CN117135775A

CN117135775A - Communication method and terminal equipment

Info

Publication number: CN117135775A
Application number: CN202310750224.3A
Authority: CN
Inventors: 罗凯治; 李海波
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2023-04-04
Filing date: 2023-06-21
Publication date: 2023-11-28
Also published as: WO2024207772A1

Abstract

The embodiment of the application provides a communication method and terminal equipment, and relates to the technical field of communication. The call drop problem in the call process is solved. The specific scheme is as follows: using the first DRB to send first data to the first network equipment, wherein the SN field length of the RLC header of the first data is a first value; transmitting a reestablishment request to the first network equipment under the condition that a response returned by the first network equipment for the first data is not received; receiving a first reconfiguration message from the first network device, wherein the first reconfiguration message carries first indication information, and the first indication information is used for indicating that the length of an SN field configured by the first DRB in the RLC layer in the first network device is a second value; transmitting a reconfiguration complete message to the first network device if the first value is not equal to the second value; and transmitting second data to the first network equipment by using the first DRB, wherein the SN field length of the RLC header information of the second data is a second value.

Description

Communication method and terminal equipment

The present application claims priority from the national intellectual property agency, application No. 20231039985. X, chinese patent application entitled "method and apparatus for talk handling", filed 4/2023, the entire contents of which are incorporated herein by reference.

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communications method and a terminal device.

Background

With the development of the fifth generation (5th generation,5G), services based on the 5G technology are increasing, for example, voice traffic is transmitted through a New Radio (NR) air interface of the 5G technology, where the voice traffic transmitted through the NR air interface of the 5G technology may be referred to as new air interface carried voice (voice over new radio, voNR). It will be appreciated that the above VoNR refers to an end-to-end bearer of voice traffic based on a 5G system and an IP multimedia system (IP Multimedia Subsystem, IMS). The VoNR call has short setup time, and the data service can still be transmitted at high speed, thus giving better experience to the user.

However, in the process that the terminal device actually performs a call with other terminals, a call drop problem easily occurs.

Disclosure of Invention

The embodiment of the application provides a communication method and terminal equipment, which are used for improving the problem of call drop (abnormal call, call interruption) in the call process.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical scheme:

in a first aspect, a communication method provided by an embodiment of the present application is applied to a call process of a terminal device, where the method includes: the terminal equipment uses a first DRB to send first data to the 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; in case the terminal device does not receive a response returned by the first network device for the first data, the terminal device sends a reestablishment request (RRC reestablishment request, also called RRC connection reestablishment request) to the first network device. The terminal device receives a first reconfiguration message (a first RRC reconfiguration message is also referred to as a first RRC connection reconfiguration message) from the first network device, where the first reconfiguration message carries first indication information, and the first indication information is used to indicate that an SN field length configured by the first DRB in the RLC layer in the first network device is a second value. In case the first value is not equal to the second value, the terminal device sends a reconfiguration complete message (RRC reconfiguration complete message) to the first network device. 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 RLC header information of the second data is a second value.

In the above embodiment, in the call process, after receiving the RRC reconfiguration message, the terminal device ignores whether it accords with the existing protocol, reconfigures the SN field length of the first DRB in the RLC layer according to the second value in the RRC reconfiguration message, and feeds back the RRC reconfiguration complete message, so that the RRC reconfiguration is not triggered again, and misjudgment as abnormal call is avoided, and the terminal device is instructed to end the call. Thus, the call drop rate can be effectively reduced.

In some embodiments, the second data may carry the same data content as the first data to ensure that data content that may not have been successfully received by the first network device before is retransmitted to the first network device. In other embodiments, the second data and the first data carry different data contents, i.e., 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 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.

In the above embodiment, the terminal device may perform cell handover during the call, so as to reduce the probability of dropped calls while ensuring the call quality.

In some embodiments, before the terminal device establishes 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.

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

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

In the above embodiments, the first DRB may ensure the reliability of data transmission.

In some embodiments, the first data and the second data are both call data, and the call procedure includes a call procedure 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 that the call is normally performed.

In some embodiments, the terminal device not receiving the response returned by the first network device for the first data includes: 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.

In the above embodiments, triggering of unnecessary re-establishment requests can be avoided.

In a second aspect, a communication method provided by an embodiment of the present application is applied to a terminal device, where the method includes: 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.

In some embodiments, before the terminal device establishes the call through the second network device, the method further comprises: after a connection is established between a terminal device and a second network device, a third reconfiguration message from the second network device is received, wherein the third reconfiguration message comprises a 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.

In some embodiments, 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 the 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.

In some embodiments, 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.

In a third aspect, an embodiment of the present application provides a terminal device, where the terminal device includes one or more processors and a memory; the processor comprises a modem processor, the memory being coupled to the processor, the memory for storing computer program code comprising computer instructions for performing the method of the first aspect, the second aspect and possible embodiments thereof, when the computer instructions are executed by one or more processors.

In a fourth aspect, an embodiment of the present application provides a computer storage medium, including computer instructions, which when executed on a terminal device, cause the terminal device to perform the method in the first aspect, the second aspect and possible embodiments thereof.

In a fifth aspect, the present application provides a computer program product for causing a terminal device to carry out the method of the first aspect, the second aspect and possible embodiments thereof, when the computer program product is run on the terminal device.

In a sixth aspect, the present application provides a chip system for application to a terminal device, storing a computer program which, when executed, causes the terminal device to perform the method of the first aspect, the second aspect and possible embodiments thereof.

It will be appreciated that the terminal device, the computer storage medium and the computer program product provided in the above aspects are all applicable to the corresponding methods provided above, and therefore, the advantages achieved by the terminal device, the computer storage medium and the computer program product may refer to the advantages in the corresponding methods provided above, and are not repeated herein.

Drawings

Fig. 1 is an exemplary diagram of a communication system provided by an embodiment of the present application;

fig. 2 is an exemplary diagram of a communication system capable of implementing a VoNR call according to an embodiment of the present application;

fig. 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;

fig. 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;

Fig. 5 is an exemplary diagram of protocol stacks supported by both a terminal device and a second network device according to an embodiment of the present application;

fig. 6 is a diagram illustrating a structure of an RLC packet according to an embodiment of the present application;

fig. 7 is a schematic diagram of a scenario in which a triggerable terminal device switches an accessed network device according to an embodiment of the present application;

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

fig. 9 is an exemplary diagram of a communication anomaly scenario occurring after a terminal device has access to a first network device through reconfiguration;

fig. 10 is one of signaling interaction diagrams of a communication method according to an embodiment of the present application;

FIG. 11 is a second signaling diagram of a communication method according to an embodiment of the present application;

FIG. 12 is a third signaling diagram illustrating a communication method according to an embodiment of the present application;

fig. 13 is a fourth signaling interaction diagram of a communication method according to an embodiment of the present application;

fig. 14 is a diagram illustrating a hardware structure of a terminal device according to an embodiment of the present application;

fig. 15 is a diagram illustrating a hardware structure of a network device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application. Wherein, in the description of the application, unless otherwise indicated, "at least one" means one or more, and "a plurality" means two or more. In addition, in order to facilitate the clear description of the technical solution of the embodiments of the present application, in the embodiments of the present application, the words "first", "second", etc. are used to distinguish the same item or similar items having substantially the same function and effect. It will be appreciated by those of skill in the art that the words "first," "second," and the like do not limit the amount and order of execution, and that the words "first," "second," and the like do not necessarily differ.

The technical solution of the embodiment of the present application may be applied to various communication systems, such as a wireless fidelity (wireless fidelity, wiFi) system, a vehicle-to-object (vehicle to everything, V2X) communication system, an inter-device (D2D) communication system, a vehicle networking communication system, a fourth generation (4th generation,4G) mobile communication system, such as a long term evolution (long term evolution, LTE) system, a worldwide interoperability for microwave access (worldwide interoperability for microwave access, wiMAX) communication system, a 5G, such as a New Radio (NR) system, a future communication system, and the like.

The present application will present various aspects, embodiments, or features about a system that may include a plurality of devices, components, modules, etc. It is to be understood and appreciated that the various systems may include additional devices, components, modules, etc. and/or may not include all of the devices, components, modules etc. discussed in connection with the figures. Furthermore, combinations of these schemes may also be used.

In addition, in the embodiments of the present application, words such as "exemplary," "for example," and the like are used to indicate an example, instance, or illustration. Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, the term use of an example is intended to present concepts in a concrete fashion.

The network architecture and the service scenario described in the embodiments of the present application are for more clearly describing the technical solution of the embodiments of the present application, and do not constitute a limitation on the technical solution provided by the embodiments of the present application, and those skilled in the art can know that, with the evolution of the network architecture and the appearance of the new service scenario, the technical solution provided by the embodiments of the present application is applicable to similar technical problems.

To facilitate understanding of the embodiments of the present application, a communication system suitable for use in the embodiments of the present application will be described in detail with reference to the communication system shown in fig. 1. Fig. 1 is a schematic diagram of a communication system to which the communication method according to the embodiment of the present application is applicable.

As shown in fig. 1, the communication system mainly includes: a terminal device (which may be referred to as a terminal) and a network apparatus (which may also be referred to as a network device).

