CN117135775A - Communication method and terminal equipment - Google Patents

Abstract

The embodiments of the present application provide a communication method and terminal equipment, which relate to the field of communication technology. Solve the problem of call drops during calls. The specific solution is: use the first DRB to send the first data to the first network device, and the SN field length of the RLC header of the first data is the first value; when the response returned by the first network device for the first data is not received Next, send a re-establishment request to the first network device; receive a first reconfiguration message from the first network device, where the first reconfiguration message carries first indication information, and the first indication information is used to instruct the first network device The length of the SN field configured by the first DRB at the RLC layer is the second value; when the first value and the second value are not equal, send a reconfiguration completion message to the first network device; use the first DRB to send the second value to the first network device. The network device sends the second data, and the SN field length of the RLC header information of the second data is the second value.

Description

A communication method and terminal equipment

This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on April 4, 2023, with application number 202310399285. middle.

Technical field

The present application relates to the field of communication technology, and in particular, to a communication method and terminal equipment.

Background technique

With the development of the fifth generation (5G), there are more and more services based on 5G technology. For example, voice services are transmitted through the new radio (NR) air interface of 5G technology. Among them, the NR air interface of 5G technology is used to transmit voice services. The transmitted language service can be called voice over new radio (VoNR). It can be understood that the above-mentioned VoNR refers to the end-to-end voice service implemented based on the 5G system and IP Multimedia Subsystem (IMS). VoNR call setup time is short, and data services can still be transmitted at high speed, giving users a better experience.

However, when the terminal device actually communicates with other terminals, call drops are prone to occur.

Contents of the invention

Embodiments of the present application provide a communication method and terminal equipment, which are used to improve the problem of call drops during calls (abnormal calls leading to call interruption).

In order to achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

In a first aspect, an embodiment of the present application provides a communication method, which is applied to a terminal device during a call. The method includes: the terminal device uses a first DRB to send first data to a first network device. The length of the sequence number SN field of the wireless link RLC header information is the first value; when the terminal device does not receive the response returned by the first network device for the first data, the terminal device sends a request to the first network device. The device sends a re-establishment request (RRC re-establishment request, also called RRC connection re-establishment request). The terminal device receives a first reconfiguration message (a first RRC reconfiguration message, also called a first RRC connection reconfiguration message) from the first network device, where the first reconfiguration message carries a first Indication information, the first indication information is used to indicate that the length of the SN field configured in the RLC layer of the first DRB in the first network device is the second value. If the first value and the second value are not equal, the terminal device sends a reconfiguration complete message (RRC reconfiguration complete message) to the first network device. After sending the reconfiguration complete message, the terminal device uses the first DRB to send second data to the first network device, and the SN field length of the RLC header information of the second data is the second value.

In the above embodiment, during the call, after the terminal device receives the RRC reconfiguration message, it ignores whether it conforms to the current protocol and reconfigures the SN field of the first DRB at the RLC layer according to the second value in the RRC reconfiguration message. length, and feeds back the RRC reconfiguration completion message, which will not trigger RRC re-establishment again and avoid being misjudged as a call abnormality and being instructed to end the call. In this way, the call drop rate can be effectively reduced.

In some embodiments, the second data and the first data may carry the same data content to ensure that data content that may not have been successfully received by the first network device is transmitted to the first network device again. In other embodiments, the second data and the first data carry different data contents, that is, the second data and the first data are different data that need to be transmitted through the first DRB.

In some embodiments, before the terminal device sends the first data to the first network device, the method further includes: the terminal device establishes a call through the second network device; during the call, the terminal device Receive a second reconfiguration message from the second network device, the second reconfiguration message carries a switching instruction, and the switching instruction is used to instruct the terminal device to switch to the terminal corresponding to the first network device. Cell, the second reconfiguration message does not carry the first indication information.

In the above embodiment, the terminal device can perform cell switching during the call, thereby ensuring call quality and reducing the probability of call drops.

In some embodiments, before the terminal device establishes the call through the second network device, the method further includes: after establishing a connection between the terminal device and the second network device, receiving from the A third reconfiguration message of the second network device, the third reconfiguration message is used to indicate that the length of the SN field configured by the first DRB in the second network device at the RLC layer is the first value.

In the above embodiment, the call can be established through the second network device, and data interaction with the second network device can be performed normally.

In some embodiments, the first DRB is a DRB that enables determining the transmission mode.

In the above embodiment, the first DRB can ensure the reliability of data transmission.

In some embodiments, the first data and the second data are call data, and the call process includes a call process established based on a 4G communication system, a 5G communication system, or a 6G communication system.

In the above embodiment, the terminal device and the first network device reduce the call drop rate while ensuring the normal progress of the call.

In some embodiments, the terminal device does not receive the response returned by the first network device for the first data, including: the terminal device uses the first DRB to retransmit the first data to the first network device. The preconfigured number of first attempts is reached, and no response corresponding to the first data is received within the first period of time after the last retransmission.

In the above embodiment, triggering unnecessary reestablishment requests can be avoided.

In the second aspect, an embodiment of the present application provides a communication method, which is applied to a terminal device. The method includes: after the terminal device establishes a call through the second network device, the terminal device uses the first DRB to send a call to the terminal device. The second network device sends third data, and the SN field length of the RLC header information of the third data is the first value; during the call, the terminal device receives the second heavy message from the second network device. Configuration message, the second reconfiguration message includes a switching indication, the switching indication is used to instruct the terminal device to switch to the cell corresponding to the first network device; it is determined that the history record data contains a second value, wherein the The second value is the length of the SN field configured at the RLC layer for the first DRB in the first network device, and the first value is not equal to the second value; the history data includes all When the second value is provided, and the second reconfiguration message does not contain the length of the SN field configured in the first network device for the first DRB at the RLC layer, the terminal device uses the first The DRB sends second data to the first network device, and the SN field length of the RLC header information of the second data is the second value.

In some embodiments, before the terminal device establishes a call through the second network device, the method further includes: after establishing a connection between the terminal device and the second network device, receiving a third reconfiguration from the second network device. message, the third reconfiguration message includes a first value, and the first value is the length of the SN field configured at the RLC layer for the first DRB in the second network device.

In some embodiments, determining that the second value is included in the history data includes: after the terminal device receives the second reconfiguration message from the second network device, the second reconfiguration message does not contain In the case where the length of the SN field configured in the RLC layer for the first DRB in the first network device is determined according to the historical record data, the length of the SN field in the RLC layer for the first DRB in the first network device is determined. The configured SN field length is the second value; the method further includes: when the first value is not equal to the second value, the terminal device sends a retry to the first network device. Configuration complete message.

In some embodiments, after the terminal device receives the second reconfiguration message, the method further includes: in response to the second reconfiguration message, the terminal device sends to the first network device Reconfiguration complete message; the terminal device uses the first DRB to send the first data to the first network device, and the SN field length of the RLC header information of the first data is the first value;

Determining that the second value is included in the historical record data includes: under the first condition, according to the historical record data, determining that the length of the SN field in the RLC header information of the first DRB in the first network device is The second value; wherein the first condition includes that the number of transmissions of the first data has reached a preconfigured second number, and no response to the first data is received within the first period of time after the last retransmission. The response corresponding to the data.

In a third aspect, embodiments of the present application provide a terminal device. The terminal device includes one or more processors and memories; the processor includes a modem processor, the memory is coupled to the processor, and the memory is used to store Computer program code. The computer program code includes computer instructions. When one or more processors execute the computer instructions, the one or more processors are used to perform the first aspect, the second aspect and possible embodiments thereof. method.

In a fourth aspect, embodiments of the present application provide a computer storage medium that includes computer instructions. When the computer instructions are run on a terminal device, the terminal device causes the terminal device to perform the above-mentioned first aspect, second aspect, and possible embodiments thereof. method.

In a fifth aspect, the present application provides a computer program product, which when the computer program product is run on the above-mentioned terminal device, causes the terminal device to execute the methods in the above-mentioned first aspect, second aspect and possible embodiments thereof.

In a sixth aspect, the present application provides a chip system, which is applied to a terminal device and stores a computer program. When the computer program is executed, the terminal device performs the above first aspect, the second aspect and possible implementations thereof. method in the example.

It can be understood that the terminal equipment, computer storage media and computer program products provided by the above aspects are all applied to the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the corresponding methods provided above. The beneficial effects will not be repeated here.

Description of the drawings

Figure 1 is an example diagram of a communication system provided by an embodiment of the present application;

Figure 2 is an example diagram of a communication system that can implement VoNR calls provided by an embodiment of the present application;

Figure 3 is a signaling interaction diagram for initiating a VoNR call between a terminal device and a network device provided by an embodiment of the present application;

Figure 4 is a schematic diagram of a scenario in which a terminal device selects a network device to be accessed according to an embodiment of the present application;

Figure 5 is an example diagram of a protocol stack supported by both the terminal device and the second network device provided by the embodiment of the present application;

Figure 6 is an example diagram of the structure of an RLC data packet provided by the embodiment of the present application;

Figure 7 is an example diagram of a scenario that can trigger a terminal device to switch an accessed network device provided by an embodiment of the present application;

Figure 8 is a signaling interaction diagram of the communication method provided in the related art;

Figure 9 is an example diagram of a communication abnormality scenario that occurs after the terminal device accesses the first network device through reconfiguration;

Figure 10 is one of the signaling interaction diagrams of the communication method provided by the embodiment of the present application;

Figure 11 is the second signaling interaction diagram of the communication method provided by the embodiment of the present application;

Figure 12 is the third signaling interaction diagram of the communication method provided by the embodiment of the present application;

Figure 13 is the fourth signaling interaction diagram of the communication method provided by the embodiment of the present application;

Figure 14 is an example diagram of the hardware structure of a terminal device provided by an embodiment of the present application;

Figure 15 is an example diagram of the hardware structure of a network device provided by an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Among them, in the description of this application, unless otherwise specified, "at least one" refers to one or more, and "plurality" refers to two or more than two. In addition, in order to facilitate a clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as “first” and “second” are used to distinguish identical or similar items with basically the same functions and effects. Those skilled in the art can understand that words such as "first" and "second" do not limit the number and execution order, and words such as "first" and "second" do not limit the number and execution order.

The technical solutions of the embodiments of the present application can be applied to various communication systems, such as wireless fidelity (WiFi) systems, vehicle to everything (V2X) communication systems, and device-to-device (D2D) communication. systems, Internet of Vehicles communication systems, fourth generation (4G) mobile communication systems, such as long term evolution (LTE) systems, global interoperability for microwave access (WiMAX) communication systems, 5G, Such as new radio (NR) system and future communication systems.

This application will present various aspects, embodiments, or features in terms of systems, which may include multiple devices, components, modules, etc. It should be understood and appreciated that various systems may include additional devices, components, modules, etc., and/or may not include all devices, components, modules, etc. discussed in connection with the figures. Additionally, a combination of these scenarios can be used.

In addition, in the embodiments of this application, words such as "exemplary" and "for example" are used to represent examples, illustrations or explanations. Any embodiment or design described herein as "example" is not intended to be construed as preferred or advantageous over other embodiments or designs. Rather, the use of the word example is intended to present a concept in a concrete way.

The network architecture and business scenarios described in the embodiments of this application are for the purpose of explaining the technical solutions of the embodiments of this application more clearly, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those of ordinary skill in the art will know that with the network With the evolution of architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

In order to facilitate understanding of the embodiments of the present application, a communication system applicable to the embodiments of the present application is first described in detail, taking the communication system shown in FIG. 1 as an example. Exemplarily, FIG. 1 is a schematic diagram 1 of the architecture of a communication system to which the communication method provided by the embodiment of the present application is applicable.

