Method for reducing call drop rate, and device and chip system

Abstract

Provided in the present application are a method for reducing a call drop rate, and a device and a chip system. During the process of a terminal device camping in a first cell to make a first call, when first DRB release information carried in a first RRC reconfiguration message issued by a base station corresponding to the first cell does not match first logical channel release information, the terminal device is configured to release a DRB according to the first DRB release information, release a logical channel according to the first logical channel release information, and then normally response to the base station corresponding to the first cell with a first RRC reconfiguration completion message. That is, the situation of there being a mismatch is ignored, such that it is ensured that the terminal device can complete RRC reconfiguration on the basis of the first RRC reconfiguration message, thereby reducing call failures, and improving the user experience.

Description

Method, device and chip system for reducing call drop rate

[0001] The present application claims priority to the Chinese patent application No. 202410814397.1, filed on June 21, 2024, and entitled "Method, device and chip system for reducing call drop rate", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, and in particular to a method, device and chip system for reducing call drop rate. BACKGROUND

[0003] In a 5G, i.e. NR (New Radio) network, an RRC reconfiguration (Radio Resource Control Reconfiguration) initiated by the network side to a terminal device can be used to modify a data radio bearer (DRB) corresponding to a packet data convergence protocol (PDCP) layer, and a logical channel or a resource bearer (RB) corresponding to a radio link control (RLC) layer, so as to better adapt to the actual service scenario.

[0004] However, there is currently a situation that the terminal device fails to verify the RRC reconfiguration message, thereby causing a call interruption. SUMMARY

[0005] To solve the above technical problems, the embodiments of the present application provide a method, device and chip system for reducing call drop rate, aiming to reduce call failure and improve user experience.

[0006] In a first aspect, the embodiments of the present application provide a method for reducing call drop rate. 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 first call in the first cell; wherein the first RRC reconfiguration message includes first release information, the first release information includes first DRB release information and first logical channel release information, the first DRB release information indicates information of a first DRB to be released, and the first logical channel release information indicates information of a first logical channel to be released; in a case where the first DRB release information and the first logical channel release information do not match, releasing the first DRB according to the first DRB release information, releasing the first logical channel according to the first logical channel release information, and replying a first RRC reconfiguration completion message to the base station corresponding to the first cell.

[0007] The first DRB is a DRB corresponding to a packet data convergence protocol (PDCP) layer.

[0008] The first logical channel is a logical channel corresponding to a radio link layer control protocol (RLC) layer.

[0009] The first DRB release information and the first logical channel release information are not matched, for example, the first DRB release information indicates that the first DRB to be released and the first logical channel release information indicates that the first logical channel to be released are not matched. That is, the first DRB release information and the first logical channel release information are determined to be released, for example, whether the first DRB to be released and the first logical channel to be released are matched is determined according to the first DRB release information and the first logical channel release information.

[0010] The first RRC reconfiguration complete message is used to inform the base station corresponding to the first cell that the RRC reconfiguration based on the first RRC reconfiguration message has been completed.

[0011] The terminal device can be referred to as a UE.

[0012] Therefore, by setting the UE to not perform strong verification on the release information in the RRC reconfiguration message issued by the network side, such as the first release information in the first RRC reconfiguration message, in the case where the DRB to be released and the logical channel to be released are not matched, the UE ignores the mismatch and completes the RRC reconfiguration. In this way, the first call currently in progress will not be interrupted, and the UE can continue to camp in the current cell, such as NR CELL A, to perform the first call, thereby achieving the effect of reducing call failure, ensuring call quality, and improving user experience.

[0013] According to the first aspect, a strong verification switch is arranged in a modem processor of the terminal device; in the case where the first DRB release information and the first logical channel release information are not matched, the first DRB is released according to the first DRB release information, the first logical channel is released according to the first logical channel release information, and a first RRC reconfiguration complete message is replied to the base station corresponding to the first cell, including: in the case where the strong verification switch is in an off state and the first DRB release information and the first logical channel release information are not matched, the first DRB is released according to the first DRB release information, the first logical channel is released according to the first logical channel release information, and the first RRC reconfiguration complete message is replied to the base station corresponding to the first cell.

[0014] The strong check switch can be understood as a software switch or a software interface. The strong check switch is used to control whether the UE performs strong check on the information for indicating the UE to release the DRB and the logical channel in the RRC reconfiguration message sent by the network side, that is, whether to strictly perform check according to the existing standard protocol or whether to ignore the mismatch.

[0015] In some implementations, the strong check switch is a functional module implemented by software code, for example.

[0016] Therefore, when the strong check switch is in the closed state, the UE is set not to perform strong check on the release information in the RRC reconfiguration message sent by the network side. In this way, in the case that the DRB to be released and the logical channel do not match, the mismatch is ignored, and the UE can be prompted to complete the RRC reconfiguration, thereby ensuring that the ongoing call will not be interrupted.

[0017] According to the first aspect, or any one of the implementation modes of the first aspect, the method further includes: when the strong check switch is in the open state and the first DRB release information and the first logical channel release information do not match, releasing the first DRB according to the first DRB release information, releasing the first logical channel according to the first logical channel release information, and triggering an RRC reestablishment procedure.

[0018] Therefore, when the strong check switch is in the open state, the UE performs strong check on the release information in the RRC reconfiguration message sent by the network side according to the existing standard protocol, and in the case that the first DRB release information and the first logical channel release information do not match, the RRC reestablishment procedure is triggered, and the ongoing call is interrupted.

[0019] According to the first aspect, or any one of the implementation modes of the first aspect, the first release information is carried in a first field of the first RRC reconfiguration message, and the first field is a field defined in the standard protocol for carrying the first DRB release information and the first logical channel release information.

[0020] For example, according to the existing standard protocol, in the case that the first DRB release information and the first logical channel release information are carried in the first field, the first DRB release information indicates that the first DRB to be released and the first logical channel release information indicates that the first logical channel to be released have a strong binding relationship, such as the number must be the same, and a corresponding relationship set by the adding link. For example, the adding link sets that DRB 4 corresponds to logical channel 3, DRB 5 corresponds to logical channel 4, and DRB 6 corresponds to logical channel 5. In the case that the first DRB release information indicates that DRB 4, DRB 5 and DRB 6 are to be released, the first logical channel information indicates that the first logical channel to be released must be logical channel 3, logical channel 4 and logical channel 5.

[0021] According to the first aspect, or any one of the implementations of the above first aspect, the first field is a CellGroupConfig field of a cell group configuration.

[0022] According to the first aspect, or any one of the implementations of the above first aspect, in the case that the first release information is carried in the first field, the step of releasing the first DRB according to the first DRB release information, releasing the first logical channel according to the first logical channel release information, and replying to the first RRC reconfiguration complete message to the base station corresponding to the first cell is performed in the case that the first DRB release information and the first logical channel release information do not match.

[0023] According to the first aspect, or any one of the implementations of the above first aspect, the first release information is carried in a second field of the first RRC reconfiguration message, the second field is different from the first field, and the first field is a field defined in the standard protocol for carrying the first DRB release information and the first logical channel release information.

[0024] In the case that the first release information is carried in the second field, the first DRB release information indicates that the first DRB to be released and the first logical channel release information indicates that the first logical channel to be released have a strong binding relationship.

[0025] According to the first aspect, or any one of the implementations of the above first aspect, the second field is a masterCellGroup field of a master cell group.

[0026] According to the first aspect, or any one of the implementations of the above first aspect, in the case that the first release information is carried in the second field, the step of releasing the first DRB according to the first DRB release information, releasing the first logical channel according to the first logical channel release information, and replying to the first RRC reconfiguration complete message to the base station corresponding to the first cell is performed in the case that the first DRB release information and the first logical channel release information do not match.

[0027] According to the first aspect, or any one of the implementations of the above first aspect, the method further comprises: in a case where the first release information is carried in the first field, and the first DRB release information and the first logical channel release information do not match, releasing the first DRB according to the first DRB release information, releasing the first logical channel according to the first logical channel release information, and triggering an RRC reestablishment procedure; wherein, after the RRC reestablishment procedure is completed, in a case where a message for configuring the second DRB and the second logical channel, which is issued by a base station corresponding to a cell accessed in the RRC reestablishment procedure, is not received within the first time length, releasing the first call.

[0028] According to the first aspect, or any one of the implementations of the above first aspect, the first call in the first cell uses an acknowledgement mode for receiving and sending data.

[0029] According to the first aspect, or any one of the implementations of the above first aspect, the method further comprises: in a case where the first DRB release information and the first logical channel release information do not match, recording as one exception; in a case where a number of accumulated exceptions is greater than a first exception threshold, adding identification information of the first cell to an exception cell list, setting an exception time length of the first cell as a second time length, and prohibiting access to the first cell within a third time length, the second time length being greater than the third time length.

[0030] Thus, by setting the UE to not perform strong checking on the release information in the RRC reconfiguration message issued by the network side, in a case where the DRB to be released and the logical channel do not match, the mismatch is ignored, and the UE is prompted to complete the RRC reconfiguration. The number of exceptions due to the mismatch between the DRB to be released and the logical channel is recorded, and an exception cell punishment mechanism is used for the cell, to avoid re-entering the cell in a short time afterwards, so as to ensure that the ongoing call will not be interrupted, and to reduce the probability of the UE camping on the cell afterwards, so that the call can occur in a normal cell as much as possible, further reducing call failure, ensuring call quality, and improving user experience.

[0031] According to a first aspect, or any possible implementation mode of the above first aspect, the method further comprises: receiving a second RRC reconfiguration message sent by the base station corresponding to the first cell in the process of the second call in the second time period; wherein the second RRC reconfiguration message comprises second release information, the second release information comprises second DRB release information and second logical channel release information, the second DRB release information indicates information of the second DRB to be released, and the second logical channel release information indicates information of the second logical channel to be released; in the case that the second DRB release information and the second logical channel release information do not match, releasing the second DRB according to the second DRB release information, releasing the second logical channel according to the second logical channel release information, replying a second RRC reconfiguration complete message to the base station corresponding to the first cell, and accumulating a number of times of abnormality; in the case that the accumulated number of times of abnormality is greater than a second abnormality threshold, prohibiting access to the first cell in a fourth time period, the second abnormality threshold is greater than the first abnormality threshold, and the fourth time period is greater than the third time period.

[0032] According to the first aspect, or any possible implementation mode of the above first aspect, the method further comprises: performing a third call through the base station corresponding to the second cell in the fourth time period, the second cell not being in the list of abnormal cells.

[0033] According to the first aspect, or any possible implementation mode of the above first aspect, in the case that the number of the first DRB to be released indicated by the first DRB release information and the number of the first logical channel to be released indicated by the first logical channel release information are different, the first DRB release information and the first logical channel release information do not match.