The terminal device may be a terminal device with a transceiver function, or a chip system that may be disposed in the terminal device. The terminal device may also be referred to as a User Equipment (UE), an access terminal, a subscriber unit (subscriber unit), a subscriber station, a Mobile Station (MS), a remote station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment. The terminal device in the embodiment of the present application may be a mobile phone (mobile phone), a cellular phone (cellular phone), a smart phone (smart phone), a tablet (Pad), a wireless data card, a personal digital assistant (personal digital assistant, PDA), a wireless modem (modem), a handheld device (handset), a laptop computer (laptop computer), a machine type communication (machine type communication, MTC) terminal, a computer with a wireless transceiving function, a Virtual Reality (VR) terminal, an augmented reality (augmented reality, AR) terminal, a wireless terminal in an industrial control (industrial control), a wireless terminal in an unmanned aerial vehicle (self driving), a wireless terminal in a smart grid (smart grid), a wireless terminal in a transportation security (transportation safety), a wireless terminal in a smart city (smart city), a wireless terminal in a smart home (smart home), a terminal with a roadside unit (RSU), etc. The terminal of the present application may also be an in-vehicle module, an in-vehicle part, an in-vehicle chip, or an in-vehicle unit built in a vehicle as one or more parts or units.

The network apparatus may be a network device, such as AN Access Network (AN) device, or may be referred to as a radio access network device (radio access network, RAN) device. The RAN device may provide an access function for the terminal, and is responsible for radio resource management, quality of service (quality of service, qoS) management, data compression, encryption, and other functions on the air interface side. The RAN device may comprise a 5G, such as a gNB in an NR system, or one or a group of base stations (including multiple antenna panels) in the 5G, or may also be a network node, such as a baseband unit (building base band unit, BBU), or a Centralized Unit (CU) or a Distributed Unit (DU), an RSU with base station functionality, or a wired access gateway, constituting a gNB, a transmission point (transmission and reception point, TRP or transmission point, TP), or a transmission measurement function (transmission measurement function, TMF), or a core network element of the 5G. Alternatively, the RAN device may also include an Access Point (AP) in a wireless fidelity (wireless fidelity, wiFi) system, a wireless relay node, a wireless backhaul node, various forms of macro base stations, micro base stations (also referred to as small stations), relay stations, access points, wearable devices, vehicle devices, and so on. Alternatively, the RAN device may also include a next generation mobile communication system, such as a 6G access network device, such as a 6G base station, or in the next generation mobile communication system, the network device may also have other naming manners, which are covered by the protection scope of the embodiments of the present application, which is not limited in any way.

It will be appreciated that fig. 1 is a simplified schematic diagram that is merely illustrative for ease of understanding, and that other network devices, and/or other terminal devices, may be included in the communication system, not shown in fig. 1.

In some embodiments, the terminal device in the communication system may access, through the network device, a communication network (e.g., a 5G network) corresponding to the network device, so that the terminal device may enable various communication services based on the accessed communication network. The communication service may include a call service, for example. The 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 (e.g., a 6G communication system).

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

Wherein the above-mentioned terminal device 100 corresponds to the terminal device in fig. 1, and NG RAN101 corresponds to the network apparatus in fig. 1.

Illustratively, the NG RAN101 may include at least one node device, such as a Base Station (BS). It will be appreciated that the base station may be a device capable of communicating with a terminal device or other communication site (e.g., a relay site), and that the base station may provide communication coverage for a particular physical area. For example, the base station may be specifically a base transceiver station (Base Transceiver Station, abbreviated BTS) or a base station controller (Base Station Controller, abbreviated BSC) in GSM or CDMA; or may be a Node B (NB, abbreviated as Node B) in UMTS or a radio network controller (Radio Network Controller, abbreviated as RNC) in UMTS; an evolved base station (Evolutional Node B, abbreviated eNB or eNodeB) in LTE; but also the next generation base station (next generation Node B, abbreviated as gNB) in 5G NR; alternatively, the present invention is not limited to the present invention, and other access network devices providing access services in the wireless communication network may be used.

In the case where the ngnb is included in the NG RAN101, after the terminal device 100 establishes a connection with the gcb in the NG RAN101, the terminal device 100 may communicate with the gcb using a New Radio (NR) access technology, so that communication between the terminal device 100 and the gcb may be performed through an NR link, which may also be referred to as accessing the NG RAN101 by the terminal device 100.

Also illustratively, the 5GC102 described above is used for exchanging, forwarding, continuing, routing data. The network elements in 5GC are functional virtual units, which may include, but are not limited to: a unit (access and mobility management function, AMF) for access and mobility management functions, a unit (session management function, SMF) for session management functions, a network element (unified data management, UDM) for unified data management, etc.

In some embodiments, a Stand Alone (SA) networking mode may be employed between NG RAN101 and 5GC 102. It can be appreciated that in the SA networking mode, both NG RAN and 5GC are built based on the 5G technology, and the low latency experience is better. In the subsequent embodiments, the communication network consisting of NG RAN and 5GC may also be referred to as a 5G system. In other embodiments, the networking mode between the NG RAN101 and the 5GC102 may also be a non-independent (NSA) networking, which is not limited in the embodiment of the present application.

Also illustratively, the IMS103 is configured to manage IP packets formed by encapsulating multimedia data such as voice and video, and distinguish a signaling portion and a multimedia data portion of the IP packets, and transmit the multimedia data portion of the IP packets between the terminal device 100 and a called end of a call, so that the IMS103 can provide audio and video services to the terminal device 100. The IMS103 may mainly include call session control function entities (call session control function, CSCF) and home subscriber servers (home subscriber server, HSS). The CSCF is used to control signaling, authentication, control sessions in coordination with other network entities, etc. during the multimedia call session. The HSS is used to manage user data.

As shown in fig. 2, communication between the 5G system and the IMS103 is possible. Thus, after the terminal device 100 accesses the NG RAN101, a communication connection with the IMS103 can be established through the NG RAN101 and the 5GC 102.

In some embodiments, after the terminal device 100 accesses the 5G system composed of the NG RAN101 and the 5GC102 through the NG RAN101, the terminal device 100 may initiate a call to other terminals through the IMS103 using various voice solutions, and perform audio and video communication after the other terminals answer the call. Among these, the above VoNR is one of the alternative voice solutions.

It will be appreciated that after the 5G system is connected to the IMS103, the 5G system may package the multimedia data in the process of initiating a call and communication from the terminal device 100 to other terminals into IP packets, and transmit the IP packets to the other terminals through the IMS 103. That is, the 5G system is capable of providing IMS-based audio and video services over a circuit switched (PS) session, for example, control plane signaling (IMS signaling) and user plane data (IMS traffic) generated during a call between the terminal device 100 and other terminal devices are packaged into IP packets, and the IP packets are transmitted between the terminal device 100 and other terminals being called through the IMS 103.

In some embodiments, other terminal devices being called (e.g., terminal device 106 in fig. 2) also need to establish a connection with IMS103 via the accessed communication network during the call.

As shown in fig. 2, the communication system may further include a terminal device 106, NG RAN105, and 5GC104. In the scenario shown in fig. 2, the terminal device 106 may establish a connection with the IMS103 through a 5G system consisting of NG RAN105 and 5GC104.

The terminal device 106 is a different device than the terminal device 100, and of course, the terminal device 106 is similar to the terminal device 100, including a smart terminal (e.g., a mobile phone, etc.), a desktop, a laptop, a tablet, a handheld computer, a notebook, an Ultra-mobile personal computer (UMPC), a netbook, a cellular phone, a personal digital assistant (Personal Digital Assistant, PDA), a television, a VR device, an AR device, etc. having communication capabilities, and can be connected to various communication systems.

Similarly, the NG RAN105 and the 5GC104 may adopt an SA networking mode or an NSA networking mode.

It will be appreciated that the communication network to which the terminal device 106 has access may also be different in the case of different voice solutions, and embodiments of the present application are not limited in this regard.

Taking the terminal device 100 as a calling device (i.e., a terminal that initiates a call), and the terminal device 106 as a called device (i.e., a device that listens to the call), the procedure in which the terminal device 100 actively initiates a VoNR call to the terminal device 106 is described:

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

(2) The terminal device 100 transmits call request information, which carries an identification (e.g., a telephone number) of the terminal device 106, to the 5GC102 through the NG RAN 101. Wherein the identity of the terminal device 106 may be used to instruct the IMS103 to page the terminal device 106.

(3) After the 5GC102 receives the call request information from the terminal device 100, a response message may also be sent to the terminal device 100 by the NG RAN101, indicating that the 5GC102 is handling the caller initiated by the terminal device 100. In addition, the 5GC102 may also send call request information to the terminal device 106 through the IMS103 to page the terminal device 106.

(4) After the 5GC102 receives the call request information from the terminal device 100, the 5GC102 may also establish a quality of service (Quality of Service, qos) flow for carrying session initiation protocol (session initiation protocol, SIP) signaling for the terminal device 100, and the 5G Qos identifier (5 QI) of the established Qos flow may be 5.

In addition, NG RAN101 may also set up a data radio bearer (Data Radio Bearer, DRB) for terminal device 100 to transport SIP signaling.

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

(6) After the terminal device 106 requests to establish an RRC connection with the NG RAN105, the 5GC104 may also establish a quality of service Qos flow for the terminal device 106 for carrying SIP signaling, and the 5QI of the established Qos flow may be 5.

In addition, NG RAN105 may also establish a DRB for terminal device 106 to transport SIP signaling.

(7) The terminal device 100 and the terminal device 106 perform SIP session negotiation, such as negotiating information of coding scheme, IP address, port number, etc., through the IMS 103.

(8) After the negotiation is completed, the 5GC102 may also establish Qos flows for the terminal device 100 to carry real-time transport protocol (real-time transport protocol, RTP) and for real-time transport control protocol (real-time transport control protocol, RTCP). In this step, the 5QI of the established Qos flow may be 1.

In addition, NG RAN101 may also establish DRBs for transmitting RTP and RTCP for terminal device 100.

(9) After the negotiation is completed, the 5GC104 may also establish Qos flows for the terminal device 106 to carry RTP and RTCP. The 5QI of the established Qos flow may be 1.