As shown in Figure 1, the communication system mainly includes: terminal equipment (can be called terminal) and network device (can also be called network equipment).

The terminal device may be a terminal device with a transceiver function, or a chip or a chip system that can be installed on the terminal device. The terminal equipment may also be called user equipment (UE), access terminal, subscriber unit (subscriber unit), user station, mobile station (MS), mobile station, remote station, remote terminal, mobile device , user terminal, terminal, wireless communication device, user agent or user device. The terminal device in the embodiment of the present application may be a mobile phone, a cellular phone, a smart phone, a tablet, a wireless data card, or a personal digital assistant. PDA), wireless modem, handheld device (handset), laptop computer, machine type communication (MTC) terminal, computer with wireless transceiver function, virtual reality (VR) Terminals, augmented reality (AR) terminals, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical, smart grid Wireless terminals in transportation safety (transportation safety), wireless terminals in smart city (smart city), wireless terminals in smart home (smart home), vehicle-mounted terminals, road side units with terminal functions unit, RSU), etc. The terminal of this application may also be a vehicle-mounted module, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip, or vehicle-mounted unit built into the vehicle as one or more components or units.

The network device may be a network device, such as an access network (AN) device, or may be called a radio access network (RAN) device. RAN equipment can provide access functions for terminals and is responsible for wireless resource management, quality of service (QoS) management, data compression and encryption on the air interface side. The RAN equipment may include 5G, such as gNB in the NR system, or one or a group (including multiple antenna panels) of antenna panels of a base station in 5G, or may also constitute a gNB, transmission and reception point, TRP (transmission point, TP) or transmission measurement function (TMF) network node, such as baseband unit (building base band unit, BBU), or centralized unit (centralized unit, CU) or distributed unit (distributed unit) , DU), RSU with base station function, or wired access gateway, or 5G core network element. Alternatively, RAN equipment may also include access points (APs) in wireless fidelity (WiFi) systems, wireless relay nodes, wireless backhaul nodes, various forms of macro base stations, and micro base stations (also known as (for small stations), relay stations, access points, wearable devices, vehicle-mounted devices, etc. Alternatively, the RAN equipment may also include next-generation mobile communication systems, such as 6G access network equipment, such as 6G base stations, or in the next-generation mobile communication system, the network devices may also have other naming methods, which are all covered in this article. Within the protection scope of the application embodiments, this application does not impose any limitations on this.

It can be understood that Figure 1 is only a simplified schematic diagram for ease of understanding. The communication system may also include other network devices and/or other terminal equipment, which are not shown in Figure 1 .

In some embodiments, the terminal equipment in the above communication system can access the communication network (such as the 5G network) corresponding to the network device through the network device. In this way, the terminal equipment can enable based on the accessed communication network. Various communication services. By way of example, the above communication service may include a call service. The above call service may be a call based on a 5G communication system, such as a VoNR call, a call based on a 4G communication system, or a call based on a future communication system (such as a 6G communication system).

Taking the above call service as a VoNR call as an example, as shown in Figure 2, the above communication system may include a terminal device 100, NG RAN101, 5GC102 and IMS103.

Among them, the above-mentioned terminal equipment 100 corresponds to the terminal equipment in Figure 1, and the NG RAN 101 corresponds to the network device in Figure 1.

Exemplarily, the above-mentioned NG RAN 101 may include at least one node device, such as a base station (base station, BS). It can be understood that the above-mentioned base station may be a device capable of communicating with terminal equipment or other communication sites (such as relay sites). In addition, the above-mentioned base station may provide communication coverage in a specific physical area. For example, the base station may be a Base Transceiver Station (BTS) or a Base Station Controller (BSC) in GSM or CDMA; it may also be a Node B (Node B) in UMTS. NB) or the Radio Network Controller (RNC) in UMTS; it can also be the evolutionary base station (Evolutional Node B, referred to as eNB or eNodeB) in LTE; it can also be the next generation in 5G NR A base station (next generation Node B, gNB for short); or, it may also be other access network equipment that provides access services in a wireless communication network, which is not limited by the present invention.

In the case where the above-mentioned NG RAN 101 includes a gNB, after the terminal device 100 establishes a connection with the gNB in the NG RAN 101, the terminal device 100 and the gNB can communicate with each other using new radio (NR) access technology. In this way, The above-mentioned terminal equipment 100 and gNB can communicate through the NR link. This process can also be called the terminal equipment 100 accessing the NG RAN 101.

As another example, the above-mentioned 5GC 102 is used to exchange, forward, connect, and route data. Network elements in 5GC are functional virtual units, which may include but are not limited to: units used for access and mobility management functions (AMF), units used for session management functions (SMF) ), network elements for unified data management (unified data management, UDM), etc.

In some embodiments, the above-mentioned NG RAN101 and 5GC102 may adopt a standalone (Standaloner, SA) networking mode. Understandably, in the above SA networking mode, NG RAN and 5GC are both built based on 5G technology, resulting in a better low-latency experience. In subsequent embodiments, the communication network composed of NG RAN and 5GC may also be called a 5G system. In other embodiments, the above-mentioned networking mode between the NG RAN 101 and the 5GC 102 may also be a non-standalone (NSA) networking, which is not specifically limited in the embodiments of this application.

As another example, the above-mentioned IMS 103 is used to manage IP data packets packaged into multimedia data such as voice and video, distinguish between the signaling part and the multimedia data part of these IP data packets, between the terminal device 100 and the called end of the call. The multimedia data part in the IP data packet is transmitted, so that the IMS 103 can provide audio and video services for the terminal device 100 . IMS103 may mainly include a call session control function (CSCF) and a home subscriber server (HSS). CSCF is used to control signaling and authentication during multimedia call sessions, and cooperate with other network entities to control sessions, etc. HSS is used to manage user data.

As shown in Figure 2, communication can be carried out between the above-mentioned 5G system and the above-mentioned IMS103. In this way, after the terminal device 100 accesses the NG RAN 101, a communication connection can be established with the IMS 103 through the NG RAN 101 and 5GC 102.

In some embodiments, after the terminal device 100 accesses the 5G system composed of the NG RAN 101 and 5GC 102 through the NG RAN 101, the terminal device 100 can use various voice solutions to initiate calls to other terminals through the IMS 103, and make calls to other terminals through the IMS 103. After the terminal answers the call, it conducts audio and video communication. Among them, the above-mentioned VoNR is one of the optional voice solutions.

It can be understood that after the 5G system is connected to the IMS 103, the 5G system can package the multimedia data during the call and communication process initiated by the terminal device 100 to other terminals into IP data packets, and transmit them to the other terminals through the IMS 103. That is to say, the 5G system can provide IMS-based audio and video services on a circuit switch (PS) session, such as controlling the control plane signaling (IMS signaling) generated during the call between the terminal device 100 and other terminal devices. ) and user plane data (IMS traffic) are packaged into IP data packets, and these IP data packets are transmitted between the terminal device 100 and other called terminals through the IMS 103.

In some embodiments, during the call, other terminal devices being called (such as the terminal device 106 in Figure 2) also need to establish a connection with the IMS 103 through the accessed communication network.

As shown in Figure 2, the above communication system may also include a terminal device 106, an NG RAN 105 and a 5GC 104. In the scenario shown in Figure 2, the terminal device 106 can establish a connection with the IMS 103 through the 5G system composed of the NG RAN 105 and the 5GC 104.

The terminal device 106 and the terminal device 100 are different devices. Of course, the terminal device 106 is similar to the terminal device 100, including smart terminals (for example, mobile phones, etc.), desktops, laptops, tablets, handheld computers, notebook computers, super computers, etc. Mobile personal computers (Ultra-mobile Personal Computers, UMPCs), netbooks, and devices with communication capabilities such as cellular phones, personal digital assistants (PDAs), televisions, VR devices, and AR devices can access various types of devices. in the communication system.

Similarly, the above-mentioned NG RAN105 and 5GC104 can adopt the SA networking mode or the NSA networking mode.

It can be understood that when different voice solutions are adopted, the communication network connected to the terminal device 106 may also be different, and the embodiment of the present application does not specifically limit this.

Taking the terminal device 100 as the calling device (that is, the terminal that initiates the call) and the terminal device 106 as the called device (that is, the device that answers the call) as an example, the method in which the terminal device 100 actively initiates a VoNR call to the terminal device 106 is introduced. process:

(1) The terminal device 100 requests to establish a Radio Resource Control (RRC) connection with the NG RAN 101.

(2) The terminal device 100 sends call request information to the 5GC 102 through the NG RAN 101, and the call request information carries the identification of the terminal device 106 (for example, a phone number). The identification of the terminal device 106 may be used to instruct the IMS 103 to page the terminal device 106.

(3) After the 5GC 102 receives the call request information from the terminal device 100, it may also send a response message to the terminal device 100 through the NG RAN 101, indicating that the 5GC 102 is processing the call initiated by the terminal device 100. In addition, the 5GC 102 can also send call request information to the terminal device 106 through the IMS 103 to page the terminal device 106.

(4) After the 5GC 102 receives the call request information from the terminal device 100, the 5GC 102 can also establish a Quality of Service (Qos) for the terminal device 100 for carrying session initiation protocol (session initiation protocol, SIP) signaling. )flow, the 5G QoS identifier (5QI) of the established Qosflow can be 5.

In addition, the NG RAN 101 may also establish a data radio bearer (Data Radio Bearer, DRB) for the terminal device 100 for transmitting SIP signaling.

(5) After the terminal device 106 receives the call request information, it may also establish an RRC connection with the NG RAN 105.

(6) After the terminal device 106 requests to establish an RRC connection with the NG RAN 105, the 5GC 104 can also establish a quality of service Qos flow for carrying SIP signaling for the terminal device 106. The 5QI of the established Qosflow can be 5.

In addition, the NG RAN 105 may also establish a DRB for the terminal device 106 for transmitting SIP signaling.

(7) The terminal device 100 and the terminal device 106 perform SIP session negotiation through the IMS 103, for example, negotiating encoding mode, IP address, port number and other information.

(8) After the negotiation is completed, the 5GC 102 can also establish a Qos flow for the terminal device 100 for carrying the real-time transport protocol (RTP), and a Qos flow for carrying the real-time transport control protocol (real-time transport control protocol). , RTCP) Qos flow. In this step, the 5QI of the established Qosflow may be 1.

In addition, the NG RAN 101 may also establish a DRB for transmitting RTP and RTCP for the terminal device 100.

(9) After the negotiation is completed, the 5GC 104 can also establish Qosflow for the terminal device 106 for carrying RTP and RTCP. The 5QI of the established Qos flow may be 1.

In addition, the NG RAN 105 may also establish a DRB for transmitting RTP and RTCP for the terminal device 106.

(10) Afterwards, the terminal device 106 can remind the user of the incoming call from the terminal device 100 by ringing, displaying, etc. After the terminal device 106 detects the user's operation of answering the incoming call, the terminal device 100 and the terminal device 106 can transmit voice data through the corresponding 5G system and IMS 103 to start a call.

