration items that may be updated in the above embodiments appear, update these configuration items using the method for a user call provided in the embodiments of the present application, so as to complete RRC reconfiguration, i.e., handover from the currently accessed 5G base station to a target base station.

[0269] The settings application may also, for example, provide an entry for enabling a compatibility function.

[0270] For example, in the case that the compatibility function is enabled by the user in the above-mentioned embodiments, an entry for enabling the compatibility function can be integrated in the settings application. In this way, the user does not need to separately install an application for enabling the compatibility function in the mobile phone, but can enable the compatibility function through the entry provided by the settings application.

[0271] It should be understood that the above description is only an example for better understanding the technical solutions of the embodiments and is not the only limitation of the embodiments.

[0272] Continuing to refer to Figure 7 In the technical solutions provided by the embodiments of the present application, the application program framework layer can include a telephone / IMS service, a camera service, a CS Phone, a PS Phone, and the like.

[0273] The telephone / IMS service is used to call the SIP module in the Modem to make various SIP request messages, such as INVITE, ACK, 200 OK, and the like, when a media session is established and after the media session is established, i.e., during the call.

[0274] The camera service is used to call the devices and functional modules related to the camera when the user initiates a video call, such as calling the camera driver to make the camera driver drive the camera to work, and calling the functional modules for processing the video stream collected by the camera, and the like.

[0275] The CS Phone is used for the call of the CS (Circuit Switched) network, and can be used for the call through the CS when the IMS service is unavailable (the mobile phone is camped on the 2G / 3G or the IMS is not successfully registered), and can be used for the domain switching redial (commonly referred to as CS redial) when the IMS call fails.

[0276] The PS Phone is used for the call of the PS (Packet Switched) network, and can be used for the IMS call (VOLTE, VONR) through the PS domain when the IMS service is available.

[0277] It should be understood that the above description is only an example for better understanding the technical solutions of the embodiments and is not the only limitation of the embodiments.

[0278] In addition, it can be understood that the kernel layer in the Android system is the layer between the hardware and the software. Continuing to refer to Figure 7To the technical solutions provided in the embodiments of the present application, the kernel layer can include a Transmission Control Protocol / Internet Protocol STACK (TCP / IP STACK).

[0279] The TCP / IP refers to a protocol cluster capable of realizing information transmission among multiple different networks. To the actual application, the TCP / IP STACK of the kernel layer mainly serves the online service, and also provides services for video-related data processing during the call service.

[0280] Continuing to refer to Figure 8 To the technical solutions provided in the embodiments of the present application, the hardware can include a Modem, an ADSP (Digital Signal Processor), a camera, an antenna, a MIC (Microphone), a receiver, a speaker, etc.

[0281] The antenna is used to receive the content sent by the network side, such as the RRC connection configuration message, the SIP request message, and the SRS that needs to be round-robin sent in the above embodiments.

[0282] The camera is used to collect the video stream when the initiated call service is a video call.

[0283] The MIC is used to collect the audio data of the user during the call process, and transmit the collected audio data to the ADSP.

[0284] The AFE (Audio Front-End) module, the 3A module, and the encoder in the ADSP are used to sequentially process the audio data collected by the MIC, and then the processed data is transmitted to the RTP / RTCP module in the Modem for processing, and then the processed data is transmitted to the TCP / UDP layer and the IP layer for processing, and then the processed data is transmitted to the PDCP layer for encryption by using an open algorithm, such as the ROHC algorithm in the above embodiments.

[0285] It should be noted that the 3A module specifically refers to a functional module integrating three audio algorithms, namely, Acoustic Echo Cancelling (AEC), Active Noise Control (ANS), and Automatic Gain Control (AGC).

[0286] The data packet encrypted by the PDCP is sequentially transmitted to the RLC layer, the MAC layer, and the PHY layer, and then transmitted to the antenna, and finally transmitted to the network side through the antenna.

[0287] Correspondingly, the data packet received by the antenna from the network side will be transmitted to the PDCP layer in sequence through the PHY layer, the MAC layer and the RLC layer. For example, the data packet is decrypted based on the ROHC algorithm, and then the decrypted RTP packet / RTCP packet is processed through the IP layer and the TCP / UDP layer, and is transmitted to the ADSP after being processed by the RTP / RTCP module. The ADSP sequentially processes the data provided by the RTP / RTCP module through the decoder, the 3A module and the AFE module, analyzes the audio data that can be played, and finally transmits the audio data to the receiver, the loudspeaker or the earphone for playing.