In addition, NG RAN105 may also establish DRBs for terminal device 106 to transport RTP and RTCP.

(10) Thereafter, the terminal device 106 may alert the user to the receipt 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 may transmit voice data through the corresponding 5G system and IMS103, and start a call.

In summary, through the above steps, before the call starts, the terminal device 100 and the terminal device 106 may respectively establish corresponding bearers, and then establish an IMS session based on the bearers. In the embodiment of the application, in the process of initiating the VoNR call, the established bearer comprises a default bearer and a special bearer. The default bearer includes a bearer corresponding to Qosflow of 5IQ5, and is used for carrying control signaling during call and talk. Also exemplary, the dedicated bearers include bearers corresponding to Qosflow of 5IQ1 for meeting Qos requirements of multimedia data transmitted between terminal device 100 and terminal device 106, e.g., voice packets and/or video streams for carrying media planes. The IMS session is used to transfer audio and video data during a call between terminal device 100 and terminal device 106. In this way, after the terminal device 106 makes an incoming call in response to a user operation, a VoNR call can be started between the terminal device 100 and the terminal device 106.

In addition, in the above embodiments, the procedure of the terminal device 100 for initiating a call is only described as an example, and in a specific implementation, the procedure includes more or less steps, which are not described herein. In addition, in other embodiments, the terminal device 106 may be a calling device, the terminal device 100 may be a called device, and the process of the terminal device 106 communicating with the terminal device 100 through the VoNR may refer to the foregoing embodiments, which are not described herein. In the following embodiments, the description will be given mainly taking 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 located within the service range of the NG RAN to request access to the NG RAN. Where the service range of the NG RAN may be determined by the signal coverage of node devices (e.g., 5G base stations) in the NG RAN. In addition, the service area of the NG RAN may be divided into at least one cell, such as what is referred to as an NG RAN cell. In case the NG RAN comprises a plurality of 5g base stations, there may be differences or overlaps in signal coverage of different 5g base stations. In addition, each cell of the NG RAN corresponds to the signal coverage of one 5G base station. The 5G base stations corresponding to different cells may be different or the same, which is not particularly limited. In the following embodiments, node devices in the NG RAN may be referred to collectively as network devices.

In addition, the above-mentioned accessing of the terminal device 100 to the NG RAN101 in the process of establishing the VoNR call may refer to accessing of the terminal device 100 to one NG RAN cell in the NG RAN101, so that the establishment of the RRC connection between the terminal device and the NG RAN may be that the terminal device establishes the RRC connection with the network device corresponding to the NG RAN cell.

Referring to fig. 3, in the process of initiating a VoNR call by a terminal device, the interaction situation with a network device is as follows:

a1, establishing RRC connection between the terminal equipment and the second network equipment.

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

For example, when the terminal device is located in a cell corresponding to a network device, the terminal device may be selectively accessed to the network device.

Taking fig. 4 as an example, cells corresponding to the second network device and the first network device are adjacent to each other, and there is an overlapping area between the two. It may be understood that the 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 is not specifically limited in the embodiment of the present application.

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

Also, for example, when the terminal device is located in the overlapping area of the cells corresponding to the plurality of network devices, signal quality of the plurality of network devices at the current location may be evaluated, and then, an optimal network device may be selected and accessed according to the signal quality. For example, the terminal device determines the signal quality of the radio signal from the second network device, better than the signal quality of the radio signal from the first network device, and determines to access the second network device.

Thus, in some embodiments, the terminal device may listen for radio signals from the network device in the context of the network device that needs to select access. Then, based on the detected radio signal, the signal quality corresponding to the network device that sent out the radio signal is evaluated. Then, the network equipment with the best signal quality is selected and accessed.

For example, the radio signal may be a synchronization signal and channel state information from a network device. After the radio signal is monitored, the reference signal received power (reference signal received power, RSRP), the received signal strength indicator (received signal strengthindicator, RSSI), the reference signal received quality (reference signal receiving quality, RSRQ) and the signal to interference plus noise ratio (signal to interference plus noise ratio, SINR) corresponding to the network device may be evaluated, and details of implementation may be referred to the related art and are not described herein. And then, evaluating the signal quality corresponding to the network equipment according to the value of one or more of the detected RSRP, RSSI, RSRQ and SINR.

In the following embodiments, the determination of accessing the second network device is described as an example.

In some embodiments, the terminal device may initiate an RRC connection request to the second network device, which may establish an RRC connection with the terminal device. For the specific procedure of establishing the RRC connection, reference may be made to the provisions in the relevant protocol, and will not be described here again.

A2, the second network device sends a configuration message 1 to the terminal device, wherein the configuration message 1 comprises the configuration of the first DRB in the second network device in the RLC layer.

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

Illustratively, the RRC layer is a higher 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 (e.g., non-access layers). For example, the RRC layer may be used for management of functions such as system message broadcasting, RRC connection control, mobility management, measurement configuration reporting, and the like. The RRC connection control management includes paging, establishing/modifying/suspending/resuming/releasing RRC connection, initial security activation, establishing/modifying/activating SRB/DRB, cell management in DC, CA modes, and radio link failure recovery, etc.

Also illustratively, the PDCP layer described above is used to process RRC messages on the control plane, and internet protocol (Internet Protocol, IP) packets on the user plane. Illustratively, on the user plane, after the PDCP layer obtains the IP data packet from the upper layer, the IP data packet may be header compressed and ciphered and then delivered to the RLC layer. The PDCP layer also provides sequential commit and duplicate packet detection functions to upper layers. In the control plane, the PDCP layer provides signaling transmission service for the upper RRC and realizes encryption and consistency protection of the RRC signaling and decryption and consistency check of the RRC signaling in the opposite direction.

Further exemplary, the RLC layer mainly provides radio link control functions, and provides services such as segmentation, retransmission control, and on-demand transmission for upper layers. The RLC layer includes 3 transmission modes, namely a Transparent Mode (TM), a non-acknowledged Mode (Unacknowledged Mode, UM) and an acknowledged Mode (Acknowledged Mode, AM), and mainly provides functions of error correction, segmentation, reassembly, etc.

In the TM mode, after receiving a message from PDCP (e.g., referred to as PDCP data), the RLC layer can directly transfer the message to the MAC layer without processing.

In the AM mode, PDCP data from the PDCP layer, RLC layer header information (which may also be referred to as RLC header information) is added through the RLC layer, and after being transmitted, a response from the peer device needs to be obtained, otherwise, it is considered that a data transmission abnormality occurs. Similarly, after receiving RLC data sent by the peer device in AM mode, 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, the terminal device and the network device that mutually communicate data may be mutually referred to as an opposite terminal device, and thus, the opposite terminal device of the network device may be a terminal device, and the opposite terminal device of the terminal device is a network device.

In UM mode, PDCP data from the PDCP layer adds RLC header information through the RLC layer, and after being sent out, does not need to get a response of the peer device. Also, after receiving RLC data transmitted by the peer device in UM mode, the peer device does not need to feed back a corresponding response. Thus, timeliness of data transmission is improved.

Still further exemplary, the MAC layer is configured to provide a mapping between logical channels and transport channels, multiplex RLC data from one or more logical channels into one transport block and pass to the PHY layer; demultiplexing the transport block transmitted from the PHY layer into a plurality of RLC data and transmitting to one or more logical channels; reporting scheduling information; error correction is carried out through HARQ; managing priorities among users through dynamic scheduling; logical channel priority management, etc.

The PHY layer provides the mechanical, electrical, functional and normative features for the physical links required to transmit data to be created, maintained, and torn down. The physical layer may be used to ensure that the original data may be transmitted over a variety of physical media.

In some embodiments, the NR wireless protocol stack may further include a protocol layer not shown in fig. 5, for example, a non-access (non access stratum, NAS) layer, a physical layer (PHY) layer, etc., which is not specifically limited in the embodiments of the present application.

It will be appreciated that the NR radio protocol stack of the terminal device may be configured in a communication chip. For example, it may be configured in a modem processor (modem) of the terminal device. Thus, the modem processor can process the data to be received and transmitted according to the specification of the NR wireless protocol stack.

In an exemplary scenario where the terminal device sends data to other devices, after receiving the data to be sent, the PDCP layer configured in the modem processor adds PDCP layer header information to the data according to a corresponding protocol, to obtain a PDCP protocol data unit (protocol data unit, PDU), and transfers the PDCP protocol data unit to the RLC layer. Then, the RLC layer adds RLC layer header information to the PDCP PDU (also referred to as PDCP data) according to a corresponding protocol to obtain an RLC PDU. Thereafter, the MAC layer may add MAC layer header information to each RLC PDU (also referred to as RLC data) to obtain a MAC PDU. One or more MAC PDUs are then combined according to the transport block size to obtain a MAC transport block protocol data unit (transport block PDU), also referred to as a data packet, and the PHY layer is instructed to send the MAC transport block PDU using the corresponding physical link.

Illustratively, in a scenario where the terminal device receives a data packet (MAC transport block PDU) from another device, the PHY layer in the modem processor may pass the data packet to the MAC layer. The MAC layer may split a plurality of MAC PDUs from the data packet, then parse the MAC layer header information of each MAC PDU, and acquire the data content carried in the MAC PDU, that is, the RLC PDU. Then, the MAC layer delivers the parsed RLC PDU to the RLC layer, and then the RLC layer parses RLC layer header information of the RLC PDU from the MAC layer and acquires data contents carried in the RLC PDU, that is, PDCP PDU. Then, the RLC layer delivers the parsed PDCP PDU to the PDCP layer, and the PDCP layer parses the PDCP PDU according to a 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 a configuration message 1, which may also be referred to as a third reconfiguration message, or as RRC reconfiguration message, to the terminal device. The configuration message 1 may include configuration parameters corresponding to a plurality of DRBs. The DRB is a bearer negotiated by the second network device with the corresponding core network for transferring data between the second network device and the terminal device. For example, the first DRB and the second DRB are configured to communicate traffic 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 may be different.