In short, through the above steps, the terminal device 100 and the terminal device 106 can respectively establish corresponding bearers before starting a call, and then establish an IMS session based on the above bearers. In this embodiment of the present application, during the process of initiating a VoNR call, the bearers established include default bearers and dedicated bearers. For example, the default bearer includes a bearer corresponding to the Qosflow of 5IQ5, which is used to carry the call and control signaling during the call. As another example, the dedicated bearer includes a bearer corresponding to the Qosflow of 5IQ1, which is used to meet the Qos requirements of the multimedia data transmitted between the terminal device 100 and the terminal device 106, for example, used to carry voice packets and/or videos of the media plane. flow. The IMS session is used to transmit audio and video data during the call between the terminal device 100 and the terminal device 106. In this way, after the terminal device 106 answers the user operation and answers the incoming call, the VoNR call can be started between the terminal device 100 and the terminal device 106 .

In addition, in the above embodiments, the process of the terminal device 100 initiating a call is only exemplarily introduced. In specific implementation, the process includes more or fewer steps, which will not be described again here. In addition, in other embodiments, the terminal device 106 can also be the calling device, and the terminal device 100 can also be the called device. The process of the terminal device 106 communicating with the terminal device 100 through VoNR can refer to the aforementioned embodiments, which will not be discussed here. Again. In subsequent embodiments, the description is mainly based on the example that the calling device is the terminal device 100 and the called device is the terminal device 106.

In the above embodiment, the terminal device needs to be within the service range of the NG RAN before it can request to access the NG RAN. The service range of the NG RAN may be determined by the signal coverage of the node equipment (eg, 5G base station) in the NG RAN. In addition, the service range of NG RAN can be divided into at least one cell, such as called an NG RAN cell. When the NG RAN includes multiple 5g base stations, the signal coverage of different 5g base stations may be different or overlap. In addition, each cell of NG RAN corresponds to the signal coverage of a 5G base station. The 5G base stations corresponding to different cells can be different or the same, and there is no specific limit on this. In subsequent embodiments, the node devices in the NG RAN may be collectively referred to as network devices.

In addition, the terminal device 100 accessing the NG RAN 101 mentioned in the above process of establishing a VoNR call may refer to the terminal device 100 accessing an NG RAN cell in the NG RAN 101. In this way, the RRC between the terminal device and the NG RAN is established. The connection may be that the terminal device establishes an RRC connection with the network device corresponding to the NG RAN cell.

Referring to Figure 3, when the terminal device initiates a VoNR call, the interaction with the network device is as follows:

A1: Establish an RRC connection between the terminal device and the second network device.

In some embodiments, before actually initiating a VoNR call, the terminal device can determine the NG RAN cell to be accessed and connect to the network device corresponding to the cell.

For example, when the terminal device is located in a cell corresponding to a network device, it can choose to access the network device.

Taking Figure 4 as an example, the cells corresponding to the second network device and the first network device are adjacent to each other, and there is an overlapping area between them. It can be understood that the above-mentioned second network device and the first network device may be node devices in the same NG RAN, or may be node devices in different NG RANs, which are not specifically limited in the embodiments of the present application.

As shown in Figure 4, the user carrying the terminal device is located in the cell corresponding to the second network device, but has not entered the cell corresponding to the first network device. In this scenario, the terminal device chooses to access the second network device.

As another example, when the terminal device is located in the overlapping area of cells corresponding to multiple network devices, the signal quality of the multiple network devices at the current location can be evaluated, and then the optimal network device is selected based on the signal quality. and access. For example, the terminal device determines that the signal quality of the radio signal from the second network device is better than the signal quality of the radio signal from the first network device, and determines to access the second network device.

In this way, in some embodiments, the terminal device can monitor radio signals from the network device in a scenario where it needs to select a network device to access. Then, based on the detected radio signal, the signal quality corresponding to the network device that emits the radio signal is evaluated. Then, select the network device with the best signal quality and connect it.

For example, the above-mentioned radio signals may be synchronization signals and channel status information from network devices. After listening to the radio signal, you can evaluate the reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal receiving quality (RSRQ) and reference signal received quality (RSRQ) corresponding to the network device. For signal to interference plus noise ratio (SINR), specific implementation details can be found in related technologies and will not be described in detail here. Then, the signal quality corresponding to the network device is evaluated based on the detected value of one or more of RSRP, RSSI, RSRQ, and SINR.

In subsequent embodiments, determining the access to the second network device is taken as an example for introduction.

In some embodiments, the terminal device may initiate an RRC connection request to the second network device, and the second network device may establish an RRC connection with the terminal device. For the specific process of establishing an RRC connection, please refer to the regulations in the relevant protocols and will not be described again here.

A2. The second network device sends a configuration message 1 to the terminal device. The configuration message 1 includes the configuration of the first DRB in the second network device at the RLC layer.

Wherein, the above-mentioned second network device and terminal device both support the NR wireless protocol stack. As shown in Figure 5, the NR wireless protocol stack indicates that both the second network device and the terminal device include an RRC layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a MAC layer. wait.

For example, the above-mentioned RRC layer is the upper layer of the control plane and is mainly responsible for controlling L1/L2 to complete air interface resource transmission and providing information transmission services for other layers (such as non-access layers). For example, the RRC layer can be used to manage functions such as system message broadcast, RRC connection control, mobility management, and measurement configuration reporting. Among them, RRC connection control management includes paging, establishment/modification/pause/resumption/release of RRC connection, initial security activation, establishment/modification/activation of SRB/DRB, cell management in DC and CA modes, and wireless link failure recovery, etc. .

As another example, the above-mentioned PDCP layer is used to process RRC messages on the control plane and Internet Protocol (IP) data packets on the user plane. For example, on the user plane, after the PDCP layer obtains the IP data packet from the upper layer, it can perform header compression and encryption on the IP data packet, and then submit it to the RLC layer. The PDCP layer also provides in-order submission and duplicate packet detection functions to the upper layer. On the control plane, the PDCP layer provides signaling transmission services for the upper layer RRC, and implements encryption and consistency protection of RRC signaling, as well as decryption and consistency checking of RRC signaling in the reverse direction.

As another example, the RLC layer mainly provides wireless link control functions and provides upper layers with services such as segmentation, retransmission control, and on-demand transmission. The RLC layer includes three transmission modes: Transparent Mode (TM), Unacknowledged Mode (UM) and Acknowledged Mode (AM), which mainly provide error correction, segmentation, reassembly and other functions.

Among them, in TM mode, after the RLC layer receives a message from PDCP (for example, called PDCP data), it can be directly passed to the MAC layer without processing.

In AM mode, the PDCP data from the PDCP layer adds RLC layer header information (also called RLC header information) through the RLC layer, and after being sent, it needs to get a response from the peer device, otherwise it is regarded as a data transmission exception. . Similarly, after receiving the RLC data sent by the peer device in AM mode, and if it is determined that the data is not abnormal, a corresponding response needs to be fed back to the peer device. In this way, the reliability of data transmission is improved. In addition, terminal devices and network devices that transmit data to each other can be called peer devices. In this way, the peer device of the network device can be the terminal device, and the peer device of the terminal device can be the network device.

In UM mode, the PDCP data from the PDCP layer adds RLC header information through the RLC layer and is sent without receiving a response from the peer device. Similarly, after receiving RLC data sent by the peer device in UM mode, there is no need to feed back a corresponding response to the peer device. In this way, the timeliness of data transmission is improved.

As another example, the MAC layer is used to provide mapping between logical channels and transport channels, multiplexing RLC data from one or more logical channels into a transport block and passing it to the PHY layer; Transport blocks are demultiplexed into multiple RLC data and delivered to one or more logical channels; reporting scheduling information; error correction through HARQ; managing priorities between users through dynamic scheduling; logical channel priority management and other functions.

The PHY layer creates, maintains, and dismantles the physical links required to transmit data, and provides mechanical, electronic, functional, and normative characteristics. The physical layer can be used to ensure that raw data can be transmitted over various physical media.

In some embodiments, the above-mentioned NR wireless protocol stack may also include protocol layers not shown in Figure 5, such as a non-access stratum (NAS) layer and a physical layer (PHY) layer. This application The examples do not specifically limit this.

It can be understood that the NR wireless protocol stack of the terminal device can be configured in the communication chip. For example, it can be configured in the modem processor of the terminal device. In this way, the modem processor can receive and send data according to the provisions of the NR wireless protocol stack.

For example, in the above scenario where the terminal device sends data to other devices, after the PDCP layer configured in the modem processor receives the data to be sent, it adds PDCP layer header information to the data according to the corresponding protocol to obtain the PDCP protocol. Data unit (protocol data unit, PDU) and passed to the RLC layer. Then, the RLC layer adds RLC layer header information to the above PDCP PDU (also called PDCP data) according to the corresponding protocol to obtain the RLCPDU. Afterwards, the MAC layer can add MAC layer header information to each RLC PDU (also called RLC data) to obtain a MAC PDU. Then, one or more MAC PDUs are combined according to the size of the transport block to obtain the MAC transport block protocol data unit (transport block PDU), which can also be called a data packet, and instruct the PHY layer to use the corresponding physical link to transport the MAC transport block PDU is sent.

For example, in the above scenario where the terminal device receives a data packet (MAC transport blockPDU) from another device, the PHY layer in the modem processor can pass the data packet to the MAC layer. The MAC layer can split multiple MAC PDUs from the data packet, then parse the MAC layer header information of each MAC PDU, and obtain the data content carried in the MAC PDU, that is, the RLC PDU. Then, the MAC layer passes the parsed RLC PDU to the RLC layer, and then the RLC layer parses the RLC layer header information of the RLC PDU from the MAC layer, and obtains the data content carried in the RLC PDU, that is, the PDCP PDU. Then, the RLC layer passes the parsed PDCP PDU to the PDCP layer, which parses it according to the corresponding protocol.

In some embodiments, after the RRC connection between the second network device and the terminal device is established, the second network device may send the configuration message 1 to the terminal device, which may also be called a third reconfiguration message, or may be called an RRCreconfiguration message. . The configuration message 1 may include configuration parameters corresponding to multiple DRBs. The above-mentioned DRB is a bearer negotiated between the second network device and the corresponding core network and used to transmit data between the second network device and the terminal device. For example, the first DRB and the second DRB are used to transmit communication service data between the second network device and the terminal device. Each DRB corresponds to a set of configurations, and the configurations corresponding to different DRBs can be different.

It can be understood that the configuration related to the DRB can indicate how each layer of the NR wireless protocol stack (such as the PDCP layer, RLC layer, MAC layer, PHY layer, etc.) processes the data that needs to be transmitted through the DRB.

For example, the RLC layer supports data transmission modes such as TM mode, UM mode, and AM mode. The second network device may configure the DRB in the RLC layer as TM mode, UM mode or AM mode.

For example, if the first DRB in the second network device is configured in AM mode at the RLC layer, after the communication service data a sent to the terminal device using the first DRB is sent out, the RLC layer needs to wait for the feedback response from the terminal device, otherwise the data will be resent. a.

Correspondingly, the configuration related to the first DRB in the configuration message 1 includes an identifier indicating the AM mode, the response waiting time, the number of retransmissions in the AM mode, etc. In this way, after the terminal device is configured according to the configuration message 1, it receives the communication service data from the second network device through the first DRB. If the RLC layer header information of the communication service data is successfully parsed, it can send the corresponding communication service data to the second network device. the response to.

In addition, after the terminal device uses the first DRB to send communication service data to the second network device, if a corresponding response is not received within the response waiting time, retransmission of the communication service data is triggered. If the number of retransmissions of the communication service data reaches the number of retransmissions in the configuration message 1, it is determined that there is a communication abnormality between the terminal device and the second network device.