[0034] For example, in the case that the first DRB release information indicates that the first DRB to be released are DRB 4, DRB 5 and DRB 6, and the first logical channel release information indicates that the first logical channel to be released is logical channel 3, it is determined that the first DRB release information and the first logical channel release information do not match.

[0035] According to the first aspect, or any possible implementation mode of the above first aspect, in the case that the first DRB to be released indicated by the first DRB release information and the first logical channel to be released indicated by the first logical channel release information do not correspond, the first DRB release information and the first logical channel release information do not match.

[0036] For example, in the adding link, DRB 4 corresponds to logical channel 3, DRB 5 corresponds to logical channel 4, and DRB 6 corresponds to logical channel 5. In a case where the first DRB release information indicates that the first DRBs to be released are DRB 4, DRB 5, and DRB 6, and the first logical channel release information indicates that the first logical channel to be released is logical channel 3, it is determined that the first DRB release information and the first logical channel release information do not match.

[0037] In a second aspect, an embodiment of 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, and the program instructions are executed by the processor to enable the terminal device to perform the method in the first aspect or any possible implementation manner of the first aspect.

[0038] In a third aspect, an embodiment of the present application provides a computer readable medium for storing a computer program, the computer program comprising instructions for performing the method in the first aspect or any possible implementation manner of the first aspect.

[0039] In a fourth aspect, an embodiment of the present application provides a computer program, the computer program comprising instructions for performing the method in the first aspect or any possible implementation manner of the first aspect.

[0040] In a fifth aspect, an embodiment of the present application provides a chip system, comprising a processor. The processor is configured to support the terminal device to implement the method in the first aspect or any possible implementation manner of the first aspect.

[0041] According to the fifth aspect, the processor comprises a modem processor.

[0042] Correspondingly, the processor is configured to support the terminal device to implement the method in the first aspect or any possible implementation manner of the first aspect, and specifically comprises:

[0043] The modem processor is configured to support the terminal device to implement the method in the first aspect or any possible implementation manner of the first aspect.

[0044] The fifth aspect and any one of the implementation manners of the fifth aspect correspond to the first aspect and any one of the implementation manners of the first aspect respectively. The technical effects of the fifth aspect and any one of the implementation manners of the fifth aspect can refer to the technical effects of the first aspect and any one of the implementation manners of the first aspect, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0045] FIG. 1 is a schematic diagram of a network architecture provided by an embodiment of the present application;

[0046] Fig. 2 is a schematic diagram of a voice call scenario according to an example of the present application;

[0047] Fig. 3 is a schematic diagram of interaction between a UE and a gNB on the network side in a scenario of successful RRC reconfiguration according to an example of the present application;

[0048] Fig. 4 is a schematic diagram of interaction between a UE and a gNB on the network side in a scenario of failed RRC reconfiguration according to an example of the present application;

[0049] Fig. 5 is a schematic diagram of a scenario of releasing a bearer abnormally based on an RRC reconfiguration message, resulting in call drop according to an example of the present application;

[0050] Fig. 6 is a schematic diagram of adding information of adding a DRB and a logical channel in an RRC reconfiguration message according to an example of the present application;

[0051] Fig. 7 is a schematic diagram of release information of releasing a DRB and a logical channel in an RRC reconfiguration message according to an example of the present application;

[0052] Fig. 8 is a schematic diagram of a method for reducing call drop rate according to an example of the present application;

[0053] Fig. 9 is a schematic diagram of another method for reducing call drop rate according to an example of the present application;

[0054] Fig. 10 is a schematic diagram of another method for reducing call drop rate according to an example of the present application;

[0055] Fig. 11 is a schematic diagram of a hardware structure of a terminal device according to an example of the present application;

[0056] Fig. 12 is a schematic diagram of a relationship between a software structure of a terminal device and a hardware device, and interaction with a gNB according to an example of the present application. DETAILED DESCRIPTION

[0057] The technical solutions in the examples of the present application will be described clearly and completely below with reference to the drawings in the examples of the present application. It should be understood that the described examples are part of the examples of the present application, rather than all the examples. Based on the examples in the present application, all other examples obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0058] The term “and / or” herein is only used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone.

[0059] The terms “first”, “second”, “third”, “fourth” and the like in the description and claims of the application do not denote any particular order or sequence. For example, the first target object and the second target object are used to distinguish different target objects, rather than to describe the specific order of the target objects.

[0060] In the embodiments of the present application, the words “exemplary” or “for example” are used to mean serving as an example or illustration. Any embodiment or design presented as “exemplary” or “for example” in the embodiments of the present application should not be construed as preferred or advantageous over other embodiments or design solutions. Rather, the use of “exemplary” or “for example” is intended to present concepts in a concrete manner.

[0061] In the description of the embodiments of the present application, unless otherwise specified, “a plurality of” means 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.

[0062] Based on the above premise, the technical solutions provided by the embodiments of the present application are described below.

[0063] Specifically, the technical solutions provided by the embodiments of the present application are directed to the RRC reconfiguration process between the network side and the terminal device (the calling terminal device and / or the called terminal device) during the process of the calling party and the called party calling. In order to better illustrate the technical solutions provided by the embodiments of the present application, first, the network architecture to which the technical solutions provided by the embodiments of the present application are directed, and the voice call scenario implemented based on the communication architecture are described in conjunction with the accompanying drawings.

[0064] Referring to FIG. 1, an exemplary network architecture schematic diagram is shown. As shown in FIG. 1, the network architecture can include a terminal device, a network device of LTE, a network device of NR, a core network, and an IMS or Internet.

[0065] The terminal device (terminal equipment) can also be referred to as user equipment (User Equipment, UE), user terminal, mobile station (Mobile Station, MS), mobile terminal (Mobile Terminal, MT), etc. In some embodiments of the present application, the terminal device can be a mobile phone, a wearable device (such as a smart watch), etc.

[0066] LTE (Long Term Evolution) can be understood as the wireless access network of the 4th generation mobile communication technology (4G) network. In the LTE network (i.e., commonly known as: 4G network), because of the evolution relationship, the access network part is called Evolved UMTS Terrestrial Radio Access Network (E-UTRAN). In the embodiments of the present application, the meaning of LTE is the same as that of E-UTRAN, both of which refer to the access network part of the 4G network.

[0067] NR (New Radio) can be understood as the wireless access network of the 5G network. In the 5G network, the access network part is called Next Generation Radio Access Network (NG-RAN or NG RAN). In the embodiments of the present application, the meaning of NR is the same as that of NG-RAN (or NG RAN), both of which refer to the access network part of the 5G network.

[0068] It can be understood that both LTE and NR are access networks. The access network is responsible for connecting and communicating with the end user (End User) to the core network (also known as: backbone network) level by level, to realize the connection with the network. The access network is the edge part of the entire network, i.e., the part closest to the user, which is also commonly known as "the last kilometer".

[0069] The network device is a device used by the network side to communicate with the terminal device. In some embodiments of the present application, the network device can be a base station. That is, in some embodiments of the present application, the network device of LTE is, for example, a 4G base station; the network device of NR is, for example, a 5G base station, such as gNB (the next Generation Node B, gNodeB).

[0070] For example, in some embodiments of the present application, the terminal device can access LTE through a 4G base station. In some other embodiments of the present application, the terminal device can access NR through a gNB.

[0071] The core network mainly provides user connection, user management, and service bearing, and provides an interface to external networks as a bearing network. The establishment of user connection includes mobile management (MM), call management (CM), switching / routing, voice notification (connection to intelligent network peripherals in combination with intelligent network services), and the like.

[0072] Understandably, the core network of the 4G network is an evolved packet core (EPC) network. The EPC network belongs to the category of core networks, has traditional capabilities of mobile networks such as user subscription data storage, mobility management, and data exchange, and can provide users with a super-fast Internet experience. The core network of the 5G network is a 5G core (which can be referred to as 5GC for short). The 5GC will use general network function virtualization devices instead of the dedicated communication devices of the 4G network.

[0073] It should be noted that in some embodiments of the present application, the core network in the network architecture shown in FIG. 1 can be obtained by fusing the EPC network and the 5GC. That is, the core network in the network architecture can include network elements in the EPC network and network elements in the 5GC. For example, the core network in the network architecture can include an access and mobility management function (AMF) network element, a mobility management entity (MME) network element, a serving gateway (SGW) network element, a packet data network gateway (PGW) network element, a session management function (SMF) network element, a user plane function (UPF) network element, a unified data management function (UDM) network element, and a home subscriber server (HSS) network element, and the like.

[0074] For example, in some embodiments of the present application, the core network in the network architecture includes a fused network element, that is, a fused network element obtained by network elements in the EPC network and network elements in the 5GC, such as SMF+PGW-C, or UPF+PGW-U, or UDM+HSS, and the like. Among them, PGW-C is a control plane node of the PGW network element, and PGW-U is a user plane node of the PGW network element.

[0075] Further, it should be noted that in some other embodiments of the present application, the core network in the network architecture shown in Fig. 1 can comprise a Proxy Session Border Control (PSBC) network element. The PSBC can be understood as a converged network element that integrates the functions of a Session Border Control (SBC), a Proxy-CSCF (P-CSCF), an Access Transfer Control Function (ATCF), and an Access Transfer Gateway (ATGW).

[0076] When the PSBC network element functions as an SBC network element, it connects the IMS core network / softswitch network and an external user access area, and performs functions such as service access of IMS / softswitch users, interworking of user services in different network environments, security protection of the IMS / softswitch network, support of QoS management, CAC traffic control, media management, CDR media call detail, and the like.

[0077] When the PSBC network element functions as a built-in P-CSCF network element, the P-CSCF functions as an entry point for the control plane of the IMS visited domain, and proxies and forwards Session initialization Protocol (SIP) messages such as registration, session, and Presence messages from the access network of the visited domain to the S-CSCF or I-CSCF of the home domain.

[0078] When the PSBC network element functions as a built-in ATCF / ATGW network element, by setting the ATCF / ATGW functional entity between the P-CSCF and the I-CSCF / S-CSCF, the media stream is anchored to the ATGW for a possible enhanced Single Radio Voice Call Continuity (eSRVCC) handover. In this way, when the sSRVCC handover occurs, only the media information on the ATGW needs to be updated, and the media information of the terminal device does not need to be updated, so that the entire eSRVCC handover time is shorter.

[0079] Further, it should be understood that each network element in the core network can also be referred to as a functional entity. That is, the core network can be a network element implemented on a dedicated hardware, a software instance running on a dedicated hardware, or an instance of virtualized functions on a suitable platform.

