Communication methods, and communication apparatus

Abstract

Communication methods, and a communication apparatus, which can be applied to the technical field of communications. A method comprises: a second node sends a first request message, and correspondingly, a first node receives the first request message, the first request message being used for requesting to migrate context information of a terminal device; and when the first node or the second node is a WAB node, the first node sends a first response message, and the second node receives the first response message, the first response message comprising the context information of the terminal device. The present solution enables context information of terminal devices to be migrated in a timely manner.

Description

Communication method and communication apparatus

[0001] The present application claims priority to the Chinese patent application No. 202411381344.1, filed on September 29, 2024, and entitled "Communication method and communication apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, and in particular to a communication method and a communication apparatus. BACKGROUND

[0003] In a wireless communication system, the triggering conditions for a terminal device in a radio resource control (RRC) inactive state (INACTIVE) to initiate an RRC resume procedure include: the UE perceives that a new cell for reselection moves out of the range of a radio access network (RAN) notification area (RNA) to trigger an RNA update (RNAU), a periodic RNAU timer expires, the terminal device has uplink (UL) traffic data to transmit, and the terminal device receives a RAN paging from the network side. When any of the triggering conditions is met, the terminal device initiates the RRC resume procedure. After receiving a context migration request message for the terminal device, the last serving base station can decide to migrate the context of the terminal device or not. The last serving base station is the base station that releases the terminal device to the RRC inactive state.

[0004] However, in a wireless access and backhaul (WAB) scenario, there is a problem of not timely migrating the context of the terminal device. SUMMARY

[0005] Embodiments of the present application provide a communication method and a communication apparatus, which can timely migrate the context of the terminal device.

[0006] In a first aspect, embodiments of the present application provide a communication method. The method is applied to a first node. The method can be executed by the first node or a component (such as a circuit, a chip or a chip system, etc.) of the first node, and the present application does not make any limitation. The method comprises:

[0007] receive a first request message from a second node, the first request message being used to request migration of context information of a terminal device, the second node being a current serving node of the terminal device, and the first node being a last serving node of the terminal device; in a case where it is determined that the first node and / or the second node is a wireless access backhaul (WAB) node, or the first request message includes first indication information, send a first response message to the second node, the first response message including the context information of the terminal device; and wherein the first indication information is used to indicate that the first node migrates the context information of the terminal device.

[0008] In the embodiments of the present application, the terminal device is in an RRC inactive state. The terminal device in the RRC inactive state reselects from a cell under a first node to a cell under a second node. The first node is a serving node before the terminal device reselects a cell, and the second node is a serving node after the terminal device reselects a cell. Or, the first node is a cell in which the terminal device is released to the RRC inactive state. The WAB node is movable. The movement of the first node or the second node can cause the Xn interface between the first node and the second node to be disconnected and unable to migrate the context of the terminal device. Therefore, the first node determines to migrate the context of the terminal device in a case where it is determined that the first node or the second node is a WAB node, which can migrate the context of the terminal device before the Xn interface between the first node and the second node is disconnected, that is, can timely migrate the context of the terminal device, thereby guaranteeing the performance of the terminal device in the RRC inactive state. Alternatively, the second node carries the first indication information in the first request message, and the first indication information is used by the first node to determine to migrate the context of the terminal device. The first node determines to migrate the context of the terminal device in a case where the first request message includes the first indication information, which can timely migrate the context of the terminal device.

[0009] In combination with the first aspect, in a possible implementation, the first node is a WAB node, and the method further includes: sending a first broadcast message, the first broadcast message including second indication information, the second indication information indicating that a first cell does not belong to the first node, or the second indication information indicating a length of an identifier of the first node; and wherein the first cell is a neighboring cell of a second cell, and the second cell is a cell under the first node.

[0010] In the embodiments of the present application, in a case where the first node is a WAB node, the first node can indicate whether a neighboring cell of a cell under the first node belongs to the first node, or indicate the length of the identifier of the first node, so that the terminal device can determine whether the serving node changes after cell reselection.

[0011] In a second aspect, an embodiment of the present application provides a communication method, which is applied to a second node. The method can be executed by the second node or by a component (for example, a circuit, a chip or a chip system) of the first node, which is not limited in the present application. The method comprises the following steps.

[0012] receiving a second request message from the terminal device, the second request message being used for requesting to resume a radio resource control (RRC) connection of the terminal device; and sending a first request message to a first node, the first request message being used for requesting to migrate context information of the terminal device; wherein the first node is a last serving node of the terminal device, the second node is a current serving node of the terminal device, and the first node and / or the second node is a wireless access backhaul (WAB) node.

[0013] In the embodiment of the present application, when the first node and / or the second node is the WAB node, after the second node receives the second request message, the second node requests the first node to migrate the context information of the terminal device, so that the context information of the terminal device can be migrated in time, and the situation that the context information of the terminal device cannot be migrated due to disconnection of an Xn interface between the first node and the second node caused by movement of the first node or the second node can be avoided.

[0014] With reference to the second aspect, in a possible implementation, the method further comprises: receiving a first response message from the first node, the first response message comprising the context information of the terminal device.

[0015] With reference to the second aspect, in a possible implementation, the first request message comprises first indication information, the first indication information being used for instructing the first node to migrate the context information of the terminal device.

[0016] In the embodiment of the present application, the second node can carry the first indication information in the first request message, so that the first node decides to migrate the context information of the terminal device, and the context information of the terminal device can be migrated in time.

[0017] With reference to the second aspect, in a possible implementation, the second request message comprises third indication information, the third indication information being used for instructing the first node to migrate the context information of the terminal device.

[0018] In the embodiment of the present application, the third indication information is used for the first node to determine to migrate the context information of the terminal device, or the third indication information is used for instructing the second node to carry the first indication information in the first request message. Through the third indication information, the first node can make a decision to migrate the context information of the terminal device, and the context information of the terminal device can be migrated in time.

[0019] With reference to the second aspect, in a possible implementation, the second request message is an RRC resume request message, and the third indication information is carried in an RRC resume cause information element of the RRC resume request message.

[0020] In the embodiments of the present application, the third indication information is carried in the RRC resume cause information element, so that the RRC resume cause information element can be reused, and additional overheads can be avoided.

[0021] With reference to the second aspect, in a possible implementation, the second node is a WAB node, and the method further includes: sending a second broadcast message, the second broadcast message including fourth indication information, the fourth indication information indicating that the second node is a WAB node.

[0022] In the embodiments of the present application, when the second node is a WAB node, the second node can broadcast the second indication information, so that the terminal device can learn that the second node is a WAB node.

[0023] In a third aspect, the embodiments of the present application provide a communication method, which can be applied to a terminal side, for example, a terminal device or a communication module in the terminal device, or a circuit or chip responsible for a communication function in the terminal device (such as a Modem chip, also known as a baseband chip, or a System on Chip (SoC) chip or a System in Package (SIP) chip containing a modem core), and the method is taken as an example in which the method is applied to a terminal device. In the method, the terminal device reselects from a second cell to a first cell, the second cell corresponds to a first node, and the first cell corresponds to a second node; in the case where the first node and / or the second node is a wireless access backhaul (WAB) node, a second request message is sent to the second node, the second request is used to request to resume a radio resource control (RRC) connection of the terminal device.

[0024] In the embodiments of the present application, the terminal device is in an RRC inactive state, and the terminal device can initiate an RRC resume procedure through the second request message, or in other words, the terminal device can initiate an RNAU through the second request message. In the case where the first node and / or the second node is a WAB node, the terminal device sends the second request message after reselecting from the second cell to the first cell, so as to initiate the RRC resume procedure or the RNAU, so that the context information of the terminal device can be timely migrated from the first node to the second node.

[0025] With reference to the third aspect, in a possible implementation manner, the first node is a WAB node, and the communication method further includes: receiving a first broadcast message from the first node, the first broadcast message including second indication information, the second indication information indicating that the first cell does not belong to the first node, or the second indication information indicating a length of an identity of the first node.

[0026] With reference to the third aspect, in a possible implementation manner, the second node is a WAB node, and the communication method further includes: receiving a second broadcast message from the second node, the second broadcast message including fourth indication information, the fourth indication information indicating that the second node is a WAB node.

[0027] With reference to the third aspect, in a possible implementation manner, the second request message includes third indication information, the third indication information being used to indicate that the first node migrates context information of the terminal device.

[0028] In the embodiments of the present application, in the case that the first node is a WAB node or the second node is a WBA node, the terminal device can carry third indication information in the second request message, so that the first node determines to migrate the context information of the terminal device, and ensures that the context information of the terminal device can be timely migrated to the second node.

[0029] With reference to the third aspect, in a possible implementation manner, the second request message includes an RRC resume request message, and the third indication information is carried in an RRC resume cause information element of the RRC resume request message.

[0030] In a fourth aspect, the embodiments of the present application provide a communication method, which is applied to a third node. The method can be executed by the third node, or can be executed by a component (for example, a circuit, a chip or a chip system) of the third node, and the present application does not make any limitation. The method includes:

[0031] determining a radio access network notification area (RNA) corresponding to a wireless access backhaul (WAB) node; and sending a first message to the WAB node, the first message including information of the RNA and a node list, the node list including information of one or more nodes, and the first message indicating that the WAB node establishes an Xn interface with the one or more nodes.

[0032] In the embodiments of the present application, the third node is configured to manage the WAB node. For example, the third node is a network management server of the WAB node. The RNA corresponding to the WAB node is configured to represent the paging range of the WAB node, and the WAB node is capable of paging the terminal device within the RNA range. The WAB node has an Xn interface with the nodes within the RNA range. The third node can configure the RNA of the WAB node and the node list corresponding to the Xn interface, so that the WAB node can better maintain the Xn interface with the neighboring nodes and reduce the impact on the performance of the non-active terminal device within the RNA range caused by the frequent disconnection of the Xn interface between the WAB node and the neighboring nodes.

[0033] In combination with the fourth aspect, in a possible implementation manner, when the update condition of the RNA is met, a second message is sent to the WAB node, and the second message is configured to update the node list and the information of the RNA.

[0034] In the embodiments of the present application, when the update condition of the RNA is met, the third node synchronously updates the information of the RNA corresponding to the WAB node and the node list corresponding to the Xn interface. For example, the nodes in the node list can be updated along with the change of the RNA of the WAB node, so that the WAB node can better maintain the Xn interface with the neighboring nodes and reduce the impact on the performance of the non-active terminal device within the RNA range caused by the frequent disconnection of the Xn interface between the WAB node and the neighboring nodes.

[0035] In the fifth aspect, the embodiments of the present application provide a communication method applied to a WAB node. The method can be executed by the WAB node or the component (such as a circuit or a chip or a chip system) of the WAB node, and the present application does not make any limitation. The method comprises the following steps.

[0036] receiving a first message from a third node, wherein the first message comprises information of an RNA corresponding to the WAB node and a node list, the node list comprises information of one or more nodes, and the first message indicates that the WAB node establishes an Xn interface with the one or more nodes; and sending a radio resource control (RRC) release message to a terminal device, wherein the RRC release message comprises information of the RNA, and the RRC release message is used for the terminal device to switch to an RRC inactive state.

[0037] In the embodiments of the present application, when the terminal device is released to the RRC inactive state, the WAB node configures the RNA of the terminal device to be the same as the RNA of the WAB node, and the WAB node has an Xn interface with the nodes within the RNA range, which can reduce the situation that the context migration of the terminal device cannot be completed due to the disconnection of the Xn interface.