For another example, if the second DRB in the second network device is configured in UM mode at the RLC layer, and the second network device uses the second DRB to send the communication service data b to the terminal device, the RLC layer of the second network device does not need to wait for the terminal device. Device feedback response. Correspondingly, the configuration related to the second DRB in the configuration message 1 includes an identifier indicating the UM mode. In this way, after the terminal device is configured according to the configuration message 1, and after receiving the communication service data from the second network device through the second DRB, the terminal device does not feed back a response to the second network device.

It can be understood that the RLC layer can add RLC layer header information (also called RLC header information) to data sent by the first DRB or the second DRB. The RLC header information includes a sequence number (SN) field. , the SN number carried in the SN field can ensure that RLC PDUs are sent in order, and when retransmission is required, the RLCPDU that needs to be retransmitted can be determined. The SN field of the above RLC header information may also be referred to as the RLC SN field for short.

In addition, the RLC layer can also split data (such as PDCP PDU) into multiple split data to facilitate transmission. For example, after one PDCPPDU is processed by the RLC layer, multiple split data can be obtained. After adding RLC header information to each split data, multiple RLC PDUs can be obtained. When the data carried by multiple RLC PDUs comes from the same PDCP PDU, the SN numbers in the RLC header information of the multiple RLC PDUs have the same value.

According to "sn-FieldLength Indicates the RLC SN field size, seeTS 38.322[4], in bits.Value size6 means 6bits, value size12 means 12bits, valuesize18 means 18bits" in protocol 38.311, the corresponding translation is: "in network equipment" sn-FieldLength" can indicate the length of the RLCSN field, see TS 38.322 for details, in bits. When the value of "sn-FieldLength" corresponding to DRB is "size6", it indicates that the length of the SN field configured by DRB at the RLC layer is 6 bits. When the value of "sn-FieldLength" corresponding to DRB is "size12", it indicates that the length of the SN field configured by DRB at the RLC layer is "size12". The SN field length configured at the RLC layer is a 12-bit value. When the "sn-FieldLength" value corresponding to the DRB is "size18", it indicates that the SN field length configured by the DRB at the RLC layer is an 18-bit value.

It can be seen that the network device can configure the SN field length corresponding to each DRB at the RLC layer in advance by configuring the "sn-FieldLength" corresponding to each DRB. For example, the "sn-FieldLength" corresponding to the first DRB (DRB in AM mode) or the second DRB (DRB in UM mode) is configured as 12 bits. For data that needs to be sent by the first DRB or the second DRB, it passes through RLC After layer processing, there is RLC layer header information with an SN field length of 12 bits. Of course, the above process of configuring "sn-FieldLength" can be called configuring the SN field length at the RLC layer.

The length of the SN field configured at the RLC layer for each DRB in the terminal device must be consistent with the length of the SN field configured at the RLC layer for the DRB in the connected network device.

In this way, the configuration related to the DRB in AM mode or UM mode in the configuration message 1 may also include the length of the SN field configured by the DRB in the network device at the RLC layer. It can be understood that the lengths of the SN fields configured in different DRBs at the RLC layer may be different or the same.

In subsequent embodiments, implementation details of the embodiments of the present application will be introduced by taking the first DRB using the AM mode as an example.

In this way, in some embodiments, the above-mentioned configuration message 1 may include the configuration of the first DRB at the RLC layer. In subsequent embodiments, the configuration of the first DRB may include an SN field length of 12 bits, an identifier indicating the AM mode, a response waiting time of t, and the number of retransmissions in the AM mode of N as an example, where the above N is a positive integer. , N can also be called the first number, the above t is a positive value, and t can also be called the first duration.

In this example, after the terminal device is configured according to configuration message 1, as shown in Figure 6, for communication service data (such as PDCP data) that needs to be transmitted through the first DRB, the RLC layer of the terminal device can add RLC header information, get RLC data. The RLC header information of the RLC data includes the SN field and other fields. Among them, the length of the SN field in the RLC header information is 12 bits.

In short, the configuration message 1 can synchronize the configuration of the DRB between the terminal device and the second network device. For example, for data that needs to be transmitted by the same DRB, the terminal device and the second network device can synchronize the processing methods of each layer (such as PDCP layer, RLC layer, MAC layer, PHY layer, etc.), such as encoding method, decoding method, Transmission methods, etc.

In this way, after the terminal device receives the data packet from the second network device and identifies the DRB used to transmit the data packet, it can accurately parse the data packet in a matching manner. Similarly, after the second network device receives the data packet from the terminal device and identifies the DRB used to transmit the data packet, it can also accurately parse the data packet in a matching manner. This enables normal communication between the terminal device and the second network device.

In addition, the above-mentioned configuration message 1 may also include time-frequency resources, wireless resource configuration, etc. required to access the second network device, which will not be described again here.

A3, the terminal device initiates a call through the second network device.

For example, a VoNR call is initiated to other terminals through the second network device in the 5G communication system. The implementation details of establishing the VoNR call may be referred to the foregoing embodiments and will not be described again here. After the call is established, the process proceeds to A4.

A4, the terminal device can send call data to the second network device through the first DRB.

The above call data may also be called communication service data. In a possible embodiment, the call data may be based on call data sent by different communication systems, such as call data sent based on a 5G communication system, call data sent based on a 6G communication system, or call data sent based on a 4G communication system.

It is understandable that during the propagation process of radio signals, signal attenuation will occur as the propagation distance increases. In this way, within the cell corresponding to the network device, the signal quality is different at different locations. In addition, the cells corresponding to the network equipment may also change, for example, due to changes in environmental factors or changes in operating power.

In this scenario (for example, the location of the user carrying the terminal device changes, or the cell range of the second network device changes), the terminal device can trigger the switching of the accessed NG RAN cell to ensure communication quality. Of course, during a call using VoNR, if the terminal device switches to an NG RAN cell and changes the connected network equipment, there is a possibility of call drop (the call is interrupted), which directly affects the call quality.

For example, during a VoNR call, the terminal device switches from connecting to a network device in the NG RAN to connecting to another network device in the NG RAN, or when the terminal device switches from connecting to a network device in one NG RAN to connecting to another network device in the NG RAN. Whenever there is an NG RAN network device, there is a possibility of call drop.

As shown in the scenario shown in Figure 7, after the user brings the terminal device into the overlapping area of the cell corresponding to the second network device and the first network device, if the second network device determines that the terminal device needs to switch to the cell corresponding to the first network device, The first network device can be accessed through reconfiguration.

For example, the above reconfiguration method may be: the terminal device modifies the RRC connection to enable communication between the terminal device and the first network device.

Referring to Figure 8, the length of the SN field configured at the RLC layer of the first DRB in the second network device is 12 bits, and the length of the SN field configured at the RLC layer for the first DRB in the first network device is 18 bits. When the terminal device initiates a VoNR call through the second network device, the length of the SN field configured by the first DRB in the terminal device at the RLC layer is 12 bits.

Afterwards, the process of switching the terminal device from the second network device to accessing the first network device is as follows:

B1, the terminal equipment performs neighbor cell detection.

B2: The terminal device reports the neighbor cell detection report to the second network device.

In some embodiments, the terminal device may perform neighbor cell detection in response to the measurement event sent by the second network device, and if the corresponding conditions are met, report the neighbor cell detection report to the base station. In this way, the second network device can instruct the terminal device to perform cell switching according to the neighbor cell detection report, or the terminal device can perform cell switching autonomously.

For example, the measurement events may include: event A3, event A2, event B1, event B2, etc.

Among them, Event A3 (Event A3) is used to trigger co-frequency measurement of neighboring cells with the same network standard. The reference signal receiving power (RSRP) value in the neighboring cell is higher than the RSRP of the resident cell, and the neighboring cell When the RSRP value of a zone exceeds the corresponding threshold, a neighbor cell detection report is uploaded.

Event A2 (Event A2) is used to trigger measurement of the resident cell. When the RSRP value of the resident cell is lower than the corresponding threshold, a neighbor cell detection report is uploaded.

Event B1 (Event B1) can be used to trigger measurement of high-priority inter-system cells. When the RSRP of the neighboring cell is higher than the corresponding threshold, the terminal uploads the neighbor cell detection report.

Event B2 (Event B2) can be used to trigger measurement of inter-system cells of the same or lower priority. When the RSRP of the resident cell is lower than the corresponding threshold and the RSRP of the neighbor cell in the different system is higher than the corresponding threshold, the terminal uploads the neighbor cell detection report.

In the above embodiment, after the terminal device generates the neighbor cell detection report corresponding to the measurement event, it may report it to the second network device.

In addition, the above-mentioned neighbor cell detection report can also be called neighbor cell detection report. For example, the neighbor cell detection report records the signal quality corresponding to multiple accessible network devices. The plurality of accessible network devices include a second network device and a neighboring network device. In addition, the above-mentioned neighbor network device may be a device using the same network standard as the second network device. In other embodiments, the terminal device may perform neighbor cell detection at least once under preset conditions. By way of example, the above preset conditions include at least one of the following:

(1) The terminal device is configured with a detection cycle, and the detection time point of each detection cycle is reached at the system time.

(2) The terminal device receives the user's instruction to refresh the network status.

(3) The terminal device detects that the signal quality of the second network device is lower than the preset first threshold.

(4) The terminal device detects that the signal quality of other network devices is higher than a preset second threshold, where the first threshold may be smaller than the second threshold.

Similarly, each time the terminal device generates a neighbor cell detection report, it can report it to the second network device. Similarly, the above neighbor cell detection report records the signal quality corresponding to multiple accessible network devices. The plurality of accessible network devices include a second network device and a neighboring network device.

B3. The second network device determines, based on the neighbor cell detection report, to instruct the terminal device to access the first network device with better communication quality.

For example, in a scenario where the second network device sends a measurement event to the terminal device, if the second network device receives the neighbor cell detection report corresponding to the measurement event, it determines that it is necessary to instruct the terminal device to access a network with better signal quality. equipment. For another example, in the scenario where the second network device sends a measurement event to the terminal device, if the second network device receives the neighbor cell detection report corresponding to the measurement event, the second network device may send the same measurement event to the terminal device again, instructing the terminal The device performs neighborhood detection again. After the second network device receives the neighbor cell detection report from the terminal device again, it may be determined that it is currently necessary to instruct the terminal device to access a network device with better signal quality. That is, the second network device can send the same measurement event to the terminal device multiple times, and after receiving neighbor cell detection reports corresponding to high measurement events multiple times, determine that the terminal device needs to switch to other network devices. In this way, the timing of switching NG RAN cells can be accurately identified, meaningless cell switching can be avoided, and the communication quality of terminal equipment can be ensured.

As another example, in a scenario where the terminal device actively performs neighbor cell detection in response to a preset condition, the second network device may first determine whether the terminal device needs to switch to a new network device, for example, determine the third network device from the neighbor cell detection report. 2. Whether the signal quality of the network device is lower than the first threshold. If the signal quality of the second network device is lower than the first threshold, it is identified that the scenario conditions that trigger the terminal device to switch to other network devices are currently met.

In some embodiments, after determining that the terminal device needs to switch to other network devices, the second network device may also determine the signal quality of multiple network devices in the neighbor detection report, the supported network standards, and whether they are compatible with the terminal device. Evaluate target network equipment from multiple dimensions. For the specific evaluation process, please refer to relevant technologies and will not be described again here. In addition, the target network device can be regarded as a network device with the best communication quality that can be accessed by the current terminal device. In subsequent embodiments, the target network device is the first network device as an example for description.

B4. The second network device sends a handover request (handover request) to the first network device.