[0080] In addition, it should also be understood that the names of all network elements in the embodiments of the present application are only examples. In future communications, such as 6G networks, these network elements can also be referred to by other names. Alternatively, in future communications, such as 6G networks, these network elements can also be replaced by other entities or devices with the same function, and the present application does not limit this. Here, a unified description is made, and details will not be repeated in the following. Alternatively, various network elements in the embodiments of the present application can be communication devices, or can be chips or chip systems used in the communication devices, and the embodiments of the present application do not limit this.

[0081] In addition, it should also be understood that the core network in the network architecture shown in FIG. 1 can also include other devices, network elements, network entities or network subsystems, such as a policy control function (PCF) network element, and the present application does not limit this.

[0082] In addition, the embodiments of the present application do not limit the distribution mode of each network element in the core network, and the distribution mode can be referred to related technical documents, which will not be described herein.

[0083] The IMS is an IP Multimedia Subsystem, which is a network architecture based on an Internet Protocol (IP) network to provide voice and multimedia communication services (such as voice, video and text messages, etc.). The IMS can realize safe and reliable multimedia communication between different devices of different networks. The architecture model of the IMS provides a unified infrastructure and general mechanism for controlling, operating, routing and managing sessions, and realizing identity verification, authorization and accounting control. The IMS specification includes widely used The Internet Engineering Task Force (IETF) recommendations. For example, the Session initialization Protocol (SIP) used for session control signaling.

[0084] The Internet generally refers to the Internet, also known as the international network, which refers to a huge network formed by connecting networks with each other. These networks are connected by a common set of protocols to form a logically single huge international network. From the perspective of network communication, the Internet is a data communication network that connects computers in various countries, regions and institutions around the world through Transmission Control Protocol (TCP) / Internet Protocol (IP).

[0085] It should be noted that the network architecture shown in FIG. 1 is not limited to only including the devices and networks shown in the figure, and can also include other devices not shown in the figure, which will not be illustrated one by one in the present application.

[0086] Referring to FIG. 2, a schematic diagram of a voice call scenario is exemplarily shown. As shown in FIG. 2, the first terminal can transmit voice data with the second terminal through the first network device, the IMS and the second network device, that is, make a call. Among them, the first network device is the network device corresponding to the cell where the first terminal currently resides, and the second network device is the network device corresponding to the cell where the second terminal currently resides.

[0087] Exemplarily, in some embodiments of the present application, the first network device and the second network device can be the same network device.

[0088] Exemplarily, in some embodiments of the present application, the first terminal can be the party initiating the voice call to request a voice call with the second terminal.

[0089] Exemplarily, in some embodiments of the present application, the second terminal can be the party initiating the voice call to request a voice call with the first terminal.

[0090] Exemplarily, in some embodiments of the present application, the first terminal and the second terminal can be 5G mobile phones, that is, smartphones using the fifth generation communication system.

[0091] Exemplarily, in some embodiments of the present application, in the scenario where the first terminal and the second terminal are both 5G mobile phones, but neither of them has turned on the standalone networking (SA) switch / function, or both of them are 4G mobile phones, the first network device and the second network device can be 4G base stations.

[0092] Exemplarily, in some embodiments of the present application, in the scenario where the first terminal and the second terminal are both 5G mobile phones, and both of them have turned on the SA switch / function, the first network device and the second network device can be gNBs. In this way, the first terminal and the second terminal can be directly connected to the 5G network without relying on the 4G network, thereby obtaining faster network speed and lower delay, and better improving the call experience.

[0093] In addition, it should be understood that the normal progress of the call relies on the wireless network resources determined by the UE and the base station on the network side 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 (adding) / modifying / releasing DRB, logical channel / RB, performing cell switching (handover of base station), setting / modifying / releasing measurement report, etc.

[0094] In addition, it should be understood that RRC reconfiguration can also be implemented in 4G network. In 4G network, RRC reconfiguration is referred to as RRC connection reconfiguration. For ease of illustration, the embodiments of the present application take RRC reconfiguration in 5G network as an example for illustration.

[0095] Specifically, in 5G network, RRC reconfiguration is initiated by the network side (5G base station, such as gNB). That is, the gNB actively sends the RRC reconfiguration message to the corresponding UE, as shown in FIG. 3 “RRC Reconfiguration”.

[0096] For example, the RRC reconfiguration message can carry information indicating the UE to add / modify / release DRB, logical channel / RB.

[0097] For example, the RRC reconfiguration message can also carry measurement configuration indicating UE measurement operation, configuration of SRS resource indicating antenna switching mode, configuration of encryption and decryption algorithm for data packets interacting with the base station, etc., which will not be listed one by one here.

[0098] 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 repeated here.

[0099] Based on the provisions of the existing standard protocol, after receiving the RRC reconfiguration message issued by the gNB, the UE needs to first check the content in the RRC reconfiguration message. If the check is successful, the RRC reconfiguration will be completed according to the RRC reconfiguration message, and after the RRC reconfiguration is completed, i.e. the RRC reconfiguration is successful, the UE will reply to the gNB with an RRC reconfiguration complete message as shown in FIG. 3, to inform the gNB that the RRC reconfiguration based on the RRC reconfiguration message has been completed. Conversely, if the check fails, the UE will not reply to the gNB with the RRC reconfiguration complete, but will trigger the RRC re-establishment procedure as shown in FIG. 4.

[0100] Based on the provisions of the existing standard protocol, in the scenario of RRC reconfiguration failure and UE triggering RRC re-establishment procedure, the UE will first perform the radio link failure (RLF) procedure, such as releasing the connection with the gNB of the current cell. Then, the UE will reselect a cell and perform the RRC re-establishment procedure with the gNB corresponding to the reselected cell, such as sending an RRC re-establishment request (carrying a reconfiguration failure reason value such as Reconfiguration failure) to the reselected gNB.

[0101] Correspondingly, after receiving the RRC re-establishment request, the reselected gNB will reply to the UE with a radio resource control connection setup (RRC Connection Setup) message indicating the radio bearer and the serving cell group, so that the UE establishes an RRC connection with the reselected gNB.

[0102] Understandably, in the RRC re-establishment stage, the UE can select the original cell (the cell where the UE resides before triggering the RRC re-establishment procedure) to reside, or can select a new cell to reside. That is, the gNB selected by the UE can be the gNB accessed before triggering the RRC re-establishment procedure (hereinafter referred to as: original base station), can be other gNBs in the original cell, or can be gNBs of other cells.

[0103] For the specific implementation procedure of the UE and the gNB to perform RRC connection re-establishment, and the specific implementation details of the RLF procedure, please refer to the existing standard protocol, which will not be described here.

[0104] Embodiments of the present application take the case of RRC re-establishment stage, UE selects the original base station to reside as an example. For this scenario, since the gNB of reselection is the original base station that has just been disconnected, the original base station will consider that the current RRC connection is abnormal after completing the RRC Connection re-establishment with the UE. Based on the existing standard protocol provisions, the gNB of reselection, i.e. the original base station, will issue a BYE message to the UE to end the current call, and then hang up the current call.

[0105] That is, RRC reconfiguration failure will cause the ongoing call to be interrupted.

[0106] In order to better understand, the specific process of RRC reconfiguration is described in the case that the UE resides in a 5G cell gNB to make a call, and the UE performs RRC reconfiguration according to the information of adding / releasing DRB (all DRBs in embodiments of the present application are PDCP layer corresponding DRBs) and logical channel / RB (hereinafter uniformly described as: logical channel, and all logical channels in embodiments of the present application are RLC layer corresponding logical channels) indicated in the RRC reconfiguration message issued by the gNB.

[0107] Referring to FIG. 5, in the case that the UE resides in a 5G cell gNB to make a call, the process of RRC reconfiguration is described according to the information of adding / releasing DRB indicated in the RRC reconfiguration message issued by the gNB, which specifically includes:

[0108] S101, in the process of the UE residing in a 5G cell (such as NR CELL A) to make a call, the UE receives the RRC reconfiguration message 1 sent by the NR CELL A.

[0109] Exemplarily, the RRC reconfiguration message 1 received by the UE is issued by the gNB corresponding to the NR CELL A.

[0110] Exemplarily, the gNB issuing the RRC reconfiguration message 1 is the gNB in the NR CELL A that establishes an RRC connection with the UE to make a call.

[0111] Exemplarily, in the process of the UE residing in the NR CELL A to make a call, the RRC reconfiguration message received by the UE can include (or carry) addition information for indicating the UE to add DRB and logical channel, and / or modification information for indicating the UE to modify DRB and logical channel, and / or release information for indicating the UE to release DRB and logical channel.

[0112] As a possible implementation, the RRC reconfiguration message 1 received by the UE in step S101 from the NR CELL A in the embodiment of the present application is taken as an example, which is an RRC reconfiguration message carrying addition information for indicating the UE to add DRBs and logical channels.

[0113] In step S102, the UE checks the addition information carried in the RRC reconfiguration message 1, and in the case of successful checking, adds the DRBs and logical channels according to the addition information.

[0114] For example, the addition information carried in the RRC reconfiguration message 1 for indicating the UE to add DRBs and logical channels includes DRB addition information and logical channel addition information.

[0115] In addition, it should be noted that, in order to ensure the normal progress of the call, one DRB needs to correspond to one logical channel, and there is a one-to-one correspondence between the two. In some embodiments of the present application, the addition information carried in the RRC reconfiguration message for indicating the UE to add DRBs and logical channels can include the identity (such as an identification number) information of each DRB to be added, the identity (such as an identification number) information of each logical channel to be added, and the correspondence between each DRB and logical channel to be added.

[0116] For example, in some embodiments of the present application, the addition information can be configured in the field specified in the RRC reconfiguration message, such as rlc-BearerToAddModList, and the DRBs and logical channels with a corresponding relationship can appear in pairs. For example, in the case where the DRBs to be added include DRBs with identity information 4, 5 and 6, the logical channels to be added include logical channels with identity information 3, 4 and 5, and DRB 4 corresponds to logical channel 3, DRB 5 corresponds to logical channel 4, and DRB 6 corresponds to logical channel 5, the addition information configured under the rlc-BearerToAddModList field of the RRC reconfiguration message can be as shown in FIG. 6.

[0117] It can be understood that the ellipsis “...” part in FIG. 6 omits the configuration information of other fields that can be configured under the rlc-BearerToAddModList field in the RRC reconfiguration message. For the specific content and format of the RRC reconfiguration message under different configurations, please refer to the existing standard protocol, which will not be described here.

[0118] The adding information carried in the RRC reconfiguration message 1 is shown in FIG. 6. Since the number of DRBs to be added and the number of logical channels to be added are the same, and each DRB corresponds to a single logical channel, the UE successfully checks the adding information, and can add the corresponding DRB and logical channel according to the adding information shown in FIG. 6.