It will be appreciated that the configuration associated with a DRB may dictate the manner in which the layers of the NR radio protocol stack (e.g., PDCP layer, RLC layer, MAC layer, PHY layer, etc.) are processed for data to be transmitted through the DRB.

Illustratively, the RLC layer supports data transfer modes such as TM mode, UM mode, and AM mode. The second network device may configure the DRB in the RLC layer to be in TM mode, UM mode or AM mode.

For example, if the first DRB in the second network device is configured in AM mode in 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, resends the data a.

Correspondingly, the configuration related to the first DRB in the configuration message 1 includes an identification indicating the AM mode, a response waiting duration, the number of retransmissions in the AM mode, and the like. In this way, after the terminal device performs configuration according to the configuration message 1, the first DRB receives the communication service data from the second network device, and if the RLC layer header information of the communication service data is successfully analyzed, a corresponding response may be sent to the second network device.

In addition, after the terminal device sends the communication service data to the second network device by using the first DRB, if the corresponding response is not received within the response waiting time, the terminal device triggers retransmission of the communication service data. And if the number of times of retransmitting the communication service data reaches the retransmission number in the configuration message 1, judging that communication abnormality exists between the terminal equipment and the second network equipment.

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

It can be appreciated that, for the data to be sent by the first DRB or the second DRB, RLC layer header information (also referred to as RLC header information) may be added by the RLC layer, where the RLC header information includes a Sequence Number (SN) field, an SN number carried in the SN field may ensure that RLC PDUs are sent in sequence, and when retransmission is required, RLC PDUs that need to be retransmitted may be determined. The SN field of the RLC header information may also be referred to as an RLC SN field.

In addition, the RLC layer may split data (e.g., PDCP PDU) into a plurality of split data for convenient transmission. Illustratively, after one pdcp PDU is processed by the RLC layer, a plurality of split data may be obtained, and each split data may obtain a plurality of RLC PDUs after adding RLC header information. When the data carried by the plurality of RLC PDUs comes from the same PDCP PDU, the SN numbers in the RLC header information of the plurality of RLC PDUs have the same value.

According to protocol 38.311, "sn-FieldLength Indicates the RLC SN field size, see TS 38.322[4], in bits.value size6 means 6bits,value size12 means 12bits,value size18 means 18bits", the corresponding translations are: the "SN-FieldLength" in the network device may indicate the RLC SN field length, see TS 38.322 in detail, in bits. When the SN-field length value corresponding to the DRB is "size6", the SN field length of the DRB configured in the RLC layer is indicated to be 6bits, when the SN-field length value corresponding to the DRB is "size12", the SN field length of the DRB configured in the RLC layer is indicated to be 12bits, and when the SN-field length value corresponding to the DRB is "size18", the SN field length of the DRB configured in the RLC layer is indicated to be 18 bits.

It can be seen that the network device may configure the SN field length corresponding to each DRB in the RLC layer in advance by configuring the "SN-FieldLength" corresponding to each DRB. For example, the "SN-field length" corresponding to the first DRB (DRB in AM mode) or the second DRB (DRB in UM mode) is configured to be 12 bits, and after the RLC layer processes the data to be transmitted by the first DRB or the second DRB, the RLC layer header information with the SN field length of 12 bits is provided. Of course, the above-described procedure of configuring the "SN-FieldLength" may be referred to as configuring the SN field length at the RLC layer.

The length of the SN field configured by each DRB in the RLC layer in the terminal equipment is required to be consistent with the length of the SN field configured by the DRB in the RLC layer in the accessed network equipment.

Thus, in the configuration related to the DRB in AM mode or UM mode in the configuration message 1, the SN field length configured in RLC layer by the DRB in the network device may be further included. It is understood that the lengths of SN fields configured by different DRBs at the RLC layer may be different or the same.

In the following embodiments, implementation details of the embodiments of the present application will be described by taking the first DRB in AM mode as an example.

Thus, in some embodiments, the configuration message 1 may include a configuration of the first DRB at the RLC layer. In the subsequent embodiment, the configuration of the first DRB may include an SN field length of 12 bits, an identifier indicating an AM mode, a response waiting duration of t, and a number of retransmissions in the AM mode of N, where N is a positive integer, N may also be referred to as a first number of times, t is a positive value, and t may also be referred to as a first duration.

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

In summary, configuration message 1 may synchronize the configuration of the DRB between the terminal device and the second network device. For example, the terminal device and the second network device may synchronize processing methods of layers (e.g., PDCP layer, RLC layer, MAC layer, PHY layer, etc.), such as coding methods, decoding methods, transmission methods, etc., with respect to data to be transmitted by the same DRB.

In this way, after the terminal device receives the data packet from the second network device and identifies the DRB used for transmitting the data packet, the data packet can be accurately resolved in a matching manner. Similarly, after the second network device receives the data packet from the terminal device and identifies the DRB used for transmitting the data packet, the second network device can accurately analyze the data packet in a matching manner. And normal communication between the terminal equipment and the second network equipment can be realized.

In addition, the configuration message 1 may further include time-frequency resources, radio resource configuration, etc. that are required to be occupied by the second network device, which are not described herein.

And A3, the terminal equipment initiates a call through the second network equipment.

For example, the second network device in the 5G communication system initiates a VoNR call to other terminals, and details of implementation for establishing the VoNR call are referred to the foregoing embodiments and are not described herein. After the call is established, the flow proceeds to A4.

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

The call data may also be referred to as communication service data. In a possible embodiment, the call data may be call data sent based on 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 will be appreciated that signal attenuation occurs as the propagation distance increases during the propagation of the radio signal. Thus, the signal quality is different at different locations within the cell to which the network device corresponds. In addition, the cell to which the network device corresponds may also be subject to changes, for example, changes due to environmental factors, or changes due to operating power, etc.

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 may trigger the NG RAN cell mode of handover access, so as to ensure the communication quality. Of course, in the process of the terminal device performing the call by using the VoNR, if the access to the NG RAN cell is switched, and the connected network device is changed, there is a possibility that a call drop occurs (the call is interrupted), and the call quality is directly affected.

For example, during a VoNR call by a terminal device, there is a possibility that a call drop occurs when the terminal device is switched from one network device connected to an NG RAN to another network device connected to the NG RAN, or when the terminal device is switched from a network device connected to one NG RAN to a network device connected to another NG RAN.

As shown in fig. 7, after the user carries the terminal device into the overlapping area of the cells corresponding to the second network device and the first network device, if the second network device determines that the terminal device needs to be switched to the cell corresponding to the first network device, the user can access the first network device in a reconfiguration manner.

Illustratively, the manner of reconfiguration described above may be: the terminal device enables communication between the terminal device and the first network device by modifying the RRC connection.

Referring to fig. 8, the SN field length of the first DRB in the second network device configured at the RLC layer is 12 bits, and the SN field length of the first DRB in the first network device configured at the RLC layer is 18 bits. Under the condition that the terminal equipment initiates the VoNR call through the second network equipment, the length of an SN field configured by the first DRB in the RLC layer in the terminal equipment is 12 bits.

The procedure for switching the terminal device from the second network device to the first network device is as follows:

b1, the terminal equipment detects the neighbor cell.

And B2, the terminal equipment reports the neighbor detection report to the second network equipment.

In some embodiments, the terminal device may respond to the measurement event sent by the second network device, perform neighbor detection, and report a neighbor detection report to the base station if the corresponding condition is met. In this way, the second network device may instruct the terminal device to perform cell switching according to the neighbor cell detection report, or the terminal device autonomously performs cell switching.

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

The Event A3 (Event A3) is used for triggering the neighboring cells of the same network system to perform the same-frequency measurement, and when the reference signal received power (Reference Signal Receiving Power, RSRP) value of the neighboring cells is higher than the RSRP of the resident cell and the RSRP value of the neighboring cells exceeds the corresponding threshold, the neighboring cell detection report is uploaded.

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

Event B1 (Event B1) may be used to trigger measurement of a high priority inter-system cell. And uploading the neighbor detection report by the terminal under the condition that the RSRP of the neighbor is higher than the corresponding threshold.

Event B2 (Event B2) may be used to trigger measurements on the same or lower priority inter-system cells. And uploading the neighbor cell detection report by the terminal under the condition that the RSRP of the resident cell is lower than the corresponding threshold and the RSRP of the neighbor cells of the different systems is higher than the corresponding threshold.

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

In addition, the above neighbor cell detection report may also be referred to as neighbor cell detection report. Illustratively, signal quality corresponding to a plurality of accessible network devices is recorded in the neighbor detection report. The plurality of accessible network devices includes a second network device and a neighboring network device. In addition, the neighboring network device may be a device adopting the same network system as the second network device. In other embodiments, the terminal device may perform at least one neighbor detection under a preset condition. Illustratively, the preset conditions include at least one of:

(1) The terminal equipment is internally provided with detection periods, and the detection time point of each detection period is reached at the system time.

(2) The terminal device receives an operation of refreshing the network state indicated by the user.

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

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

Likewise, each time the terminal device generates a neighbor cell detection report, the neighbor cell detection report may be reported to the second network device. Similarly, the neighbor cell detection report records signal quality corresponding to a plurality of accessible network devices. The plurality of accessible network devices includes a second network device and a neighboring network device.

And B3, the second network equipment determines the first network equipment with better communication quality to be indicated to be accessed by the terminal equipment according to the neighbor cell detection report.