[0288] In addition, it should be noted that the processing of various SIP signaling messages involved in the embodiments of the present application is implemented by the SIP module in the Modem. The processing of various RRC messages involved in the embodiments of the present application, such as RRCReconfiguration, RRC Reconfiguration Complete, RRC Connection re-establishment, etc., is implemented by the RRC module in the Modem.

[0289] As for the software structure of the mobile phone, it can be understood that, Figure 8 The layers in the software structure and the components included in each layer shown do not constitute a specific limitation on the mobile phone. In other embodiments of the present application, the mobile phone can include more or fewer layers than shown, and each layer can include more or fewer components, which are not limited in the present application.

[0290] In order to better understand the technical solutions provided by the embodiments of the present application, still taking the terminal device as a mobile phone for example, referring to Figure 8 The specific structure of the mobile phone and the implementation of the devices involved in the embodiments of the present application will be specifically described.

[0291] Referring to Figure 7 The mobile phone 100 can include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a loudspeaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a key 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, etc.

[0292] Antenna 1 and antenna 2 are used for transmitting and receiving electromagnetic wave signals. Each antenna in the mobile phone 100 can be used to cover a single or multiple communication frequency bands. Different antennas can also be multiplexed to improve the utilization of the antennas. For example, antenna 1 can be multiplexed as a diversity antenna for wireless local area networks. In some other embodiments, the antennas can be used in combination with a tuning switch.

[0293] In the embodiments of the present application, the messages sent by the base station, such as the gNB, to the mobile phone 100, such as the RRC reconfiguration message corresponding to the current cell, the RRC connection configuration message corresponding to the cell to which the handover is required, and the SIP signaling message sent by the gNB to the UE in the multimedia session process, can be implemented through antenna 1 or antenna 2.

[0294] Correspondingly, the messages sent by the mobile phone 100 to the gNB, such as the RRC Reconfiguration Complete, the RRCConnection Reestablishment, and the SIP signaling message sent by the UE to the gNB in the multimedia session process, are also implemented through antenna 1 or antenna 2.

[0295] The mobile communication module 150 can provide a solution for wireless communication including 2G / 3G / 4G / 5G, etc. applied to the mobile phone 100. The mobile communication module 150 can include at least one filter, a switch, a power amplifier, a low noise amplifier (LNA), etc. The wireless communication module 160 can provide a solution for wireless communication including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), infrared (IR) technology, etc. applied to the mobile phone 100.

[0296] For example, in some implementations, the antenna 1 of the mobile phone 100 can be coupled with the mobile communication module 150, and the antenna 2 can be coupled with the wireless communication module 160. Thus, the mobile phone 100 can communicate with the network and other devices through mobile communication technology or wireless communication technology.

[0297] Continuing to refer to Figure 8For example, the audio module 170 of the mobile phone 100 can include a speaker 170A, a receiver 170B, a microphone 170C, a headphone jack 170D, and the like.

[0298] For example, the mobile phone 100 can implement audio functions such as music playback, recording, and voice call services described in embodiments of the present application through the speaker 170A, the receiver 170B, the microphone 170C, the headphone jack 170D, the application processor, and the like in the audio module 170.

[0299] In addition, regarding the sensor module 180 in the mobile phone 100, in some implementations, it can include a pressure sensor, a gyroscope sensor, a barometric pressure sensor, a magnetic sensor, an acceleration sensor, a distance sensor, a proximity light sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, a bone conduction sensor, and the like, which are not listed one by one here, and the present application does not limit this.

[0300] In addition, it should be noted that in some implementations, the processor 110 can include one or more processing units, for example: the processor 110 can include an application processor (application processor, AP), a modem processor, a graphics processing unit (graphics processing unit, GPU), an image signal processor (image signal processor, ISP), a controller, a memory, a video codec, a digital signal processor (digital signal processor, DSP), a baseband processor, and / or a neural-network processing unit (neural-network processing unit, NPU), and the like.

[0301] Understandably, in specific implementations, different processing units can be independent devices or can be integrated into one or more processors.

[0302] It should be noted that in actual applications, the mobile phone 100 can implement the technical solutions provided by the embodiments of the present application through the two processing units of the AP 110A and the Modem 110B. For example, by the AP, the call request initiated by the user is responded to, and then the application program framework layer related to the call service as shown in Figure 8 and the corresponding driver in the kernel layer are called to hand over the call request to the Modem. The Modem can interact with the network side according to the processing logic involved in the method for calling provided by the embodiments of the present application. For specific implementation details, please refer to the above embodiments, which will not be repeated here.

[0303] In addition, it is also understandable that the processing unit of the controller included in the processor 110 can be the nerve center and command center of the mobile phone 100. In actual application, the controller can generate operation control signals according to instruction operation codes and timing signals to complete the control of instruction fetching and instruction execution.