[0119] Correspondingly, after the operation of step S102 is completed, based on the case that the RRC reconfiguration shown in FIG. 3 is successful, the interaction logic between the UE and the gNB can know that the UE will reply to the NR CELL A with the RRC reconfiguration complete message 1, that is, step S103 is performed.

[0120] Understandably, if the adding information carried in the RRC reconfiguration message 1 indicates that the number of DRBs to be added by the UE and the number of logical channels to be added do not match, such as the number of DRBs to be added is 3 and the number of logical channels to be added is 2; or indicates that the DRBs to be added by the UE and the logical channels do not correspond one by one, such as 1 DRB corresponds to 2 logical channels, or 1 logical channel corresponds to 2 DRBs. In this case, according to the existing standard protocol, the UE will fail to check the RRC reconfiguration message 1, and based on the case that the RRC reconfiguration shown in FIG. 4 fails, the interaction logic between the UE and the gNB can know that the UE will trigger the RRC re-establishment process.

[0121] In addition, according to the existing standard protocol, the adding information indicating that the UE adds DRBs and logical channels in the RRC reconfiguration message appears in pairs, as shown in FIG. 6. Therefore, the checking of the adding information will not fail in general. That is, in the scenario where the RRC reconfiguration message is used to instruct the UE to add DRBs and logical channels, after the UE receives the reconfiguration message 1 issued by the NR CELL A, it will normally perform steps S102 and S103.

[0122] S103, the UE replies to the NR CELL A with the RRC reconfiguration complete message 1.

[0123] Illustratively, the UE replies to the gNB that issues the RRC reconfiguration message 1 to the NR CELL A with the RRC reconfiguration complete message 1.

[0124] Illustratively, the RRC reconfiguration complete message 1 is used to inform the gNB that issues the RRC reconfiguration message 1 that the RRC reconfiguration (adding DRBs and logical channels) based on the RRC reconfiguration message 1 has been completed.

[0125] Understandably, in the case of RRC reconfiguration completion based on RRC reconfiguration message 1, the ongoing call of the UE camping on the NR CELL A can still be normally conducted until the UE of the calling party or the UE of the called party triggers the hang-up operation, such as pressing the button of the UE user interface for hanging up the call, and the current call is ended. In order to distinguish, the call ended in this case can be understood as a normal end scenario.

[0126] Embodiments of the present application take the ongoing call of the UE camping on the NR CELL A after the RRC reconfiguration completion based on RRC reconfiguration message 1 as an example, that is, the UE camping on the NR CELL A continues the call.

[0127] In S104, the UE camping on the NR CELL A continues the call, and receives the RRC reconfiguration message 2 sent by the NR CELL A.

[0128] Understandably, in order to better adapt to the actual business scenario, in the process of the UE camping on the NR CELL A continuing the call, along with the change of the wireless network resources of the NR CELL A or the change of the camping cell, the network side (the base station of the current camping cell) will reissue the RRC reconfiguration message to the UE to re-add new DRBs and logical channels, and / or modify the previously added DRBs and logical channels, and / or release the previously added DRBs and logical channels, so as to guarantee the quality of the ongoing call.

[0129] Embodiments of the present application take the change of the wireless network resources of the NR CELL A in the process of the UE camping on the NR CELL A continuing the call, and the RRC reconfiguration message reissued by the NR CELL A to the UE as an example, which is the RRC reconfiguration message 2 carrying the release information indicating the UE to release the previously added DRBs and logical channels.

[0130] In S105, the UE checks the release information carried in the RRC reconfiguration message 2, and determines the matching of the DRBs and logical channels to be released.

[0131] Exemplarily, the release information carried in the RRC reconfiguration message 2 for indicating the UE to release the DRBs and logical channels includes the DRB release information and the logical channel release information. The DRB release information can include the identity (such as identification number) information of each DRB to be released, and the logical channel release information can include the identity (such as identification number) information of each logical channel to be released.

[0132] According to the existing standard protocol, there is a one-to-one correspondence between the DRB and the logical channel. Therefore, the number of DRBs to be released indicated by the DRB release information carried in the RRC reconfiguration message 2 and the number of logical channels to be released indicated by the logical channel release information need to be the same, and the RRC reconfiguration based on the RRC reconfiguration message 2 can be successful only when the DRBs to be released and the logical channels to be released meet the correspondence configured at the adding stage. For example, in the case where the correspondence between the DRB and the logical channel configured at the adding stage is as shown in FIG. 6, if the DRBs to be released by the release stage are DRB 4, DRB 5 and DRB 6 respectively, the logical channels to be released indicated by the logical channel release information need to be logical channel 3, logical channel 4 and logical channel 5. In this case, the DRBs to be released and the logical channels to be released are matched. Otherwise, the DRBs to be released and the logical channels to be released are not matched.

[0133] For example, in some embodiments of the present application, the release information can be configured in the field specified in the RRC reconfiguration message, such as the DRB release information configured in the drb-ToReleaseList field and the logical channel release information configured in the rlc-BearerToReleaseList field.

[0134] For example, in the case where the DRBs to be released and the logical channels to be released are matched, as shown in (1) of FIG. 7, the DRB release information configured in the drb-ToReleaseList field indicates to release DRB 5, DRB 4 and DRB 6, and the logical channel release information configured in the rlc-BearerToReleaseList field indicates to release logical channel 3, logical channel 4 and logical channel 5. According to the correspondence configured at the adding stage described above, the UE successfully verifies the RRC reconfiguration message 2, and according to the existing protocol standard, the UE can release the DRBs and the logical channels according to the release information, and reply to the NR CELL A with the RRC reconfiguration complete message 2, i.e. step S106 is performed.

[0135] For example, in the case where the DRBs to be released and the logical channels to be released are not matched, as shown in (2) of FIG. 7, the DRB release information configured in the drb-ToReleaseList field indicates to release DRB 5, DRB 4 and DRB 6, while the logical channel release information configured in the rlc-BearerToReleaseList field only indicates to release logical channel 3. According to the correspondence configured at the adding stage described above, the UE fails to verify the RRC reconfiguration message 2, and according to the existing protocol standard, the UE can release the DRBs and the logical channels according to the release information, and trigger the RRC re-establishment procedure, i.e. step S107 is performed.

[0136] S106, the UE releases the DRBs and the logical channels according to the release information carried in the RRC reconfiguration message 2, and replies to the NR CELL A with an RRC reconfiguration complete message 2.

[0137] Illustratively, the UE replies to the gNB that issues the RRC reconfiguration message 2 with the RRC reconfiguration complete message 2.

[0138] Illustratively, the RRC reconfiguration complete message 2 is used to inform the gNB that issues the RRC reconfiguration message 2 that the RRC reconfiguration (release the DRBs and the logical channels) based on the RRC reconfiguration message 2 has been completed.

[0139] Illustratively, in the case that the RRC reconfiguration based on the RRC reconfiguration message 2 is completed, the ongoing call in which the UE camps on the NR CELL A can still be conducted normally until the UE of the calling party or the UE of the called party triggers a hang-up operation, such as pressing a button for hanging up the call in the user interface of the UE, and the current call is ended.

[0140] S107, the UE releases the DRBs and the logical channels according to the release information carried in the RRC reconfiguration message 2, and triggers an RRC reestablishment procedure.

[0141] For the specific implementation details of triggering the RRC reestablishment procedure in the case of the RRC reconfiguration failure, please refer to the description part of the embodiment shown in FIG. 4, which will not be described here again.

[0142] According to the existing standard protocol, after the RRC reestablishment procedure is triggered in the case of the RRC reconfiguration failure, the RRC connection between the UE and the network side is reestablished, the original base station considers that the RRC connection between the UE and the network side is abnormal. For this case, the network side, i.e., the original base station, does not issue information for configuring the DRBs and the logical channels, such as does not reissue the RRC reconfiguration message for instructing the UE to add / modify / release the DRBs and the logical channels. Correspondingly, the UE does not receive the RRC reconfiguration message issued by the network side, and thus cannot recover the bearers, such as cannot configure the DRBs and the logical channels required for the call.

[0143] Since the bearers between the UE and the network side are not recovered, the UE cannot send voice data packets generated in the call process to the network side, nor can it receive voice data packets generated in the call process from the network side, i.e., there is no sound in the current call. According to the existing standard protocol, in the case that there is no sound within a first time length (T1 time length), a timeout drop call is triggered, and thus the ongoing call in the NR CELL A is interrupted.

[0144] Illustratively, the first time length is, for example, 20 seconds (s).

[0145] Exemplarily, there is no sound in the first time length, a timeout drop call is triggered, and for example, a gNB of the NR CELL A sends a BYE message to the UE to release the current call. In order to distinguish, the call ended in this case can be understood as an abnormal end scenario or an interruption scenario.

[0146] As known from the above description of the scenario shown in FIG. 5, in the case where the DRB and the logical channel indicated by the UE to release are not configured in a one-to-one corresponding strong binding relationship according to the existing standard protocol, the RRC reconfiguration message check fails, the RRC reconfiguration fails, and the RRC reestablishment process is triggered, thereby interrupting the current call.

[0147] Therefore, some embodiments of the present application provide a method for reducing the drop call rate, which aims to enable the UE to complete the RRC reconfiguration in the case where the network side does not completely configure the DRB and the logical channel to release according to the existing standard protocol, so that the current call is not interrupted, the call failure is reduced, and the user experience is improved.

[0148] In order to better understand the method for reducing the drop call rate, the method for reducing the drop call rate is introduced on the basis of the scenario shown in FIG. 5. The specific implementation of the method for reducing the drop call rate is described below in combination with FIG. 8 and FIG. 9.

[0149] Before describing the method for reducing the drop call rate provided by the embodiments shown in FIG. 8 and FIG. 9, some descriptions involved in the two embodiments are described.

[0150] Specifically, in the embodiments shown in FIG. 8 and FIG. 9, the DRB and the logical channel to release have been successfully added in a one-to-one corresponding strong binding relationship according to the existing standard protocol as an example.

[0151] Exemplarily, the DRB and the logical channel successfully added in a one-to-one corresponding strong binding relationship according to the existing standard protocol are, for example, the DRB and the logical channel shown in FIG. 6. That is, before receiving the RRC reconfiguration message indicating the UE to release the DRB and the logical channel, the UE has added the DRB 4, the DRB 5, and the DRB 6, and the logical channel 3, the logical channel 4, and the logical channel 5, and the DRB 4 and the logical channel 3 correspond to each other, the DRB 5 and the logical channel 4 correspond to each other, and the DRB 6 and the logical channel 5 correspond to each other.

[0152] For specific implementation details of adding the DRB and the logical channel, refer to the description of steps S101 to S103 in the embodiment shown in FIG. 5, which will not be described here.

[0153] In addition, it should be noted that in the embodiments shown in FIGS. 8 and 9, the UE can be a calling UE or a called UE.