In an exemplary scenario, in which the second network device sends a measurement event to the terminal device, if the second network device receives a neighbor cell detection report corresponding to the measurement event, it is determined that the terminal device needs to be instructed to access a network device with better signal quality. Also, for example, in a scenario in which the second network device sends a measurement event to the terminal device, if the second network device receives a neighbor detection report corresponding to the measurement event, the same measurement event may be sent to the terminal device again, and the terminal device is instructed to perform neighbor detection again. After the second network device receives the neighbor detection report from the terminal device again, it can determine that the terminal device needs to be instructed to access the network device with better signal quality. That is, the second network device may send the same measurement event to the terminal device multiple times, and determine that the terminal device needs to be switched to other network devices after receiving the neighbor detection report corresponding to the high measurement event multiple times. Therefore, the opportunity of switching the NG RAN cell can be accurately identified, the cell switching without value is avoided, and the communication quality of the terminal equipment is ensured.

Still further exemplary, in a scenario in which the terminal device actively performs neighbor detection in response to a preset condition, the second network device may first determine whether the terminal device needs to switch a new network device, for example, determine, from a neighbor detection report, whether the signal quality of the second network device is lower than a first threshold value. And if the signal quality of the second network equipment is lower than the first threshold value, identifying that the scene condition triggering the terminal equipment to switch other network equipment is met currently.

In some embodiments, after determining that the terminal device needs to be switched to another network device, the second network device may further evaluate the target network device according to a plurality of dimensions, such as signal quality of a plurality of network devices in the neighbor detection report, a supported network system, and whether the second network device is adapted to the terminal device. For the specific evaluation process, reference may be made to the related art, and details thereof are not described herein. In addition, the target network device may be regarded as a network device with optimal communication quality that is accessible by the current terminal device, and in the subsequent embodiment, the target network device is taken as the first network device for example and described.

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

The above-mentioned switching request may indicate that the terminal device needs to be accessed, and at the same time, the switching request may also carry capability information of the terminal device.

And B5, the first network equipment feeds back a switching request confirmation message to the second network equipment, wherein the switching request confirmation message comprises configuration information corresponding to the first network equipment and does not contain the length of an SN field configured in the RLC layer aiming at the first DRB in the first network equipment.

In some embodiments, the first network device may send a handover request confirm message to the second network device in response to the handover request, assessing that the terminal device is accessible. In the current protocol, the length of the SN field configured by the first DRB at the RLC layer must be carried in the handover request acknowledgement message is not specified, so in a practical scenario, a part of the handover request acknowledgement message sent by the first network device to the second network device does not include the length of the SN field configured by the first DRB at the RLC layer.

B6, the second network device sends an RRC reconfiguration message 1 (including a handover indication, without the SN length configured in the RLC layer for the first DRB in the first network device) to the terminal device.

The RRC reconfiguration message 1 may also be referred to as RRC reconfiguration message. The RRC reconfiguration message 1 may be generated according to configuration information from the first network device. It may be understood that the configuration information from the first network device does not include the SN field length configured by the first DRB in the RLC layer, and the above RRC reconfiguration message 1 does not include the SN field length configured by the first DRB in the RLC layer in the first network device.

The handover indication 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 handover to a cell corresponding to the first network device, or referred to as instructing the terminal device to access the first network device.

And B7, the terminal equipment performs switching according to the RRC reconfiguration message 1.

It can be appreciated that the RRC reconfiguration message 1 contains a handover indication, belonging to a message with a synchronization function. Meanwhile, the RRC reconfiguration message 1 does not contain the length of the SN field where the first DRB is configured in the RLC layer. In this way, the terminal device does not modify the SN field length of the first DRB configured at the RLC layer even after accessing the first network device according to the RRC reconfiguration message 1, i.e. the terminal device continues to inherit the configuration result of the second network device for the SN field length of the first DRB at the RLC layer.

And B8, the terminal equipment sends an RRC reconfiguration complete message (indicating the completion of the switching) to the first network equipment.

The RRC reconfiguration complete message may also be referred to as RRC reconfiguration complete. In this way, the terminal device may start sending traffic data to the first network device.

And B9, the terminal equipment uses the first DRB of the AM mode to send the data packet 1 to the first network equipment, and the length of an SN field in the RLC header information of the data packet 1 is 12 bits.

In some embodiments, before the terminal device sends the data to the first network device, the corresponding DRB may be determined according to the QOSflow to which the data belongs. And then, according to the configuration of the DRB in each layer in the NR wireless protocol stack, encapsulating the data layer by layer to obtain a corresponding data packet, and transmitting the data packet to the first network equipment.

In this embodiment, the determined DRB is exemplified as the first DRB. As shown in fig. 9, in the terminal device, data 1 (e.g., PDCP status report) is obtained after the PDCP layer processing of the data to be transmitted through the first DRB. The PDCP layer may then transfer the data 1 to the RLC layer, which adds RLC header information to the data 1 according to the SN field length inherited from the second network device (e.g., 12 bits), so that the SN field length of the RLC header information is 12 bits in the resulting RLC data. After the encapsulation of the MAC layer, the packet 1 carrying the data 1 is obtained.

The MAC layer may then instruct the PHY layer to send the packet 1 to the first network device over the matched physical link. The SN field length of the RLC header information corresponding to the data 1 in the data packet 1 is 12 bits.

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

If the SN field length of the RLC layer configuration of the first DRB in the first network device is not equal to 12 bits, as shown in fig. 9, the flow proceeds to B10 if the SN field length of the RLC layer configuration of the first DRB in the first network device is 18 bits.

And B10, the first network equipment analyzes according to the length of the SN field of the RLC header information as 18 bits, and the analysis of the data packet 1 is abnormal.

In some embodiments, after the MAC layer of the first network device parses RLC data including data 1 from the data packet 1, the RLC data is transferred to the RLC layer, as shown in fig. 9, where the SN field configured by the first DRB in the RLC layer in the first network device is 18 bits in length. Thus, the RLC layer parses the data packet 1 transmitted through the above DRB according to the SN field length of 18 bits, that is, the RLC SN field actual length of 12 bits. Obviously, not only the accurate SN number but also the accurate RLC header information cannot be resolved, and the analysis abnormality of the packet 1 occurs.

In the case of an analysis anomaly of the data packet 1, the first network device does not send a response to the data packet 1 to the terminal device.

And the terminal equipment does not receive the response to the data packet 1 within the response waiting time corresponding to the first DRB, and can resend the data packet 1. When the number of times of retransmission of the packet 1 reaches the number of times of retransmission corresponding to the DRB, the flow proceeds to B11.

And B11, the terminal equipment sends an RRC reestablishment request to the first network equipment under the condition that the data packet 1 is sent for a plurality of times and no response is received.

In the case where the number of retransmissions configured by the first DRB in the RLC layer is N and the response waiting duration is t, the "sending the data packet 1 multiple times and not receiving the response" may be sending the data packet 1N times through the first DRB, and not receiving the response corresponding to the data packet 1 in the duration t after sending the data packet 1N times.

In addition, the above-mentioned RRC reestablishment request may also be referred to as RRC Reestablishment Request, for indicating to reestablish 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 flow proceeds to B12.

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

The RRC reconfiguration message 2 may be 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 an indication of handover, and the RRC reconfiguration message 2 does not have a synchronization function according to the specifications of the current protocol.

It can be appreciated that when a change occurs in a network device accessed by a terminal device, for example, when a cell corresponding to one network device is handed over from a cell corresponding to another network device, a handover instruction is included in an RRC reconfiguration message received by the terminal device.

And when the network equipment accessed by the terminal equipment is unchanged, the received RRC reconfiguration message does not contain a switching instruction. For example, after the terminal device has accessed the first network device and sends RRC reestablishment to the first network device, the RRC reconfiguration message 2 received by the terminal device does not include a handover instruction.

And B13, under the condition that the SN field length (18 bit) of the first DRB configured in the RLC layer carried by the RRC reconfiguration message 2 is not equal to the SN field length (12 bit) of the first DRB configured in the RLC layer in the terminal equipment, the terminal equipment sends an RRC reestablishment request to the first network equipment.

Among them, the protocol 38.311 specifies "The value of SN-FieldLength for a DRB shall be changed only using reconfiguration with sync. The network configures only value size in SN-FieldLengthAM for SRB", which translates to: the "sn-FieldLength" value corresponding to the DRB can only be changed by synchronous reconfiguration. The network configures only the value size12 for SRBs in SN-fieldlength am.

That is, the protocol specifies that the SN field length of the DRB in the RLC layer can only be changed by a reconfiguration message with a synchronization function (e.g., an RRC reconfiguration message carrying a handover indication) during the call traffic. Thus, according to the rule of the existing protocol, the RRC reconfiguration message 2 does not have a function of changing the SN field length of the first DRB configured in the RLC layer, but carries the SN field length of the first network device configured in the RLC layer for the first DRB, and the terminal device can trigger RRC reestablishment when the RRC reconfiguration message 2 is abnormal. For example, an RRC reestablishment request is sent to the first network device, i.e., RRC Reestablishment Request.

And B14, the first network equipment sends bye information to the terminal equipment, and the terminal equipment is instructed to end the call.

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

It will be appreciated that prior to B12, the first network device may negotiate with the core network to determine a plurality of DRBs for use in transmitting traffic data between the first network device and the terminal device. The plurality of DRBs includes a first DRB. After negotiation, the first network device sends an RRC reconfiguration message 2 to the terminal device, where the RRC reconfiguration message 2 includes the configuration of the plurality of DRBs in the first network device, for example, includes the length of the SN field where the first DRB is configured in the RLC layer. However, since the SN field length of the first DRB configured in the RLC layer carried in the RRC reconfiguration message 2 is different from the SN field length of the first DRB of the terminal device itself configured in the RLC layer, and the RRC reconfiguration message 2 does not have a synchronization function (e.g., does not include a handover indication), the terminal device may determine that the RRC reconfiguration message 2 does not conform to the protocol specification, and may not send an RRC reconfiguration complete message to the first network device.