The above handover request may indicate that the terminal device needs to access, and at the same time, the handover request may also carry capability information of the terminal device.

B5, the first network device feeds back a handover request confirmation message to the second network device. The handover request confirmation message includes the configuration information corresponding to the first network device and does not contain the SN configured in the RLC layer for the first DRB in the first network device. The length of the field.

In some embodiments, in response to the handover request, the first network device may send a handover request confirmation message to the second network device when it evaluates that the terminal device is accessible. In the current protocol, there is no requirement that the handover request confirmation message must carry the length of the SN field configured by the first DRB at the RLC layer. In this way, in actual scenarios, some first network devices send handover request confirmation messages to the second network device. The length of the SN field configured in the RLC layer of the first DRB is not included.

B6. The second network device sends the RRC reconfiguration message 1 to the terminal device (including the handover indication and excluding the SN length configured in the RLC layer for the first DRB in the first network device).

The above-mentioned RRC reconfiguration message 1 may also be called an RRC reconfiguration message. The RRC reconfiguration message 1 may be generated according to the configuration information from the first network device. It can be understood that the configuration information from the first network device does not contain the SN field length of the first DRB configured at the RLC layer, and the above-mentioned RRC reconfiguration message 1 does not contain the first DRB configured at the RLC layer in the first network device. The length of the SN field.

The above handover instruction may carry characteristic information of the first network device, such as a cell center frequency point, a cell identifier, etc., and is used to instruct the terminal device to switch to the cell corresponding to the first network device, or to instruct the terminal device to access the third network device. A network device.

B7: The terminal device performs handover according to RRC reconfiguration message 1.

It can be understood that the RRC reconfiguration message 1 contains a handover indication and is a message with synchronization function. At the same time, RRC reconfiguration message 1 does not contain the length of the SN field configured by the first DRB at the RLC layer. In this way, even after the terminal device accesses the first network device according to the RRC reconfiguration message 1, the SN field length configured by the first DRB at the RLC layer will not be modified. That is, the terminal device continues to inherit the second network device's configuration of the first DRB. Configuration result of the SN field length at the RLC layer.

B8: The terminal device sends an RRC reconfiguration completion message to the first network device (indicating that the handover is completed).

The above RRC reconfiguration complete message may also be called RRC reconfiguration complete. In this way, the terminal device can start sending service data to the first network device.

B9: The terminal device uses the first DRB in AM mode to send data packet 1 to the first network device. The length of the SN field in the RLC header information of data packet 1 is 12 bits.

In some embodiments, before the terminal device sends data to the first network device, the corresponding DRB may be determined based on the QOSflow to which the data belongs. Then, according to the configuration of each layer of the DRB in the NR wireless protocol stack, the data is encapsulated layer by layer to obtain the corresponding data packet and send it to the first network device.

In this embodiment, the determined DRB is the first DRB for example. As shown in Figure 9, in the terminal device, data that needs to be transmitted through the first DRB is processed by the PDCP layer to obtain data 1 (for example, PDCP status report). Then, the PDCP layer can pass data 1 to the RLC layer. The RLC layer adds RLC header information to data 1 according to the SN field length inherited from the second network device (for example, 12 bits). In this way, in the obtained RLC data, the RLC header The length of the SN field of the information is 12 bits. Afterwards, after encapsulation by the MAC layer, data packet 1 carrying data 1 is obtained.

Afterwards, the MAC layer may instruct the PHY layer to send the data packet 1 to the first network device through the matching physical link. The SN field length of the RLC header information corresponding to data 1 in this data packet 1 is 12 bits.

Of course, if the SN field length configured in the RLC layer of the first DRB in the first network device is also 12 bits, after the first network device parses the RLC data containing data 1 from the data packet 1, the first network device The RLC layer of the device can successfully parse the RLC header information of the RLC data and send the corresponding response to the terminal device.

If the length of the SN field configured by the first DRB in the first network device at the RLC layer is not equal to 12 bits, as shown in Figure 9, the length of the SN field configured by the first DRB at the RLC layer in the first network device is 18 bits. Next, the process enters B10.

B10, the first network device parses the SN field of the RLC header information according to the length of 18 bits, and the parsing of data packet 1 is abnormal.

In some embodiments, after the MAC layer of the first network device parses the RLC data containing data 1 from the data packet 1, it passes the RLC data to the RLC layer. As shown in Figure 9, the first network device in the first network device The length of the SN field configured by DRB at the RLC layer is 18 bits. In this way, the RLC layer will parse the data packet 1 transmitted through the above DRB according to the SN field length of 18 bits, that is, the actual length of the RLC SN field is 12 bits. Obviously, not only the accurate SN number cannot be parsed, but also the accurate RLC header information cannot be parsed, and a packet 1 parsing exception occurs.

In the case of abnormal parsing of data packet 1, the first network device does not send a response to data packet 1 to the terminal device.

If the terminal device does not receive a response to data packet 1 within the response waiting time corresponding to the first DRB, it can resend data packet 1. When the number of retransmissions of data packet 1 reaches the number of retransmissions corresponding to the DRB, the process enters B11.

B11: When data packet 1 is sent multiple times and no response is received, the terminal device sends an RRC re-establishment request to the first network device.

Wherein, when the number of retransmissions configured by the first DRB at the RLC layer is N and the response waiting time is t, the above "sending data packet 1 multiple times without receiving a response" may be to send data N times through the first DRB Packet 1, and the response corresponding to data packet 1 is not received within the time period t after sending data packet 1 for the Nth time.

In addition, the above-mentioned RRC reestablishment request may also be called an RRC Reestablishment Request, which is used to instruct re-establishment of the RRC connection between the terminal device and the first network device. After the RRC connection between the terminal device and the first network device is re-established, the process enters B12.

B12, the first network device sends an RRC reconfiguration message 2 to the terminal device, including the length (18 bits) of the SN field configured by the first network device at the RLC layer for the first DRB.

Among them, RRC reconfiguration message 2 may also be an RRC reconfiguration message. The difference between the RRC reconfiguration message 2 and the RRC reconfiguration message 1 is that the RRC reconfiguration message 2 does not contain a handover indication. According to the provisions of the current protocol, the RRC reconfiguration message 2 does not have a synchronization function.

It can be understood that when the network device connected to the terminal device changes, for example, when switching from a cell corresponding to one network device to a cell corresponding to another network device, the RRC reconfiguration message received by the terminal device contains a switching instruct.

When the network device connected to the terminal device does not change, the RRC reconfiguration message that can be received does not contain a handover indication. For example, after accessing the first network device and the terminal device sends RRC re-establishment to the first network device, the RRC reconfiguration message 2 received by the terminal device does not contain a handover indication.

B13, when the length of the SN field (18 bits) configured in the RLC layer for the first DRB carried in the RRC reconfiguration message 2 is not equal to the length (12 bits) of the SN field configured in the RLC layer for the first DRB in the terminal device. , the terminal device sends an RRC re-establishment request to the first network device.

Among them, protocol 38.311 stipulates that "The value of sn-FieldLength for a DRB shall be changed only using reconfiguration with sync.The network configures onlyvalue size12 in SN-FieldLengthAM for SRB", and its translation is: "sn-FieldLength" value corresponding to DRB Can only be changed via synchronous reconfiguration. The network only configures the value size12 for SRB in SN-FieldLengthAM.

That is, the protocol stipulates that during the call service process, the length of the SN field of the DRB at the RLC layer can only be changed through a reconfiguration message with synchronization function (such as an RRC reconfiguration message carrying a handover indication). In this way, according to the provisions of the current protocol, the above-mentioned RRC reconfiguration message 2 does not have the function of changing the SN field length of the first DRB configured at the RLC layer, but it carries the information in the first network device that the first DRB is configured at the RLC layer. The SN field length of the terminal device indicates that there is an exception in the RRC reconfiguration message 2 and triggers RRC re-establishment. For example, an RRC reestablishment request, that is, an RRC Reestablishment Request, is sent to the first network device.

B14. The first network device sends a bye message to the terminal device, instructing the terminal device to end the call.

B15, the terminal device determines that the call is abnormal and ends the call.

It can be understood that before B12, the first network device may negotiate with the core network to determine multiple DRBs used to transmit communication service data between the first network device and the terminal device. The plurality of DRBs include the first DRB. After negotiation, the first network device sends an RRC reconfiguration message 2 to the terminal device. The RRC reconfiguration message 2 includes the configuration of multiple DRBs in the first network device, for example, includes the SN configured by the first DRB at the RLC layer. The length of the field. However, because the length of the SN field of the first DRB configured in the RLC layer carried in the RRC reconfiguration message 2 is different from the length of the SN field of the first DRB configured in the RLC layer of the terminal device itself, and the RRC reconfiguration message 2 Without the synchronization function (for example, without handover indication), the terminal device may determine that the RRC reconfiguration message 2 does not comply with the protocol requirements, and will not send the RRC reconfiguration completion message to the first network device.

Without feeding back the RRC reconfiguration completion message to the first network device, the terminal device sends an RRC re-establishment request to the first network device again. In response to the RRC re-establishment request, the first network device requests negotiation with the core network again. Since the core network did not receive the last DRB negotiation feedback for the terminal device, when receiving the negotiation request again, the core network may be triggered to determine that the DRB between the first network device and the terminal device is abnormal (for example, DRB is lost), and indicate The first network device sends a bye message to the terminal device to instruct the terminal device to end the call.

In order to improve the above call drop problem, in the embodiment of the present application, during a VoNR call, if the terminal device switches from one network device (for example, the second network device) to access another network device (the first network device), it can Reduce the possibility of dropped calls.

As shown in Figure 10, the length of the SN field configured in the RLC layer of the first DRB in the second network device is the first value. In this way, the length of the SN field in the RLC header information generated by the RLC layer of the second network device for the data corresponding to the first DRB is the first value. In addition, the RLC layer of the second network device parses data from other devices and passes the first DRB When the RLC header information of the transmitted data is included, parsing is performed according to the first value of the RLC header information.

Similarly, the length of the SN field configured by the first DRB in the first network device at the RLC layer is the second value. In this way, the length of the SN field in the RLC header information generated by the RLC layer of the first network device for the data corresponding to the first DRB is the second value. In addition, when the RLC layer of the first network device parses the RLC header information of the data transmitted from other devices and using the first DRB, it performs parsing according to the second value of the RLC header information. In addition, the cells corresponding to the second network device and the first network device are adjacent cells to each other.

As shown in Figure 10, the communication method according to the embodiment of the present application may include the following steps:

S101. The terminal device establishes a VONR call through the second network device.

In some embodiments, before the above S101, a connection may be established between the terminal device and the second network device. After the connection between the terminal device and the second network device is established, the second network device sends a configuration message 1 to the terminal device. , the specific implementation process may refer to A1 and A2 in the previous embodiment. Among them, the configuration message 1 includes that the length of the SN field configured by the first DRB in the second network device at the RLC layer is the first value. In this way, after the terminal device is configured based on the configuration message 1, the data that needs to be transmitted through the first DRB , after processing by the RLC layer, the length of the SN field of the RLC header information is the first value.

In addition, the implementation process of the above S101 may refer to A3 in the previous embodiment, and will not be described again here. In this embodiment, the terminal device may initiate a VONR call while accessing the second network device. During the call, the terminal device uses the first DRB to send third data to the second network device, and the SN field length of the RLC header information of the third data is the first value. Then, the process proceeds to S102.

S102: The terminal device performs neighbor cell detection.