[0154] In addition, it should be noted that in the embodiments shown in FIGS. 8 and 9, the cell in which the UE is camped is taken as an example of a 5G cell.

[0155] Referring to FIG. 8, the method for reducing the call drop rate provided in the embodiments of the present application specifically includes the following steps.

[0156] S201, during the process of the UE camping in the NR CELL A for the first call, the UE receives a first RRC reconfiguration message sent by the NR CELL A.

[0157] For example, the first RRC reconfiguration message received by the UE is issued by the gNB corresponding to the NR CELL A.

[0158] For example, the gNB issuing the first RRC reconfiguration message is the gNB in the NR CELL A that establishes an RRC connection with the UE and conducts a call.

[0159] For example, the first RRC reconfiguration message carries first release information.

[0160] For example, the first release information includes first DRB release information indicating that the UE releases a DRB corresponding to a PDCP layer, and first logical channel release information indicating that the UE releases a first logical channel corresponding to an RLC layer.

[0161] In the embodiments of the present application, the first DRB release information indicates that the UE releases DRB 4, DRB 5, and DRB 6. The first logical channel release information indicates that the UE releases logical channel 3.

[0162] S202, according to the first release information in the first RRC reconfiguration message, if the UE determines that the DRB and the logical channel to be released do not match, the UE releases the DRB and the logical channel according to the first release information, and replies to the NR CELL A with a first RRC reconfiguration completion message.

[0163] For example, the first release information, such as the first DRB release information and the first logical channel release information, can be carried in a first field of the first RRC reconfiguration message, or can be carried in a second field of the first RRC reconfiguration message.

[0164] The first field, for example, is a field in which release information, such as the first DRB release information and the first logical channel information, is required to be configured. For example, in the case where DRB 4 is configured to correspond to logical channel 3, DRB 5 is configured to correspond to logical channel 4, and DRB 6 is configured to correspond to logical channel 5 in the adding link, according to the existing standard protocol, the first field is configured with the first DRB release information indicating that the UE releases DRB 4, DRB 5, and DRB 6, and the first logical channel release information configured in the first field needs to indicate that the UE releases logical channel 3, logical channel 4, and logical channel 5 to meet the requirements.

[0165] For example, the first field is a CellGroupConfig field. That is, the first DRB release information configured in the drb-ToReleaseList field and the first logical channel release information configured in the rlc-BearerToReleaseList field are both carried in the CellGroupConfig field.

[0166] For the existing standard protocol for the CellGroupConfig field, refer to the provisions of the 3GPP protocol 38.331 in section 5.3.5.6.4 for DRB release. The following is part of the content extracted from the standard protocol "The UE shall:

[0167] 1>for each drb-Identity value included in the drb-ToReleaseList that is part of the current UE configuration;or

[0168] 1>for each drb-Identity value that is to be released as the result of full configuration according to 5.3.5.11:

[0169] 2>release the PDCP entity and the drb-Identity;

[0170] 2>if SDAP entity associated with this DRB is configured:

[0171] 3> indicate the release of the DRB to SDAP entity associated with this DRB (TS 37.324

[0024] , clause 5.3.3);

[0172] 2> if the DRB is associated with an eps-BearerIdentity:

[0173] 3> if a new bearer is not added either with NR or E-UTRA with same eps-BearerIdentity:

[0174] 4> indicate the release of the DRB and the eps-BearerIdentity of the released DRB to upper layers.

[0175] NOTE 1: The UE does not consider the message as erroneous if the drb-ToReleaseList includes any drb-Identity value that is not part of the current UE configuration.

[0176] NOTE 2: Whether or not the RLC and MAC entities associated with this PDCP entity are reset or released is determined by the CellGroupConfig”.

[0177] That is, if the first release information is carried in the CellGroupConfig field according to the existing standard protocol, the number of DRBs indicated by the first DRB release information and the number of logical channels indicated by the first logical channel release information are the same, and the DRBs and the logical channels are one-to-one correspondence. But in some implementation scenarios, the network side may not fully comply with the existing standard protocol to configure the first release information carried in the CellGroupConfig field, that is, the number of DRBs indicated by the first DRB release information and the number of logical channels indicated by the first logical channel release information are not the same. If the DRBs to be released are DRB 4, DRB 5 and DRB 6, and the logical channels to be released are only logical channel 3 corresponding to DRB 4. This leads to the mismatch between the DRBs to be released and the logical channels.

[0178] Since DRB 4, DRB 5 and DRB 6 are released according to the first DRB release information, these three DRBs are in an unusable state, so after releasing DRB 4, DRB 5 and DRB 6, logical channel 3, logical channel 4 and logical channel 5 corresponding to DRB 4, DRB 5 and DRB 6 respectively cannot be accessed and used. Therefore, in some embodiments of the present application, the UE can ignore the mismatch between the DRBs to be released and the logical channels to be released, that is, not to perform strong check on the first release information in the first RRC reconfiguration message (not to comply with the existing standard protocol for the first release information configured in the CellGroupConfig field), and then prompt the UE to complete the RRC reconfiguration based on the first RRC reconfiguration message. In this way, the UE can reply to the NR CELL A with the first RRC reconfiguration complete message, and then inform the NR CELL A that the RRC reconfiguration based on the first RRC reconfiguration message has been completed.

[0179] Exemplarily, in some other implementations of the present disclosure, the UE can also not ignore the mismatching case, i.e., perform strong check on the first release information in the first RRC reconfiguration message (follow the existing standard protocol for the first release information configured in the CellGroupConfig field), and then trigger the RRC reestablishment procedure, in the case that the UE determines that the DRBs to be released and the logical channels do not match according to the first RRC release information in the first RRC reconfiguration message. As to the scenario that the RRC reconfiguration fails due to the mismatching between the DRBs to be released and the logical channels, and the RRC reestablishment procedure is triggered to release the first call, the UE can perform subsequent processing according to the method for reducing the call drop rate provided by the embodiment shown in FIG. 10. For specific details of this implementation, refer to the description of the embodiment shown in FIG. 10, which will not be repeated here.

[0180] For example, the second field is a field that does not require release information configured therein, such as the first DRB release information and the first logical channel information, to have a strong binding relationship. That is, in the case that the first release information is carried in the second field, the first DRB release information and the first logical channel release information configured in the second field do not have a strong binding relationship.

[0181] Exemplarily, the second field is, for example, a masterCellGroup field. That is, the first DRB release information configured in the drb-ToReleaseList field and the first logical channel release information configured in the rlc-BearerToReleaseList field are both carried in the masterCellGroup field. The masterCellGroup field can be used to carry cellGroupId, rlc-BearerToAddModList, mac-CellGroupConfig, physicalCellGroupConfig, and the like.

[0182] For the provisions of the masterCellGroup field in the existing standard protocol, refer to the content of chapter 6.3.2 in 3GPP protocol 38.311, which will not be repeated here.

[0183] That is, in the scenario that the first release information is carried in the masterCellGroup field, the UE can not perform strong check on the first release information in the first RRC reconfiguration message. In this way, no matter whether the DRB to be released and the logical channel match or not, the UE can complete the RRC reconfiguration based on the first RRC reconfiguration message, and then reply the first RRC reconfiguration complete message to the NR CELL A to inform the NR CELL A that the RRC reconfiguration based on the first RRC reconfiguration message has been completed.

[0184] In addition, it should be noted that in some embodiments of the present application, in the case that the UE determines that the DRB to be released and the logical channel do not match according to the first release information in the first RRC reconfiguration message, the UE can release the DRB according to the first DRB release information and release the first logical channel according to the first logical channel release information. That is, the release processing of the DRB and the logical channel is performed according to the first DRB release information and the first logical channel information carried in the received first RRC reconfiguration message.

[0185] In addition, it should be noted that in some embodiments of the present application, in the case that the UE determines that the DRB to be released and the logical channel do not match according to the first release information in the first RRC reconfiguration message, the UE can release the DRB according to the first DRB release information and release the first logical channel according to the first logical channel release information. That is, the release processing of the DRB and the logical channel is performed according to the first DRB release information and the first logical channel information carried in the received first RRC reconfiguration message.

[0186] Thus, by setting the UE not to perform strong check on the release information in the RRC reconfiguration message sent by the network side, such as the first release information in the first RRC reconfiguration message as mentioned in the above embodiments, in the case that the DRB to be released and the logical channel do not match, the UE is prompted to complete the RRC reconfiguration regardless of the mismatch. In this way, the ongoing first call will not be interrupted, and the UE can continue to camp in the current cell, such as the NR CELL A, to perform the first call, thereby achieving the effect of reducing call failure, guaranteeing call quality, and improving user experience.

[0187] Referring to FIG. 9, the method for reducing the call drop rate provided by the embodiments of the present application specifically includes:

[0188] S301, in the process that the UE camps in the NR CELL A to perform the first call, the UE receives the first RRC reconfiguration message sent by the NR CELL A.

[0189] S302, in a case where the UE determines that the DRB to be released and the logical channel to be released do not match according to the first release information in the first RRC reconfiguration message, the UE releases the DRB and the logical channel according to the first release information, and the UE returns a first RRC reconfiguration complete message to the NR CELL A.

[0190] The step S301 and the step S302 in the embodiments of the present application are similar to the step S201 and the step S202 in the embodiments shown in FIG. 8, and the specific implementation details can be referred to the description of the step S201 and the step S202, which will not be described here.

[0191] S303, in a case where the UE determines that the DRB to be released and the logical channel to be released do not match according to the first release information in the first RRC reconfiguration message, the UE records the number of exceptions.

[0192] For example, when the UE camps on the NR CELL A for the first time and makes a call, the UE can initialize an exception number N. For example, N is set to 0, that is, the initial value of N is 0. In this way, during the call, each time the UE determines that the DRB to be released and the logical channel to be released do not match according to the release information in the received RRC reconfiguration message, the UE performs self-increment processing on N, that is, N=N+1.

[0193] Understandably, N before “=” is the number of exceptions that need to be compared with the first exception threshold value, such as K1, and N after “=” is the number of exceptions recorded before the cumulative processing, such as the initial value.

[0194] In addition, it should also be understood that the setting of the initial value of N is only an example listed for better understanding of the technical solutions of the embodiments, and is not the only limitation of the embodiments.

[0195] In addition, it should be noted that the step S302 and the step S303 can not be distinguished by the execution order. That is, in a case where the UE determines that the first DRB release information and the first logical channel release information carried in the first RRC reconfiguration message do not match, the UE can trigger the operations of releasing the DRB and the logical channel according to the first release information, returning the first RRC reconfiguration complete message to the NR CELL A, and recording the number of exceptions at the same time.