[0038] With reference to the fifth aspect, in a possible implementation manner, the communication method further includes: receiving a second message from the third node, the second message being used to update the node list and information of the RNA.

[0039] With reference to the sixth aspect, in a possible implementation manner, the communication method further includes: receiving a second request message from a terminal device, the second request message being used to request to resume RRC connection of the terminal device; and in a case where it is determined that there is no Xn interface between the first node and the second node, sending a third request message to a fourth node, the third message being used to request the first node to migrate context information of the terminal device; wherein the second node is a current serving node of the terminal device, the first node is a last serving node of the terminal device, the fourth node is a host node of the second node, and the second node is a WAB node.

[0040] In the embodiment of the present application, in a case where it is determined that there is no Xn interface between the second node and the first node, the second node can forward the request for migrating the context information of the terminal device through the host node of the second node, so as to ensure that the context information of the terminal device can be migrated to the second node, thereby guaranteeing the performance of the terminal device in the inactive state.

[0041] With reference to the sixth aspect, in a possible implementation manner, the method further includes: receiving a third response message from the fourth node, the third response message including the context information of the terminal device.

[0042] With reference to the sixth aspect, in a possible implementation manner, the third request message includes identification information of the first node.

[0043] With reference to the sixth aspect, in a possible implementation manner, the third request message is an Xn message.

[0044] With reference to the sixth aspect, in a possible implementation manner, the third request message is an RRC message.

[0045] With reference to the sixth aspect, in a possible implementation manner, the third request message includes fifth indication information, the fifth indication information being used to indicate that the first node migrates the context information of the terminal device.

[0046] With reference to the seventh aspect, in a possible implementation manner, the communication method further includes:

[0047] receiving a third request message from the second node, the third request message being used to request the first node to migrate the context information of the terminal device; and sending a fourth request message to the first node, the fourth request message being used to request the first node to migrate the context information of the terminal device; wherein the first node is a last serving node of the terminal device, the second node is a current serving node of the terminal device, and there is no Xn interface between the first node and the second node.

[0048] In the embodiments of the application, the second node is a WAB node, and the fourth node is a host node of the second node. After receiving the third request message, the fourth node can forward the request of the second node for migrating the context information of the terminal device through the fourth request message, so that the context information of the terminal device can be migrated to the second node, and the performance of the terminal device in the inactive state is ensured.

[0049] With reference to the seventh aspect, in a possible implementation manner, the method further includes: receiving a second response message from the first node, the second response message including the context information of the terminal device; and sending a third response message to the second node, the third response message including the context information of the terminal device.

[0050] With reference to the seventh aspect, in a possible implementation manner, the third request message includes fifth indication information, the fifth indication information being used to indicate that the first node migrates the context information of the terminal device.

[0051] With reference to the seventh aspect, in a possible implementation manner, the fourth request message includes sixth indication information, the sixth indication information being used to indicate that the first node migrates the context information of the terminal device.

[0052] An eighth aspect provides a communication method, which is applied to a first node. The method can be executed by the first node, or can be executed by a component (such as a circuit or a chip or a chip system) of the first node, and the application does not make any limitation. The method includes:

[0053] receiving a fourth request message from the fourth node, the fourth request message being used to request the first node to migrate the context information of the terminal device; and sending a second response message to the fourth node, the second response message including the context information of the terminal device.

[0054] With reference to the eighth aspect, in a possible implementation manner, the fourth request message includes sixth indication information, the sixth indication information being used to indicate that the first node migrates the context information of the terminal device.

[0055] In a ninth aspect, an embodiment of the present application provides a communication apparatus, configured to perform the method in any one of the first aspect to the eighth aspect or any possible implementation of the method.

[0056] In a tenth aspect, an embodiment of the present application provides a communication apparatus, comprising a processor configured to cause the communication apparatus to perform the method in any one of the first aspect to the eighth aspect or any possible implementation of the method.

[0057] Optionally, the communication apparatus further comprises a transceiver configured to transmit and / or receive information. For example, the transceiver is configured to cause the communication apparatus to perform the transmitting and / or receiving step in the method in any one of the first aspect to the eighth aspect or any possible implementation of the method.

[0058] In an eleventh aspect, an embodiment of the present application provides a communication apparatus, comprising a logic circuit and an interface, wherein the interface is configured to input and / or output information, and the logic circuit is configured to cause the communication apparatus to perform the processing step in the method in any one of the first aspect to the eighth aspect or any possible implementation of the method.

[0059] In a twelfth aspect, an embodiment of the present application provides a computer readable storage medium, configured to store a computer program, which when executed on a computer, causes the method in any one of the first aspect to the eighth aspect or any possible implementation of the method to be performed.

[0060] In a thirteenth aspect, an embodiment of the present application provides a computer program product, which when executed on a computer, causes the method in any one of the first aspect to the eighth aspect or any possible implementation of the method to be performed.

[0061] In a fourteenth aspect, an embodiment of the present application provides a communication system, comprising a first node configured to perform the method in the first aspect or any possible implementation of the first aspect, a second node configured to perform the method in the second aspect or any possible implementation of the second aspect, and a terminal device configured to perform the method in the third aspect or any possible implementation of the third aspect.

[0062] In a fifteenth aspect, an embodiment of the present application provides a communication system, comprising a third node configured to perform the method in the fourth aspect or any possible implementation of the fourth aspect, and a WAB node configured to perform the method in the fifth aspect or any possible implementation of the fifth aspect.

[0063] In a sixteenth aspect, an embodiment of the present application provides a communication system, comprising a first node configured to perform the method in the eighth aspect or any possible implementation of the eighth aspect, a second node configured to perform the method in the sixth aspect or any possible implementation of the sixth aspect, and a fourth node configured to perform the method in the seventh aspect or any possible implementation of the seventh aspect. BRIEF DESCRIPTION OF DRAWINGS

[0064] FIG. 1A is a structural schematic diagram of a WAB communication system according to an embodiment of the present application;

[0065] FIG. 1B is an architecture diagram of an open radio access network (O-RAN) communication system according to an embodiment of the present application;

[0066] FIG. 2 is an example of a vehicle mounted relay (VMR) scenario according to an embodiment of the present application;

[0067] FIG. 3 is a flowchart of a process of resuming an RRC connection by a UE according to an embodiment of the present application;

[0068] FIG. 4 is a flowchart of a communication method according to an embodiment of the present application;

[0069] FIG. 5A is a flowchart of another communication method according to an embodiment of the present application;

[0070] FIG. 5B is a flowchart of still another communication method according to an embodiment of the present application;

[0071] FIG. 6 is a flowchart of still another communication method according to an embodiment of the present application;

[0072] FIG. 7 is a flowchart of still another communication method according to an embodiment of the present application;

[0073] FIG. 8 is a structural schematic diagram of a communication apparatus according to an embodiment of the present application;

[0074] FIG. 9 is a structural schematic diagram of another communication apparatus according to an embodiment of the present application;

[0075] FIG. 10 is a structural schematic diagram of another communication apparatus provided by an embodiment of the present application. DETAILED DESCRIPTION

[0076] The terms "first" and "second" and the like in the description, claims and drawings of the present application merely mean different objects and do not imply a sequence, a time sequence, a priority or a degree of importance of the objects. "Multiple" in the embodiments of the present application means two or two or more. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, a method, a system, a product or an apparatus and the like including a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed or other steps or units inherent to the process, the method, the product or the apparatus. In addition, the character " / ", if not specifically stated, generally indicates that the associated objects before and after are in an "or" relationship.

[0077] "Embodiments" mentioned in the present application means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It can be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0078] It should be understood that in the present application, "at least one" means one or more, "multiple" means two or more, "at least two" means two or three and more, and "and / or" is used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or the like means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can mean a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b and c can be single or multiple.

[0079] The technical solutions in the embodiments of the present application can be applied to various communication systems, for example, a universal mobile telecommunications system (UMTS), a wireless local area network (WLAN), a wireless fidelity (Wi-Fi) system, a 4th generation (4G) mobile communication system such as a long term evolution (LTE) system, a 5th generation (5G) mobile communication system such as a new radio (NR) system, and a future evolved communication system, and the like.

[0080] The present application will present various aspects, embodiments or features around a system that can include a plurality of devices, components, modules, and the like. It should be understood and appreciated that each of the various systems can include additional devices, components, modules, and the like, and / or can not include all of the devices, components, modules, and the like discussed in conjunction with the figures. Additionally, a combination of these schemes can also be used.

[0081] In addition, in the embodiments of the present application, the words "exemplary", "for example", and the like are used on the basis of their ordinary meanings. Any embodiment or design presented as "example" in the present application should not be interpreted as more preferred or having more advantages than other embodiments or design solutions. Rather, the word "example" is used to present the concept in a specific manner. In the embodiments of the present application, "of", "corresponding" and "corresponding" are sometimes mixed. It should be pointed out that when the distinction is not emphasized, the meanings expressed are consistent.

[0082] In the present application, "sending" and "receiving" represent the direction of signal transmission. For example, "sending information to XX" can be understood as the destination of the information is XX, which can include direct transmission through the air interface, and also includes indirect transmission through the air interface by other units or modules. "Receiving information from YY" can be understood as the source of the information is YY, which can include direct reception from YY through the air interface, or indirect reception from YY through the air interface from other units or modules. "Sending" can also be understood as the "output" of the chip interface, and "receiving" can also be understood as the "input" of the chip interface. In other words, sending and receiving can be between devices, such as between network devices and terminal devices, or within devices, such as between components, modules, chips, software modules or hardware modules within a device through a bus, wire or interface.

[0083] The communication system and service scenarios described in the embodiments of the present application are used to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, with the evolution of network architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0084] The terminal device in the embodiments of the present application is a device with wireless transceiving function. The terminal device can communicate with an access network device (or also referred to as an access device or a network device shown below) in a radio access network (RAN). The terminal device can also be referred to as a user equipment (UE), an access terminal, a terminal, a subscriber unit, a user station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a user agent, or a user device, etc. In a possible implementation manner, the terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; or can be deployed on water, including a ship; or can be deployed in the air, such as an airplane, a balloon or a satellite, etc. In another possible implementation manner, the terminal device can be a handheld device, a vehicle-mounted device, a wearable device, a sensor, a terminal in Internet of Things, a terminal in Internet of Vehicles, a drone, a terminal device in 5G network or future network with wireless communication function, etc., and the embodiments of the present application do not limit this. In yet another possible implementation manner, the terminal device can also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in remote medical treatment, a wireless terminal in smart power grid, a wireless terminal in smart city, or a wireless terminal in smart home, etc.

[0085] In the embodiments of the present application, the device for implementing the function of the terminal device can be the terminal device; or can be a device capable of supporting the terminal device to implement the function, such as a chip system. The device can be installed in the terminal device or used in matching with the terminal device. In the embodiments of the present application, the chip system can be composed of a chip, or can include the chip and other discrete devices. For ease of description, when some examples are involved below, the device for implementing the function of the terminal device is taken as an example to describe the technical solutions provided by the embodiments of the present application.