In some embodiments, when the terminal device accesses the second network device, the terminal device may actively trigger neighbor cell detection, or may be triggered by the second network device to perform neighbor cell detection. In addition, the method of triggering neighbor cell detection may refer to step B1 in the foregoing embodiment, and the adopted neighbor cell detection method may also refer to related technologies, which will not be described again here.

In addition, in a scenario where the terminal device triggers multiple neighbor cell detections under preset conditions, it can perform multiple neighbor cell detections continuously or perform multiple neighbor cell detections at specified intervals. After each neighbor detection is completed, a corresponding neighbor detection report can be generated, which can be called a neighbor detection report. For example, the neighbor cell detection report records the signal quality of multiple access network devices. The plurality of access network devices may include the second network device and the access network device corresponding to the neighboring cell. For example, the plurality of access network devices may include the second network device and the first network device.

In this way, whether it is a scenario where the user moves with the terminal device, or the signal quality of the second network device is affected by factors such as itself or the environment, the terminal device can promptly and accurately identify the degradation of the communication service quality provided by the second network device. , and trigger the subsequent network device switching process in a timely manner.

S103. The terminal device sends a neighbor cell detection report to the second network device.

In some embodiments, the implementation details of the above-mentioned S103 may refer to step B2 in the previous embodiments, and will not be described again here.

S104. The second network device determines that it needs to switch to the first network device based on the neighbor cell detection report.

In some embodiments, the second network device may evaluate the target network device from at least one network device recorded in the neighbor detection report according to the neighbor detection report. For example, the target network device is determined to be the first network device, and the first network device is determined to be the network device that the terminal device needs to switch to.

For example, the second network device evaluates the target network device based on multiple dimensions such as signal quality of multiple network devices in the neighbor cell detection report, supported network standards, and whether it is compatible with the terminal device. For the specific evaluation process, please refer to relevant technologies and will not be described again here. In subsequent embodiments, descriptions will be mainly made by taking the determined target network device as the first network device as an example.

S105. The second network device sends a switching request to the first network device.

The above-mentioned handover request may be called a handover request. For the implementation details of the above-mentioned S105, reference may be made to B4 in the above-mentioned embodiment, which will not be described again here.

S106. The first network device feeds back a handover request confirmation message to the second network device. The handover request confirmation message includes the configuration information corresponding to the first network device and does not contain the SN configured in the RLC layer for the first DRB in the first network device. The length of the field.

In some embodiments, reference may be made to B5 for the implementation details of the above S106, which will not be described again here.

It can be understood that in the current protocol, there is no provision that the handover request confirmation message sent by the first network device to the second network device must carry the SN field length configured by the first DRB at the RLC layer. In this way, the handover request confirmation message does not need to Contains the length of the SN field configured at the RLC layer of the first DRB in the first network device.

In some embodiments, after receiving the handover request confirmation message of the first network device, the second network device may generate a corresponding RRC reconfiguration message (RRC reconfiguration message), such as called RRC reconfiguration message 3. At the same time, the process Enter S107.

In some embodiments, the implementation details of the above-mentioned S105 and S106 may refer to the solution of the terminal device switching cells in related technologies, and will not be described again here.

S107: The second network device sends an RRC reconfiguration message 3 to the terminal device, including the handover instruction and not including the SN length configured in the RLC layer for the first DRB in the first network device.

In some embodiments, the handover indication in the RRC reconfiguration message 3 (called the second reconfiguration message) is used to instruct the terminal device to switch from the cell of the second network device to the first by modifying the RRC connection. The cell corresponding to the network device may also be referred to as accessing the first network device. For example, the handover instruction carries information such as the center frequency point of the cell corresponding to the first network device. In this embodiment, the above-mentioned RRC reconfiguration message 3 does not contain "the length of the SN field configured in the RLC layer of the first DRB in the first network device is the second value".

S108: The terminal device performs handover according to the RRC reconfiguration message 3.

In some embodiments, the terminal device reconfigures wireless resources (for example, the communication link corresponding to VoNR) according to the RRC reconfiguration message 3, so that the terminal device can access the first network device and perform data exchange.

Of course, in this embodiment, the RRC reconfiguration message 3 has a synchronization function, but does not include "the SN field length of the first DRB in the first network device at the RLC layer". After the terminal device uses RRC reconfiguration message 3 to modify the RRC connection, the length of the SN field configured by the first DRB in the terminal device at the RLC layer will not be modified. In this way, the length of the SN field actually configured by the first DRB in the terminal device at the RLC layer is still the first value. That is, the terminal device and the first network device do not synchronize the SN field length configured by the first DRB at the RLC layer.

S109: The terminal device sends an RRC reconfiguration completion message to the first network device (indicating that the handover is completed).

The above RRC reconfiguration complete message may also be called RRC reconfiguration complete.

In some embodiments, after the terminal device accesses the first network device according to the RRC reconfiguration message 3, the terminal device may send an RRC reconfiguration completion message to the first network device. After that, data may be exchanged between the terminal device and the first network device. transfer.

It can be understood that during the process of accessing the first network device through reconfiguration, the terminal device does not interrupt the ongoing VoNR call service. After the reconfiguration is completed, the terminal device can send service data corresponding to the VoNR call through the first network device. For example, sending a PDCP status report is used to test whether normal communication can be achieved after accessing the first network device.

S110: The terminal device sends data packet 2 to the first network device through the first DRB in AM mode, and the SN field length of the RLC header in the data packet 2 is the first value.

For the implementation details of the above S110, reference can be made to B9 in the previous embodiment, which will not be described again here. Data packet 2 and data packet 1 both refer to communication service data that needs to be transmitted through the first DRB, and will not be described again here. The above-mentioned data packet 2 may be the first data.

S111: The first network device parses the RLC header information in the data packet 2 according to the second value of the SN field. If the first value and the second value are different, the parsing is abnormal.

It can be understood that the length of the SN field configured by the first DRB at the RLC layer in the first network device is the second value, that is, the length of the SN field configured by the first DRB at the RLC layer is the second value. In this way, after the first network device receives the data packet 2 transmitted through the first DRB, the RLC layer of the first network device parses the RLC header information in the data packet 2 according to the RLC SN field length being the second value.

In some embodiments, when the first value and the second value are different, the RLC data parsed by the first network device is inaccurate. In this way, the first network device may not send the response corresponding to the RLC data to the terminal device.

In practical applications, the first network device responds to RLC data (e.g., PDCP status) sent by DRBs using AM mode (e.g., DRBs carrying IMS signaling) that have abnormalities (e.g., data that the first network device cannot accurately parse). reports, live video streams, etc.) without feedback response.

It can be understood that the first DRB is also configured with the number of retransmissions (N) and the response waiting time (t) at the RLC layer. The response waiting time (t) refers to the length of time to wait for a feedback response from the peer device after each data is sent through the first DRB.

For example, if the terminal device does not receive a response from the first network device within a time period t after sending the data packet 2 through the first DRB, a retransmission of the data packet 2 is triggered.

The above-mentioned number of retransmissions (N) refers to the maximum number of retransmissions of the same data through the first DRB.

For example, after the i-th retransmission of data packet 2 through the first DRB, the value of i is a positive integer less than N, and no response from the first network device is received within the time period t, the i+1-th retransmission is triggered. Transmit data packet 2. After the data packet 2 is retransmitted through the first DRB for the Nth time, if no response from the first network device is received within the time period t, it is determined that an abnormality occurs, and the process may proceed to S112.

In other embodiments, when the first value and the second value are the same, the first network device can accurately parse the data packet from the terminal device and obtain the data content carried by it. In this way, the terminal device and the first network device can communicate normally, and the terminal device can continue the VoNR call through the first network device. In addition, there is no need to perform subsequent process steps.

S112: When data packet 2 is sent multiple times and no response is received, the terminal device sends an RRC re-establishment request to the first network device.

In some embodiments, if the data packet 2 sent through the first DRB does not receive a response corresponding to the data packet 2 within the response waiting time corresponding to the first DRB, retransmission may be triggered. When the number of retransmissions of data packet 2 reaches the number of retransmissions N corresponding to the first DRB and no response is received for data packet 2, the terminal device may determine that there is an abnormality in the communication with the first network device. In this scenario, the terminal device may send an RRC reestablishment request (RRCReestablishment Reques) to the first network device to instruct the RRC connection to be re-established between the terminal device and the first network device. That is, the above "sending data packet 2 multiple times without receiving a response" may refer to sending data packet 2 N times and not receiving a corresponding response within a time period t after each transmission.

After the RRC connection between the terminal device and the first network device is re-established, the process proceeds to S113.

S113. The first network device sends an RRC reconfiguration message 4 to the terminal device, including the length (second value) of the SN field configured by the first network device at the RLC layer for the first DRB.

The above-mentioned RRC reconfiguration message 4 may also be an RRC reconfiguration message. In addition, the above-mentioned RRC reconfiguration message 4 does not have a synchronization function. However, the RRC reconfiguration message 4 carries the second value of the SN field configured by the first DRB in the first network device at the RLC layer. It can also be said to carry the second value. an instruction message. The above-mentioned RRC reconfiguration message 4 may be called the first reconfiguration message.

S114. During the call, if the second value is not equal to the first value, the terminal device configures the SN field length corresponding to the first DRB at the RLC layer to the second value.

In this embodiment of the present application, after the terminal device receives the RRC reconfiguration message 4 from the first network device, even if the RRC reconfiguration message 4 does not have the synchronization function (for example, it is not an RRC reconfiguration message carrying a handover indication), it will According to the RRC reconfiguration message 4, the SN field length configured by the first DRB at the RLC layer is modified to the second value. The above process is incompatible with the current protocol, but the terminal device can ignore the non-compliant problem of modifying the SN field length this time.

After the SN field length of the first DRB in the terminal device is configured at the RLC layer to the second value, the communication service data that needs to be sent through the first DRB is processed by the RLC layer, and the SN field length of the obtained RLC header information is configured as Second value.

In addition, it can be understood that in this embodiment, the first DRB is mainly used as an example, and the above method is also applicable to other DRBs between the terminal device and the first network device.

S115: The terminal device sends an RRC reconfiguration complete message to the first network device.

The above RRC reconfiguration complete message may also be called RRC reconfiguration complete.

Afterwards, the SN field length of the RLC header information of the data to be transmitted through the first DRB in the terminal device is the second value, and the terminal device and the first network device can also communicate normally. When the terminal device modifies the SN field length configured by the first DRB at the RLC layer, it does not trigger another RRC re-establishment request to the first network device. Instead, after the modification is completed, it sends an RRC reconfiguration complete message to avoid the first network device The core network corresponding to the device misjudges that the data bearer is lost, thereby reducing the frequency of dropped calls and improving the quality of communication services.

After the SN field length configured by the first DBR at the RLC layer is modified to the second value, the terminal device may send second data to the first network device, and the SN field length of the RLC header information of the second data is the second value.

In some embodiments, the above steps performed by the terminal device may be processed by modem processing.

For example, the above S101 may be executed by the call request module in the terminal device. The above S102 ~ S103 can be executed by the PHY layer in the terminal device. The above S108-S109 may be executed by the RRC layer in the terminal device. S110 can be executed collaboratively by the PDCP layer, RLC layer, MAC layer, and PHY layer in the terminal device. S112 may be performed by the RRC layer in the terminal device. S114 may be executed by the RLC layer in the terminal device. S115 may be executed by the RLC layer in the terminal device.