In case that the RRC reconfiguration complete message is not fed back to the first network device, the terminal device sends the RRC reestablishment request to the first network device again. The first network device requests negotiation with the core network again in response to the RRC reestablishment request. Since the core network does not receive the last negotiation feedback of the DRB for the terminal device, when receiving the negotiation request again, the core network can be triggered to determine that the DRB between the first network device and the terminal device is abnormal (for example, the DRB is lost), and instruct the first network device to send bye information to the terminal device, and instruct the terminal device to end the call.

In order to improve the above-mentioned call drop problem, in the embodiment of the present application, if a terminal device is switched from one network device (e.g., a second network device) to access another network device (a first network device) during a VoNR call, the possibility of occurrence of the call drop problem may be reduced.

As shown in fig. 10, the SN field length of the first DRB configured at the RLC layer in the second network device is a first value. In this way, the RLC layer of the second network device generates the SN field length of the RLC header information for the data corresponding to the first DRB to be the first value, and when the RLC layer of the second network device analyzes the RLC header information of the data transmitted through the first DRB from another device, the RLC layer analyzes the RLC header information according to the RLC header information to be the first value.

Also, the SN field length configured by the first DRB in the RLC layer in the first network device is a second value. Thus, 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. When the RLC layer of the first network device analyzes RLC header information of data transmitted by another device using the first DRB, the RLC layer analyzes the RLC header information as a second value. In addition, the cells corresponding to the second network device and the first network device are adjacent cells.

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

s101, the terminal equipment establishes a VONR call through the second network equipment.

In some embodiments, before S101, a connection may be established between the terminal device and the second network device, and 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, where the specific implementation procedure may refer to A1 and A2 in the foregoing embodiments. The configuration message 1 includes that the SN field length of the first DRB configured in the RLC layer of the second network device is a first value, so that after the terminal device is configured based on the configuration message 1, data that needs to be transmitted through the first DRB is processed by the RLC layer, and the SN field length of the RLC header information is the first value.

In addition, the implementation process of S101 may refer to A3 in the foregoing embodiment, which is not described herein. In this embodiment, the terminal device may initiate the VONR call during access to the second network device. And in the call process, the terminal equipment uses the third data sent by the first DRB to the second network equipment, wherein the SN field length of the RLC header information of the third data is a first value. Then, the flow advances to S102.

S102, the terminal equipment detects the neighbor cell.

In some embodiments, in the case that the terminal device accesses the second network device, the terminal device may actively trigger to perform neighbor detection, or may be triggered by the second network device to perform neighbor detection. In addition, the method of triggering the 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 are not described herein again.

In addition, under the preset condition, the terminal equipment can continuously perform multiple neighbor cell detection or perform multiple neighbor cell detection at intervals with specified duration under the scene of triggering multiple neighbor cell detection. After each time of neighbor detection, a corresponding neighbor detection report, which may be referred to as neighbor detection report, may be generated. Illustratively, the neighbor detection report has recorded therein signal qualities of a plurality of access network devices. The plurality of access network devices may include a second network device and access network devices corresponding to the neighboring cells, for example, the plurality of access network devices may include the second network device and the first network device.

Therefore, whether the user carries the scene that the terminal equipment moves or the signal quality of the second network equipment is influenced by factors such as self or environment, the terminal equipment can timely and accurately identify the degradation of the communication service quality provided by the second network equipment and timely trigger the subsequent network equipment switching flow.

S103, the terminal equipment sends a neighbor cell detection report to the second network equipment.

In some embodiments, the implementation details of S103 may refer to step B2 in the foregoing embodiments, which is not described herein.

And S104, the second network equipment determines that the first network equipment needs to be switched according to 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 to be cut into by the terminal device.

The second network device evaluates the target network device according to a plurality of dimensions, such as signal quality of a plurality of network devices in the neighbor cell detection report, supported network system, whether the second network device is adapted to the terminal device, and the like. For the specific evaluation process, reference may be made to the related art, and details thereof are not described herein. In the following embodiments, description will be made mainly taking the determined target network device as the first network device as an example.

S105, the second network device sends a handover request to the first network device.

The above-mentioned handover request may be referred to as a handover request, and details of implementation of S105 may be referred to B4 in the above-mentioned embodiment, which is not described herein.

S106, the first network device feeds back a switching request confirmation message to the second network device, wherein the switching request confirmation message comprises configuration information corresponding to the first network device and does not contain the length of an SN field configured in the RLC layer aiming at the first DRB in the first network device.

In some embodiments, details of implementation of S106 may refer to B5, which is not described herein.

It may be appreciated that in the current protocol, the SN field length of the first DRB configured in the RLC layer must be carried in the handover request acknowledgement message sent by the first network device to the second network device, which is not specified in the current protocol.

In some embodiments, after receiving the handover request acknowledgement message of the first network device, the second network device may generate a corresponding RRC reconfiguration message (RRC reconfiguration message), such as the RRC reconfiguration message 3, and the flow proceeds to S107.

In some embodiments, the implementation details of S105 and S106 may refer to a scheme of cell switching of the terminal device in the related art, which is not described herein.

S107, the second network device sends an RRC reconfiguration message 3 to the terminal device, including the handover indication, and without 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 (e.g., referred to as a second reconfiguration message) is used to instruct the terminal device to handover from the cell of the second network device to the cell corresponding to the first network device by modifying the RRC connection, which may also be referred to as accessing the first network device. For example, the handover instruction carries information such as a center frequency point of a cell corresponding to the first network device. In this embodiment, the RRC reconfiguration message 3 does not include "the SN field length of the first DRB configured in the RLC layer in the first network device is the second value".

S108, the terminal equipment performs switching according to the RRC reconfiguration message 3.

In some embodiments, the terminal device reconfigures the radio resource (e.g., the communication link corresponding to VoNR) according to the RRC reconfiguration message 3, so that the terminal device may access the first network device and perform data interaction.

Of course, in this embodiment, the RRC reconfiguration message 3 has a synchronization function, but does not include "SN field length of the first DRB in the RLC layer in the first network device". The terminal device uses the RRC reconfiguration message 3, and after modifying the RRC connection, the SN field length configured by the first DRB in the RLC layer in the terminal device is not modified. Thus, the SN field length actually configured by the first DRB in the RLC layer in the terminal device 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 complete message (indicating handover complete) to the first network device.

The RRC reconfiguration complete message may also be referred to as RRC reconfiguration complete.

In some embodiments, after the terminal device accesses the first network device according to the RRC reconfiguration message 3, an RRC reconfiguration complete message may be sent to the first network device, and then data transfer may be performed between the terminal device and the first network device.

It can be appreciated that the terminal device does not interrupt the ongoing VoNR call service during the access to the first network device by means of reconfiguration. After the reconfiguration is completed, the terminal device may send service data corresponding to the VoNR call through the first network device. For example, a PDCP status report is sent to test whether normal communication is possible after accessing the first network device.

S110, the terminal equipment sends a data packet 2 to the first network equipment through a first DRB of an AM mode, wherein the SN field length of the RLC header in the data packet 2 is a first value.

The implementation details of S110 may refer to B9 in the foregoing embodiment, and are not described herein. Both the data packet 2 and the data packet 1 refer to communication service data to be transmitted through the first DRB, and are not described herein. The data packet 2 may be first data.

S111, the first network device analyzes the RLC header information in the data packet 2 according to the SN field length as a second value, wherein the first network device analyzes the abnormality when the first value is different from the second value.

It can be appreciated that the SN field length of the first DRB in the RLC layer configuration in the first network device is a second value, i.e. the SN field length of the first DRB in the RLC layer configuration is a second value. Thus, after the first network device receives the data packet 2 transmitted through the first DRB, the RLC layer of the first network device parses RLC header information in the data packet 2 according to the RLC SN field length as the second value.

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

In practical applications, the first network device does not feed back a response to RLC data (e.g., PDCP status report, real-time video stream, etc.) sent by a DRB (e.g., DRB carrying IMS signaling) in AM mode, which has an exception (e.g., data that the first network device cannot accurately parse).

It can be appreciated that the first DRB is also configured with the number of retransmissions (N) and the response waiting duration (t) at the RLC layer. The response waiting duration (t) refers to the length of time for waiting for the peer device to feed back the response after sending data through the first DRB each time.

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

The number of retransmissions (N) refers to the maximum number of retransmissions of the same data via the first DRB.

For example, after the ith retransmission of the data packet 2 through the first DRB, the value of i is a positive integer smaller than N, and no response fed back by the first network device is received within the duration t, and the (i+1) th retransmission of the data packet 2 is triggered. After retransmitting the data packet 2 through the first DRB for the nth time, the response fed back by the first network device is not received within the time period t, and it is determined that an abnormality occurs, and the flow may proceed to S112.

In other embodiments, the first network device may accurately parse the data packet from the terminal device and obtain the data content carried by the data packet when the first value is the same as the second value. 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, and in addition, the subsequent flow steps do not need to be executed.

And S112, the terminal equipment sends an RRC reestablishment request to the first network equipment under the condition that the data packet 2 is sent for a plurality of times and no response is received.