[0086] Please refer to FIG. 1A, which is an example of a wireless access and backhaul (WAB) communication system provided by an embodiment of the present application. In the WAB communication system, a relay node RN or WAB node can provide wireless access services for user equipment (UE). The relay node can access a macro station (which can be referred to as a WAB donor) through a wireless backhaul link. Traffic data of the UE is transmitted by the WAB node to the WAB donor through the wireless backhaul link. In the present application, the WAB donor can also be referred to as a backhaul (BH) base station gNB or a BH radio access network (RAN) node (BH-RAN-NODE) or a donor node.

[0087] The WAB node includes a mobile termination (MT) function part (which can be referred to as WAB-MT) and a gNB function part (which can be referred to as WAB-gNB). When the WAB node faces its parent node (such as the BH-RAN-NODE), it can be regarded as a terminal device, i.e., WAB-MT. When the WAB node faces its child node (such as a normal UE), it is regarded as a network device, i.e., WAB-gNB. As shown in FIG. 1A, a Uu interface is established between the UE and the WAB-gNB, an Xn interface is established between the WAB-gNB and the BH-RAN-NODE, and a Uu interface is established between the WAB-MT and the BH-RAN-NODE. Exemplarily, the WAB-gNB can also establish an N3 interface with a user plane function (UPF) of the UE, and can also establish an N2 interface with an access and mobility management function (AMF) of the UE or the WAB-gNB. The WAB-gNB can be an access network element with complete base station functions, or can be an access network element in a centralized unit (CU) and distributed unit (DU) separation form. For ease of description, the centralized unit of the WAB-gNB is referred to as WAB-CU, and the distributed unit of the WAB-gNB is referred to as WAB-DU.

[0088] The BH-RAN-NODE can be an access network element with complete base station functions, and can also be an access network element in the form of separation of centralized unit (CU) and distributed unit (DU). The BH-RAN-NODE is connected to a core network (for example, connected to a 5G core network, 5GC) element serving the UE, and provides a wireless backhaul function for the WAB node. For ease of description, the centralized unit of the BH-RAN-NODE is referred to as BH-RAN-NODE-CU, and the distributed unit of the BH-RAN-NODE is referred to as BH-RAN-NODE-DU. The BH-RAN-NODE-CU can also be in the form of separation of control plane (CP) and user plane (UP), for example: the BH-RAN-NODE-CU can be composed of one CU-CP and one (or more) CU-UP.

[0089] As shown in FIG. 1A, an N3 interface is established between the BH-RAN-NODE and the UPF (which can be referred to as BH UPF) of the WAB-MT, and an N2 interface is established between the BH-RAN-NODE and the AMF (which can be referred to as BH AMF) of the WAB-MT. The BH AMF is responsible for the authorization of the WAB-MT.

[0090] The UE accesses the WAB-gNB through the Uu interface, and then the WAB-MT wraps the data of the UE in the protocol data unit (PDU) session of the MT, and transmits the data through the Uu interface of the WAB-MT, through the BH-RAN-NODE connected to the WAB-MT, to the UPF (which can be referred to as BH UPF) of the WAB-MT, and then the BH UPF removes the header information related to the WAB-MT, exposes the header information related to the UE, and sends the data to the UPF of the UE according to the IP routing (through the N6 interface). Logically, a PDU session is also established between the UE and the UPF of the UE, but it is transmitted in the PDU session of the WAB-MT.

[0091] In the WAB scenario, the UE data is directly packed in the PDU session of the WAB-MT, and during the MT backhaul process, these data are all regarded as the user plane data of the WAB-MT. After these data arrive at the BH-RAN-NODE through the data radio bearer (DRB) of the WAB-MT, the BH-RAN-NODE understands these data as the data of the WAB-MT instead of the data of the UE. After these data are transmitted to the BH UPF, the BH UPF removes the MT-related packet header information to expose the UE-related packet header information, so as to determine that these data are the data of the UE and forward to the UPF of the UE.

[0092] The above illustrates the process of user plane data transmission between the UE and the UPF, and the control plane transmission between the WAB-gNB and the AMF is similar, which is also packed in the PDU session of the MT and forwarded by the UPF of the WAB-MT to the AMF of the WAB-gNB through IP routing.

[0093] In addition, the WAB-gNB can also establish a logical Xn interface with the BH-RAN-NODE and other gNBs nearby, and the transmission mode of data on the Xn interface (taking the WAB-gNB sending to the BH-RAN-NODE as an example) is also that the WAB-gNB sends to the UPF of the WAB-MT first, and then the UPF of the WAB-MT forwards to the BH-RAN-NODE through IP routing.

[0094] FIG. 1B is an architecture diagram of an open RAN (O-RAN) communication system provided by an embodiment of the present application. As shown in FIG. 1B, the O-RAN communication system can include a RAN intelligent controller (RIC), a BH-RAN-NODE-CU, a BH-RAN-NODE-DU, a WAB-MT, a WAB-CU, and a WAB-DU. There is a Uu interface between the WAB-MT and the BH-RAN-NODE-DU, and there is an F1 interface between the BH-RAN-NODE-CU and the BH-RAN-NODE-DU. There is also an F1 interface between the WAB-CU and the WAB-DU.

[0095] The RIC is used to collect network information and perform necessary optimization tasks, and communicates with the gNB-CU (such as BH-RAN-NODE-CU, WAB-CU) and the gNB-DU (such as BH-RAN-NODE-DU, WAB-DU) through the E2 interface. That is, the RIC can directly control the DU of the network device. Among them, the gNB-CU is a gNB-CU supporting O-RAN functions, including BH-RAN-NODE-CU and WAB-CU; the gNB-DU is a gNB-DU supporting O-RAN functions, including BH-RAN-NODE-CU and WAB-DU.

[0096] Exemplarily, the WAB communication system can be applied to a vehicle mounted relay (VMR) scenario, as shown in FIG. 2. In the VMR scenario, a relay node (i.e., a WAB node) can be deployed on a mobile device such as a vehicle (or an airplane) to provide wireless coverage for UEs in the vehicle to overcome the problem of poor wireless signals in the vehicle. The relay node accesses a macro station (or a host RAN) through wireless backhaul.

[0097] It should be noted that the communication system shown in FIGS. 1A and 1B is only an example and does not limit the application scenarios to which the embodiments of the present application are applicable. It should be understood that the WAB node used in the embodiments of the present application is only for the purpose of description, and does not mean that the scheme of the embodiments of the present application is only used in the new radio (NR) scenario.

[0098] Exemplarily, the radio resource control (RRC) state of the UE can include one of a connected (CONNECTED) state, an inactive (INACTIVE) state, and an idle (IDLE) state. When the UE enters the inactive state or the idle state from the connected state, the base station sends an RRC release (RRCRelease) message to the UE, and the RRC connection between the base station and the UE is released.

[0099] When the UE is in the idle state, the UE side and the base station side delete the context of the UE, the next generation application protocol (NGAP) connection between the base station and the core network about the UE is also released, and the core network perceives that the UE enters the idle state. When the DL data of the UE arrives at the CN, the CN initiates CN paging, all base stations in the registration area of the UE page the UE, and the UE initiates access to the network after hearing the paging message, and establishes an RRC connection (RRCSetup). When the UE has UL data, the UE also initiates access to the network and establishes an RRC connection. When the UE enters the CONNECTED state from the IDLE state, a new RRC connection needs to be established from the beginning, and the core network needs to authenticate the UE.

[0100] When the UE is in the inactive state, the RRC connection between the UE and the base station is released, but the UE and the base station both retain part of the UE context, and the NAGP connection between the base station and the core network about the UE is not released. The core network does not perceive the inactive state, and the core network considers that the UE is still under the service of the last serving gNB in the connected state, where the last serving gNB refers to the gNB that last served the UE, that is, the gNB that released the UE to the inactive state. After being released to the inactive state, the UE can reselect to other gNBs, but this is not perceived by the core network, and the core network considers that the RRC between the UE and the last serving gNB of the UE is not released. When the DL data of the UE arrives at the CN, the CN sends the DL data packet to the last serving gNB. After receiving the data packet, the last serving gNB knows that it is an UE released to the inactive state by itself, initiates RAN paging in the RNA (RAN Notification Area) notification range of the UE through the Xn interface, pages the UE, and the UE initiates access to the network after hearing the paging message, and resumes the RRC connection (RRCResume). When the UE has UL data, the UE also initiates access to the network and resumes the RRC connection (RRCResume). Alternatively, when the UE in the inactive state perceives that the reselected new cell moves out of the RNA range configured by the last serving gNB, the UE actively triggers RNA update (RNAU) and initiates the RRCResume process. In addition, the UE in the inactive state performs periodic RNAU and actively initiates the RRCResume process.

[0101] The UE resumes the RRC connection process can be triggered by the UE side or triggered by the network side. For example, when the UE perceives that the new cell reselected moves out of the RNA range configured by the last serving base station, or the UE periodically initiates RANU, or the UE has uplink data transmission, the UE can trigger the RRC connection to be resumed. For another example, when the network side has downlink data transmission, the network side can trigger the UE to resume the RRC connection. The last serving base station sends a RAN paging message to all base stations in the RNA range of the UE through the Xn interface, and the RAN paging message carries the inactive radio network temporary identifier (I-RNTI) of the UE. All base stations in the RNA range of the UE send a paging message on the air interface. After receiving the paging message of the current serving base station, the UE initiates the RRC connection resume process (also referred to as the RRC resume process).

[0102] The UE resumes the RRC connection process can be triggered by the UE side or triggered by the network side. For example, when the UE perceives that the new cell reselected moves out of the RNA range configured by the last serving base station, or the UE periodically initiates RANU, or the UE has uplink data transmission, the UE can trigger the RRC connection to be resumed. For another example, when the network side has downlink data transmission, the network side can trigger the UE to resume the RRC connection. The last serving base station sends a RAN paging message to all base stations in the RNA range of the UE through the Xn interface, and the RAN paging message carries the inactive radio network temporary identifier (I-RNTI) of the UE. All base stations in the RNA range of the UE send a paging message on the air interface. After receiving the paging message of the current serving base station, the UE initiates the RRC connection resume process (also referred to as the RRC resume process).

[0103] 301, the UE sends an RRC resume request (RRCResumeRequest) message to the current serving base station, and the current serving base station receives the RRC resume request message.

[0104] The current serving base station is the base station where the UE currently resides, or in other words, the current serving base station is the base station currently providing access services for the UE. The current serving base station can also be referred to as a resident base station.

[0105] For example, the UE in the inactive state sends an RRC resume request message to the current serving base station when it detects that the cell reselected is not located in the RNA range. It can be understood that when the new cell reselected by the UE is not located in the RNA range, it indicates that the UE has moved far away, and the UE needs to initiate the RNAU and resume the RRC connection with the network to migrate the UE context from the last serving base station to the current serving base station. The RNA represents a geographical area, which can be identified by a cell ID list or a RAN notification area code (RANAC), indicating the range of RAN paging.

[0106] For another example, the UE also periodically initiates the RNAU, that is, the UE periodically sends an RRC resume request message to the network to confirm the state of the UE.

[0107] For example, the RRC resume request message carries the cause value of resume as RNAU.