[0304] In addition, the memory in the processor 110 is mainly used for storing instructions and data. In some embodiments, the memory in the processor 110 is a cache memory.

[0305] In addition, with regard to Figure 8 The USB interface 130 shown in the figure is an interface conforming to the USB standard specification, which can be a Mini USB interface, a Micro USB interface, a USB Type C interface, etc.

[0306] The charging management module 140 is used to receive charging input from a charger. In addition, Figure 8 The power management module 141 shown in the figure is used to connect the battery 142 and the charging management module 140. The power management module 141 receives input from the battery 142 and / or the charging management module 140 to power the processor 110, the internal memory 121, the external memory, the display screen 194, the camera 193, and the wireless communication module 160, etc. The wireless communication function of the mobile phone 100 can be realized through the antenna 1, the antenna 2, the mobile communication module 150, the wireless communication module 160, the modem processor, and the baseband processor, etc.

[0307] In addition, Figure 8 The mobile phone 100 shown in the figure realizes the display function through the GPU, the display screen 194, and the application processor, etc. The GPU is a microprocessor for image processing, which is connected to the display screen 194 and the application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. The processor 110 can include one or more GPUs, which execute program instructions to generate or change display information.

[0308] With regard to the display screen 194, it is specifically used for displaying images, videos, etc. The display screen 194 includes a display panel. In some embodiments, the mobile phone 100 can include 1 or N display screens 194, N being a positive integer greater than 1.

[0309] In addition, the mobile phone 100 can realize the shooting function through the ISP, the camera 193, the video codec, the GPU, the display screen 194, and the application processor, etc. Among them, the camera 193 is used to capture still images or videos. In some embodiments, the mobile phone 100 can include 1 or N cameras 193, N being a positive integer greater than 1.

[0310] For example, if the initiated call service is a video call service, such as a video call, a video conference, etc., in the process of implementing the call service, in addition to the audio module 170, the camera 193 also needs to be involved.

[0311] In addition, Figure 8 The external memory interface 120 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the mobile phone 100. The external memory card communicates with the processor 110 through the external memory interface 120 to implement a data storage function. For example, music, video, and other files are saved in the external memory card.

[0312] In addition, Figure 8 The internal memory 121 can be used to store computer executable program code, which includes instructions. The processor 110 executes various function applications and data processing of the mobile phone 100 by running the instructions stored in the internal memory 121.

[0313] Specifically, the file recording the updatable configuration item in the above embodiments can be pre-configured into the internal memory 121 of the mobile phone 100 when the mobile phone 100 is manufactured.

[0314] In addition, Figure 8 The motor 191 shown in FIG. 10 can be a vibration motor, for example; and the indicator 192 can be an indicator light.

[0315] In addition, Figure 8 The SIM card interface 195 shown in FIG. 10 can be used to connect a SIM card or a USIM card. The SIM card can be inserted into or pulled out of the SIM card interface 195 to achieve contact and separation with the mobile phone 100. The mobile phone 100 can support one or N (N is an integer greater than 1) SIM card interfaces 195. That is, multiple SIM cards or USIM cards can be inserted into the terminal.

[0316] The hardware structure of the mobile phone 100 is introduced here, and it should be understood that, ​ The mobile phone 100 shown in the figure is only an example. In a specific implementation, the mobile phone 100 can have more or fewer components than those shown in the figure, can combine two or more components, or can have a different component configuration. ​ The various components shown in FIG. 10 can be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and / or application specific integrated circuits.

[0317] In addition, it should be noted that the method for calling provided by the above-mentioned embodiments realized by the terminal device can also be executed by a chip system included in the terminal device. Based on this, the embodiments of the present application further provide a chip system, which can include a processor. The chip system can be coupled with a memory, so that the processor in the chip system calls the computer program stored in the memory when running, to realize the steps executed by the terminal device. The processor in the chip system can be an application processor (AP), or a non-application processor, such as a modem (Modem).

[0318] In addition, the embodiments of the present application further provide a computer readable storage medium, which stores computer instructions. When the computer instructions run on the terminal device, the terminal device executes the above-mentioned related method steps to realize the method for calling in the above-mentioned embodiments.

[0319] In addition, the embodiments of the present application further provide a computer program product, which, when running on the terminal device, makes the terminal device execute the above-mentioned related steps to realize the method for calling in the above-mentioned embodiments.

[0320] In addition, as known from the above description, the terminal device, computer readable storage medium, computer program product or chip provided by the embodiments of the present application are all used to execute the corresponding methods provided above, so the beneficial effects that can be achieved thereby can refer to the beneficial effects of the corresponding methods provided above, which will not be described here again.