In some embodiments, the retransmission may be triggered by the data packet 2 sent by the first DRB, and the response corresponding to the data packet 2 is not received within the response waiting duration corresponding to the first DRB. When the number of times of retransmitting the data packet 2 reaches the retransmission number N corresponding to the first DRB and the response of the data packet 2 is not received, the terminal device may determine that there is an abnormality in communication with the first network device. In this scenario, the terminal device may send an RRC reestablishment request (RRC Reestablishment Reques) to the first network device, indicating that an RRC connection is reestablished between the terminal device and the first network device. That is, the above-mentioned "transmitting the data packet 2 a plurality of times and not receiving the response" may mean that the data packet 2 is transmitted N times and the corresponding response is not received within the time period t after each transmission.

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

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

The RRC reconfiguration message 4 may be RRC reconfiguration message. In addition, the RRC reconfiguration message 4 does not have a synchronization function, but the RRC reconfiguration message 4 carries the SN field length configured by the first DRB in the RLC layer in the first network device to be a second value, which may also be referred to as carrying the first indication information. The above RRC reconfiguration message 4 may be referred to as a first reconfiguration message.

And S114, under the condition that the second value is not equal to the first value in the call process, the terminal equipment configures the SN field length corresponding to the first DRB in the RLC layer as the second value.

In the embodiment of the present application, after receiving the RRC reconfiguration message 4 from the first network device, the terminal device modifies the SN field length configured by the first DRB in the RLC layer to the second value according to the RRC reconfiguration message 4 even if the RRC reconfiguration message 4 does not have a synchronization function (e.g., is not an RRC reconfiguration message carrying a handover indication). The above process is not consistent with the current protocol, but the terminal device may ignore the problem that the length of the SN field modified at this time is not compliant.

After the length of the SN field configured by the RLC layer in the terminal equipment is a second value, the first DRB needs to transmit communication service data through the first DRB, and after the communication service data is processed by the RLC layer, the length of the SN field of the obtained RLC header information is configured to be the 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 equally 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.

And then, the SN field length of the RLC header information of the data to be transmitted through the first DRB in the terminal equipment is a second value, and normal communication can be performed between the terminal equipment and the first network equipment. When the terminal equipment modifies the SN field length configured by the first DRB in the RLC layer, the terminal equipment does not trigger to send the RRC reestablishment request to the first network equipment again, but sends an RRC reconfiguration completion message after the modification is completed, so that the core network corresponding to the first network equipment is prevented from misjudging that the data bearing is lost, the call drop frequency is reduced, and the communication service quality is improved.

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

In some embodiments, the steps performed by the terminal device may be processed by a modem process

The above S101 may be exemplarily performed by a call request module in the terminal device. The above S102 to S103 may be performed by a PHY layer in the terminal device. The above S108 to S109 may be performed by an RRC layer in the terminal device. S110 may be cooperatively performed by a PDCP layer, an RLC layer, a MAC layer, a PHY layer, and the like in the terminal device. S112 may be performed by an RRC layer in the terminal device. S114 may be performed by the RLC layer in the terminal apparatus. S115 may be performed by the RLC layer in the terminal apparatus.

In some embodiments, the process of the terminal device executing the above method may be as follows: using a first DRB to send first data to a first network device, wherein the SN field length of the RLC header information of the first data is a first value; under the condition that the terminal equipment does not receive a response returned by the first network equipment for the first data, sending a reestablishment request to the first network equipment; receiving a first reconfiguration message from the first network device, wherein the first reconfiguration message carries first indication information, and the first indication information is used for indicating that the length of an SN field configured by the first DRB in the RLC layer in the first network device is a second value; and sending a reconfiguration complete message to the first network device if the first value is not equal to the second value. And after the reconfiguration completion message is sent, using the first DRB to send second data to the first network equipment, wherein the SN field length of the RLC header information of the second data is a second value, and the second data and the first data carry the same data content.

In other possible embodiments, as shown in fig. 11, the above communication method may further include:

s201, the terminal equipment establishes the VONR call through the second network equipment.

S202, the terminal equipment detects the neighbor cell.

And S203, the terminal equipment sends a neighbor detection report to the second network equipment.

S204, the second network equipment determines that the first network equipment needs to be switched according to the neighbor cell detection report.

S205, the second network device sends a handover request to the first network device.

S206, the first network device feeds back a switching request confirmation message to the second network device, wherein the switching request confirmation message comprises configuration information corresponding to the first network device and does not contain the length of an SN field configured in the RLC layer for the first DRB in the first network device.

S207, the second network device sends an RRC reconfiguration message 3 to the terminal device, including the handover indication, and without the SN length configured in the RLC layer for the first DRB in the first network device.

The implementation details of S201 to S207 may refer to S101 to S107 in the foregoing embodiments, and are not described herein.

And S208, the terminal equipment determines that the SN field length configured in the RLC layer for the first DRB in the first network equipment is a second value according to the historical record data.

In some embodiments, after the terminal device accesses any network device, the configuration situation of each DRB in the accessed network device may be recorded, so as to obtain the history record data.

Thus, when the terminal device has accessed the first network device and records the configuration of each DRB in the first network device, the history data can inquire that the SN field length configured by the first network device in the RLC layer for the first DRB is a second value.

In some embodiments, after receiving the RRC reconfiguration message 3, the terminal device determines, according to the content carried in the handover indication, to instruct the terminal device to handover to the cell corresponding to the first network device. The terminal device may then determine that the history data includes a second value corresponding to the first network device.

Illustratively, the terminal device determining that the second value is included in the history data may include: after receiving the RRC reconfiguration message 3, it is determined that the SN field length configured by the first network device at the RLC layer for the first DRB is not included in the RRC reconfiguration message 3. Then, the terminal device may query in the history data according to the identifier of the first network device, and determine that the SN field length configured by the first network device in the RLC layer for the first DRB is a second value, and the flow proceeds to S209.

S209, in the case that the first value is different from the second value, the terminal device performs handover 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.

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, may be referred to as accessing the first network device. And then, according to a second value inquired from the historical record data, modifying the SN field length configured by the terminal equipment in the RLC layer aiming at the first DRB from the first value to the second value so as to realize synchronization with the first network equipment.

S210, the terminal equipment sends an RRC reconfiguration complete message to the first network equipment.

S211, the terminal equipment sends a data packet 3 to the first network equipment through the first DRB of the AM mode, wherein the SN field length of the RLC header in the data packet 3 is a second value.

In some embodiments, the implementation details of S210 and S211 may refer to S109 and S110 in the foregoing embodiments, which are not described herein. The above-described data packet 3 may also be referred to as second data.

In addition, in some embodiments, the modification of the SN field length of the first DRB configured in the RLC layer from the first value to the second value in S209 may be performed after S210 and before S211, which is not specifically limited in the embodiments of the present application.

S212, the first network device analyzes the RLC header information in the data packet 3 according to the SN field length as the second value.

In some embodiments, the first network device determines that the data packet 3 is from a DRB in AM mode, and after successfully parsing out the data packet 3, the flow 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 realizes synchronization of the SN field length of the RLC layer with the first network device by using the history data, so that an anomaly in the call process, for example, silence in the call, triggering RRC reestablishment, is avoided, and the probability of occurrence of call anomaly is reduced.

In other embodiments, as shown in fig. 12, the method may further include:

s301, the terminal equipment establishes a VONR call through the second network equipment.

S302, the terminal equipment detects the neighbor cell.

S303, the terminal equipment sends a neighbor cell detection report to the second network equipment.

S304, the second network equipment determines that the first network equipment needs to be switched according to the neighbor cell detection report.

S305, the second network device sends a handover request to the first network device.

S306, the first network device feeds back a switching request confirmation message to the second network device, wherein the switching request confirmation message comprises configuration information corresponding to the first network device and does not contain the length of an SN field configured in the RLC layer for the first DRB in the first network device.

S307, the second network device sends an RRC reconfiguration message 3 to the terminal device, including the handover indication, and without the SN length configured in the RLC layer for the first DRB in the first network device.

S308, the terminal equipment performs switching 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 equipment sends a data packet 2 to the first network equipment through a first DRB of an AM mode, wherein the SN field length of the RLC header in the data packet 2 is a first value.

The data packet 2 may be referred to as first data.

S311, the first network device analyzes the RLC header information in the data packet 2 according to the SN field length as the second value, wherein the first network device analyzes the exception when the first value is different from the second value.

In some embodiments, the RLC data parsed by the first network device is inaccurate if the first value is different from the second value. 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 that no response is received from the first network device, the terminal device may determine that the history data includes a second value corresponding to the first network device. Illustratively, the manner of determining that the history data includes the second value corresponding to the first network device may refer to S312.

S312, under the first condition, the terminal equipment determines the length of the SN field configured in the RLC layer by the first DRB in the first network equipment as a second value from the history data.

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

In some embodiments, L may be a pre-configured value, such as referred to as a second number. Taking the first DRB configured in the RLC layer as an example, the number of retransmissions is N and the response waiting duration is t, where N is a positive integer greater than 1, the L may be a positive integer value smaller than N, for example, L may be equal to N-1.

Thus, after the terminal device sends out the data packet 2, no response is received in the duration t, and the data packet 2 can be retransmitted through the first DRB. After retransmitting the data packet 2 through the first DRB for the L-th time, the corresponding response is not received in the time period t, and it is determined that the first condition is currently met.

In a possible embodiment, L may be equal to N, after retransmitting the data packet 2 through the first DRB for the L-th time, the corresponding response is not received within the time period t, and the terminal device may be configured to not initiate the RRC reestablishment request, and determine that the first condition is currently met.

In some embodiments, the determining, by the terminal device, that the SN field length configured by the first DRB in the RLC layer in the first network device is the second value may refer to S208 in the foregoing embodiment, which is not described herein.

