Communication method and device

Abstract

The embodiment of the invention relates to a communication method and device, and relates to the technical field of communication. The method comprises the following steps: receiving a release message from a first access network device, wherein the release message is used for indicating that the release message is released to an inactive state by the first access network device; receiving a paging message from the second access network equipment in the inactive state, wherein the paging message is used for indicating the access network equipment initiating paging; and when it is determined that the access network device initiating paging is not the first access network device, sending a synchronization message to the second access network device, the synchronization message being used for indicating a request to access the second access network device. Therefore, the problem of paging failure can be avoided.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communication technology, and in particular, to a communication method and device. Background Art

[0002] In the fifth generation (5G) communication system, there are three radio resource control (RRC) states for terminal devices, namely RRC-connected state, RRC-idle state and RRC-inactive state. When the terminal device is in the RRC-inactive state, there is no RRC connection between the terminal device and the base station, and the base station does not release the context of the terminal device. However, the base station and the access and mobility management function (AMF) network element are still in the connected state. When the terminal device enters the RRC-inactive state, the AMF network element is not aware of it, and the terminal device service recovery delay is relatively small.

[0003] When the terminal device is in the RRC inactive state, the base station can page the terminal device through the radio access network (RAN), and when the terminal device is in the RRC idle state, the AMF network element can page the terminal device through the core network (CN). However, when the terminal device enters the RRC inactive state in a cell of a base station and then moves to the cell of another base station in the inactive state, there may be a problem of failure in paging the terminal device. Summary of the invention

[0004] The embodiments of the present application provide a communication method and apparatus, which solve the problem of possible failure of paging terminal equipment in the prior art.

[0005] In order to achieve the above purpose, the embodiment of the present application adopts the following technical solution:

[0006] In a first aspect, a communication method is provided, the method comprising: receiving a release message from a first access network device, the release message being used to indicate that the first access network device has released the device to an inactive state. In the inactive state, receiving a paging message from a second access network device, the paging message being used to indicate the access network device that initiated the paging. When it is determined that the access network device that initiated the paging is not the first access network device, sending a synchronization message to the second access network device, wherein the synchronization message is used to indicate a request to access the second access network device.

[0007] In the above technical solution, a release message is received from the first access network device, and a paging message is received from the second access network device in an inactive state. According to the release message and the paging message, it is identified whether the access network device that initiates the paging is the first access network device. If the access network device that initiates the paging is indicated by the paging message as the first access network device, it means that the link (Xn) interface between the first access network device and the second access network device is successfully established. If the access network device that initiates the paging is not indicated by the second identifier carried by the paging message as the first access network device, it means that there may be no Xn interface between the first access network device and the second access network device, or the establishment of the Xn interface may fail. At this time, a synchronization message is sent to the second access network device to request access to the second access network device. In this way, after accessing the second access network device, the core network network element directly sends the call message to the second access network device, and the second access network device initiates RAN paging, and there is no need to broadcast RAN paging through the first access network device, thereby avoiding the lack of Xn interface between the first access network device and the second access network device, or the failure to establish the Xn interface, resulting in paging failure. The technical solution avoids paging failure by identifying in advance that the RAN paging message cannot be normally transmitted between the first access network device and the second access network device, and sending a synchronization message to request access to the second access network device.

[0008] In a possible implementation of the first aspect, the release message includes a first identifier, the first identifier is used to indicate the first access network device, and the paging message includes a second identifier, the second identifier is used to indicate the access network device that initiates the paging. The method also includes: when the first identifier is different from the second identifier, determining that the access network device that initiates the paging is not the first access network device. In the above possible implementation, the first access network device that sends the release message can be identified by the first identifier in the release message, and the access network device that initiates the paging can be identified by the second identifier in the paging message. Therefore, it can be determined that the access network device that initiates the paging is not the first access network device based on whether the first identifier and the second identifier are the same, which provides a basis for identifying in advance that the RAN paging message cannot be transmitted normally between the first access network device and the second access network device, sending a synchronization message to request access to the second access network device, and thus avoiding paging failure.

[0009] In a possible implementation of the first aspect, the first identifier is the first data of the specified length at the specified position in the release message, and the second identifier is the second data of the specified length at the specified position in the paging message. In the above possible implementation, the position and length of the information indicating the first access network device in the release message and the position and length of the information indicating the access network device initiating the paging in the paging message can be known according to the protocol. Therefore, according to the first data of the specified length at the specified position in the release message being different from the second data of the specified length at the specified position in the paging message, it can be determined that the first identifier is different from the second identifier, thereby determining that the access network device initiating the paging is not the first access network device. In this way, a basis can be provided for identifying in advance that the RAN paging message cannot be transmitted normally between the first access network device and the second access network device, sending a synchronization message to request access to the second access network device, and avoiding paging failures.

[0010] In a possible implementation of the first aspect, the method further includes: receiving indication information, where the indication information is used to indicate a specified length. In the above possible implementation, the specified length is determined according to the indication information, so as to know whether the first data of the specified length at the specified position in the release message is the same as the second data of the specified length at the specified position in the paging message, thereby providing a basis for identifying in advance that the RAN paging message cannot be normally transmitted between the first access network device and the second access network device, sending a synchronization message to request access to the second access network device, and avoiding paging failure.

[0011] In a possible implementation of the first aspect, the indication information is located in a system information block from the first access network device. In the above possible implementation, the specified length is determined according to the indication information in the system information block from the first access network device, so as to know whether the first data of the specified length at the specified position in the release message is the same as the second data of the specified length at the specified position in the paging message, thereby providing a basis for identifying in advance that the RAN paging message cannot be normally transmitted between the first access network device and the second access network device, sending a synchronization message to request access to the second access network device, and avoiding paging failure.

[0012] In a possible implementation of the first aspect, the synchronization message includes a recovery message or a mobile registration message. In the above possible implementation, if the access network device that initiates the paging indicated by the paging message is not the first access network device, it means that there may be no Xn interface between the first access network device and the second access network device, or the Xn interface may fail to be established. At this time, a recovery message or a mobile registration message is sent to the second access network device to request access to the second access network device, so that the network device knows that the communication device is located in the cell of the second access network device, providing a basis for avoiding paging failure.

[0013] In a possible implementation of the first aspect, when it is determined that the access network device that initiated the paging is not the first access network device, a synchronization message is sent to the second access network device, including: when a specified number of paging messages are received, and the access network device that initiated the paging indicated by each paging message is not the first access network device, a synchronization message is sent to the second access network device; and / or, when the time period for receiving the paging message times out, and the access network device that initiated the paging indicated by the paging message is not the first access network device, a synchronization message is sent to the second access network device. In the above possible implementation, when a specified number of paging messages are received, and / or, when the time period for receiving the paging message times out, it can be estimated that the first access network device has initiated paging to the communication device. If the access network devices that initiated the paging are not the first access network device, then there may be no Xn interface between the first access network device and the second access network device or the establishment of the Xn interface fails. By sending a synchronization message to the second access network device when a specified number of paging messages are received and the access network device that initiates the paging indicated by each paging message is not the first access network device; and / or, when the time period for receiving the paging message times out and the access network device that initiates the paging indicated by the paging message is not the first access network device, sending a synchronization message to the second access network device, a basis is provided for identifying in advance that the RAN paging message cannot be normally transmitted between the first access network device and the second access network device, sending a synchronization message to request access to the second access network device, and avoiding paging failure.