[0196] S304, in a case where the UE determines that the DRB to be released and the logical channel to be released do not match according to the first release information in the first RRC reconfiguration message, the UE releases the DRB and the logical channel according to the first release information, and the UE returns a first RRC reconfiguration complete message to the NR CELL A.

[0197] The abnormal cell list is a list maintained by the UE. In this way, in a subsequent use scenario, the UE can determine whether to perform a voice call service in the currently camped cell by determining whether the currently camped cell is recorded in the abnormal cell list.

[0198] For example, K1 can be set to 1. In this way, in the case of a first occurrence of a mismatch between a DRB to be released and a logical channel, the cell in which the problem occurs can be timely marked.

[0199] For example, T2 can be greater than T3.

[0200] For example, T2 is 2 days. For example, within 2 days, the identifier of NR CELL A is recorded in the abnormal cell list, and after 2 days, the identifier of NR CELL A can be removed from the abnormal cell list.

[0201] For example, T3 is 5 minutes (min). In this way, after the normal end of the first call, the UE is prohibited from accessing NR CELL A within 5 min. That is, the prohibited access time set for the abnormal cell takes effect after the UE ends the call in the cell.

[0202] For example, in some embodiments, after the UE completes step S302 and normally ends the first call, the UE can camp on a normal cell, such as a cell not recorded in the abnormal cell list, for example, camp on NR CELL B. In this way, within the T3 duration, the UE will not camp on NR CELL A for a new call, thereby avoiding the reissuance of unreasonable RRC reconfiguration messages by NR CELL A, such as the issuance of an RRC reconfiguration message carrying release information indicating a mismatch between a DRB to be released and a logical channel by NR CELL A.

[0203] For example, in some embodiments, after the T3 duration, the UE can re-camp on NR CELL A or remain in another cell. The embodiments of the present application take the case where the UE re-camps on NR CELL A after the T3 duration as an example.

[0204] It should be understood that the values of K1, T2, and T3 are only examples for better understanding the technical solutions of the embodiments and are not the only limitation of the embodiments.

[0205] S305, after the UE re-camps on NR CELL A after the normal end of the first call and the T3 duration, but NR CELL A is still in the abnormal duration, the UE receives a second RRC reconfiguration message sent by NR CELL A during the process of performing a second call in NR CELL A.

[0206] That is, after the normal end of the first call, the UE re-camps in the NR CELL A recorded in the abnormal cell list for a new call, such as the second call, within the T2 time period but beyond the T3 time period, and receives the second RRC reconfiguration message sent by the NR CELL A.

[0207] For example, the second RRC reconfiguration message carries second release information.

[0208] For example, the second release information includes second DRB release information indicating that the UE releases the DRB corresponding to the PDCP layer, and release information of a second logical channel indicating that the UE releases the RLC layer.

[0209] In the embodiments of the present application, before receiving the second RRC reconfiguration message, the UE has successfully added the DRB and the logical channel in a one-to-one strong binding relationship according to the existing standard protocol, for example, the number and relationship of the DRB and the logical channel shown in FIG. 6, and the second release information carried in the second RRC reconfiguration message is the same as the first release information carried in the first RRC reconfiguration message.

[0210] S306, in the case that the UE determines that the DRB and the logical channel to be released do not match according to the second release information in the second RRC reconfiguration message, the UE releases the DRB and the logical channel according to the second release information, and replies to the NR CELL A with a second RRC reconfiguration complete message.

[0211] Step S306 in the embodiments of the present application is similar to step S202, and the specific implementation details can be referred to the description of step S202, which will not be described here.

[0212] S307, in the case that the UE determines that the DRB and the logical channel to be released do not match according to the second release information in the second RRC reconfiguration message, the UE performs accumulation processing on the abnormal number N.

[0213] That is, the operation of N=N+1 is performed. Wherein, N before “=” is the abnormal number to be compared with the second abnormal threshold value, such as K2, and N after “=” is the abnormal number recorded before the accumulation processing.

[0214] In addition, it should be noted that steps S306 and S307 can not be distinguished by the order of execution. That is, in the case that the UE determines that the second DRB release information and the second logical channel release information carried in the second RRC reconfiguration message do not match, the UE can trigger the operations of releasing the DRB and the logical channel according to the second release information, replying to the NR CELL A with the second RRC reconfiguration complete message, and recording the abnormal number at the same time.

[0215] S308, in a case where the accumulated N is greater than the second abnormal threshold, the UE sets a fourth time length (T4 time length) within which access to the NR CELL A is prohibited.

[0216] For example, K2 can be set to 5.

[0217] For example, T4 can be greater than T3 and less than or equal to T2. For example, in a case where T2 is 2 days and T3 is 5 minutes, T4 can be 1 day, 30 hours (h), 2 days, etc.

[0218] For example, in some embodiments of the present application, in a case where the accumulated N is greater than the second abnormal threshold, the UE can modify the abnormal time length set for the NR CELL A in the abnormal cell list from T2 to T5 (T5 is greater than T2).

[0219] For example, T5 is 7 days. For this case, T4 can be greater than T3 and less than or equal to T5.

[0220] It should be understood that the values of K2, T4, and T5 are only examples for better understanding the technical solutions of the embodiments and are not the only limitation of the embodiments.

[0221] Thus, by setting the UE to not perform strong checking on the release information in the RRC reconfiguration message issued by the network side, in a case where the DRB to be released does not match the logical channel, the UE ignores the mismatch and completes the RRC reconfiguration. The number of times of the abnormality occurring due to the mismatch between the DRB to be released and the logical channel is recorded, and an abnormal cell punishment mechanism (such as adding the cell to the abnormal cell list and setting the corresponding abnormal time length and a shorter access prohibition time length for the first time the abnormality occurs, and increasing the punishment, such as setting a longer access prohibition time length, for the case where the abnormality occurs again and the number of times of the abnormality is greater than a certain number of times) is adopted, to avoid re-entering the cell in a short time after the fact, so as to not only ensure that the ongoing call will not be interrupted, but also reduce the probability of the UE camping on the cell in the future, so that the call can occur in a normal cell (not a cell in the abnormal cell list) as much as possible, for example, the UE can perform a third call through the gNB corresponding to the NR CELL B which is not recorded in the abnormal cell list within the T4 time length, further reducing the call failure, ensuring the call quality, and improving the user experience.

[0222] It can be understood that in some embodiments of the present application, the NR CELL A can be referred to as a first cell, and the NR CELL B can be referred to as a second cell.

[0223] In addition, some embodiments of the present application also provide a method for reducing the call drop rate, which aims to reduce the probability of the UE camping on an abnormal cell (a cell that does not completely configure the DRB and logical channel to be released according to the existing standard protocol), so as to ensure that the ongoing call can occur in a normal cell (a cell that completely configures the DRB and logical channel to be released according to the existing standard protocol) as much as possible, so that the call can proceed normally, reduce call failure, and improve user experience.

[0224] In order to better understand the method for reducing the call drop rate, the method for reducing the call drop rate is introduced on the basis of the scenario shown in FIG. 5. The specific implementation of the method for reducing the call drop rate is described below in combination with FIG. 10.

[0225] Before describing the method for reducing the call drop rate provided by the embodiment shown in FIG. 10, some descriptions involved in the embodiment are described.

[0226] Specifically, in the embodiment shown in FIG. 10, still taking the premise that the DRB and logical channel to be released have been successfully added in a one-to-one corresponding strong binding relationship according to the provisions of the existing standard protocol as an example.

[0227] For example, the DRB and logical channel that have been successfully added in a one-to-one corresponding strong binding relationship according to the provisions of the existing standard protocol are, for example, the DRB and logical channel of the number and relationship shown in FIG. 6. That is, before receiving the RRC reconfiguration message indicating that the UE releases the DRB and logical channel, the UE has added DRB 4, DRB 5, and DRB 6, and logical channel 3, logical channel 4, and logical channel 5, and DRB 4 and logical channel 3 correspond one-to-one, DRB 5 and logical channel 4 correspond one-to-one, and DRB 6 and logical channel 5 correspond one-to-one.

[0228] For specific implementation details of adding the DRB and logical channel, refer to the description of steps S101 to S103 in the embodiment shown in FIG. 5, which will not be described here.

[0229] In addition, it should be noted that in the embodiment shown in FIG. 10, the UE can be a calling UE or a called UE.

[0230] In addition, it should be noted that in the embodiment shown in FIG. 10, still taking the cell in which the UE camps as a 5G cell as an example.

[0231] Referring to FIG. 10, the method for reducing the call drop rate provided by the embodiments of the present application specifically includes:

[0232] S401, during the process of the UE camping on the NR CELL A for the first call, receiving the first RRC reconfiguration message sent by the NR CELL A.

[0233] The step S401 in the embodiment of the present application is similar to the step S201 in the embodiment shown in FIG. 8, and the specific implementation details can be referred to the description part of the step S201, which will not be repeated here.

[0234] S402, the UE determines that the DRB and the logical channel to be released do not match according to the first release information in the first RRC reconfiguration message, releases the DRB and the logical channel according to the first release information, and triggers an RRC re-establishment process.

[0235] The step S402 in the embodiment of the present application is similar to the step S107 in the embodiment shown in FIG. 5, and the specific implementation details can be referred to the description part of the step S107, which will not be repeated here.

[0236] S403, the UE determines that the DRB and the logical channel to be released do not match according to the first release information in the first RRC reconfiguration message, and records the number of exceptions.

[0237] It should be noted that the step S402 and the step S403 can not distinguish the execution order. That is, the UE can trigger the operations of releasing the DRB and the logical channel according to the first release information, replying the first RRC reconfiguration complete message to the NR CELL A, and recording the number of exceptions at the same time in the case of determining that the first DRB release information and the first logical channel release information carried in the first RRC reconfiguration message do not match.

[0238] S404, in the case of the accumulated N being greater than the first exception threshold (K1), the UE adds the identification information of the NR CELL A to the exception cell list, sets the exception duration of the NR CELL A as the second duration (T2 duration), and sets the third duration (T3 duration) within which the NR CELL A is prohibited to be accessed.

[0239] The step S403 and the step S404 in the embodiment of the present application are similar to the step S303 and the step S304 in the embodiment shown in FIG. 9, and the specific implementation details can be referred to the description part of the step S303 and the step S304, which will not be repeated here.

[0240] S405, in the case of the NR CELL A still being in the exception duration after the first call is interrupted, the UE receives the second RRC reconfiguration message sent by the NR CELL A in the process of camping in the NR CELL A for the second call.

[0241] That is, after the first call is abnormally ended due to the first RRC reconfiguration failure, triggering the RRC reestablishment, after the T3 time length, in the T2 time length, the UE camps on the NR CELL A recorded in the abnormal cell list to perform a new call, such as the process of the second call, the second RRC reconfiguration message sent by the NR CELL A is received.