[0108] For the UE in the INACTIVE state, the RNA of the UE is indicated by the last serving base station when the last serving base station sends the UE an RRC release (RRCRelease) message, which is carried in a SuspendConfig information element of the RRC release message. If the RRC release message carries the SuspendConfig information element, the UE is released to the INACTIVE state, and the last serving base station suspends (or saves) some contexts of the UE. If the RRC release message does not carry the SuspendConfig information element, the UE is released to the IDLE state, and the last serving base station releases all contexts of the UE. In addition to the RNA information, the SuspendConfig information element can also include the identity of the last serving base station and the identity of the UE context when the UE is released to the INACTIVE state by the last serving base station. The UE can carry the above information (the RNA information, the identity of the last serving base station, the identity of the UE context, etc.) in an RRC resume request message.

[0109] 302, the current serving base station sends a retrieve UE context request (RETRIEVE UE CONTEXT REQUEST) message to the last serving base station, and the last serving base station receives the retrieve UE context request message.

[0110] After the current serving base station receives the RRC resume request message from the UE, the current serving base station initiates a retrieve UE context request message to the last serving base station to request the UE context.

[0111] For example, the RRC resume request message includes at least one of the RNA information, the identity of the last serving base station, and the identity of the UE context. After the current serving base station receives the RRC resume request message, the current serving base station identifies the last serving base station of the UE and sends a retrieve UE context request message to the last serving base station to request the UE context.

[0112] 303, the last serving base station sends a retrieve UE context response (RETIREVE UE CONTEXT RESPONSE) message to the current serving base station, and the current serving base station receives the retrieve UE context response message.

[0113] As an example, after the last serving base station receives the retrieve UE context request message, if it is determined that the UE indeed needs to update the RNA, the last serving base station replies with a retrieve UE context response message. The last serving base station can verify the UE to verify the legality of the UE. If the verification is passed, the last serving base station sends a retrieve UE context response message to migrate the context of the UE to the current serving base station of the UE, and then deletes the context of the UE.

[0114] As yet another example, after receiving the RETIREVE UE CONTEXT REQUEST message, the last serving base station can also decide to reply with a RETIREVE UE CONTEXT FAILURE message and not migrate the context. For example, when the last serving base station finds that the UE is only a periodic RNAU but has not moved out of the RNA range, the last serving base station can still find the UE in the current RNA range by RAN paging the UE and thus can not migrate the context of the UE.

[0115] For a periodic RNAU, the last serving base station can also decide to reply with a RETIREVE UE CONTEXT RESPONSE message to migrate the context or a RETIREVE UE CONTEXT FAILURE message to not migrate the context.

[0116] By way of example, the last serving base station can determine whether the current RNAU is initiated due to the UE moving out of the RNA range or due to a periodic RNAU by a target cell ID carried in the RETIREVE UE CONTEXT REQUEST message. The target cell ID refers to a cell ID of a cell in which the UE resumes the RRC connection under the current serving base station.

[0117] As one example, the RNA is identified using a list of cell IDs. The last serving base station can determine whether the target cell ID is included in the list of cell IDs for the RNA. In the case that the target cell ID is included in the list of cell IDs, the last serving base station determines that the UE has not moved out of the RNA and that the current RNAU is a periodic RNAU and can not update the RNA. In the case that the target cell ID is not included in the list of cell IDs, the last serving base station determines that the UE has moved out of the RNA and needs to update the RNA.

[0118] As another example, the RNA is identified using a RANAC. The last serving base station has exchanged the RANAC information of each cell with the current serving base station over the Xn interface and thus knows the RANAC information of the cell corresponding to the target cell ID. The last serving base station can thus determine whether the RANAC of the cell corresponding to the target cell ID is the same as the RANAC of the UE indicated in the RRC release message. If the RANAC of the cell corresponding to the target cell ID is the same as the RANAC of the UE indicated in the RRC release message, it indicates that the current RNAU is a periodic RNAU and the context of the UE can not be migrated. Otherwise, it indicates that the RNA needs to be updated and the last serving base station replies with a RETIREVE UE CONTEXT RESPONSE message to the current serving base station.

[0119] 304, the current serving base station sends an RRC resume (RRCResume) message to the UE, and correspondingly, the UE receives the RRC resume message.

[0120] 305, the UE sends an RRC resume complete (RRCResumeComplete) message, and correspondingly, the current serving base station receives the RRC resume complete message.

[0121] 306, the current serving base station sends an Xn-U address indication to the last serving base station, and correspondingly, the last serving base station receives the Xn-U address indication.

[0122] 307, the current serving base station sends a path switch request message to the AMF, and correspondingly, the AMF receives the path switch request message.

[0123] 308, the AMF sends a path switch request response message, and correspondingly, the current serving base station receives the path switch request response message.

[0124] 309, the current serving base station sends a UE context release message to the last serving base station, and correspondingly, the last serving base station receives the UE context release message.

[0125] After receiving the UE context release message, the last serving base station releases (or deletes) the context of the UE.

[0126] Generally, the trigger conditions for the UE to initiate the RRC resume procedure include: the UE perceives that the new cell for reselection moves out of the RNA range to trigger the RNAU, the periodic RNAU timer expires, the UE has UL traffic data to transmit, and the UE receives the RAN paging from the network side. When any of the trigger conditions is met, the UE initiates the RRCResume procedure. After receiving the migration UE context request message, the last serving base station can decide to migrate the context of the UE or not.

[0127] However, in the WAB scenario, there is a problem that the context of the UE is not migrated in time. For example, due to the movement of the WAB-gNB, the WAB-gNB can frequently disconnect with the Xn interface of the neighboring base station. If none of the trigger conditions is met before the Xn interface is disconnected, or the last serving base station does not timely decide and migrate the context, it can cause that when the trigger condition is met, the Xn interface has been disconnected, resulting in that the context of the UE in the inactive state cannot be migrated, and the UE in the inactive state cannot normally return to the connected state, affecting the UE experience.

[0128] In view of this, the embodiment of the present application provides a communication method and a communication device, which can timely migrate the context of the UE. The method provided by the embodiment of the present application can be applied to the communication system shown in FIG. 1A or FIG. 1B. Alternatively, the communication method provided by the embodiment of the present application can be applied to a terminal device, a first node and a second node. The terminal device can be the terminal device described above, the first node can be the last serving base station of the terminal device, or the first node is a component (such as a circuit, a chip or a chip system, etc.) in the last serving base station of the terminal device. The second node is the current serving base station of the terminal device, or the second node is a component (such as a circuit, a chip or a chip system, etc.) in the current serving base station of the terminal device. Hereinafter, the first node is taken as the last serving base station of the terminal device, and the second node is taken as the current serving base station of the terminal device as an example for description.

[0129] Please refer to FIG. 4, which is a flowchart of a communication method provided by the embodiment of the present application. As shown in FIG. 4, the method includes but is not limited to the following steps.

[0130] 401. The terminal device reselects from a second cell to a first cell.

[0131] The second cell corresponds to the first node (i.e., the second cell is a cell under the first node), and the first cell corresponds to the second node (i.e., the first cell is a cell under the second node). The first node is the last serving node of the terminal device, i.e., the first node is the serving node of the terminal device before the cell reselection. The second node is the current serving node of the terminal device, i.e., the second node is the serving node of the terminal device after the cell reselection. That is, the terminal device reselects from a cell under the first node to a cell under the second node.

[0132] Exemplarily, the terminal device is in an RRC inactive state, and the first node is a node that releases the terminal device to the RRC inactive state. For example, before the terminal device reselects from the second cell to the first cell, the terminal device can switch from an RRC connected state to an RRC inactive state based on an RRC release (RRCRelease) message from the first node. The RRC release message can also include information of the RNA of the terminal device. In the RRC inactive state, the terminal device reselects from the second cell to the first cell.

[0133] 402. In the case that the first node or the second node is a WAB node, the terminal device sends a second request message to the second node, and correspondingly, the second node receives the second request message.

[0134] The second request message is used to request to resume the RRC connection of the terminal device. Alternatively, the second request message is used to trigger the second node to request to migrate the context information of the terminal device. The terminal device can initiate the RNAU through the second request message to trigger the second node to request to migrate the context information of the terminal device.

[0135] As an example, the first node is a WAB node, and the second node is a non-WAB node. After the terminal device determines to reselect from a cell under the WAB node to a cell under the non-WAB node, the terminal device initiates the RNAU actively.

[0136] As another example, the second node is a WAB node, the first cell is a WAB cell, and the first node is a non-WAB node. After the terminal device determines to reselect from a cell under the non-WAB node to a cell under the WAB node, the terminal device initiates the RNAU actively.

[0137] As yet another example, the first node is a WAB node, and the second node is a WAB node. In a case where the terminal device determines to reselect from a cell under the WAB node to a cell under another WAB node, the terminal device initiates the RNAU through the second request message. Exemplarily, the second request message is an RRC resume request (RRCResumeRequest) message.

[0138] Exemplarily, the terminal device can determine that the first node or the second node is a WAB node based on a broadcast message of the first node or the second node. For example, in a case where the second node is a WAB node, the second node can broadcast a second broadcast message, the second broadcast message including fourth indication information used to indicate that the second node is a WAB node. After the terminal device receives the second broadcast message, the terminal device determines that the second node is a WAB node based on the fourth indication information.

[0139] In a possible implementation, the second request message includes third indication information used to indicate that the first node migrates the context information of the terminal device, or in other words, the third indication information is used for the first node to determine to migrate the context information of the terminal device, or in other words, the third indication information is used to indicate that the first node makes a decision to determine to migrate the context information of the terminal device. Alternatively, the third indication information is used to indicate that the second node carries the first indication information in the first request message. The first request message is used to request the first node to migrate the context information of the terminal device, and the first indication information is used to indicate that the first node migrates the context information of the terminal device.

[0140] In this implementation, the terminal device carries the third indication information in the second request message in a case where the first node or the second node is a WAB node, so that the first node determines to migrate the context information of the terminal device, thereby avoiding that the context information of the terminal device is not migrated in time.

[0141] Exemplarily, the second request message is an RRC resume request message, and the third indication information can be carried in an RRC resume cause (ResumeCause) information element in the RRC resume request message. For example, the RRC resume cause information element is set to a preset value (a special value), indicating that the RRC resume cause information element carries the third indication information.

[0142] Exemplarily, a new information element for carrying the third indication information can be added in the RRC resume request message.

[0143] It can be understood that the WAB node is movable, and therefore, after the terminal device performs cell reselection under the WAB node, the terminal device initiates the RNAU through the second request message to trigger the second node to request migration of the context information of the terminal device, so as to avoid disconnection of the Xn interface between the first node and the second node due to movement of the WAB node, and migration of the context information of the terminal device being unable to be performed, and to ensure that the context information of the terminal device is migrated in time.

[0144] In a possible implementation, after the terminal device reselects from the second cell to the first cell, the terminal device can further determine whether the first cell and the second cell belong to the same node (or base station), that is, whether the service node of the terminal device changes. If the first cell and the second cell belong to the same node, the service node of the terminal device does not change, and the terminal device can not initiate the RNAU. In the case that the first cell and the second cell do not belong to the same node (that is, the service node of the terminal device changes), and the first node and / or the second node is a WAB node, the terminal device sends the second request message to the second node to initiate the RNAU.

[0145] As an example, in the case that the first node is a WAB node, the first node can send a first broadcast message, and the first broadcast message includes the second indication information, the second indication information indicating that the first cell does not belong to the first node, or the second indication information indicating the length of the identifier of the first node. The terminal device can determine whether the second cell belongs to the first node based on the second indication information, so as to determine whether the service node of the terminal device changes.