[0014] In a possible implementation of the first aspect, the specified number of paging messages includes: paging messages received at all or part of the specified paging occasions in the paging cycle. In the above possible implementation, receiving the specified number of paging messages from the second access network device at all paging occasions in the paging cycle can receive multiple paging messages from the second access network device more quickly, thereby more quickly confirming whether the paging messages can be transmitted normally between the first access network device and the second access network device. Receiving the paging message from the second access network device at some of the specified paging occasions in the paging cycle can estimate that the first access network device has initiated paging to the communication device, and only receiving the paging message at some of the specified paging occasions can save power consumption. In this way, a basis is provided for identifying in advance that the RAN paging message cannot be transmitted normally between the first access network device and the second access network device, sending a synchronization message to request access to the second access network device, and avoiding paging failure.

[0015] In a second aspect, a communication device is provided, the device comprising: a first receiving unit, configured to receive a release message from the first access network device, the release message being used to indicate that the first access network device has released the device to an inactive state; a second receiving unit, configured to receive a paging message from the second access network device in an inactive state, the paging message being used to indicate an access network device that initiated the paging; and a processing unit, configured to send a synchronization message to the second access network device when the access network device that initiated the paging is not the first access network device, wherein the synchronization message is used to indicate a request to access the second access network device.

[0016] In a possible implementation of the second aspect, the release message includes a first identifier, the first identifier is used to indicate the first access network device, the paging message includes a second identifier, the second identifier is used to indicate the access network device that initiated the paging. The processing unit is also used to determine that the access network device that initiated the paging is not the first access network device when the first identifier is different from the second identifier.

[0017] In a possible implementation manner of the second aspect, the first identifier is first data of a specified length at a specified position in the release message, and the second identifier is second data of the specified length at the specified position in the paging message.

[0018] In a possible implementation manner of the second aspect, the first receiving unit is further used to receive indication information, where the indication information is used to indicate a specified length.

[0019] In a possible implementation manner of the second aspect, the indication information is located in a system information block from the first access network device.

[0020] In a possible implementation manner of the second aspect, the synchronization message includes a recovery message or a mobile registration message.

[0021] In a possible implementation of the second aspect, the processing unit is specifically used to send the synchronization message to the second access network device when a specified number of the paging messages are received and the access network device that initiates the paging indicated by each of the paging messages is not the first access network device; and / or, when the time period for receiving the paging message times out and the access network device that initiates the paging indicated by the paging message is not the first access network device, send the synchronization message to the second access network device.

[0022] In a possible implementation manner of the second aspect, the designated number of paging messages includes: the paging messages received at all or designated paging occasions in a paging cycle.

[0023] In a third aspect, a communication device is provided, the communication device comprising a processor and an interface circuit. The interface circuit is used to receive code instructions and transmit them to the processor. The processor is used to run the code instructions to execute the method provided in the first aspect or any possible implementation of the first aspect.

[0024] In a fourth aspect, a communication device is provided, the communication device comprising a processor and a memory, wherein the memory stores code instructions, and the processor is used to run the code instructions to execute the method provided in the first aspect or any possible implementation of the first aspect.

[0025] In a fifth aspect, a computer-readable storage medium is provided, which includes a computer program or instructions. When the computer program or instructions are run on a computer, the computer executes the method provided in the first aspect or any possible implementation of the first aspect.

[0026] According to another aspect of the present application, a computer program product is provided. When the computer program product is run on a computer, the computer is enabled to execute the method provided by the first aspect or any possible implementation manner of the first aspect.

[0027] It can be understood that any of the above-mentioned communication devices, computer-readable storage media or computer program products all use the above-mentioned communication method to implement the corresponding functions. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects of the corresponding communication method provided above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a wireless communication system provided in an embodiment of the present application;

[0029] Figure 2 A schematic diagram of a radio resource control state of a communication device provided in an embodiment of the present application;

[0030] Figure 3 A schematic diagram of a paging process of a communication device provided in an embodiment of the present application Figure 1 ;

[0031] Figure 4 A schematic diagram of a paging process of a communication device provided in an embodiment of the present application Figure 2 ;

[0032] Figure 5 A schematic diagram of a paging process of a communication device provided in an embodiment of the present application Figure 3 ;

[0033] Figure 6 A schematic diagram of a paging process of a communication device provided in an embodiment of the present application Figure 4 ;

[0034] Figure 7 A communication method according to an embodiment of the present invention is provided. Figure 1 ;

[0035] Figure 8 A schematic diagram of a first identification provided in an embodiment of the present application;

[0036] Fig. 9 A schematic diagram of a paging opportunity provided in an embodiment of the present application;

[0037] Fig.10 A communication method according to an embodiment of the present invention is provided. Figure 2 ;

[0038] Fig.11 A communication method according to an embodiment of the present invention is provided. Figure 3 ;

[0039] Fig.12 A schematic diagram of a communication device provided in an embodiment of the present application Figure 1 ;

[0040] Fig.13 A schematic diagram of a communication device provided in an embodiment of the present application Figure 2 . DETAILED DESCRIPTION

[0041] In the embodiments of the present application, "at least one" refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can represent: a, b, c, ab, ac, bc or abc, where a, b and c can be single or multiple. In addition, in the embodiments of the present application, words such as "first" and "second" do not limit the quantity and execution order.

[0042] In the embodiments of the present application, the words "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0043] In the embodiments of the present application, "information", "signal", "message", "channel" and "signaling" can sometimes be used interchangeably. It should be noted that when the distinction between them is not emphasized, the meanings to be expressed are matched. "of", "corresponding, relevant" and "corresponding" can sometimes be used interchangeably. It should be noted that when the distinction between them is not emphasized, the meanings to be expressed are matched. In addition, the " / " mentioned in the present application can be used to express an "or" relationship.

[0044] The embodiments of the present application will present various aspects, embodiments or features around a system that may include multiple devices, components, modules, etc. It should be understood and appreciated that each system may include additional devices, components, modules, etc., and / or may not include all devices, components, modules, etc. discussed in conjunction with the accompanying drawings. In addition, each embodiment may also be arranged and combined to form a complete solution.

[0045] For ease of understanding, the application scenarios and related technical terms of the embodiments of the present application are first introduced. The embodiments of the present application are mainly applicable to wireless communication systems. The wireless communication system can comply with the wireless communication standards of the third generation partnership project (3GPP), or can comply with other wireless communication standards, such as the wireless communication standards of the 802 series (such as 802.11, 802.15, or 802.20) of the Institute of Electrical and Electronics Engineers (IEEE).

[0046] Combine the following Figure 1 The wireless communication system is introduced. In the wireless communication system, devices can be divided into devices that provide wireless network services and devices that use wireless network services.

[0047] In one example, the equipment providing wireless network services refers to the equipment constituting the wireless communication network, which can be referred to as network equipment or network element, and the network element can be referred to as network element. Network equipment usually belongs to operators or infrastructure providers. Network equipment can be further divided into radio access network (RAN) equipment and core network (CN) network element. In the embodiment of the present application, RAN equipment is referred to as access network equipment.