[0242] The second RRC reconfiguration message received by the step S405 in the embodiment of the application is the same as the second RRC reconfiguration message received in the step S305 in the embodiment shown in FIG. 9. The description of the second RRC reconfiguration message can be referred to the description part of the step S305, and details are not described herein.

[0243] In the step S406, the UE determines whether the DRB and the logical channel to be released do not match according to the second release information in the second RRC reconfiguration message, and releases the DRB and the logical channel according to the second release information and triggers the RRC reestablishment process in the case that the DRB and the logical channel to be released do not match.

[0244] The step S406 in the embodiment of the application is similar to the step S107 in the embodiment shown in FIG. 5. The specific implementation details can be referred to the description part of the step S107, and details are not described herein.

[0245] In the step S407, the UE accumulates the abnormal number N in the case that the DRB and the logical channel to be released do not match according to the second release information in the second RRC reconfiguration message.

[0246] It should be noted that the step S406 and the step S407 can not be distinguished by the execution order. That is, the UE can trigger the operations of releasing the DRB and the logical channel according to the second release information, replying the second RRC reconfiguration complete message to the NR CELL A, and recording the abnormal number at the same time in the case that the second DRB release information and the second logical channel release information carried in the second RRC reconfiguration message do not match.

[0247] In the step S408, the UE sets the fourth time length (T4 time length) to prohibit accessing the NR CELL A in the case that the accumulated N is greater than the second abnormal threshold.

[0248] The step S407 and the step S408 in the embodiment of the application are similar to the step S307 and the step S308 in the embodiment shown in FIG. 9. The specific implementation details can be referred to the description part of the step S307 and the step S308, and details are not described herein.

[0249] Thus, in the case that the DRB to be released and the logical channel do not match, the RRC reestablishment process is triggered according to the existing standard protocol, the ongoing call is interrupted, the number of times of the abnormality due to the mismatch between the DRB to be released and the logical channel is recorded, and the abnormal cell punishment mechanism is adopted (for example, the cell is added to the list of abnormal cells and the corresponding abnormal duration and a short access prohibition duration are set when the abnormality occurs for the first time, and the punishment is aggravated, for example, a long access prohibition duration is set when the abnormality occurs again and the number of times of the abnormality is greater than a certain number of times), so as to avoid re-entering the cell in a short time afterwards, thereby effectively reducing the probability of the UE camping on an abnormal cell (a cell in which the DRB to be released and the logical channel are not completely configured according to the existing standard protocol), ensuring that the subsequent call is as much as possible to occur in a normal cell (a cell in which the DRB to be released and the logical channel are completely configured according to the existing standard protocol), and enabling the call service to be normally performed, thereby achieving the effect of reducing call failure and improving user experience.

[0250] In addition, it should be noted that, in each embodiment of the present application, the call performed by the UE camping on the 5G cell, such as the first call, the second call, the third call, etc., can be the reception and transmission of data in the acknowledged mode (AM).

[0251] The specific working principle of AM can be referred to the existing standard protocol, which will not be described here.

[0252] In addition, the hardware structure of the terminal device for implementing the method for reducing the call drop rate provided in each embodiment of the present application can be as shown in FIG. 11.

[0253] Referring to FIG. 11, the terminal device includes 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, a headset 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.

[0254] It can be understood that the structure illustrated in the embodiments of the present application does not constitute a specific limitation on the terminal. In other embodiments, the terminal can include more or fewer components than illustrated, or combine certain components, or split certain components, or different component arrangements. The illustrated components can be implemented in hardware, software, or a combination of software and hardware.

[0255] Among them, the antenna 1 and the antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in the terminal device can be used to cover a single or multiple communication frequency bands. Different antennas can also be multiplexed to improve the utilization rate of the antenna. For example: the antenna 1 can be multiplexed as a diversity antenna of a wireless local area network. In some other embodiments, the antenna can be used in combination with a tuning switch.

[0256] Specific to the embodiments of the present application, the messages sent by the base station, such as the gNB as described in the above embodiments, to the terminal device, such as the first RRC reconfiguration message, the second RRC reconfiguration message, etc., can be received through the antenna 1 or the antenna 2.

[0257] Correspondingly, the messages sent by the terminal device to the gNB, such as the first RRC reconfiguration completion message, the second RRC reconfiguration completion message, the message sent to the gNB in the RRC re-establishment process, etc., can be sent through the antenna 1 or the antenna 2.

[0258] Among them, the mobile communication module 150 can provide a solution including 2G / 3G / 4G / 5G wireless communication applied to the terminal device. The mobile communication module 150 can include at least one filter, switch, power amplifier, low noise amplifier (LNA), etc. The wireless communication module 160 can provide a solution including wireless local area network (WLAN) (such as wireless fidelity (Wi-Fi) network), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), infrared technology (IR), etc. Wireless communication solutions applied to the terminal device.

[0259] For example, in some embodiments, the antenna 1 of the terminal device can be coupled with the mobile communication module 150, and the antenna 2 can be coupled with the wireless communication module 160. Thus, the terminal device can communicate with the network and other devices through mobile communication technology or wireless communication technology.

[0260] Continuing to refer to FIG. 11, the audio module 170 of the terminal device may, for example, include a speaker 170A, a receiver 170B, a microphone 170C, a headphone jack 170D, and the like.

[0261] The terminal device may, for example, implement audio functions such as music playback, recording, and voice call services described in the embodiments of the present disclosure 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.

[0262] In addition, regarding the sensor module 180 in the terminal device, in some embodiments, it may, for example, 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 disclosure does not limit this.

[0263] In addition, it should be noted that, in some embodiments, the processor 110 may, for example, include one or more processing units. For example, the processor 110 may, for example, include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), and the like.

[0264] Understandably, in a specific implementation, different processing units may, for example, be independent devices or may be integrated in one or more processors.

[0265] It should be noted that, in actual applications, the terminal device may, for example, implement the technical solutions provided in the embodiments of the present disclosure through the two processing units of the AP 110A and the Modem 110B. For example, through the AP, the call request initiated by the user is responded to, and then the application program framework layer service related to the call service and the corresponding driver in the kernel layer are called, and the call request is handed over to the Modem. The Modem may, for example, interact with the network side to establish a call. Accordingly, during the call, the Modem may, for example, interact with the network side according to the processing logic involved in the method for reducing the call drop rate provided in the embodiments of the present disclosure. The specific implementation details may, for example, be referred to in the above embodiments, and will not be described here.

[0266] In addition, it is also understandable that the controller included in the processor 110 can be the nerve center and command center of the terminal device. 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.

[0267] 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.

[0268] In addition, the USB interface 130 shown in FIG. 11 is an interface conforming to the USB standard specification, and can be a Mini USB interface, a Micro USB interface, a USB Type C interface, etc.

[0269] The charging management module 140 is configured to receive charging input from a charger. In addition, the power management module 141 shown in FIG. 11 is configured to connect the battery 142 and the charging management module 140. The power management module 141 receives input of the battery 142 and / or the charging management module 140 to supply power to 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 terminal device 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.

[0270] In addition, the terminal device shown in FIG. 11 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.

[0271] Regarding 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 terminal device can include 1 or N display screens 194, and N is a positive integer greater than 1.

[0272] In addition, the terminal device 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. The camera 193 is used to capture still images or videos. In some embodiments, the terminal device can include 1 or N cameras 193, and N is a positive integer greater than 1.

[0273] In addition, the external memory interface 120 shown in FIG. 11 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the terminal device. The external memory card communicates with the processor 110 through the external memory interface 120 to implement a data storage function. For example, files such as music and video are saved in the external memory card.

[0274] In addition, the internal memory 121 shown in FIG. 11 can be used to store computer executable program code, which includes instructions. The processor 110 executes various functional applications and data processing of the terminal device by running the instructions stored in the internal memory 121.

[0275] Specifically, the abnormal cell list recorded in the above embodiments can be saved in the internal memory 121 of the terminal device.

[0276] In addition, the motor 191 shown in FIG. 11 can be, for example, a vibration motor; and the indicator 192 can be an indicator light.

[0277] In addition, the SIM card interface 195 shown in FIG. 11 can be used to connect a SIM card or a USIM card. The SIM card can be inserted into or removed from the SIM card interface 195 to achieve contact and separation with the terminal device. The terminal device 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.

[0278] In addition, it should be noted that an operating system runs on the above components. For example, the iOS operating system developed by Apple Inc., the Android open source operating system developed by Google Inc., the Windows operating system developed by Microsoft Corp., etc.

[0279] The operating system of the terminal device can adopt a layered architecture, or an event-driven architecture, or a microkernel architecture, or a microservice architecture, or a cloud architecture. The embodiments of the present application take the Android system with a layered architecture as an example to exemplarily illustrate the software structure of the terminal device. It should be noted that the embodiments of the present application take the Android system as an example for illustration, but the basic principles are also applicable to terminal devices based on iOS or Windows operating systems.

[0280] Referring to FIG. 12, a schematic diagram of the relationship between the software structure of a terminal device and hardware devices, and the interaction with a gNB is exemplarily shown.

[0281] As shown in FIG. 12, the software structure adopts a layered architecture, which divides the software into several layers, each of which has a clear role and division of labor. The layers communicate with each other through software interfaces. In some embodiments, the Android system is divided into five layers, from top to bottom, the application layer, the application framework layer (Framework), the Android runtime and system library, the hardware abstraction layer (HAL), and the system kernel layer (Kernel).

[0282] The application layer can include a series of application packages. The application packages can include systemUI, camera, gallery, calendar, call, map, WLAN, Bluetooth, music, video, short message, and the like.

[0283] The systemUI is used to display the interface of the terminal device, such as displaying the signal icon corresponding to the SIM card, displaying the call interface, and the like.

[0284] The application framework layer provides application programming interfaces (APIs) and programming frameworks for the applications of the application layer. In some embodiments of the present application, these programming interfaces and programming frameworks can be described as functions. As shown in FIG. 12, the application framework layer can include a window manager, a content provider, a view system, a telephony, a resource manager, a notification manager, and the like.

[0285] The telephony is used to provide the call function of the terminal device, such as the management of the call state (including call connection, call hang-up, and the like).

[0286] Referring back to FIG. 12, the application framework layer can also include a radio interface layer (RIL).

[0287] In the call scenario of the embodiments of the present application, the Modem can interact with the telephony through the RIL.

[0288] The Android Runtime includes a core library and a virtual machine. The Android Runtime is responsible for the scheduling and management of the Android system.

[0289] The core library includes two parts: one part is the function function that the java language needs to call, and the other part is the core library of Android.

[0290] The application program layer and the application framework layer run in a virtual machine. The virtual machine executes the java files of the application program layer and the application framework layer into binary files. The virtual machine is used to perform functions such as management of object life cycle, stack management, thread management, management of security and exceptions, and garbage collection.