[0146] Exemplarily, the second indication information indicates that the first cell does not belong to the first node. The first broadcast message can be a system message of the second cell. For example, the first broadcast message is a system information block (SIB) 3 (SIB3) message of the second cell, and the second indication information can be carried in an IntraFreqNeighCellInfo information element. For another example, the first broadcast message can be a SIB4 message of the second cell, and the second indication information can be carried in an InterFreNeighCellInfo information element. The first cell is a neighbor cell of the second cell, that is, the first node can carry an indication of whether the neighbor cell of the second cell is a cell under the first node in the system message of the second cell, so that the terminal device can determine whether the service node of the terminal device changes after cell reselection based on the system message of the second cell.

[0147] For another example, the second indication information indicates the length of the identity of the first node. The first broadcast message can be a SIB1 message of the second cell, and the length of the identity of the first node (gNB-ID-Length) is indicated in the SIB1 message of the second cell, so that the terminal device can read the identity of the first node according to the SIB1 message, and the terminal device can determine whether the service node of the terminal device changes by comparing the identities of the first node and the second node.

[0148] In this example, the WAB node can indicate whether the neighbor cell of the cell under the WAB node belongs to the WAB node, or indicate the length of the identity of the WAB node, so that the terminal device can determine whether the service node changes after cell reselection.

[0149] Exemplarily, in the case where the second node is a WAB node, the second node can also carry indication information for indicating that the first cell does not belong to the second cell or indicating the length of the identity of the second node in the corresponding broadcast message. The broadcast message of the second node can refer to the related description of the first broadcast message above, and will not be described in detail here.

[0150] 403, the second node sends a first request message to the first node, and correspondingly, the first node receives the first request message. The first request message is used to request to migrate the context information of the terminal device.

[0151] Exemplarily, the first request message is a RETRIEVE UE CONTEXT REQUEST message.

[0152] Exemplarily, the first request message can comprise first indication information, the first indication information being used for indicating the first node to migrate the context information of the terminal device, or the first indication information being used for the first node to determine to migrate the context information of the terminal device.

[0153] As an example, the second request message comprises third indication information, and the second node can determine, based on the third indication information, that the first indication information is carried in the first request message.

[0154] As another example, the second request message does not comprise the third indication information, and the second node sends the first request message after determining that the first node or the second node is a WAB node, and carries the first indication information in the first request message.

[0155] Exemplarily, after receiving the second request message from the terminal device, the second node can further determine whether the last serving node of the terminal device is the second node. If the last serving node of the terminal device is the second node, the context information of the terminal device does not need to be migrated, and thus the second node does not send the first request message. If the last serving node of the terminal device is not the second node, i.e., the serving node of the terminal device has changed, the second node sends the first request message to the first node to request to migrate the context information of the terminal device.

[0156] Exemplarily, the second request message comprises identification information of the last serving node of the terminal device, and the second node can determine, based on the identification information, the last serving node (i.e., the first node) of the terminal device.

[0157] 404. The first node sends a first response message to the second node, and correspondingly, the second node receives the first response message.

[0158] The first response message comprises the context information of the terminal device. The context information of the terminal device comprises at least one of a PDU session context, a security key, a mobility restriction list, and UE capability information.

[0159] The first node sends the first response message to migrate the context information of the terminal device in a case that the first node and / or the second node is determined to be a WAB node, or the first request message comprises the first indication information.

[0160] As an example, the first request message comprises the first indication information, and the first node can directly determine, based on the first indication information, to migrate the context information of the terminal device, and send the first response message.

[0161] As another example, the first request message does not include the first indication information, and the first node can determine whether to migrate the context information of the terminal device based on the node type of the first node and / or the second node. For example, in the case where the first node and / or the second node are WAB nodes, it is determined to migrate the context information of the terminal device, and the first response message is sent.

[0162] It can be understood that in the case where neither the first node nor the second node is a WAB node, the first node can determine to migrate the context information of the terminal device or not to migrate the context information of the terminal device, which is not limited in the present application.

[0163] Exemplarily, the first response message can be a RETRIEVE UE CONTEXT RESPONSE message.

[0164] In the embodiments of the present application, the WAB node is movable. In order to avoid the Xn interface between the first node and the second node being disconnected due to the movement of the first node or the second node, so that the context information of the terminal device cannot be migrated, the first node determines to migrate the context information of the terminal device in the case where the first node and / or the second node are WAB nodes, which can timely migrate the context information of the terminal device and guarantee the performance of the terminal device in the inactive state.

[0165] Please refer to FIG. 5A, which is a flowchart of another communication method provided by the embodiments of the present application. The method shown in FIG. 5A can be applied to a terminal device, a first node and a second node, wherein the first node is the last serving node of the terminal device, the second node is the current serving node of the terminal device, the first node is a non-WAB node, and the second node is a WAB node (for example, the second node can be a vehicle-mounted device or the second node can be deployed on a vehicle). That is, the method shown in FIG. 5A can be applied to the scenario of the terminal device in the RRC inactive state reselecting from a non-WAB cell to a WAB cell (such as the scenario of the terminal device getting on a vehicle). As shown in FIG. 5A, the method includes but is not limited to the following steps.

[0166] 501. The second node sends a second broadcast message, and correspondingly, the terminal device receives the second broadcast message.

[0167] The second broadcast message includes fourth indication information. The fourth indication information is used to indicate that the second node is a WAB node. Alternatively, the fourth indication information indicates that the first cell is a WAB cell, and the first cell is a cell under the second node. The fourth indication information can also be referred to as a WAB cell indication. The terminal device can determine that the second node is a WAB node based on the second broadcast message.

[0168] Exemplarily, the second broadcast message can be a SIB1 message of the first cell.

[0169] 502, the terminal device reselects from the second cell to the first cell.

[0170] The first cell corresponds to the second node, and the second cell corresponds to the first node. The first node is a non-WAB node, and the second node is a WAB node, that is, the terminal device reselects from the cell under the non-WAB node to the cell under the WAB node.

[0171] It can be understood that the specific implementation of step 502 can refer to the specific implementation of step 401 in FIG. 4, which will not be described here in detail.

[0172] 503, the terminal device sends a second request message to the second node, and correspondingly, the second node receives the second request message.

[0173] The terminal device sends the second request message to initiate the RNAU in the case of determining that the second node is a WAB node.

[0174] It can be understood that the specific description of the second request message can refer to the related description of step 402 in FIG. 4, which will not be described here in detail.

[0175] 504, the second node sends a first request message to the first node, and correspondingly, the first node receives the first request message.

[0176] 505, the first node sends a first response message to the second node, and correspondingly, the second node receives the first response message.

[0177] As an example, the first request message includes first indication information, the first node determines to migrate the context information of the terminal device, and sends the first response message.

[0178] As another example, the first node determines to migrate the context information of the terminal device in the case of determining that the second node is a WAB node, and sends the first response message.

[0179] It can be understood that the specific implementation of steps 504 and 505 can refer to the related description of steps 403 and 404 in FIG. 4, which will not be described here in detail.

[0180] In the embodiments of the present application, in the scenario that the terminal device in the RRC inactive state reselects from a non-WAB cell to a WAB cell, the terminal device can actively initiate the RNAU, and the first node determines to migrate the context information of the terminal device, so as to timely migrate the context information of the terminal device, and further guarantee the performance of the UE in the RRC inactive state.

[0181] It can be understood that after the terminal device reselects from a non-WAB cell to a WAB cell, the terminal device initiates the RNAU actively even if it has not moved out of the range of its RNA.

[0182] Please refer to FIG. 5B, which is a flowchart of another communication method provided by the embodiments of the present application. The method shown in FIG. 5B can be applied to a terminal device, a first node and a second node, wherein the first node is the last serving node of the terminal device, and the second node is the current serving node of the terminal device. The first node is a WAB node (for example, the first node can be a vehicle-mounted device or the first node can be deployed on a vehicle). The second node can be a WAB node, that is, the method shown in FIG. 5B can be applied to the scenario that the terminal device in RRC inactive state reselects from a cell under one WAB node to a cell under another WAB node (for example, the scenario that the terminal device changes to another vehicle). Alternatively, the second node is a non-WAB node, that is, the method shown in FIG. 5B can be applied to the scenario that the terminal device in RRC inactive state reselects from a cell under one WAB node to a cell under a non-WAB node (for example, the scenario that the terminal device gets off a vehicle). As shown in FIG. 5B, the method includes but is not limited to the following steps.

[0183] Optionally, the method shown in FIG. 5B can include step 511.

[0184] 511. The first node sends a first broadcast message, and correspondingly, the terminal device receives the first broadcast message.

[0185] The first broadcast message includes second indication information, which is used by the terminal device to determine whether the serving node changes after cell reselection. For example, the second indication information is used to indicate that the first cell does not belong to the first node, or the second indication information indicates the length of the identity of the first node. Wherein, the first cell is a neighboring cell of the second cell, and the second cell is a cell under the first node (that is, the second cell belongs to the first node).

[0186] It can be understood that the specific description of the first broadcast message can refer to the related description in step 402 in FIG. 4, which will not be repeated here.

[0187] 512. The terminal device reselects from the second cell to the first cell.

[0188] The second cell corresponds to the first node, and the first cell corresponds to the second node. The first node is a WAB node, that is, the terminal device reselects from a cell under a WAB node to another cell.

[0189] It can be understood that the specific implementation of step 512 can refer to the specific implementation of step 401 in FIG. 4, which will not be described in detail here.

[0190] 513. The terminal device sends a second request message, and correspondingly, the second node receives the second request message.

[0191] The second request message is used to request to resume the RRC connection of the terminal device. The terminal device initiates the RNAU through the second request message.

[0192] As an example, the terminal device sends the second request message to initiate the RNAU in a case where the serving node after cell reselection (i.e., the second node) is determined to be different from the serving node before cell reselection (i.e., the first node). That is, after the terminal device reselects from the second cell to the first cell, if the nodes to which the first cell and the second cell belong are different, the terminal device initiates the RNAU.

[0193] As an example, the terminal device can determine whether the serving node after cell reselection changes according to the second indication information.

[0194] As another example, the terminal device initiates the RNAU after reselecting from a cell under the first node (i.e., the WAB node) to another cell. In this example, the terminal device can not determine whether the serving node after cell reselection changes, but directly initiates the RNAU as long as the cell reselection occurs from the WAB node. After receiving the second request message, the second node can determine whether the last serving node of the terminal device is the second node to determine whether to initiate the context migration request for the terminal device. If the last serving node of the terminal device is the second node, the second node does not need to initiate the context migration request for the terminal device, i.e., the second node does not send the first request message. If the last serving node of the terminal device is not the second node, the second node needs to initiate the context migration request for the terminal device, i.e., the second node sends the first request message to the first node.

[0195] In this example, the first node can not send the first broadcast message, or the first node can not carry the second indication information in the first broadcast message.

[0196] 514, the second node sends the first request message, and correspondingly, the first node receives the first request message.

[0197] 515, the first node sends the first response message, and correspondingly, the second node receives the first response message.

[0198] As an example, the first request message includes the first indication information, and the first node determines to migrate the context information of the terminal device and sends the first response message.

[0199] As another example, the first node determines to migrate the context information of the terminal device and sends the first response message in a case where the first node is determined to be the WAB node.