[0048] Access network equipment is used to implement access-related functions. It can provide network access functions for authorized users in a specific area, and can determine transmission links of different qualities to transmit user data according to the user level, business requirements, etc. Access network equipment forwards control signals and user data between the terminal and the core network element. Access network equipment includes base stations (BS). Base stations are sometimes also called wireless access points (AP) or transmission reception points (TRP). Specifically, the base station can be a general node B (gNB) in the 5G new radio (NR) system and an evolutionary node B (eNB) in the 4G long term evolution (LTE) system. Depending on the physical form or transmission power of the base station, the base station can be divided into a macro base station or a micro base station. A micro base station is sometimes also called a small base station or a small cell.

[0049] The core network elements are mainly responsible for maintaining the subscription data of the mobile network and providing functions such as session management, mobility management, policy management and security authentication for the terminal. The core network elements include the user plane function (UPF), authentication server function (AUSF), access and mobility management function (AMF), session management function (SMF), network slice selection function (NSSF), network exposure function (NEF), network function repository function (NRF), policy control function (PCF), unified data management (UDM), unified data repository (UDR), and application function (AF). Among them, the AMF network element is mainly used for mobility management in the mobile network, such as user location update, user registration network, user switching, etc.

[0050] The access network equipment can be connected to the core network elements wirelessly or by wire. The core network elements and the access network equipment can be independent and different physical devices, or the functions of the core network elements and the logical functions of the access network equipment can be integrated on the same physical device, or the functions of some core network elements and some access network equipment can be integrated on one physical device.

[0051] In another example, a device using a wireless network service is usually located at the edge of the network and can be referred to as a terminal device. The terminal device can establish a connection with the network device and provide wireless communication services to the user based on the services of the network device. It should be understood that due to the closer relationship between the terminal device and the user, the terminal device is sometimes also referred to as a user equipment (UE) or a subscriber unit (SU). In addition, compared to base stations that are usually placed in fixed locations, terminal devices often move with the user and are sometimes referred to as mobile stations (MS). In addition, some network devices, such as relay nodes (RN) or wireless routers, etc., are sometimes also considered terminal devices because they have a UE identity or belong to the user.

[0052] The communication method provided in the embodiments of the present application can be applied to a communication device, which may include at least a terminal device or a chip in the terminal device, for example, a mobile phone, a tablet computer, a laptop computer, a wearable device (such as a smart watch, a smart bracelet, a smart helmet, smart glasses), and other devices with wireless access capabilities, such as smart cars, various Internet of Things (IOT) devices, including various smart home devices (such as smart meters and smart appliances) and smart city devices (such as security or monitoring equipment, smart road traffic facilities), etc.

[0053] Combine the following Figure 2 The radio resource control (RRC) state of the communication device is introduced. In the fifth generation (5G) communication system, the communication device has three RRC states: RRC idle state, RRC connected state and RRC inactive state. When the communication device enters the RRC inactive state, there is no service power consumption.

[0054] In one example, the idle state refers to the state that the communication device is in when it is not connected to the network device. The idle state referred to in the embodiments of the present application generally refers to the RRC idle state unless otherwise specified.

[0055] Among them, when the communication device is in an idle state, the air interface connection between the communication device and the network device is disconnected, the context information is no longer stored, the communication device only receives limited downlink information, and does not send uplink information. Uplink information may refer to information sent by the communication device to the network device, and downlink information may refer to information sent by the network device to the communication device. Limited downlink information may include downlink synchronization messages required for the communication device to complete the residency in the cell, information contained in the master information block (MIB), and information contained in the system information block (SIB) 1 (or remaining minimum system information (RMSI)), etc. For details, please refer to the description of the relevant 3GPP standard protocols, which will not be repeated here.

[0056] Furthermore, in the idle state, the communication device can perform processes such as public land mobile network (PLMN) selection, cell selection, cell reselection and system message broadcasting. In addition, in the idle state, since the communication device is not connected to the network device, has not accessed the network, does not occupy the service resources of the network device, and has not obtained the context and key of the communication device, it is unable to transmit service data.

[0057] In another example, the connected state corresponds to the idle state, and refers to the state that the communication device is in after completing the connection with the network device. The connected state referred to in the embodiments of the present application generally refers to the RRC connected state unless otherwise specified.

[0058] When the communication device is in a connected state, it establishes an air interface connection with the network device and communicates with the network device according to the air interface connection. In the connected state, the communication device can obtain context and key from the network device to transmit service data using the context and key.

[0059] Furthermore, the communication device can enter the connected state from the idle state. For example, in the idle state, the communication device can establish an RRC connection with the network device by sending an RRC message to the network device, such as sending an RRC connection establish request message, thereby entering the connected state. Alternatively, the communication device can also enter the connected state from the inactive state. For example, in the inactive state, the communication device can restore the RRC connection with the network device by sending an RRC message to the network device, such as an RRC resume request message, thereby entering the connected state. In addition, in the connected state, the communication device can also be released to the idle state or the inactive state according to an RRC message sent by the network device, such as an RRC release message, thereby reducing resource overhead, reducing power consumption, and improving the battery life of the communication device.

[0060] In another example, the inactive state is a state between the connected state and the idle state. The inactive state referred to in the embodiments of the present application generally refers to the RRC inactive state unless otherwise specified, and may also be referred to as the "third state".

[0061] Among them, for the communication device in the inactive state, the user plane bearer of the air interface has been suspended, and the user plane bearer and control plane bearer between the access network device and the core network element are still maintained. When the communication device initiates a call or service request, it is necessary to activate the user plane bearer of the air interface and reuse the existing user plane bearer and control plane bearer between the access network device and the core network element.

[0062] Furthermore, when the communication device is in an inactive state, the air interface connection between the communication device and the network device is disconnected, but the context information continues to be saved. When the communication device enters a connected state from an inactive state, the communication device can quickly recover to the connected state based on the saved context information.

[0063] In addition, in the inactive state, the communication device can perform cell reselection, and can also send RRC messages, such as RRC recovery request messages, to perform early data transmission to reduce resource overhead and improve communication efficiency. In addition, in the inactive state, the communication device can receive RRC messages, such as receiving RRC release messages, enter the idle state, and delete the context.

[0064] Combine the following Figures 3 to 6The paging process of the communication device is introduced. The communication device 111 is located in the cell of the base station 112, and the base station 112 is connected to the core network element 113. The communication device 121 is located in the cell of the base station 122, and the base station 122 is connected to the core network element 123. The core network element 113 and the core network element 123 support the internet protocol multimedia subsystem (IMS) service. The communication device 121, the base station 122, and the core network element 123 are the active calling party, referred to as the calling party. The communication device 111, the base station 112, and the core network element 113 are the called party, referred to as the called party.

[0065] In a possible implementation, Figure 3 As shown, the communication device 111 enters an inactive state in the cell of the base station 112. When the communication device 121 sends a call (invite) message to the communication device 111 in the inactive state, the communication device 121 sends the call message to the base station 122, and the base station 122 sends the call message to the core network element 123 corresponding to the base station 122. The core network element 123 sends the call message to the core network element 113 corresponding to the base station 112, and the core network element 113 sends the call message to the base station 112, and the base station 112 sends a RAN paging message for the communication device 111 to the communication device 111. In this way, the communication device 121 can call the communication device 111. Exemplarily, base station 122 and base station 112 may be the same base station, core network element 123 and core network element 113 may be the same core network element, and when communication device 121 sends a call (invite) message to communication device 111 in an inactive state, communication device 121 sends a call message to base station 112.

[0066] In another possible implementation, Figure 4 As shown, the communication device 111 enters an inactive state in the cell of the base station 112 and moves to the base station 114 while in the inactive state.