[0291] The system library can include a plurality of functional modules. For example, a surface manager, media libraries, a three-dimensional (3D) graphics processing library (such as OpenGL ES), a two-dimensional (2D) graphics engine (such as SGL), and the like.

[0292] The kernel layer is a layer between hardware and software. The kernel layer can include various drivers, such as a display driver, a camera driver, an audio driver, a sensor driver, and the like.

[0293] The Modem can include a Non-Access Stratum (NAS layer), an RRC layer, a PDCP layer, an RLC layer, a Medium Access Control Layer (MAC layer), and a Physical (PHY) layer.

[0294] For example, in some implementations of the present application, a strong check switch can be set in the RRC layer of the Modem.

[0295] For example, in the case where the strong check switch is in the off state, if the UE determines that the DRB to be released and the logical channel do not match according to the received RRC reconfiguration message, the operation of step S202 in the embodiment shown in FIG. 8 can be performed, or the operations of steps S302, S306 in the embodiment shown in FIG. 9 can be performed. That is, in the case where the strong check switch is in the off state, the UE is set not to perform strong check on the release information in the RRC reconfiguration message issued by the network side. In this way, in the case where the DRB to be released and the logical channel do not match, the mismatch is ignored, which can promote the UE to complete the RRC reconfiguration, and thus ensure that the ongoing call will not be interrupted.

[0296] Exemplarily, in the case that the strong check switch is in the on state, if the UE determines that the DRB and the logical channel that need to be released do not match according to the received RRC reconfiguration message, the operation of step S402 and the following steps shown in FIG. 10 can be performed. That is, in the case that the strong check switch is in the on state, the UE follows the existing standard protocol to perform strong check on the release information in the RRC reconfiguration message issued by the network side, triggers the RRC reestablishment process, interrupts the ongoing call, records the number of abnormal times due to the mismatch between the DRB and the logical channel that need to be released, and adopts the abnormal cell punishment mechanism for the cell. In this way, the UE can be prevented from re-entering the cell in a short time afterwards, so as to effectively reduce the probability of the UE camping on the abnormal cell, ensure that the subsequent call can occur in a normal cell as much as possible, and enable the call service to be normally performed.

[0297] Exemplarily, in the embodiments of the present application, the strong check switch arranged in the RRC layer is only visible to the UE and invisible to the user. That is, the strong check switch is pre-set to the RRC layer by the terminal manufacturer before the UE is manufactured, and the switch state thereof is set.

[0298] Exemplarily, in some embodiments of the present application, the strong check switch can be understood as a software switch or a software interface. The strong check switch is used to control whether the UE performs strong check on the information for indicating the UE to release the DRB and the logical channel in the RRC reconfiguration message issued by the network side, that is, whether to strictly perform check according to the existing standard protocol or to ignore the mismatching case.

[0299] Exemplarily, in some embodiments of the present application, the strong check switch is a functional module realized by software code, for example.

[0300] Exemplarily, in some embodiments of the present application, the strong check switch can be in the on state by default.

[0301] Exemplarily, in some embodiments of the present application, the strong check switch can be in the off state by default.

[0302] In addition, it can be understood that each layer in the Modem can be a software module.

[0303] Continuing to refer to FIG. 12, the Modem can interact with the base station through an antenna, such as to implement the receiving of the first RRC reconfiguration message and the second RRC reconfiguration message issued by the network side, the sending of the first RRC reconfiguration complete message and the second RRC reconfiguration complete message to the network side, the interaction involved in the RRC reestablishment process, and the like in the embodiments of the present application.

[0304] The software structure of the first terminal is introduced here, and it can be understood that the layers and components in the software structure shown in FIG. 12 do not constitute a specific limitation on the first terminal. In other embodiments of the present application, the first terminal can include more or fewer layers than shown, and each layer can include more or fewer components, and the present application is not limited.

[0305] In addition, it can be understood that the terminal device includes hardware and / or software modules corresponding to the functions to implement the above functions. The algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented in hardware or a combination of hardware and computer software. Whether a certain function is implemented in hardware or computer software driven 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.

[0306] In addition, it should be noted that the method for reducing the call drop rate provided by the above embodiments implemented by the terminal device in the actual application scenario 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, and implements the steps executed by the terminal device described above. The processor in the chip system can be an application processor (AP), or a non-application processor such as a modem.

[0307] In addition, the embodiments of the present application further provide a computer readable storage medium, which stores computer instructions, and when the computer instructions run on the terminal device, the terminal device executes the related method steps to implement the method for reducing the call drop rate in the above embodiments.

[0308] In addition, the embodiments of the present application further provide a computer program product, which, when running on the terminal device, causes the terminal device to execute the above related steps to implement the method for reducing the call drop rate in the above embodiments.

[0309] In addition, as known from the above description, the terminal device, computer readable storage medium, computer program product or chip system provided by the embodiments of the present application are all used to execute the corresponding methods provided above, and therefore the beneficial effects that can be achieved are referred to the beneficial effects in the corresponding methods provided above, which will not be described here.

[0310] In addition, it should also be understood that the above embodiments are only used to illustrate the technical solutions of the present application, but not limit it. Although the present application is 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 replacement for part of the technical features. The modification or replacement does not make the essence of the corresponding technical solution deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of reducing the rate of dropped calls, characterized by, The method is applied to a terminal device, and comprises the following steps: In a process of making a first call in a first cell, a first RRC reconfiguration message sent by a base station corresponding to the first cell is received; wherein the first RRC reconfiguration message comprises first release information, the first release information comprises first data radio bearer (DRB) release information and first logical channel release information, the first DRB release information indicates information of a first DRB to be released, and the first logical channel release information indicates information of a first logical channel to be released; In a case where the first DRB release information and the first logical channel release information do not match, the first DRB is released according to the first DRB release information, the first logical channel is released according to the first logical channel release information, and a first RRC reconfiguration completion message is replied to the base station corresponding to the first cell.

2. The method of claim 1, wherein, A strong check switch is arranged in a modem processor of the terminal device. The step of releasing the first DRB according to the first DRB release information, releasing the first logical channel according to the first logical channel release information, and replying the first RRC reconfiguration completion message to the base station corresponding to the first cell in the case where the first DRB release information and the first logical channel release information do not match comprises the following steps: In a case where the strong check switch is in a closed state and the first DRB release information and the first logical channel release information do not match, the first DRB is released according to the first DRB release information, the first logical channel is released according to the first logical channel release information, and the first RRC reconfiguration completion message is replied to the base station corresponding to the first cell.

3. The method of claim 2, wherein, The method further comprises the following steps: In a case where the strong check switch is in an open state and the first DRB release information and the first logical channel release information do not match, the first DRB is released according to the first DRB release information, the first logical channel is released according to the first logical channel release information, and an RRC reestablishment procedure is triggered.

4. The method of claim 1, wherein, The first release information is carried in a first field of the first RRC reconfiguration message, and the first field is a field defined in a standard protocol for carrying the first DRB release information and the first logical channel release information.

5. The method of claim 4, wherein, The first field is a cell group configuration (CellGroupConfig) field.

6. The method of claim 4, wherein, In the case where the first release information is carried in the first field, the step of releasing the first DRB according to the first DRB release information, releasing the first logical channel according to the first logical channel release information, and replying the first RRC reconfiguration completion message to the base station corresponding to the first cell in the case where the first DRB release information and the first logical channel release information do not match is performed.

7. The method of claim 1, wherein, The first release information is carried in a second field of the first RRC reconfiguration message, the second field is different from a first field, and the first field is a field defined in a standard protocol for carrying the first DRB release information and the first logical channel release information.

8. The method of claim 7, wherein, The second field is a master cell group field.

9. The method of claim 7, wherein, In the case where the first release information is carried in the second field, the step of releasing the first DRB according to the first DRB release information, releasing the first logical channel according to the first logical channel release information, and replying to the first cell corresponding base station with the first RRC reconfiguration complete message in the case where the first DRB release information and the first logical channel release information do not match is performed.

10. The method of claim 9, wherein, The method further comprises: In the case where the first release information is carried in the first field and the first DRB release information and the first logical channel release information do not match, the first DRB is released according to the first DRB release information, the first logical channel is released according to the first logical channel release information, and an RRC reestablishment procedure is triggered; Wherein, in the case where no message for configuring a second DRB and a second logical channel issued by a base station corresponding to a cell accessed in the RRC reestablishment procedure is received within a first time duration after the RRC reestablishment procedure is completed, the first call is released.

11. The method of claim 1, wherein, The first call in the first cell uses an acknowledgement mode for receiving and sending data.

12. The method according to any one of claims 1 to 11, characterized in that, The method further comprises: In the case where the first DRB release information and the first logical channel release information do not match, it is recorded as an abnormality once; In the case where the number of the abnormality is accumulated and is greater than a first abnormality threshold, identification information of the first cell is added to an abnormal cell list, an abnormal duration of the first cell is set as a second duration, and the first cell is prohibited from being accessed within a third duration, the second duration being greater than the third duration.

13. The method of claim 12, wherein, The method further comprises: In the second duration, a second RRC reconfiguration message sent by a base station corresponding to the first cell is received in the process of a second call in the first cell; wherein, the second RRC reconfiguration message comprises second release information, the second release information comprises second DRB release information and second logical channel release information, the second DRB release information indicates information of a second DRB to be released, and the second logical channel release information indicates information of a second logical channel to be released; In the case where the second DRB release information and the second logical channel release information do not match, the second DRB is released according to the second DRB release information, the second logical channel is released according to the second logical channel release information, a second RRC reconfiguration complete message is replied to the base station corresponding to the first cell, and the number of the abnormality is accumulated once. In a case where the accumulated number of the exceptions is greater than a second exception threshold, access to the first cell is prohibited for a fourth time duration, the second exception threshold is greater than the first exception threshold, and the fourth time duration is greater than the third time duration.

14. The method according to any one of claims 1 to 13, characterized in that, In a case where the number of the first DRBs indicated by the first DRB release information and the number of the first logical channels indicated by the first logical channel release information are different, the first DRB release information and the first logical channel release information are not matched.

15. The method according to any one of claims 1 to 13, characterized in that, In a case where the first DRBs indicated by the first DRB release information and the first logical channels indicated by the first logical channel release information do not correspond, the first DRB release information and the first logical channel release information are not matched.

16. A terminal device, comprising: The terminal device comprises a memory and a processor, which 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 reducing the call drop rate according to any one of claims 1 to 15.

17. A chip system, characterized by The chip system comprises a processor configured to support a terminal device to implement the method for reducing the call drop rate according to any one of claims 1 to 15.

18. The chip system according to claim 17, characterized by The processor comprises a modem processor.

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