[0200] It can be understood that the specific implementation of steps 514 and 515 can refer to the related description in steps 403 and 404 in FIG. 4, and will not be described in detail here.

[0201] In the embodiment of the application, in the scenario that the terminal device in the inactive state performs cell reselection on the cell under the WAB node, the terminal device initiates the RNAU after reselecting from the second cell to the first cell, and in this scenario, the first node determines the context information of the terminal device to be migrated, so that the context information of the terminal device can be timely migrated to the second node, and the performance of the terminal device in the inactive state is ensured.

[0202] Please refer to FIG. 6, which is a flowchart of another communication method provided by the embodiment of the application. The method can be applied to the third node and the WAB node. The WAB node here can be the WAB node described above or the WAB-gNB in the WAB node. As shown in FIG. 6, the method includes but is not limited to the following steps.

[0203] 601, the third node sends a first message to the WAB node, and correspondingly, the WAB node receives the first message.

[0204] The first message includes the information of the RNA corresponding to the WAB node and the node list. The node list includes the information of one or more nodes, and the first message indicates that the WAB node establishes an Xn interface with one or more nodes. That is, the first message is used to indicate that the WAB node establishes an Xn interface with the nodes in the node list.

[0205] The third node determines the RNA corresponding to the WAB node before sending the first message.

[0206] Exemplarily, the RNA corresponding to the WAB node is used to represent the paging range of the WAB node, and the WAB node can page the terminal device in the RNA range. The WAB node has an Xn interface with the nodes in the RNA range. The third node configures the RNA corresponding to the WAB node, so that the WAB node can configure the corresponding RNA for the terminal device based on the configuration of the third node.

[0207] Exemplarily, the third node is used to manage the WAB node. For example, the third node is the network management server of the WAB node, which can be local (directly connected through a network cable when the WAB node is opened, and configured) or remote (configured remotely through the PDU session of the MT).

[0208] Exemplarily, the third node is an orchestration and management (OAM) server, or the third node can also be a RAN intelligent controller (RIC) in an O-RAN system.

[0209] Exemplarily, the one or more nodes include one or more base stations, and the node list can also be referred to as a list of Xn interface base stations.

[0210] Exemplarily, the information of the one or more nodes can include an identifier of the one or more nodes or address information of the one or more nodes. After receiving the first message, the WAB node determines the one or more nodes based on the node list, and establishes an Xn interface between the first node and the one or more nodes.

[0211] As an example, the one or more nodes are included in an RNA corresponding to the WAB node.

[0212] As another example, part of the one or more nodes are included in an RNA corresponding to the WAB node, and another part of the one or more nodes are not included in the RNA corresponding to the WAB node. That is, the node list corresponding to the Xn interface includes nodes outside the RNA range, and through the node list, the WAB node can be instructed to establish an Xn interface with the nodes outside the RNA range, so that the WAB node maintains more Xn interfaces, and reduces the situation that the context information of the terminal device cannot be migrated due to the disconnection of the Xn interface between the WAB node and the adjacent node.

[0213] As yet another example, the one or more nodes are not included in the RNA corresponding to the WAB node. After receiving the first message, the WAB node establishes an Xn interface with the nodes in the RNA and the nodes in the node list. Through the node list, the WAB node can establish an Xn interface not only with the nodes within the RNA range, but also with the nodes outside the RNA range, so that the WAB node maintains more Xn interfaces, and reduces the situation that the context information of the terminal device cannot be migrated due to the disconnection of the Xn interface between the WAB node and the adjacent node.

[0214] 602, the WAB node sends an RRC release message to the terminal device, and correspondingly, the terminal device receives the RRC release message.

[0215] The RRC release message includes information of the RNA corresponding to the WAB node, and the RRC release message is used for the terminal device to switch to an RRC inactive state.

[0216] Exemplarily, the terminal device camps on the WAB node, and the WAB node provides the terminal device with an access service. When the terminal device switches from the RRC connected state to the RRC inactive state, the WAB node can make the terminal device switch from the RRC connected state to the RRC inactive state through the RRC release message. The WAB node can also configure the RNA of the terminal device through the RRC release message. For example, the RRC release message includes information of the RNA of the WAB node, that is, the RNA of the terminal device configured through the RRC release message is the same as the RNA of the WAB node.

[0217] In the embodiments of the present application, the RNA of the WAB node is configured by the third node. When the terminal device camping on the WAB node switches to the RRC inactive state, the WAB node can configure the RNA of the terminal device to be the same as the RNA of the WAB node, so as to ensure that the terminal device can be paged by the WAB node within the RNA of the WAB node.

[0218] Optionally, the method shown in FIG. 6 further includes step 603.

[0219] 603. When the update condition of the RNA of the WAB node is met, the third node sends a second message to the WAB node, and correspondingly, the WAB node receives the second message. The second message is used to update the node list and the information of the RNA.

[0220] Exemplarily, the update condition of the RNA includes periodic update of the RNA, change of the Xn interface of the WAB node, and change of the location of the WAB node. When the update condition of the RNA is met, the third node can synchronously update the RNA of the WAB node and the node list corresponding to the Xn interface, so that the WAB node can better maintain the Xn interface with the neighboring nodes and reduce the influence on the performance of the terminal device in the inactive state within the RNA range caused by frequent disconnection of the Xn interface between the WAB node and the neighboring nodes.

[0221] As an example, the third node can periodically update the RNA of the WAB node. For example, when a timer expires, the third node sends a second message to the WAB node to update the RNA of the WAB node and the node list corresponding to the Xn interface. The timing duration of the timer is the update period of the RNA of the WAB node.

[0222] As another example, the third node sends, to the WAB node, a second message to update the RNA and the list of nodes corresponding to the Xn interface of the WAB node in a case where the third node determines that the Xn interface of the WAB node changes. The change of the Xn interface of the WAB node can include that the Xn interface between the WAB node and a node A is disconnected, and / or that the WAB node establishes an Xn interface with a node B. The node A is any neighboring node of the WAB node, and the node B is any neighboring node of the WAB node. When the Xn interface of the WAB node changes, the previously configured RNA and the list of nodes corresponding to the Xn interface do not match the current Xn interface of the WAB node, and therefore the third node needs to update the WAB node and the list of nodes to ensure that the Xn interface exists between the WAB node and any neighboring node within the RNA of the WAB node.

[0223] As another example, the third node sends, to the WAB node, a second message to update the RNA and the list of nodes corresponding to the Xn interface of the WAB node in a case where the third node determines that the location of the WAB node changes. For example, as the WAB node moves, the neighboring nodes of the WAB node change, and therefore the third node reconfigures the RNA of the WAB node and the list of nodes corresponding to the Xn interface, so as to timely maintain the Xn interface between the WAB node and the neighboring nodes and maintain the RNA range of the WAB node, thereby ensuring that the Xn interface exists between the WAB node and any neighboring node within the RNA range.

[0224] In the embodiments of the present application, the third node configures the RNA and the list of nodes corresponding to the Xn interface of the WAB node, and the WAB node configures the RNA of the terminal device to be the same as the RNA of the WAB node when releasing the terminal device to the RRC inactive state, so as to better maintain the Xn interface between the WAB node and any neighboring node within the RNA range and reduce the case that the context migration of the terminal device cannot be completed due to the disconnection of the Xn interface within the RNA range.

[0225] The method shown in FIG. 6 can be combined with the method shown in FIG. 4 or FIG. 5A or FIG. 5B. The WAB node in the method shown in FIG. 6 can be the first node or the second node in the method shown in FIG. 4 or FIG. 5A or FIG. 5B. For example, in a case where the first node is the WAB node, the third node configures the corresponding RNA and the list of nodes for the first node, and the first node indicates that the corresponding RNA of the terminal device is the same as the corresponding RNA of the first node when releasing the terminal device to the RRC inactive state. For another example, in a case where the second node is the WAB node, the third node configures the corresponding RNA and the list of nodes for the second node.

[0226] Referring to FIG. 7, FIG. 7 is a flow diagram of another communication method provided by the embodiments of the present application. As shown in FIG. 7, the method includes but is not limited to the following steps.

[0227] 701. The terminal device sends a second request message, and correspondingly, the second node receives the second request message.

[0228] The second request message is used to request to resume the RRC connection of the terminal device, and the second node is a current serving node of the terminal device.

[0229] The specific implementation of the step 701 can refer to the specific implementation of the step 402 in FIG. 4, which will not be described here in detail.

[0230] 702. The second node sends a third request message to a fourth node, and correspondingly, the fourth node receives the third request message.

[0231] The second node is a WAB node, and the fourth node is a host node (also referred to as a BH-gNB) of the second node. The third request message is used to request the first node to migrate the context information of the terminal device. The first node is the last serving node of the terminal device.

[0232] When the second node determines that there is no Xn interface between the second node and the first node, the second node sends the third request message to the fourth node, and the fourth node forwards the request for migrating the context information of the terminal device.

[0233] Exemplarily, the third request message can include the identification information of the first node.

[0234] Exemplarily, the third request message can also include part or all of the information in the RETRIEVE UE CONTEXT REQUEST message.

[0235] As an example, the third request message is an Xn message, there is an Xn interface between the second node gNB part (i.e., the WAB-gNB) and the fourth node, and the WAB-gNB can send the third request message to the fourth node through the Xn interface.

[0236] As another example, the third request message is an RRC message, there is a Uu interface between the MT part of the second node (i.e., the WAB-MT) and the fourth node, and the MT part of the second node sends the third request message to the fourth node through the Uu node.

[0237] Exemplarily, the third request message includes fifth indication information, which is used to indicate the first node to migrate the context information of the terminal device, or the fifth indication information is used for the first node to determine to migrate the context information of the terminal device, or the fifth indication information is used to indicate the fourth node to carry sixth indication information in the fourth request message, and the sixth indication information is used to indicate the first node to migrate the context information of the terminal device.

[0238] 703. The fourth node sends a fourth request message to the first node, and correspondingly, the first node receives the fourth request message.

[0239] The fourth request message is used to request the context information of the terminal device. For example, the fourth request message can be a RETRIEVE UE CONTEXT REQUEST message, or the fourth request message can include a RETRIEVE UE CONTEXT REQUEST message.

[0240] Exemplarily, the fourth request message is used to forward the third request message. For example, the fourth request message and the third request message have the same data part, or the fourth request message and the third request message carry the same information, and the fourth request message and the third request message correspond to different transceiving ends. After receiving the third request message, the fourth node forwards the third request message to the first node.

[0241] Exemplarily, the fourth request message includes sixth indication information, which is used to instruct the first node to migrate the context information of the terminal device, or the sixth indication information is used for the first node to determine the context information of the terminal device.

[0242] The specific description of the fourth request message can also refer to the description of the first request message above, which will not be described in detail here.

[0243] 704. The first node sends a second response message to the fourth node, and correspondingly, the fourth node receives the second response message.

[0244] The first node is the last serving node of the terminal device, the second response message is used to migrate the context information of the terminal device, and the second response message includes the context information of the terminal device. After receiving the third request message from the fourth node, the first node migrates the context information of the terminal device through the second response message. For example, the second response message can be a RETRIEVE CONTEXT RESPONSE message.

[0245] The specific description of the second response message can also refer to the description of the first response message above, which will not be described in detail here.

[0246] 705. The fourth node sends a third response message to the second node, and correspondingly, the second node receives the third response message.