[0067] If the base station 112 and the base station 114 are located in the same RAN notification area (RAN-based notification area, RNA), and the base station 112 and the base station 114 are adjacent, there is a link (Xn) interface between the base station 112 and the base station 114, and data and signaling can be transmitted through the Xn interface. When the communication device 121 sends a call message to the communication device 111 in the inactive state, the communication device 121 sends the call message to the core network element 113 through the base station 122 and the core network element 123. Since the communication device 111 enters the inactive state, the RNA update process will not be initiated to synchronize context information when moving between cells in the same RNA. The core network element 113 will send the call message to the base station 112, and the base station 112 broadcasts a RAN paging message for the communication device 111. If the base station 112 successfully establishes the Xn interface with the base station 114, the base station 114 will receive the RAN paging message for the communication device 111 through the Xn interface and send the RAN paging message to the communication device 111. In this way, the communication device 121 can call the communication device 111 .

[0068] The description of protocol 38300 that the base station can transmit the RAN paging message through the Xn interface when the communication device is in an inactive state is as follows:

[0069] When the UE is in an inactive state, if the last served base station receives downlink (DL) data from the UPF, or UE-related downlink signaling from the AMF network element (except the UE context release command message), it pages multiple cells corresponding to this RNA. If the RNA includes cells of adjacent base stations, it may send an Xn application protocol (AP) RAN paging message to the adjacent base stations.

[0070] In another possible implementation, Figure 5 As shown, the communication device 111 enters an inactive state in the cell of the base station 112, and moves to the base station 114 while in the inactive state. If the base station 112 and the base station 114 are located in the same RNA, but the base stations 112 and 114 are not adjacent, there is no Xn interface between the base stations 112 and 114, or if the base stations 112 and the base stations 114 are located in the same RNA, and the base stations 112 and 114 are adjacent, but the base stations 112 and 114 fail to establish an Xn interface, then when the base station 112 broadcasts a RAN paging message for the communication device 111, the base station 114 cannot receive the RAN paging message for the communication device 111 through the Xn interface, and thus cannot send the RAN paging message to the communication device 111, and the RAN paging of the communication device 111 fails.

[0071] When the base station 112 senses that the RAN paging fails to reach the communication device 111, the base station 112 sends a first notification message to the AMF network element 115, where the first notification message is used to indicate that the RAN paging fails and a CN paging needs to be initiated. The AMF network element 115 switches to an idle state and sends a CN paging message to the communication device 111. In this way, the communication device 121 can call the communication device 111.

[0072] The protocol describes the conversion of RAN paging failure to CN paging as follows:

[0073] If the RAN paging procedure defined in protocol 38300 fails to successfully establish contact with the communication device, the process is handled by the network as follows:

[0074] If the next generation radio access network (NG-RAN) has at least one non-access stratum (NAS) protocol data unit (PDU) to be transmitted, the RAN node shall initiate the AN release procedure (see 4.2.6 in protocol 23502), switch the UE connection management (CM) state in the AMF network element to the idle state, and indicate to the AM device that NAS has not been sent.

[0075] If the NG-RAN has only user plane data to be transmitted, the NG-RAN node can keep the N2 connection in a connected state or initiate the AN release process according to the local configuration of the NG-RAN (see 4.2.6 in Protocol 23502).

[0076] NOTE 2: User plane data that triggers RAN paging may be lost, for example in case of RAN paging failure.

[0077] Figure 5 The illustrated implementation method introduces the mechanism of transferring RAN paging failure to CN paging in the AMF network element. At the same time, the core network element 113 supporting IMS may also have a mechanism of transferring packet switch (PS) domain paging failure to circuit switched (CS) domain paging. Next, the mechanism of transferring PS domain paging failure to CS domain paging is introduced.

[0078] In another possible implementation, Figure 6As shown, when the communication device 121 initiates a call message, the core network element 113 first performs PS domain paging. The specific process of PS domain paging includes: when the core network element 113 receives the call message from the communication device 121, since the communication device 111 has registered for IMS in the NR domain, the core network element 113 will send the call message to the base station 112, so that the base station 112 initiates RAN paging. When the RAN paging fails, the base station 112 notifies the AMF element so that the AMF element initiates CN paging. The PS domain paging starts from the time when the core network element 113 sends the call message. When the PS domain paging is timed for a period of time and there is no response to the paging, the core network element 113 will switch to circuit switched (CS) domain paging for replay.

[0079] Then in this scenario, there are the following possibilities: PS domain paging starts from the time when the core network network element 113 sends a call message, and RAN paging starts from the time when the base station 112 sends a RAN paging message. When the PS domain paging timing ends and the base station 112 has not yet sent the first notification message indicating the failure of RAN paging to the AMF network element, the core network network element 113 switches to CS domain paging. If there is no CS domain under NR, the session will be judged as failed. The core network network element 113 sends a second notification message to the communication device 121 through the core network network element 123 and the base station 122. The second notification message is used to indicate that the call message sent by the communication device 121 is unreachable. The core network network element 113 sends a call disconnection message to the communication device 111. The call disconnection message can arrive after the CN paging message arrives at the communication device 111. The call disconnection message is used to indicate the end of the session with the communication device 121. In this way, the call message of communication device 121 can actually reach communication device 111 through CN paging, but due to the PS domain to CS domain paging and the CS domain paging failure, the call message of communication device 121 is unreachable and the paging of communication device 111 ultimately fails.

[0080] Among them, protocol 33292 describes the mechanism for switching PS domain paging failure of IMS core network elements to CS domain paging as follows:

[0081] The terminating-access domain selection function (T-ADS) shall consider the access network capabilities, UE capabilities, IMS registration status, CS status, existing active sessions, user preferences, UE 3GPP PS data off status (active / inactive), 3GPP PS data interruption exemption service configuration settings, operator policies (such as access network specific voice domain preferences and media component types), and whether there is an ongoing IMS voice packet switched session. In addition, T-ADS may consider access network information directly provided by the terminal.

[0082] UE can assist T-ADS. UE Assisted T-ADS (UE T-ADS) is configured based on operator policies, user preferences and local access network capabilities to achieve the following functions:

[0083] - Detect candidate media on the CS domain associated with the incoming session.

[0084] -Determine the domain (CS or PS) in which the session is to be established.

[0085] - Determines the completion mechanism (initiation or termination) of the session establishment—applicable only to sessions established in the CS domain.

[0086] - inform the service call continuity application server (SCC AS) under what mechanism the establishment will be completed (if possible).

[0087] For delivering incoming sessions to non-internet certificate system (ICS) UEs, the SCC AS may deliver the session in other domains, for example, delivering the call message in the CS domain when the session establishment in the PS domain is unsuccessful.

[0088] Based on this, in order to improve the problem of failure of paging communication device, the embodiment of the present application provides a communication method. Figure 7 The method is applied to a communication device, and the method includes S110 to S130.

[0089] S110: Receive a release message from the first access network device, where the release message is used to indicate that the device is released to an inactive state by the first access network device.

[0090] S120: receiving a paging message from a second access network device in an inactive state, where the paging message is used to indicate the access network device that initiates the paging.

[0091] S130: When it is determined that the access network device that initiates the paging is not the first access network device, send a synchronization message to the second access network device, wherein the synchronization message is used to indicate a request to access the second access network device.