In some embodiments, the process for the terminal device to perform the above method may be as follows: use the first DRB to send the first data to the first network device, and the SN field length of the RLC header information of the first data is the first value; when the terminal device has not When receiving a response returned by the first network device for the first data, send a re-establishment request to the first network device; receive a first reconfiguration message from the first network device, wherein the first reconfiguration message carries the An indication information, the first indication information is used to indicate that the length of the SN field configured by the first DRB at the RLC layer in the first network device is the second value; when the first value and the second value are not equal, the first indication information is used to indicate to the first The network device sends a reconfiguration complete message. After sending the reconfiguration completion message, use the first DRB to send second data to the first network device. The length of the SN field of the RLC header information of the second data is the second value. The second data carries the same information as the first data. Same data content.

In other possible embodiments, as shown in Figure 11, the above communication method may also include:

S201: The terminal device establishes a VONR call through the second network device.

S202: The terminal device performs neighbor cell detection.

S203: The terminal device sends a neighbor cell detection report to the second network device.

S204: The second network device determines that it needs to switch to the first network device based on the neighbor cell detection report.

S205. The second network device sends a switching request to the first network device.

S206: The first network device feeds back a handover request confirmation message to the second network device. The handover request confirmation message includes the configuration information corresponding to the first network device and does not contain the SN configured in the RLC layer for the first DRB in the first network device. The length of the field.

S207. The second network device sends the RRC reconfiguration message 3 to the terminal device, including the handover indication and not including the SN length configured in the RLC layer for the first DRB in the first network device.

For implementation details of S201 to S207, reference may be made to S101 to S107 in the foregoing embodiment, which will not be described again here.

S208: The terminal device determines, based on historical record data, that the length of the SN field configured at the RLC layer for the first DRB in the first network device is the second value.

In some embodiments, after the terminal device accesses any network device, the configuration of each DRB in the accessed network device can be recorded to obtain historical record data.

In this way, when the terminal device has accessed the first network device and has recorded the configuration of each DRB in the first network device, the SN configured by the first network device at the RLC layer for the first DRB can be queried in the historical record data. The field length is the second value.

In some embodiments, after receiving the RRC reconfiguration message 3, the terminal device determines to instruct the terminal device to switch to the cell corresponding to the first network device according to the content carried in the handover instruction. Then, the terminal device may determine that the historical record data contains the second value corresponding to the first network device.

For example, the terminal device may determine that the history data contains the second value, which may include: after receiving the RRC reconfiguration message 3, determining that the RRC reconfiguration message 3 does not contain the first network device configured at the RLC layer for the first DRB. The length of the SN field. Then, the terminal device can query the historical record data according to the identifier of the first network device, and determine that the length of the SN field configured by the first network device at the RLC layer for the first DRB is the second value, and the process proceeds to S209.

S209: When the first value and the second value are different, the terminal device performs switching according to the RRC reconfiguration message 3, and modifies the SN field length of the first DRB configured in the RLC layer from the first value to the second value. value.

In this way, the terminal device performs cell switching according to the RRC reconfiguration message 3, and switches to the cell corresponding to the first network device, that is, it can be said to access the first network device. Afterwards, according to the second value queried from the historical record data, the SN field length configured by the terminal device at the RLC layer for the first DRB is modified from the first value to the second value to achieve synchronization with the first network device.

S210: The terminal device sends an RRC reconfiguration completion message to the first network device.

S211: The terminal device sends data packet 3 to the first network device through the first DRB in AM mode, and the SN field length of the RLC header in the data packet 3 is the second value.

In some embodiments, the implementation details of the above-mentioned S210 and S211 may refer to S109 and S110 in the previous embodiments, and will not be described again here. The above-mentioned data packet 3 may also be called second data.

In addition, in some embodiments, "Modify the SN field length configured by the first DRB at the RLC layer from the first value to the second value" in S209 above can be performed after S210 and before S211. The embodiment of this application is This is not specifically limited.

S212: The first network device parses the RLC header information in data packet 3 according to the second value of the SN field length.

In some embodiments, the first network device determines that data packet 3 comes from the DRB using AM mode. After successfully parsing data packet 3, the process proceeds to S213.

S213. The first network device sends a response corresponding to the data packet 3 to the terminal device.

In the above embodiment, the terminal device uses historical record data to synchronize the SN field length of the RLC layer with the first network device. In this way, abnormalities during the call, such as silence during the call, can be avoided to avoid triggering an RRC restart. Establish to reduce the probability of abnormal calls.

In other embodiments, as shown in Figure 12, the above method may also include:

S301: The terminal device establishes a VONR call through the second network device.

S302: The terminal device performs neighbor cell detection.

S303. The terminal device sends a neighbor cell detection report to the second network device.

S304: The second network device determines that it needs to switch to the first network device based on the neighbor cell detection report.

S305. The second network device sends a switching request to the first network device.

S306. The first network device feeds back a handover request confirmation message to the second network device. The handover request confirmation message includes the configuration information corresponding to the first network device and does not contain the SN configured in the RLC layer for the first DRB in the first network device. The length of the field.

S307: The second network device sends an RRC reconfiguration message 3 to the terminal device, including the handover instruction and not including the SN length configured in the RLC layer for the first DRB in the first network device.

S308: The terminal device performs handover according to the RRC reconfiguration message 3.

S309: The terminal device sends an RRC reconfiguration complete message to the first network device.

S310: The terminal device sends data packet 2 to the first network device through the first DRB in AM mode, and the length of the SN field of the RLC header in the data packet 2 is the first value.

Among them, the above-mentioned data packet 2 can be called the first data.

S311: The first network device parses the RLC header information in the data packet 2 according to the second value of the SN field length. If the first value and the second value are different, the parsing is abnormal.

It can be understood that the length of the SN field configured by the first DRB at the RLC layer in the first network device is the second value, that is, the length of the SN field configured by the first DRB at the RLC layer is the second value. In this way, after the first network device receives the data packet 2 transmitted through the first DRB, the RLC layer of the first network device parses the RLC header information in the data packet 2 according to the RLC SN field length being the second value.

In some embodiments, when the first value and the second value are different, the RLC data parsed by the first network device is inaccurate. In this way, the first network device may not send the response corresponding to the data packet 2 to the terminal device. In the case where no response is received from the first network device, the terminal device may determine that the historical record data contains the second value corresponding to the first network device. For example, the method of determining that the historical record data contains the second value corresponding to the first network device may refer to S312.

S312. Under the first condition, the terminal device determines from the historical record data that the length of the SN field configured in the RLC layer of the first DRB in the first network device is the second value.

The above-mentioned first condition may be that the number of retransmissions of data packet 2 reaches L times, and no response is received within the time period t after the L-th retransmission.

In some embodiments, the above-mentioned L may be a preconfigured value, such as called the second degree. As an example, take the number of retransmissions configured by the first DRB at the RLC layer as N and the response waiting time as t. When N is a positive integer greater than 1, the above L can be a positive integer value less than N. For example, L can be equal to N. -1.

In this way, after the terminal device sends the data packet 2 and does not receive a response within the time period t, the data packet 2 can be retransmitted through the first DRB. After the data packet 2 is retransmitted through the first DRB for the L-th time, no corresponding response is received within the time period t, and it is determined that the first condition is currently met.

In a possible embodiment, L may also be equal to N. After the L-th retransmission of data packet 2 through the first DRB, the corresponding response is not received within the time period t, and the terminal device may be configured not to initiate an RRC re-establishment request. Make sure the first condition is currently met.

In some embodiments, the above-mentioned terminal device determines from the historical record data that the SN field length configured by the first DRB in the first network device at the RLC layer is the second value. Reference can be made to S208 in the previous embodiment, which will not be repeated here. Repeat.

S313: When the first value and the second value are not equal, the terminal device modifies the SN field length configured by the first DRB at the RLC layer to the second value.

S314: The terminal device sends data packet 4 to the first network device through the first DRB in AM mode, and the SN field length of the RLC header in the data packet 4 is the second value.

Among them, the data content carried in data packet 4 and data packet 2 is the same, but the configured RLC header information is different. The difference lies in the different length of the RLC SN field. Data packet 4 may also be the second data. Data packet 2 and data packet 4 carry the same data content, but the length of the SN field of the configured RLC layer header information is different.

S315: The first network device parses the RLC header information in the data packet 4 according to the second value of the SN field length.

S316: The first network device sends a response corresponding to the data packet 4 to the terminal device.

In this way, by not triggering RRC re-establishment, call abnormalities caused by RRC re-establishment are avoided, thereby reducing the call drop rate.

In other embodiments, as shown in Figure 13, the above communication method may also include:

S401: The terminal device establishes a VONR call through the second network device.

S402: The terminal device performs neighbor cell detection.

S403. The terminal device sends a neighbor cell detection report to the second network device.

S404: The second network device determines that it needs to switch to the first network device based on the neighbor cell detection report.

S405. The second network device sends a switching request to the first network device.

S406: The first network device feeds back a handover request confirmation message to the second network device, where the handover request confirmation message includes the length of the SN field configured in the RLC layer for the first DRB in the first network device.

S407: The second network device sends an RRC reconfiguration message 5 to the terminal device, including the handover indication and the SN length configured in the RLC layer for the first DRB in the first network device.

S408: The terminal device performs handover according to the RRC reconfiguration message 5.

S409: The terminal device sends an RRC reconfiguration complete message to the first network device.

S410: The terminal device sends the data packet 5 to the first network device through the first DRB in AM mode, and the length of the SN field in the RLC header of the data packet 5 is the second value.

In this way, the first network device can accurately parse the data packet 5 and send a response corresponding to the data packet 5 to the terminal device. Among them, the above-mentioned data packet 5 can be called second data.

S411. The first network device parses the RLC header information in the data packet 5 according to the second value of the SN field length.

S412. The first network device sends a response corresponding to data packet 5 to the terminal device.

Figure 14 is a schematic structural diagram of a terminal device provided by an embodiment of the present application. The terminal device may be the terminal device 100, the terminal device 106, etc. mentioned in the above embodiment.

As shown in Figure 14, the above terminal device may include: a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, and a battery. 142. Antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, audio module 170, speaker 170A, receiver 170B, microphone 170C, headphone interface 170D, sensor module 180, button 190, motor 191, indicator 192, camera 193, display screen 194, and subscriber identification module (subscriber identification module, SIM) card interface 195, etc.

The sensor module 180 may include a pressure sensor, a gyroscope sensor, an air 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 other sensors.

It can be understood that the structure illustrated in this embodiment does not constitute a specific limitation on the terminal device. In other embodiments, the terminal device may include more or less components than shown in the figures, or some components may be combined, or some components may be separated, or may be arranged differently. The components illustrated may be implemented in hardware, software, or a combination of software and hardware.

The processor 110 may include one or more processing units. For example, the processor 110 may include an application processor (application processor, AP), a modem, a graphics processing unit (GPU), an image signal Processor (image signal processor, ISP), controller, memory, video codec, digital signal processor (digital signal processor, DSP), baseband processor, and/or neural-network processing unit, NPU) etc. Among them, different processing units can be independent devices or integrated in one or more processors.

The controller can be the nerve center and command center of the terminal device. The controller can generate operation control signals based on the instruction operation code and timing signals to complete the control of fetching and executing instructions.

The processor 110 may also be provided with a memory for storing instructions and data. In some embodiments, the memory in processor 110 is cache memory. This memory may hold instructions or data that have been recently used or recycled by processor 110 . If the processor 110 needs to use the instructions or data again, it can be called directly from the memory. Repeated access is avoided and the waiting time of the processor 110 is reduced, thus improving the efficiency of the system.