[0321] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for a call, applied to a terminal device, characterized in that, The method comprises: camping to a first cell, receiving a first RRC reconfiguration message during a call in the first cell, the first RRC reconfiguration message carrying information of a second cell, wherein before receiving the first RRC reconfiguration message, the terminal device stores a first configuration item matched with the first cell; in a case where a first condition is met, ignoring the first configuration item, camping to the second cell according to the first RRC reconfiguration message, and sending an RRC reconfiguration complete message to the second cell; wherein the first condition comprises that the first configuration item is not matched with the second cell, and the terminal device does not receive information indicating the terminal device to release a first resource.

2. The method of claim 1, wherein, wherein the ignoring the first configuration item comprises updating a value of a first parameter in the first configuration item from 1 to 0.

3. The method of claim 1, wherein, The first condition further comprises that a function of allowing the first configuration item to be ignored is enabled on the terminal device.

4. The method of claim 3, wherein, The method further comprises: in a case where a second condition is met, sending an RRC connection reestablishment request; wherein the second condition comprises that the first configuration item is not matched with the second cell, the terminal device does not receive information indicating the terminal device to release the first resource, and the function of allowing the first configuration item to be ignored is not enabled on the terminal device.

5. The method of claim 4, wherein, The sending the RRC connection reestablishment request in the case where the second condition is met comprises: in a case where a second condition is met, reselecting to the first cell, sending an RRC connection reestablishment request to the first cell, the RRC connection reestablishment request carrying a cause value, and the cause value being Reconfiguration failure; receiving an RRC connection setup message sent by the first cell; receiving a Bye message sent by the first cell, and hanging up the call after receiving the Bye message.

6. The method of claim 5, wherein, The Bye message carries a cause value of 503.

7. The method of any one of claims 1-6, wherein, The terminal device does not receive information indicating the terminal device to release a first resource comprises that the first RRC reconfiguration message does not carry information indicating the terminal device to release the first resource.

8. The method of any one of claims 1-6, wherein, The method further comprises: in a case where a third condition is met, ignoring the first configuration item, camping to the second cell according to the first RRC reconfiguration message, and sending an RRC reconfiguration complete message to the second cell; wherein the third condition comprises that the first configuration item is not matched with the second cell, and the terminal device receives information indicating the terminal device to release the first resource.

9. The method of claim 8, wherein, The terminal device receives information indicating the terminal device to release the first resource comprises that the first RRC reconfiguration message further carries information indicating the terminal device to release the first resource.

10. The method of any one of claims 1-6, wherein, The first cell is a cell in a TDD mode, and the second cell is a cell in an FDD mode.

11. The method of any one of claims 1-6, wherein, The first configuration item is a configuration item of an antenna switching mode sounding reference signal (SRS) resource.

12. The method of claim 2, wherein, The updating of the value of the first parameter in the first configuration item from 1 to 0 is updating the value of the parameter srs_tx_switch in the first configuration item from 1 to 0.

13. The method of any one of claims 1-6, wherein, The first RRC reconfiguration message is used to instruct the terminal device to switch to the second cell.

14. The method of any one of claims 1-6, wherein, The first configuration item matching the first cell is saved in the terminal device before the first RRC reconfiguration message is received, including: receiving a second RRC reconfiguration message in the first cell before the first RRC reconfiguration message is received, and the second RRC reconfiguration message carries the first configuration item.

15. The method of any one of claims 1-6, wherein, The receiving of the first RRC reconfiguration message is receiving the first RRC reconfiguration message sent by the first cell.

16. The method of any one of claims 1-6, wherein, The RRC reconfiguration completion message is used to indicate that the RRC reconfiguration for the first RRC reconfiguration message has been completed.

17. The method of any of claims 1-6, wherein The method further includes: continuing the call in the second cell after camping on the second cell.

18. The method of any one of claims 1-6, wherein, The first configuration item not matching the second cell includes: the second cell being a cell in FDD mode, and the second cell not supporting the terminal device to send a sounding reference signal (SRS) in an antenna switching mode.

19. The method of any one of claims 1-6, wherein, The first cell is a cell in the n78 frequency band, and the second cell is a cell in the n1 frequency band.

20. A terminal device, comprising: The terminal device includes a memory and a processor, the memory and the processor are coupled, the memory stores program instructions, and the program instructions are executed by the processor to enable the terminal device to perform the method for a call according to any one of claims 1 to 19.

21. A chip system, characterized by The chip system includes a processor configured to support a terminal device to implement the method for a call according to any one of claims 1 to 19.

22. A computer-readable storage medium, characterized in that, The computer program, when executed on a terminal device, causes the terminal device to perform the method for a call according to any one of claims 1 to 19.

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