[0092] The first access network device and the second access network device may both be base stations. The first access network device and the second access network device are located in the same RNA, and the first access network device may broadcast a paging message to the second access network device.

[0093] Furthermore, at least one paging message from the second access network device may be a RAN paging message initiated by other access network devices (including the first access network device). For example, other access network devices initiate RAN paging, broadcast RAN paging messages to the second access network device, and the second access network device forwards the RAN paging message. At least one paging message from the second access network device may also be a RAN paging message initiated by the second access network device. For example, a core network element sends a call message to the second access network device, and the second access network device initiates RAN paging based on the call message. The paging message referred to in the embodiments of the present application generally refers to a RAN paging message unless otherwise specified.

[0094] Exemplarily, when the communication device is located in the cell of the first access network device, the communication device receives a release message from the first access network device and is released to an inactive state. Subsequently, the communication device moves to the cell of the second access network device, and the communication device is still in an inactive state, and the first access network device and the second access network device are located in the same RNA. Since the communication device is in an inactive state, the core network element, the first access network device, and the second access network device do not know the current location of the communication device. When the communication device is called, the core network element will forward the call message for the communication device to the first access network device. When the first access network device receives the call message from the core network element, the first access network device broadcasts a RAN paging message.

[0095] If there is an Xn interface between the first access network device and the second access network device, the second access network device can receive the RAN paging message from the first access network device and forward the RAN paging message to the communication device. If there is no Xn interface between the first access network device and the second access network device, or the establishment of the Xn interface fails, the second access network device cannot receive the RAN paging message from the first access network device, nor can it forward the RAN paging message to the communication device. At this time, if the failure of PS domain to CS domain paging occurs before CN paging, it will cause the paging communication device to fail. Therefore, when the communication device is in an inactive state and moves to the cell of other access network devices, the reason for the failure of paging the communication device is that there is no Xn interface between the first access network device and the second access network device or the establishment of the Xn interface fails.

[0096] In the technical solution provided by the embodiment of the present application, a release message from a first access network device is received, and a paging message from a second access network device is received in an inactive state. According to the release message and the paging message, it is identified whether the access network device that initiates the paging is the first access network device. If the access network device that initiates the paging is indicated by the paging message as the first access network device, it means that the Xn interface between the first access network device and the second access network device is successfully established. If the access network device that initiates the paging is not indicated by the second identifier carried by the paging message as the first access network device, it means that there may be no Xn interface between the first access network device and the second access network device, or the establishment of the Xn interface may fail. At this time, a synchronization message is sent to the second access network device to request access to the second access network device. In this way, after accessing the second access network device, the core network network element directly sends the call message to the second access network device, and the second access network device initiates RAN paging, and there is no need to broadcast RAN paging through the first access network device, thereby avoiding the lack of Xn interface between the first access network device and the second access network device, or the failure to establish the Xn interface, resulting in paging failure. The technical solution avoids paging failure by identifying in advance that the RAN paging message cannot be normally transmitted between the first access network device and the second access network device, and sending a synchronization message to request access to the second access network device.

[0097] Next, several implementation methods for identifying whether the access network device initiating paging is the first access network device are introduced.

[0098] In a first possible implementation, the release message includes a first identifier, the first identifier is used to indicate the first access network device, and the paging message includes a second identifier, the second identifier is used to indicate the access network device that initiated the paging. The method also includes: when the first identifier is different from the second identifier, determining that the access network device that initiated the paging is not the first access network device.

[0099] The release message may carry parameters such as a full inactive-radionetwork temporary identifier (fullI-RNTI) and a paging cycle (ran-pagingCycle) of the first access network device. The fullI-RNTI carried in the release message may include an identity document (ID) of the first access network device, which is used to identify the first access network device. The first identifier may be the first access network device ID in the fullI-RNTI.

[0100] Furthermore, the paging message may carry fullI-RNTI. The fullI-RNTI carried in the paging message may include the access network device ID that initiates the paging, which is used to identify the access network device that initiates the paging. The second identifier may be the access network device ID that initiates the paging in the fullI-RNTI.

[0101] In this possible implementation, the first access network device that sends the release message can be identified by the first identifier in the release message, and the access network device that initiates the paging can be identified by the second identifier in the paging message. Therefore, it can be determined that the access network device that initiates the paging is not the first access network device based on whether the first identifier and the second identifier are the same, which provides a basis for identifying in advance that the RAN paging message cannot be normally transmitted between the first access network device and the second access network device, sending a synchronization message to request access to the second access network device, and thus avoiding paging failure.

[0102] In a second possible implementation manner, the first identifier is first data of a specified length at a specified position in the release message, and the second identifier is second data of a specified length at a specified position in the paging message.

[0103] The second implementation may be based on the TS38300 protocol. The TS38300 protocol stipulates that the fullI-RNTI includes 40 bits of data for indicating the communication device ID, base station ID and public land mobile network (PLMN). Figure 8 , fullI-RNTI can be composed in three ways.

[0104] For example, when the profile ID is 1: the number of bits for the UE-specific reference is 20 bits, the number of bits for the NG RAN node address index (e.g., base station ID) is 20 bits, the radio access technology (RAT)-specific information is not provided, and the PLMN-specific information is not provided. The NG RAN node address index can be well represented by the least significant bits (LSBs) on the base station ID. This profile can be applied to any NG RAN RAT.

[0105] For another example, when the profile ID is 2: the number of bits for the UE-specific reference is 20 bits, the number of bits for the NG RAN node address index (such as the base station ID) is 16 bits, the radio access technology (RAT)-specific information is not provided, and the number of bits for the PLMN-specific information is 4 bits (maximum 16 PLMNs). The maximum value of the PLMN ID broadcast in NR is 12, and this profile can be applied to any NG RAN RAT.

[0106] For another example, when the profile ID is 3: the number of bits of the UE-specific reference is 24 bits, the number of bits of the NG RAN node address index (such as the base station ID) is 16 bits, the radio access technology (RAT)-specific information is not provided, and the PLMN-specific information is not provided. Reduce the node address to maximize the addressable UE context. This profile can be applied to any NG RAN RAT.

[0107] However, the TS38300 protocol only specifies the number of bits of the base station ID, such as 16 bits or 20 bits of data in the 40-bit fullI-RNTI are the base station ID, and it does not specify whether the bit data of the base station ID is high bit data or low bit data in the 40-bit data. In the second embodiment, the specified position may be the high bit position and / or low bit position of the fullI-RNTI. The specified length may be the number of bits of the base station ID of the fullI-RNTI. The first data of the specified length at the specified position in the release message is different from the second data of the specified length at the specified position in the paging message, and may refer to: the low 20 bits, high 20 bits, low 16 bits and high 16 bits of the fullI-RNTI carried by the release message are not equal to the low 20 bits, high 20 bits, low 16 bits and high 16 bits of the fullI-RNTI carried by the paging message. If the bit data at any one of the designated positions are equal, it is considered that the Xn interface between the first access network device and the second access network device is successfully established, and there is no need to execute S130.