S313, when the first value is not equal to the second value, the terminal device modifies the SN field length configured by the first DRB at the RLC layer to the second value.

And S314, the terminal equipment sends a data packet 4 to the first network equipment through the first DRB of the AM mode, wherein the SN field length of the RLC header in the data packet 4 is a second value.

The data content carried in the data packet 4 and the data packet 2 are the same, but the configured RLC header information is different in that the RLC SN field lengths are different. The data packet 4 may also be second data. Packet 2 and packet 4 carry the same data content, but the SN field length of the configured RLC layer header information is different.

S315, the first network device analyzes the RLC header information in the data packet 4 according to the SN field length as the second value.

And S316, the first network equipment sends a response corresponding to the data packet 4 to the terminal equipment.

Thus, by the method of not triggering RRC reestablishment, abnormal conversation caused by RRC reestablishment is avoided, and the call drop rate is reduced.

In other embodiments, as shown in fig. 13, the above communication method may further include:

s401, the terminal equipment establishes a VONR call through the second network equipment.

S402, the terminal equipment detects the neighbor cell.

S403, the terminal equipment sends a neighbor cell detection report to the second network equipment.

S404, the second network device determines that the second network device needs to be switched to the first network device according to the neighbor cell detection report.

S405, the second network device sends a handover request to the first network device.

S406, the first network device feeds back a handover request acknowledgement message to the second network device, where the handover request acknowledgement message includes a length of an 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 a handover indication and an SN length configured in the RLC layer for the first DRB in the first network device.

S408, the terminal equipment performs switching according to the RRC reconfiguration message 5.

S409, the terminal device sends RRC reconfiguration complete information to the first network device.

S410, the terminal equipment sends a data packet 5 to the first network equipment through the first DRB of the AM mode, wherein the SN field length in the RLC header of the data packet 5 is a second value.

Thus, the first network device can accurately and first parse the data packet 5, and send a response corresponding to the data packet 5 to the terminal device. Wherein the data packet 5 may be referred to as second data.

S411, the first network device analyzes the RLC header information in the data packet 5 according to the SN field length as the second value.

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

Fig. 14 is a schematic structural diagram of a terminal device according to an embodiment of the present application. The terminal device may be the terminal device 100, the terminal device 106, or the like mentioned in the above embodiments.

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

The sensor module 180 may include a pressure sensor, a gyroscope sensor, a barometric sensor, a magnetic sensor, an acceleration sensor, a distance sensor, a proximity sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, a bone conduction sensor, and the like.

It will be appreciated 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 illustrated, or certain components may be combined, or certain components may be split, or different arrangements of components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

The processor 110 may include one or more processing units, such as: the processor 110 may include an application processor (application processor, AP), a modem processor (modem), a graphics processor (graphics processing unit, GPU), an image signal processor (image signal processor, ISP), a controller, a memory, a video codec, a digital signal processor (digital signal processor, DSP), a baseband processor, and/or a neural network processor (neural-network processing unit, NPU), etc. Wherein the different processing units may be separate devices or may be integrated in one or more processors.

The controller may be a neural hub and command center of the terminal device. The controller can generate operation control signals according to the instruction operation codes and the time sequence signals to finish the control of instruction fetching and instruction execution.

A memory may also be provided in the processor 110 for storing instructions and data. In some embodiments, the memory in the processor 110 is a cache memory. The memory may hold instructions or data that the processor 110 has just used or recycled. If the processor 110 needs to reuse the instruction or data, it can be called directly from the memory. Repeated accesses are avoided and the latency of the processor 110 is reduced, thereby improving the efficiency of the system.

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

It should be understood that the connection relationship between the modules illustrated in this embodiment is only illustrative, and does not limit the structure of the terminal device. In other embodiments, the terminal device may also use different interfacing manners in the foregoing embodiments, or a combination of multiple interfacing manners.

The terminal device implements display functions through a GPU, a display screen 194, an application processor, and the like. The GPU is a microprocessor for image processing, and is connected to the display 194 and the application processor. The GPU is 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 change display information.

The display screen 194 is used to display images, videos, and the like. The display 194 includes a display panel. The display panel may employ a liquid crystal display (liquid crystal display, LCD), an organic light-emitting diode (OLED), an active-matrix organic light emitting diode (AMOLED), a flexible light-emitting diode (flex), a mini, a Micro-OLED, a quantum dot light-emitting diode (quantum dot light emitting diodes, QLED), or the like.

The terminal device may implement photographing functions through an ISP, a camera 193, a video codec, a GPU, a display screen 194, an application processor, and the like.

The ISP is used to process data fed back by the camera 193. For example, when photographing, the shutter is opened, light is transmitted to the camera photosensitive element (image sensor) through the lens, the optical signal is converted into an electric signal, and the camera photosensitive element transmits the electric signal to the ISP for processing, so that the electric signal is converted into an image visible to the naked eye. ISP can also optimize the noise, brightness and skin color of the image. The ISP can also optimize parameters such as exposure, color temperature and the like of a shooting scene. In some embodiments, the ISP may be provided in the camera 193.

The camera 193 is used to capture still images or video. The object generates an optical image through the lens and projects the optical image onto the photosensitive element. The photosensitive element may be a charge coupled device (charge coupled device, CCD) or a Complementary Metal Oxide Semiconductor (CMOS) phototransistor. The photosensitive element converts the optical signal into an electrical signal, which is then transferred to the ISP to be converted into a digital image signal. The ISP outputs the digital image signal to the DSP for processing. The DSP converts the digital image signal into an image signal in a standard RGB, YUV, or the like format. In some embodiments, the terminal device may include N cameras 193, N being a positive integer greater than 1.

The digital signal processor is used for processing digital signals, and can process other digital signals besides digital image signals. For example, when the terminal device selects a frequency bin, the digital signal processor is used to fourier transform the frequency bin energy, etc.

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

The NPU is a neural-network (NN) computing processor, and can rapidly process input information by referencing a biological neural network structure, for example, referencing a transmission mode between human brain neurons, and can also continuously perform self-learning. Applications such as intelligent cognition of terminal equipment can be realized through NPU, for example: image recognition, face recognition, speech recognition, text understanding, etc.

Referring to fig. 15, fig. 15 is a schematic structural diagram of a network device according to an embodiment of the present application. The network device may be any node device in the NG RAN in the above embodiments.

As shown in fig. 15, the network device may include: one or more processors 1401, memory 1402, a communication interface 1403, a transmitter 1405, a receiver 1406, a coupler 1407, and an antenna 1408. These components may be connected by a bus 1404 or other means, fig. 15 being an example of a connection via a bus. Wherein:

communication interface 1403 may be used for a network device to communicate with other communication devices, such as terminal device 100, 5gc 102, or other network devices. In particular, communication interface 1403 may be a 5G or future new air interface communication interface. Not limited to wireless communication interfaces, network devices may also be configured with a wired communication interface 1403 to support wired communications, e.g., a backhaul link between one network device and other network devices may be a wired communication connection.

In some embodiments of the application, the transmitter 1405 and the receiver 1406 may be considered as one wireless modem. The transmitter 1405 may be used to perform transmission processing on the signal output from the processor 1401. The receiver 1406 may be used to receive signals. In a network device, the number of transmitters 1405 and receivers 1406 may each be one or more. The antenna 1408 may be used to convert electromagnetic energy in a transmission line to electromagnetic waves in free space or to convert electromagnetic waves in free space to electromagnetic energy in a transmission line. The coupler 1407 may be used to split the mobile communication signal into multiple paths for distribution to multiple receivers 1406. It is appreciated that the antenna 1408 of the network device may 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. In particular, memory 1402 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state storage devices.

The memory 1402 may store an operating system (hereinafter referred to as a system) such as an embedded operating system uCOS, vxWorks, RTLinux. Memory 1402 may also store network communication programs that may be used to communicate with one or more additional devices, one or more terminal devices, and one or more network devices.

The processor 1401 may be used to read and execute computer readable instructions. In particular, processor 1401 may be configured to invoke programs stored in memory 1402.

It should be noted that the network device shown in fig. 15 is only one implementation manner of the embodiment of the present application, and in practical application, the network device may further include more or fewer components, which is not limited herein.

The embodiment of the application also provides a chip system which can be applied to the terminal equipment in the embodiment. The system-on-chip includes at least one processor and at least one interface circuit. The processor may be a processor in the terminal device described above. The processors and interface circuits may be interconnected by wires. The processor may receive and execute computer instructions from the memory of the terminal device via the interface circuit. The computer instructions, when executed by the processor, may cause the terminal device to perform the steps of the above embodiments. Of course, the system-on-chip may also include other discrete devices, which are not particularly limited in accordance with embodiments of the present application.

In some embodiments, it will be clearly understood by those skilled in the art from the foregoing description of the embodiments, for convenience and brevity of description, only the division of the above functional modules is illustrated, and in practical application, the above functional allocation may be implemented by different functional modules, that is, the internal structure of the apparatus is divided into different functional modules to implement all or part of the functions described above. The specific working processes of the above-described systems, devices and units may refer to the corresponding processes in the foregoing method embodiments, which are not described herein.

The functional units in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the embodiments of the present application may be essentially or a part contributing to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to perform all or part of the steps of the method described in the embodiments of the present application. And the aforementioned storage medium includes: flash memory, removable hard disk, read-only memory, random access memory, magnetic or optical disk, and the like.

The foregoing is merely a specific implementation of the embodiment of the present application, but the protection scope of the embodiment of the present application is not limited to this, and any changes or substitutions within the technical scope disclosed in the embodiment of the present application should be covered in the protection scope of the embodiment of the present application. Therefore, the protection scope of the embodiments of the present application shall be subject to the protection scope of the claims.

Claims

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.