[0247] The third response message includes the context information of the terminal device. After receiving the second response message, the fourth node forwards the context information of the terminal device through the third response message, so that the context information of the terminal device is migrated to the second node.

[0248] Exemplarily, the third response message is used for forwarding the second response message, for example, the third response message and the second response message include the same information body, and the corresponding transceiving ends are different.

[0249] In the embodiments of the present application, in the case that the second node determines that there is no Xn interface between the second node and the first node, the second node can forward the request for migrating the context information of the terminal device through the fourth node, so as to ensure that the context information of the terminal device can be migrated to the second node, thereby guaranteeing the performance of the terminal device in the inactive state.

[0250] The communication apparatus provided by the embodiments of the present application will be introduced below.

[0251] The present application divides the function modules of the communication apparatus according to the above-mentioned method embodiments, for example, each function module can be divided according to each function, or two or more functions can be integrated in one processing module. The above-mentioned integrated module can be realized in the form of hardware or in the form of a software function module. It should be noted that the division of the modules in the present application is illustrative, and is only a logical function division. In actual implementation, another division mode can be used. The communication apparatus of the embodiments of the present application will be described in detail below with reference to FIGS. 8 to 10.

[0252] FIG. 8 is a structural schematic diagram of a communication apparatus provided by an embodiment of the present application. As shown in FIG. 8, the communication apparatus includes a processing module 801 and a transceiving module 802. The transceiving module 802 can realize corresponding communication functions, and the processing module 801 is used to realize corresponding processing functions. For example, the transceiving module 802 can also be referred to as an interface, a communication interface, or a communication module, etc.

[0253] In some embodiments of the present application, the communication apparatus can be used to execute the actions performed by the first node in the above-mentioned method embodiments. At this time, the communication apparatus can be the first node itself or a chip or a function module configured in the first node, etc. The transceiving module 802 is used to execute the transceiving related operations of the first node in the above-mentioned method embodiments, and the processing module 801 is used to execute the processing related operations of the first node in the above-mentioned method embodiments.

[0254] Exemplarily, the transceiving module 802 is used to receive or input the first request message, and send or output the first response message.

[0255] The processing module 801 is used to determine that the first node and / or the second node is a WAB node.

[0256] Optionally, the transceiving module 802 is used to send or output the first broadcast message.

[0257] It can be understood that the specific description about the first request message, the first response message, the first broadcast message, the first node, the second node, etc. can refer to the related description in the above method embodiments, which will not be repeated here.

[0258] In some embodiments of the present application, the communication apparatus can be configured to perform the actions performed by the terminal device in the above method embodiments. The transceiver module 802 is configured to perform the transceiving related operations of the terminal device in the above method embodiments, and the processing module 801 is configured to perform the processing related operations of the terminal device in the above method embodiments.

[0259] For example, the transceiver module 802 is configured to receive or input the second request message, and transmit or output the first request message.

[0260] The processing module 801 is configured to generate the first request message.

[0261] Optionally, the transceiver module 802 is further configured to receive or input the first response message.

[0262] Optionally, the transceiver module 802 is further configured to transmit or output the second broadcast message.

[0263] It can be understood that the specific description about the first node, the second node, the second request message, the first request message, the first response message, and the second broadcast message, etc. can refer to the related description in the above method embodiments, which will not be repeated here.

[0264] In some embodiments of the present application, the communication apparatus can be configured to perform the actions performed by the terminal device in the above method embodiments. The transceiver module 802 is configured to perform the transceiving related operations of the terminal device in the above method embodiments, and the processing module 801 is configured to perform the processing related operations of the terminal device in the above method embodiments.

[0265] For example, the processing module 801 is configured to reselect from the second cell to the first cell, and the transceiver module 802 is configured to transmit or output the second request message.

[0266] Optionally, the processing module 801 is further configured to determine that the first node and / or the second node is a WAB node.

[0267] Optionally, the transceiver module 802 is further configured to receive or input the first broadcast message.

[0268] Optionally, the transceiver module 802 is further configured to receive or input the second broadcast message.

[0269] It can be understood that the specific description about the first node, the second node, the second request message, the first broadcast message, the second broadcast message, and the like can refer to the related description in the method embodiments, and will not be repeated here.

[0270] In some embodiments of the application, the communication apparatus can be configured to perform the actions performed by the third node in the method embodiments. The communication apparatus can be the third node itself or a chip or functional module configured in the third node. The transceiver module 802 is configured to perform the transceiving related operations of the third node in the method embodiments, and the processing module 801 is configured to perform the processing related operations of the third node in the method embodiments.

[0271] For example, the processing module 801 is configured to determine the RNA corresponding to the WAB node, and the transceiver module 802 is configured to send or output the first message.

[0272] Optionally, the transceiver module 802 is further configured to receive or input the second message.

[0273] It can be understood that the specific description about the RNA, the first message, the second message, and the like can refer to the related description in the method embodiments, and will not be repeated here.

[0274] In some embodiments of the application, the communication apparatus can be configured to perform the actions performed by the WAB node in the method embodiments. The communication apparatus can be the WAB node itself or a chip or functional module configured in the WAB node. The transceiver module 802 is configured to perform the transceiving related operations of the WAB node in the method embodiments, and the processing module 801 is configured to perform the processing related operations of the WAB node in the method embodiments.

[0275] For example, the transceiver module 802 is configured to receive or input the first message and send or output the RRC release message.

[0276] The processing module 801 is configured to generate the RRC release message.

[0277] Optionally, the transceiver module 802 is further configured to receive or input the second message.

[0278] It can be understood that the specific description about the RNA, the first message, the second message, the RRC release message, and the like can refer to the related description in the method embodiments, and will not be repeated here.

[0279] Referring to FIG. 8, in some embodiments of the present application, the communication apparatus can be configured to perform the actions of the second node in the above method embodiments. The communication apparatus can be the second node itself or a chip or functional module configured in the second node. The transceiver module 802 is configured to perform the transceiving related operations of the second node in the above method embodiments, and the processing module 801 is configured to perform the processing related operations of the second node in the above method embodiments.

[0280] For example, the transceiver module 802 is configured to receive or input the second request message, and the processing module 801 is configured to determine that there is no Xn interface between the first node and the second node. The transceiver module 802 is further configured to send or output the third request message.

[0281] Optionally, the transceiver module 802 is further configured to receive or input the third response message.

[0282] It can be understood that the specific description of the second request message, the third request message, and the third response message can refer to the related description in the above method embodiments, and will not be described in detail here.

[0283] Referring to FIG. 8, in some embodiments of the present application, the communication apparatus can be configured to perform the actions of the fourth node in the above method embodiments. The communication apparatus can be the fourth node itself or a chip or functional module configured in the fourth node. The transceiver module 802 is configured to perform the transceiving related operations of the fourth node in the above method embodiments, and the processing module 801 is configured to perform the processing related operations of the fourth node in the above method embodiments.

[0284] For example, the transceiver module 802 is configured to receive or input the third request message, and send or output the fourth request message.

[0285] Optionally, the transceiver module 802 is further configured to receive or input the second response message, and send or output the third response message.

[0286] It can be understood that the specific description of the second request message, the third request message, the fourth request message, the second response message, and the third response message can refer to the related description in the above method embodiments, and will not be described in detail here.

[0287] Referring to FIG. 8, in some embodiments of the present application, the communication apparatus can be configured to perform the actions of the first node in the above method embodiments. The communication apparatus can be the first node itself or a chip or functional module configured in the first node. The transceiver module 802 is configured to perform the transceiving related operations of the first node in the above method embodiments, and the processing module 801 is configured to perform the processing related operations of the fourth node in the above method embodiments.

[0288] Exemplarily, the transceiver module 802 is configured to receive or input the fourth request message and transmit or output the second response message.

[0289] It can be understood that the specific description about the fourth request message, the second response message and the like can refer to the related description in the above method embodiments, and will not be described in detail here.

[0290] Exemplarily, the transceiver module 802 can include a radio frequency module, an antenna module and the like. Exemplarily, the transceiver module 802 can include a pin module and the like.

[0291] Optionally, in each of the above embodiments, the communication device can further include a storage module, which can be configured to store instructions and / or data, and the processing module 801 can read the instructions and / or data in the storage module to enable the communication device to implement the above method embodiments. Exemplarily, the storage module can store the transmission strategy of the radio frequency signal and the like shown in the above.

[0292] Exemplarily, the transceiver module 802 can be a communication module or an interface connected with the processing module 801, or the transceiver module 802 can also be an input / output interface of the processing module 801.

[0293] In each of the above embodiments, the specific description about each term or name or step and the like can refer to the introduction in the above method embodiments, and will not be described one by one here.

[0294] The specific description of the transceiver module and the processing module shown in each of the above embodiments is only an example, and for the specific functions or executed steps of the transceiver module and the processing module, the above method embodiments can be referred to, and will not be described here.

[0295] The above introduces the communication device of the embodiments of the present application, and the possible product forms of the communication device are introduced below. Any product in any form that has the functions of the communication device shown in the above FIG. 8 falls within the protection scope of the embodiments of the present application. The following introduction is only an example, and does not limit the product form of the communication device of the embodiments of the present application to only this.

[0296] In a possible implementation, in the communication apparatus shown in FIG. 8, the processing module 801 can be one or more processors, and the transceiver module 802 can be a transceiver, or the transceiver module 802 can also be a sending module and a receiving module, the sending module can be a transmitter, and the receiving module can be a receiver, and the sending module and the receiving module are integrated in one device, for example, a transceiver. In the embodiment of the present application, the processor and the transceiver can be coupled, and the connection manner between the processor and the transceiver is not limited in the embodiment of the present application. In the process of executing the above method, the process about sending information in the above method can be the process that the processor outputs the above information. When the above information is output, the processor outputs the above information to the transceiver, so as to be transmitted by the transceiver. After the above information is output by the processor, the above information can also need to be processed further, and then reaches the transceiver. Similarly, the process about receiving information in the above method can be the process that the processor receives the input above information. When the processor receives the input information, the transceiver receives the above information and inputs the processor. Further, after the transceiver receives the above information, the above information can need to be processed further, and then inputs the processor.

[0297] As shown in FIG. 9, the communication apparatus 90 includes one or more processors 920 and a transceiver 910.

[0298] In some embodiments of the present application, the communication apparatus can be used to execute the steps or methods or functions executed by the first node, for example, the processor 920 can be used to execute the functions or steps implemented by the processing module 801 shown in FIG. 8, and the transceiver 910 can be used to execute the functions or steps implemented by the transceiver module 802 shown in FIG. 8. The specific description of the processor 920 and the transceiver 910 can refer to FIG. 8 or the method embodiments shown above, and will not be described in detail here.

[0299] In some embodiments of the present application, the communication apparatus can be used to execute the steps or methods or functions executed by the first node, for example, the processor 920 can be used to execute the functions or steps implemented by the processing module 801 shown in FIG. 8, and the transceiver 910 can be used to execute the functions or steps implemented by the transceiver module 802 shown in FIG. 8. The specific description of the processor 920 and the transceiver 910 can refer to FIG. 8 or the method embodiments shown above, and will not be described in detail here.

[0300] In some embodiments of the application, the communication device can be configured to perform the steps or methods or functions performed by the third node as described above, e.g., the processor 920 can be configured to perform the functions or steps implemented by the processing module 801 as illustrated in FIG. 8, and the transceiver 910 can be configured to perform the functions or steps implemented by the transceiving module 802 as illustrated in FIG. 8. More details about the processor 920 and the transceiver 910 can be referred to the method embodiments described above or FIG. 8, and will not be repeated here.