[0108] Specifically, the execution process of the second implementation mode may be: comparing the first data A1 of the lower 20 bits of the fullI-RNTI carried by the release message with the second data B1 of the lower 20 bits of the fullI-RNTI carried by the paging message to see if they are equal. If they are equal, it is considered that the Xn interface between the first access network device and the second access network device is successfully established, and there is no need to execute S130. If they are not equal, comparing the first data A2 of the upper 20 bits of the fullI-RNTI carried by the release message with the second data B2 of the upper 20 bits of the fullI-RNTI carried by the paging message to see if they are equal. If they are equal, there is no need to execute S130. If they are not equal, comparing the first data A3 of the lower 16 bits of the fullI-RNTI carried by the release message with the second data B3 of the lower 16 bits of the fullI-RNTI carried by the paging message to see if they are equal. If they are equal, there is no need to execute S130. If they are not equal, compare the first data A4 of the high 16 bits in the fullI-RNTI carried by the release message with the second data B4 of the high 16 bits in the fullI-RNTI carried by the paging message to see if they are equal. If they are equal, there is no need to execute S130. If they are not equal, it is considered that there may be no Xn interface between the first access network device and the second access network device or the establishment of the Xn interface fails, and execute S130.

[0109] The code for this example could be:

[0110] When the communication device receives a release message from the first access network device:

[0111] SuspendConfig::=

[0112] fullI-RNTI

[0113] shortI-RNTI

[0114] ran-PagingCycle

[0115] ran-NotificationAreaInfot380

[0116] nextHopChainingCount

[0117] …

[0118] }

[0119] When the communication device receives a release message from the second access network device:

[0120] PagingUE-Identity::=

[0121] Ng-5G-S-TMSI

[0122] fullI-RNTI

[0123] …

[0124] }

[0125] In this possible implementation, the position and length of the information indicating the first access network device in the release message and the position and length of the information indicating the access network device initiating the paging in the paging message can be known according to the protocol. Therefore, the first identifier and the second identifier can be determined to be different according to the first data of the specified length at the specified position in the release message being different from the second data of the specified length at the specified position in the paging message, thereby determining that the access network device initiating the paging is not the first access network device. In this way, a basis can be provided for identifying in advance that the RAN paging message cannot be normally transmitted between the first access network device and the second access network device, sending a synchronization message to request access to the second access network device, and avoiding paging failures.

[0126] In a third possible implementation, the method further includes: receiving indication information, the indication information being used to indicate a specified length. The first data of the specified length at the specified position in the release message is different from the second data of the specified length at the specified position in the paging message, which means that the first identifier is different from the second identifier, or the access network device initiating the paging is not the first access network device. When located in a cell of the first access network device, the indication information from the first access network device is received, the indication information is retained, and the above-mentioned specified length is determined based on the indication information.

[0127] In this possible implementation, the specified length is determined based on the indication information, so as to determine whether the first data of the specified length at the specified position in the release message is the same as the second data of the specified length at the specified position in the paging message, thereby providing a basis for identifying in advance that the RAN paging message cannot be normally transmitted between the first access network device and the second access network device, sending a synchronization message to request access to the second access network device, and avoiding paging failures.

[0128] Exemplarily, the third implementation may be based on the TS38331 protocol of the R17 protocol. The indication information is located in the system information block (SIB) from the first access network device. For example, the system information block may be SIB1. In the R17 protocol version, the TS38331 protocol adds a base station identity code length (gNB-ID-length-r17) identifier carried in the SIB1 message. The indication information may be a gNB-ID-length-r17 identifier, and the specified length may be the number of bits of the first data. When located in a cell of the first access network device, SIB1 is received from the first access network device, and SIB1 includes a gNB-ID-length-r17 identifier of the first access network device, and the gNB-ID-length-r17 identifier is retained after entering an inactive state.

[0129] However, the TS38331 protocol of the R17 protocol only specifies the number of bits of the first data indicated by the gNB-ID-length-r17 identifier, and does not specify whether the first data is high-bit data or low-bit data in the fullI-RNTI. In the third implementation, the specified position may be the high-bit position and / or low-bit position of the fullI-RNTI. The specified length indicated by gNB-ID-length-r17 may be 20 bits. The first data of the specified length at the specified position in the release message is different from the second data of the specified length at the specified position in the paging message, which may mean that the low 20-bit data and the high 20-bit data of the fullI-RNTI carried by the release message are not equal to the low 20-bit data and the high 20-bit data of the fullI-RNTI carried by the paging message. If the bit data at any of the specified positions are equal, it is considered that the Xn interface between the first access network device and the second access network device is successfully established, and there is no need to execute S130.

[0130] Specifically, the execution process of the third implementation mode may be: comparing the first data A5 of the lower 20 bits in the fullI-RNTI carried by the release message with the second data B5 of the lower 20 bits in the fullI-RNTI carried by the paging message to see if they are equal. If they are equal, it is considered that the Xn interface between the first access network device and the second access network device is established successfully, and there is no need to execute S130. If they are not equal, then compare the first data A6 of the upper 20 bits in the fullI-RNTI carried by the release message with the second data B6 of the upper 20 bits in the fullI-RNTI carried by the paging message to see if they are equal. If they are equal, there is no need to execute S130. If they are not equal, it is considered that there may be no Xn interface between the first access network device and the second access network device or the establishment of the Xn interface fails, and S130 is executed.

[0131] The code for this example could be:

[0132] PLMN-IdentityInfolist::=

[0133] PLMN-IentityInfo::=

[0134] plmn-IentityList

[0135] trackingAreaCode

[0136] ranac

[0137] cellIdentity

[0138] cellReservedForOperatorUse

[0139] …, [[

[0141] Iab-Support-r16

[0142] ]], [[

[0144] trackingArea List-r17

[0145] gNB-ID-Length-r17

[0146] In this example, the specified length is determined based on the indication information in the system information block from the first access network device, so as to know whether the first data of the specified length at the specified position in the release message is the same as the second data of the specified length at the specified position in the paging message, thereby providing a basis for identifying in advance that the RAN paging message cannot be transmitted normally between the first access network device and the second access network device, sending a synchronization message to request access to the second access network device, and avoiding paging failures.

[0147] In a possible implementation, S120 may be executed when the cell of the second access network device is just moved. If there is a paging message indicating that the access network device initiating the paging is the first access network device, it is considered that the Xn interface between the first access network device and the second access network device is successfully established, and there is no need to execute S130. When it is in an inactive state after a period of time, S120 and S130 are executed again. If there is no paging message indicating that the access network device initiating the paging is the first access network device, it is considered that the Xn interface between the first access network device and the second access network device may fail to be established, and S130 is executed at this time.

[0148] In a possible implementation, S130 includes: when a specified number of paging messages are received, and the access network device that initiates the paging indicated by each paging message is not the first access network device, sending a synchronization message to the second access network device. And / or, when the time period for receiving the paging message times out, and the access network device that initiates the paging indicated by the paging message is not the first access network device, sending a synchronization message to the second access network device. The number of paging messages received from in the time period for receiving the paging message is not fixed.

[0149] In this possible implementation, when a specified number of paging messages are received, and / or when the time period for receiving the paging messages times out, it can be estimated that the first access network device has initiated paging to the communication device. If the access network devices that initiate the paging are not the first access network devices, then there may be no Xn interface between the first access network device and the second access network device or the establishment of the Xn interface fails. By sending a synchronization message to the second access network device when a specified number of paging messages are received and the access network device that initiates the paging indicated by each paging message is not the first access network device; and / or, when the time period for receiving the paging message times out and the access network device that initiates the paging indicated by the paging message is not the first access network device, sending a synchronization message to the second access network device, a basis is provided for identifying in advance that the RAN paging message cannot be normally transmitted between the first access network device and the second access network device, and sending a synchronization message to request access to the second access network device to avoid paging failure.