In some embodiments, processor 110 may include one or more interfaces. The interface may include an integrated circuit (inter-integrated circuit, I2C) interface, an integrated circuit built-in audio (inter-integrated circuitsound, I2S) interface, a pulse code modulation (PCM) interface, and a universal asynchronous receiver (universal asynchronous receiver) /transmitter, UART) interface, mobile industry processor interface (MIPI), general-purpose input/output (GPIO) interface, subscriber identity module (subscriber identity module, SIM) interface, and/or Universal serial bus (USB) interface, etc.

It can be understood that the interface connection relationships between the modules illustrated in this embodiment are only schematic illustrations and do not constitute structural limitations on the terminal equipment. In other embodiments, the terminal device may also adopt different interface connection methods in the above embodiments, or a combination of multiple interface connection methods.

The terminal device implements display functions through the GPU, the display screen 194, and the application processor. The GPU is an image processing microprocessor and is connected to the display screen 194 and the application processor. GPUs are used to perform mathematical and geometric calculations for graphics rendering. Processor 110 may include one or more GPUs that execute program instructions to generate or alter display information.

The display screen 194 is used to display images, videos, etc. The display screen 194 includes a display panel. The display panel can use a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active matrix organic light emitting diode or an active matrix organic light emitting diode (active-matrix organic light emitting diode). , AMOLED), flexible light-emitting diodes (FLED), Miniled, MicroLed, Micro-oLed, quantum dot light-emitting diodes (QLED), etc.

The terminal device can realize the shooting function through the ISP, camera 193, video codec, GPU, display screen 194 and application processor.

The ISP is used to process the data fed back by the camera 193. For example, when taking a photo, the shutter is opened and the light is transmitted to the camera sensor (image sensor) through the lens. The optical signal is converted into an electrical signal. The camera sensor passes the electrical signal to the ISP for processing and converts it into an image visible to the naked eye. ISP can also perform algorithm optimization on image noise, brightness, and skin color. ISP can also optimize the exposure, color temperature and other parameters of the shooting scene. In some embodiments, the ISP may be provided in the camera 193.

Camera 193 is used to capture still images or video. The object passes through the lens to produce an optical image that is projected onto the photosensitive element. The photosensitive element may be a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the optical signal into an electrical signal, and then passes the electrical signal to the ISP to convert it into a digital image signal. ISP outputs digital image signals to DSP for processing. DSP converts digital image signals into standard RGB, YUV and other format image signals. In some embodiments, the terminal device may include N cameras 193, where N is a positive integer greater than 1.

Digital signal processors are used to process digital signals. In addition to digital image signals, they can also process other digital signals. For example, when the terminal device selects a frequency point, the digital signal processor is used to perform Fourier transform on the frequency point energy.

Video codecs are used to compress or decompress digital video. The end device can support one or more video codecs. In this way, the terminal device can play or record videos in multiple encoding formats, such as: moving picture experts group (MPEG)1, MPEG2, MPEG3, MPEG4, etc.

NPU is a neural network (NN) computing processor. By drawing on the structure of biological neural networks, such as the transmission mode between neurons in the human brain, it can quickly process input information and can continuously learn by itself. NPU can realize intelligent cognitive applications of terminal devices, such as image recognition, face recognition, speech recognition, text understanding, etc.

Refer to Figure 15, which is a schematic structural diagram of a network device provided by an embodiment of the present application. The network device may be any node device in the NG RAN in the above embodiment.

As shown in Figure 15, the network device may include: one or more processors 1401, memory 1402, communication interface 1403, transmitter 1405, receiver 1406, coupler 1407, and antenna 1408. These components can be connected through the bus 1404 or other means. Figure 15 takes the connection through the bus as an example. in:

The communication interface 1403 may be used by the network device to communicate with other communication devices, such as the terminal device 100, the 5GC 102 or other network devices. Specifically, the communication interface 1403 may be a communication interface of 5G or future new air interface. Not limited to wireless communication interfaces, the network device can also be configured with a wired communication interface 1403 to support wired communication. For example, the backhaul link between one network device and other network devices can be a wired communication connection.

In some embodiments of the present application, transmitter 1405 and receiver 1406 may be viewed as a wireless modem. The transmitter 1405 may be used to transmit the signal output by the processor 1401. Receiver 1406 may be used to receive signals. In the network device, the number of transmitters 1405 and receivers 1406 may be one or more. The antenna 1408 may be used to convert electromagnetic energy in the transmission line into electromagnetic waves in free space, or to convert electromagnetic waves in free space into electromagnetic energy in the transmission line. The coupler 1407 can be used to split the mobile communication signal into multiple channels and distribute them to multiple receivers 1406. It can be understood that the antenna 1408 of the network device can be implemented as a large-scale antenna array.

Memory 1402 is coupled to processor 1401 for storing various software programs and/or sets of instructions. Specifically, the memory 1402 may include high-speed random access memory, and may also include non-volatile memory, such as one or more disk storage devices, flash memory devices or other non-volatile solid-state storage devices.

The memory 1402 can store an operating system (hereinafter referred to as the system), such as uCOS, VxWorks, RTLinux and other embedded operating systems. The memory 1402 can also store a network communication program, which can be used to communicate with one or more additional devices, one or more terminal devices, and one or more network devices.

Processor 1401 may be used to read and execute computer readable instructions. Specifically, the processor 1401 can be used to call a program stored in the memory 1402.

It should be noted that the network device shown in Figure 15 is only an implementation manner of the embodiment of the present application. In actual applications, the network device may also include more or fewer components, which is not limited here.

An embodiment of the present application also provides a chip system, which can be applied to the terminal device in the foregoing embodiments. The chip system includes at least one processor and at least one interface circuit. The processor may be the processor in the above-mentioned terminal device. Processors and interface circuits can be interconnected by wires. The processor can receive and execute computer instructions from the memory of the above-mentioned terminal device through the interface circuit. When the computer instructions are executed by the processor, the terminal device can be caused to perform various steps in the above embodiments. Of course, the chip system may also include other discrete devices, which are not specifically limited in the embodiments of this application.

In some embodiments, through the description of the above implementations, those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above functional modules is used as an example. In actual applications, it can be based on If necessary, the above function allocation is completed by different functional modules, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. For the specific working processes of the systems, devices and units described above, reference can be made to the corresponding processes in the foregoing method embodiments, which will not be described again here.

Each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above integrated units can be implemented in the form of hardware or software functional units.

If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application are essentially or contribute to the existing technology, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage device. The medium includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of this application. The aforementioned storage media include: flash memory, mobile hard disk, read-only memory, random access memory, magnetic disk or optical disk and other media that can store program codes.

The above are only specific implementation modes of the embodiments of the present application, but the protection scope of the embodiments of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiments of the present application shall be covered by this application. within the protection scope of the application embodiment. Therefore, the protection scope of the embodiments of the present application should be subject to the protection scope of the claims.

Claims (12)

1. A communication method, which is applied to a call process of a terminal device, the method comprising:

the terminal equipment uses a first DRB to send first data to first network equipment, and the length of a sequence number SN field of radio link RLC header information of the first data is a first value;

the terminal equipment sends a reestablishment request to the first network equipment under the condition that the terminal equipment does not receive a response returned by the first network equipment for the first data;

the terminal equipment receives a first reconfiguration message from the first network equipment, wherein the first reconfiguration message carries first indication information, and the first indication information is used for indicating that the SN field length configured by the first DRB in the RLC layer in the first network equipment is a second value;

The terminal equipment sends a reconfiguration complete message to the first network equipment under the condition that the first value is not equal to the second value;

after the reconfiguration complete message is sent, the terminal device sends second data to the first network device by using the first DRB, and the SN field length of the RLC header information of the second data is the second value.

2. The method of claim 1, wherein before the terminal device sends the first data to the first network device, the method further comprises:

the terminal equipment establishes a call through the second network equipment;

and during the call, the terminal equipment receives a second reconfiguration message from the second network equipment, wherein the second reconfiguration message carries a switching instruction, the switching instruction is used for indicating the terminal equipment to switch to a cell corresponding to the first network equipment, and the second reconfiguration message does not carry the first indication information.

3. The method of claim 2, wherein prior to the terminal device establishing the call through the second network device, the method further comprises:

And after the connection is established between the terminal equipment and the second network equipment, receiving a third reconfiguration message from the second network equipment, wherein the third reconfiguration message is used for indicating that the SN field length configured by the first DRB in the RLC layer in the second network equipment is the first value.

4. The method of any of claims 1-3, wherein the first DRB is a DRB that enables a determined transmission mode.

5. The method of any of claims 1-4, wherein the first data and the second data are call data, and wherein the call procedure comprises a call procedure established based on a 4G communication system, a 5G communication system, or a 6G communication system.

6. The method according to any of claims 1-5, wherein the terminal device not receiving the response returned by the first network device for the first data comprises: and the terminal equipment uses the first DRB to retransmit the first data to the first network equipment for the first time which reaches the preset first time, and does not receive a response corresponding to the first data in a first time period after the last retransmission.

7. A communication method, applied to a terminal device, the method comprising:

After the terminal equipment establishes a call through second network equipment, the terminal equipment uses a first DRB to send third data to the second network equipment, and the SN field length of the RLC header information of the third data is a first value;

in the call process, the terminal equipment receives a second reconfiguration message from the second network equipment, wherein the second reconfiguration message comprises a switching instruction, and the switching instruction is used for instructing the terminal equipment to switch to a cell corresponding to the first network equipment;

determining that the history data contains a second value, wherein the second value is an SN field length configured in the RLC layer for the first DRB in the first network equipment, and the first value is not equal to the second value;

and when the second value is included in the history data and the second reconfiguration message does not include an SN field length configured in the RLC layer for the first DRB in the first network device, the terminal device sends second data to the first network device using the first DRB, where the SN field length of RLC header information of the second data is the second value.

8. The method of claim 7, wherein before the terminal device establishes a call through the second network device, the method further comprises:

After a connection is established between the terminal device and the second network device, a third reconfiguration message from the second network device is received, wherein the third reconfiguration message comprises the first value, and the first value is an SN field length configured in the second network device at an RLC layer for a first DRB.

9. The method of claim 7 or 8, wherein determining that the second value is included in the history data comprises:

after the terminal device receives the second reconfiguration message from the second network device, determining, in the case that the second reconfiguration message does not contain an SN field length configured in the RLC layer for the first DRB in the first network device, that the SN field length configured in the RLC layer for the first DRB in the first network device is the second value according to the history data;

the method further comprises the steps of: and the terminal equipment sends a reconfiguration complete message to the first network equipment under the condition that the first value is not equal to the second value.

10. The method according to claim 7 or 8, characterized in that after the terminal device receives the second reconfiguration message, the method further comprises:

In response to the second reconfiguration message, the terminal device sends a reconfiguration complete message to the first network device;

the terminal equipment uses the first DRB to send first data to the first network equipment, and the SN field length of the RLC header information of the first data is the first value;

the determining that the second value is included in the history data includes:

under a first condition, determining that the SN field length of the first DRB in the RLC header information in the first network equipment is the second value according to the history data; the first condition includes that the transmission times of the first data reach a preset second times, and no response corresponding to the first data is received in a first duration after the last retransmission.

11. A terminal device, characterized in that the terminal device comprises: a processor and a memory, the processor comprising a modem processor modem, the memory for storing computer instructions which, when executed by the processor, cause the terminal device to perform the method of any of claims 1-10.

12. A chip system for application to a terminal device, characterized in that a computer program is stored which, when executed, causes the terminal device to perform the method according to any of claims 1-10.