[0150] In a possible implementation, the specified number of paging messages may include the following forms. The first form: the specified number of paging messages includes a portion of the specified paging messages. For example, the paging messages received at the paging occasions corresponding to the communication device in the paging cycle. The second form: the specified number of paging messages includes the paging messages received at all paging occasions in the paging cycle.

[0151] The communication device monitors the physical downlink control channel (PDCCH) at the specified time air interface time domain position to learn whether it is paged. The specified time air interface time domain position can be represented by a paging frame (PF) and a paging occasion (PO). Please refer to Fig. 9 A paging cycle (DRX) T includes multiple (such as N) PFs, a PF is a radio frame, a PF includes multiple (such as Ns) POs, a PO is a set of PDCCH monitoring opportunities, and a PO includes multiple time slots.

[0152] According to the 38304 agreement, PF and PO satisfy the following relationship:

[0153] The system frame number (SFN) of PF is:

[0154] (SFN+PF_offset)mod T=(T div N)*(UE_ID mod N)

[0155] i_s of PO is: i_s=floor(UE_ID / N)mod Ns

[0156] The i_s of PO indicates the starting position of a set of PDCCH monitoring opportunities, and the UE starts receiving paging messages from the i_sth PO.

[0157] Wherein: T is the paging cycle of the communication device, PF_offset is the frame offset of PF, N is the number of PFs included in the paging cycle T, UE_ID is the communication device ID, and Ns is the number of POs included in PF.

[0158] Optionally, when the second access network device receives a paging message from a core network element to page different communication devices, it will link the communication devices according to the PO value, and the communication devices with the same PO value will be on the same PO chain. When the scheduling time comes, that is, (Tdiv N)*(UE_ID mod N), the second access network device puts the paging messages of the communication devices with the same PO value together to form a new paging message, sends the paging message on the corresponding carrier, and broadcasts it to all resource pools under all cells of the second access network device.

[0159] In the first form, the communication device can calculate the paging opportunity corresponding to the communication device in the paging cycle, and receive a specified number of paging messages from the second access network device at the paging opportunity corresponding to the communication device in the paging cycle. In this possible implementation, at the paging opportunity corresponding to the communication device in the paging cycle, a specified number of paging messages from the second access network device are received, and it can be estimated that the first access network device has initiated paging to the communication device, and the paging message is only received at the paging opportunity corresponding to the communication device, which can save power consumption. In this way, a basis is provided for identifying in advance that the RAN paging message cannot be normally transmitted between the first access network device and the second access network device, and sending a synchronization message to request access to the second access network device, thereby avoiding the failure of paging the communication device.

[0160] In the second form, the communication device may receive paging messages from the second access network device at all paging occasions within the paging cycle. Optionally, in order to avoid excessive power consumption caused by the communication device receiving paging messages at all paging occasions within the paging cycle, a specified period may be pre-set, and the specified period includes a first sub-period and a second sub-period. The communication device may receive paging messages from the second access network device at all paging occasions of the first sub-period of the specified period, and receive paging messages from the second access network device at the paging occasions corresponding to the communication device in the second sub-period of the specified period, and the duration of the specified period may be greater than the duration of the paging cycle. In this possible implementation, a specified number of paging messages from the second access network device are received at all paging occasions in the paging cycle, so that multiple paging messages from the second access network device can be received more quickly, thereby more quickly confirming whether paging messages can be normally transmitted between the first access network device and the second access network device.

[0161] Next, an example of the synchronization message is given. Exemplarily, the synchronization message is used to indicate that the communication device requests to access the second access network device. After the communication device accesses the second access network device, the second access network device can know that the communication device has moved to the cell of the second access network device. The second access network device will synchronize the location of the communication device to the core network element. Thus, the context information of the communication device is synchronized between the communication device and the network device.

[0162] In a possible implementation, the synchronization message includes a resume message. The RNA update process is initiated by sending a resume message to the second access network device. In this possible implementation, if the access network device that initiates the paging indicated by the paging message is not the first access network device, it means that there may be no Xn interface between the first access network device and the second access network device, or the Xn interface may fail to be established. At this time, a resume message is sent to the second access network device to request access to the second access network device, so that the network device knows that the communication device is located in the cell of the second access network device, providing a basis for avoiding paging failure.

[0163] In another possible implementation, the synchronization message includes a mobile registration message. The mobile registration process is initiated by sending a mobile registration message to the second access network device. In this possible implementation, if the access network device that initiates the paging indicated by the paging message is not the first access network device, it means that there may be no Xn interface between the first access network device and the second access network device, or the Xn interface may fail to be established. At this time, sending a mobile registration message to the second access network device to request access to the second access network device provides a basis for avoiding paging failure.

[0164] Combine the following Fig.10A possible process of the communication method provided in an embodiment of the present application is illustrated by way of example.

[0165] When the communication device is located in the cell of the first access network device, it receives a release message from the first access network device and is released to an inactive state.

[0166] When the communication device moves to the cell of the second access network device, the paging opportunity corresponding to the communication device in the paging cycle is calculated in the inactive state, and a paging message from the second access network device is received at the paging opportunity corresponding to the communication device in the paging cycle.

[0167] The communication device compares the lower 20-bit data, upper 20-bit data, lower 16-bit data and upper 16-bit data intercepted by the fullI-RNTI carried by the release message, and whether they are equal to the lower 20-bit data, upper 20-bit data, lower 16-bit data and upper 16-bit data intercepted by the fullI-RNTI carried by the paging message.

[0168] If the bit data at any one of the designated positions are equal, the communication device considers that the Xn interface between the first access network device and the second access network device is successfully established, and no subsequent processing is required.

[0169] When a specified number of paging messages are received and the bit data at any of the above specified positions are not equal, the communication device believes that there may be no Xn interface between the first access network device and the second access network device or the establishment of the Xn interface fails, and sends a recovery message to the second access network device, thereby requesting access to the second access network device, so that the context information of the communication device is synchronized between the communication device and the network device.

[0170] Combine the following Fig.11 Another possible process of the communication method provided in the embodiment of the present application is illustrated by way of example.

[0171] When the communication device is located in the cell of the first access network device, it receives a release message from the first access network device and is released to an inactive state.

[0172] When the communication device is located in the cell of the second access network device, in an inactive state, the communication device receives the paging message from the second access network device at all paging occasions in the paging cycle. Optionally, the communication device receives the paging message from the second access network device at all paging occasions in the first sub-period of the specified period, and receives the paging message from the second access network device at the paging occasion corresponding to the communication device in the second sub-period of the specified period.

[0173] The communication device compares the first data of the specified length of the low bit and high bit of the fullI-RNTI carried by the release message (indicated by the gNB-ID-length-r17 identifier) ​​with the second data of the specified length of the low bit and high bit of the fullI-RNTI carried by the paging message (indicated by the gNB-ID-length-r17 identifier) ​​to see if they are equal.

[0174] If the bit data at any one of the designated positions are equal, the communication device considers that the Xn interface between the first access network device and the second access network device is successfully established, and no subsequent processing is required.

[0175] When a specified number of paging messages are received and the bit data at any of the above specified positions are not equal, the communication device believes that there may be no Xn interface between the first access network device and the second access network device or the establishment of the Xn interface fails, and sends a mobile registration message to the second access network device, thereby requesting access to the second access network device, so that the context information of the communication device is synchronized between the communication device and the network device.

[0176] It is understandable that, in order to realize the above functions, the communication device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the structures and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0177] The embodiment of the present application can divide the functional modules according to the communication device corresponding to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0178] In the case of dividing each functional module into corresponding functional modules, Fig.12 A possible structural diagram of the communication device involved in the above embodiment is shown. The embodiment of the present application further provides a communication device 200 , which includes: a first receiving unit 210 , a second receiving unit 220 and a processing unit 230 .

[0179] The first receiving unit 210 is used to receive a release message from the first access network device, the release message is used to indicate that the first access network device has released the device to an inactive state. The second receiving unit 220 is used to receive a paging message from the second access network device in an inactive state, the paging message is used to indicate the access network device that initiated the paging. The processing unit 230 is used to send a synchronization message to the second access network device when the access network device that initiated the paging is not the first access network device, wherein the synchronization message is used to indicate a request to access the second access network device.

[0180] In a possible implementation, the release message includes a first identifier, the first identifier is used to indicate the first access network device, and the paging message includes a second identifier, the second identifier is used to indicate the access network device that initiated the paging. The processing unit is also used to determine that the access network device that initiated the paging is not the first access network device when the first identifier is different from the second identifier.

[0181] In a possible implementation manner, the first identifier is first data of a specified length at a specified position in the release message, and the second identifier is second data of a specified length at a specified position in the paging message.

[0182] In a possible implementation manner, the first receiving unit 210 is further configured to receive indication information, where the indication information is used to indicate a specified length.

[0183] In a possible implementation manner, the indication information is located in a system information block from the first access network device.

[0184] In a possible implementation manner, the synchronization message includes a recovery message or a mobile registration message.

[0185] In one possible implementation, the processing unit 230 is specifically used to send a synchronization message to the second access network device when a specified number of paging messages are received and the access network device that initiates the paging indicated by each paging message is not the first access network device; and / or, when the time period for receiving the paging message times out and the access network device that initiates the paging indicated by the paging message is not the first access network device, send a synchronization message to the second access network device.

[0186] In a possible implementation manner, the specified number of paging messages includes: paging messages received at all or part of the specified paging occasions in the paging cycle.

[0187] It can be understood that the various components of the above-mentioned communication device 200 can be used to implement the corresponding steps in the above-mentioned method embodiment respectively. Since each step has been described in detail in the above-mentioned communication method embodiment, it will not be repeated here.

[0188] The above describes a communication device in an embodiment of the present application from the perspective of modular functional entities. The following describes a communication device in an embodiment of the present application from the perspective of hardware processing. Fig.13 The embodiment of the present application further provides a communication device 300, which includes a processor 310 and an interface circuit 320. The interface circuit 320 is used to receive a code instruction and transmit it to the processor 310. The processor 310 is used to run the code instruction to execute at least one step shown in the above method embodiment.

[0189] An embodiment of the present application also provides a computer-readable storage medium, in which program code is stored. When the computer-readable storage medium is run on a communication device, the program code therein can be called by a processor to execute at least one step in the above method embodiment.

[0190] Based on this understanding, the embodiments of the present application also provide a computer program product comprising instructions. The essence of the technical solution of the present application or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a communication device or a processor therein to perform at least one step of the method described in each embodiment of the present application.

[0191] Finally, it should be noted that the above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A communication method, characterized in that: The method comprises: receiving a release message from a first access network device, wherein the release message is used to indicate that the device is released to an inactive state by the first access network device; receiving a paging message from a second access network device in an inactive state, wherein the paging message is used to indicate the access network device that initiates the paging; When it is determined that the access network device that initiates the paging is not the first access network device, a synchronization message is sent to the second access network device, wherein the synchronization message is used to indicate a request to access the second access network device.

2. The method according to claim 1, characterized in that The release message includes a first identifier, where the first identifier is used to indicate the first access network device; the paging message includes a second identifier, where the second identifier is used to indicate the access network device that initiates the paging; The method further includes: when the first identifier is different from the second identifier, determining that the access network device that initiates the paging is not the first access network device.

3. The method according to claim 2, characterized in that The first identifier is first data of a specified length at a specified position in the release message, and the second identifier is second data of the specified length at the specified position in the paging message.

4. The method according to claim 3, characterized in that The method further comprises: Indication information is received, where the indication information is used to indicate the specified length.

5. The method according to claim 4, characterized in that The indication information is located in a system information block from the first access network device.

6. The method according to any one of claims 1 to 5, characterized in that: The synchronization message includes a recovery message or a mobile registration message.

7. The method according to any one of claims 1 to 6, characterized in that: When it is determined that the access network device that initiates the paging is not the first access network device, sending a synchronization message to the second access network device includes: When a specified number of the paging messages are received and the access network device that initiates the paging indicated by each of the paging messages is not the first access network device, sending the synchronization message to the second access network device; and / or, When the time period for receiving the paging message times out and the access network device that initiates the paging indicated by the paging message is not the first access network device, the synchronization message is sent to the second access network device.

8. The method according to claim 7, characterized in that The designated number of paging messages includes: the paging messages received at all or part of designated paging occasions in a paging cycle.

9. A communication device, characterized in that: The device comprises: A first receiving unit, configured to receive a release message from a first access network device, wherein the release message is used to indicate that the device is released to an inactive state by the first access network device; A second receiving unit, configured to receive a paging message from a second access network device in an inactive state, wherein the paging message is used to indicate the access network device that initiates the paging; A processing unit is used to send a synchronization message to the second access network device when the access network device that initiates the paging is not the first access network device, wherein the synchronization message is used to indicate a request to access the second access network device.

10. The device according to claim 9, characterized in that The release message includes a first identifier, where the first identifier is used to indicate the first access network device; the paging message includes a second identifier, where the second identifier is used to indicate the access network device that initiates the paging; The processing unit is further configured to determine, when the first identifier is different from the second identifier, that the access network device initiating the paging is not the first access network device.

11. The device according to claim 10, characterized in that The first identifier is first data of a specified length and at a specified position in the release message, and the second identifier is second data of the specified length and at the specified position in the paging message.

12. The device according to claim 11, characterized in that The first receiving unit is further used to receive indication information, where the indication information is used to indicate the specified length.

13. The device according to claim 12, characterized in that The indication information is located in a system information block from the first access network device.

14. The device according to any one of claims 9 to 13, characterized in that The synchronization message includes a recovery message or a mobile registration message.

15. The device according to any one of claims 9 to 14, characterized in that The processing unit is specifically configured to send the synchronization message to the second access network device when a specified number of the paging messages are received and the access network device that initiates the paging indicated by each of the paging messages is not the first access network device; And / or, when the time period for receiving the paging message times out and the access network device that initiates the paging indicated by the paging message is not the first access network device, sending a synchronization message to the second access network device.

16. The device according to claim 15, characterized in that The designated number of paging messages includes: the paging messages received at all or part of designated paging occasions in a paging cycle.

17. A communication device, characterized in that: The communication device includes a processor and an interface circuit; wherein, The interface circuit is used to receive code instructions and transmit them to the processor; The processor is configured to execute the code instructions to perform the method according to any one of claims 1 to 8.

18. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a computer program or instructions. When the computer program or instructions are executed on a computer, the computer is caused to perform the method according to any one of claims 1 to 8.

Images