[0301] In some embodiments of the application, the communication device can be configured to perform the steps or methods or functions performed by the WAB node as described above, e.g., the processor 920 can be configured to perform the functions or steps implemented by the processing module 801 as illustrated in FIG. 8, and the transceiver 910 can be configured to perform the functions or steps implemented by the transceiving module 802 as illustrated in FIG. 8. More details about the processor 920 and the transceiver 910 can be referred to the method embodiments described above or FIG. 8, and will not be repeated here.

[0302] In some embodiments of the application, the communication device can be configured to perform the steps or methods or functions performed by the fourth node as described above, e.g., the processor 920 can be configured to perform the functions or steps implemented by the processing module 801 as illustrated in FIG. 8, and the transceiver 910 can be configured to perform the functions or steps implemented by the transceiving module 802 as illustrated in FIG. 8. More details about the processor 920 and the transceiver 910 can be referred to the method embodiments described above or FIG. 8, and will not be repeated here.

[0303] In each of the above implementation of the communication device as illustrated in FIG. 9, the transceiver can include a receiver configured to perform the function (or operation) of receiving and a transmitter configured to perform the function (or operation) of transmitting. The transceiver can be configured to communicate with other devices / apparatuses through a transmission medium.

[0304] Optionally, the communication device 90 can further include one or more memories 930 configured to store program instructions and / or data. The memory 930 is coupled to the processor 920. The coupling between the components, units or modules in the embodiments of the application can be direct or indirect communication connection, which can be electrical, mechanical or other form, for information interaction between the components, units or modules. The processor 920 can operate in cooperation with the memory 930. The processor 920 can execute the program instructions stored in the memory 930. Optionally, at least one of the one or more memories can be included in the processor.

[0305] The specific connection medium between the transceiver 910, the processor 920 and the memory 930 in the embodiments of the present application is not limited. In FIG. 9, the memory 930, the processor 920 and the transceiver 910 are connected through a bus 940, which is represented by a thick line in FIG. 9, and the connection mode between other components is only illustrative and is not limited. The bus can be divided into an address bus, a data bus, a control bus and the like. For convenience of representation, only one thick line is used in FIG. 9, but it does not mean that there is only one bus or only one type of bus.

[0306] In the embodiments of the present application, the processor can be a general processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc., which can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application. The general processor can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as execution completed by a hardware processor, or executed by a combination of hardware and software modules in the processor, etc.

[0307] In the embodiments of the present application, the memory can include, but is not limited to, a non-volatile memory such as a hard disk drive (HDD) or a solid-state drive (SSD), a random access memory (RAM), an erasable programmable ROM (EPROM), a read-only memory (ROM) or a compact disc read-only memory (CD-ROM), etc. The memory can be any storage medium capable of carrying or storing program codes in the form of instructions or data structures and capable of being read and / or written by a computer (such as the communication device shown in the present application, etc.), but is not limited thereto. The memory in the embodiments of the present application can also be a circuit or any other device capable of realizing a storage function, used for storing program instructions and / or data.

[0308] The processor 920 is mainly used for processing communication protocols and communication data, and controlling the whole communication device, executing software programs, and processing data of the software programs. The memory 930 is mainly used for storing software programs and data. The transceiver 910 can include a control circuit and an antenna, and the control circuit is mainly used for conversion between baseband signals and radio frequency signals and processing of the radio frequency signals. The antenna is mainly used for transceiving radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, keyboards, etc., are mainly used for receiving data input by users and outputting data to users.

[0309] When the communication apparatus is powered on, the processor 920 can read the software program in the memory 930, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be transmitted wirelessly, the processor 920 performs baseband processing on the data to be transmitted, and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal, and transmits the radio frequency signal in the form of electromagnetic wave through the antenna. When data is transmitted to the communication apparatus, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor 920. The processor 920 converts the baseband signal into data and processes the data.

[0310] In another implementation, the radio frequency circuit and the antenna can be arranged independently of the processor that performs the baseband processing, for example, in a distributed scenario, the radio frequency circuit and the antenna can be arranged remotely from the communication apparatus.

[0311] The communication apparatus shown in the embodiments of the present application can also have more components than those shown in FIG. 9, which are not limited in the embodiments of the present application. The methods performed by the processor and the transceiver shown above are only examples, and the specific steps performed by the processor and the transceiver can refer to the methods introduced above.

[0312] In another possible implementation, in the communication apparatus shown in FIG. 8, the processing module 801 can be one or more logic circuits, and the transceiving module 802 can be an input / output interface, also referred to as a communication interface, or an interface circuit, or an interface, etc. Alternatively, the transceiving module 802 can also be a sending module and a receiving module. The sending module can be an output interface, and the receiving module can be an input interface. The sending module and the receiving module are integrated in one module, for example, an input / output interface. As shown in FIG. 10, the communication apparatus shown in FIG. 10 includes a logic circuit 1001 and an interface 1002. That is, the processing module 801 can be implemented by the logic circuit 1001, and the transceiving module 802 can be implemented by the interface 1002. The logic circuit 1001 can be a chip, a processing circuit, an integrated circuit, or a system on chip (SoC) chip, etc., and the interface 1002 can be a communication interface, an input / output interface, a pin, etc. For example, FIG. 10 is a chip including the logic circuit 1001 and the interface 1002, which is taken as an example of the above communication apparatus.

[0313] In the embodiments of the present application, the logic circuit and the interface can also be coupled with each other. The specific connection mode of the logic circuit and the interface is not limited in the embodiments of the present application. For example, the logic circuit 1001 can be used to execute the functions or steps implemented by the processing module 801 shown in FIG. 8, and the interface 1002 can be used to execute the functions or steps implemented by the transceiver module 802 shown in FIG. 8. The specific description of the logic circuit 1001 and the interface 1002 can refer to the method embodiments shown in FIG. 8 or the above description, and will not be described in detail here.

[0314] The communication apparatus shown in the embodiments of the present application can implement the method provided by the embodiments of the present application in the form of hardware, or implement the method provided by the embodiments of the present application in the form of software, etc., and the embodiments of the present application do not limit this.

[0315] In addition, the embodiments of the present application also provide a communication system, which includes a first node, a second node and a terminal device, and the first node, the second node and the terminal device can be used to execute the method in any of the preceding embodiments. Alternatively, the communication system includes a third node and a WAB node, and the third node and the WAB node can be used to execute the method in any of the preceding embodiments. Alternatively, the communication system includes a first node, a second node and a fourth node, and the first node, the second node and the fourth node can be used to execute the method in any of the preceding embodiments.

[0316] The present application also provides a computer program for implementing the operations and / or processes performed by each communication apparatus or node in the method provided by the present application.

[0317] The present application also provides a computer readable storage medium, which stores computer code, when the computer code is run on a computer, so that the computer executes the operations and / or processes performed by each communication apparatus or node in the method provided by the present application.

[0318] The present application also provides a computer program product, which includes computer code or a computer program, when the computer code or the computer program is run on a computer, so that the operations and / or processes performed by each communication apparatus or node in the method provided by the present application are executed.

[0319] In several embodiments provided in the present application, it should be understood that the disclosed system, communication device and method can be implemented in other manners. For example, the division of the above-described communication device embodiments is merely a logical function division, and there can be another division manner for the actual implementation, for example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections can be indirect couplings or communication connections through some interfaces, communication devices or modules, and can be electric, mechanical or in other forms.

[0320] The modules illustrated as separated components can or can not be physically separated, and the components illustrated as modules can or can not be physical modules, i.e., can be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the technical effects of the solutions provided in the embodiments of the present application.

[0321] In addition, each functional module in the various embodiments of the present application can be integrated into one processing module, or each module can exist physically independently, or two or more modules can be integrated into one module. The above integrated module can be realized in the form of hardware or in the form of a software functional module.

[0322] The integrated module, if realized in the form of a software functional module and sold or used as an independent product, can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part of the prior art that contributes to the technical solutions, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a readable storage medium, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned readable storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0323] The above description is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication method characterized by comprising: The communication method applied to a first node comprises: receiving a first request message from a second node, the first request message being used for requesting migration of context information of a terminal device, the second node being a current serving node of the terminal device, and the first node being a last serving node of the terminal device; in a case where it is determined that the first node and / or the second node is a wireless access backhaul (WAB) node or the first request message comprises first indication information, sending a first response message to the second node, the first response message comprising the context information of the terminal device, wherein the first indication information is used for indicating that the first node migrates the context information of the terminal device.

2. The communication method according to claim 1, characterized by, The first node is a WAB node, and the method further comprises: sending a first broadcast message, the first broadcast message comprising second indication information, the second indication information indicating that a first cell does not belong to the first node, or the second indication information indicating a length of an identity of the first node, wherein the first cell is a neighbor cell of a second cell, and the second cell is a cell under the first node.

3. A communication method characterized by comprising: The communication method applied to a second node comprises: receiving a second request message from a terminal device, the second request message being used for requesting resumption of a radio resource control (RRC) connection of the terminal device; sending a first request message to a first node, the first request message being used for requesting migration of context information of the terminal device; wherein the first node is a last serving node of the terminal device, the second node is a current serving node of the terminal device, and the first node and / or the second node is a wireless access backhaul (WAB) node.

4. The communication method according to claim 3, characterized by, The communication method further comprises: receiving a first response message from the first node, the first response message comprising the context information of the terminal device.

5. The communication method according to claim 3 or 4, characterized by, The second request message comprises third indication information, the third indication information being used for indicating that the first node migrates the context information of the terminal device.

6. The communication method according to claim 5, wherein, The second request message is an RRC resume request message, and the third indication information is carried in an RRC resume cause information element of the RRC resume request message.

7. The communication method according to any one of claims 3 to 6, characterized by, The first request message comprises first indication information, the first indication information being used for indicating that the first node migrates the context information of the terminal device.

8. The communication method according to any one of claims 3 to 7, characterized by, The second node is a WAB node, and the communication method further comprises: sending a second broadcast message, the second broadcast message comprising fourth indication information, the fourth indication information indicating that the second node is a WAB node.

9. A communication method characterized by comprising: The communication method applied to a terminal device comprises: reselecting from a second cell to a first cell, the second cell corresponding to a first node, and the first cell corresponding to a second node; in a case where the first node and / or the second node is a wireless access backhaul (WAB) node, sending a second request message to the second node, the second request being used for requesting resumption of a radio resource control (RRC) connection of the terminal device.

10. The communication method according to claim 9, wherein, The first node is a WAB node, and the communication method further comprises: receiving a first broadcast message from the first node, the first broadcast message comprising second indication information, the second indication information indicating that the first cell does not belong to the first node, or the second indication information indicating a length of an identity of the first node.

11. The communication method according to claim 9 or 10, characterized by, The second node is a WAB node, and the communication method further comprises: receiving a second broadcast message from the second node, the second broadcast message comprising fourth indication information, the fourth indication information indicating that the second node is a WAB node.

12. The communication method according to any one of claims 9-11, characterized by, The second request message comprises third indication information, the third indication information being used to instruct the first node to migrate context information of the terminal device.

13. The communication method according to claim 12, wherein, The second request message comprises an RRC resume request message, and the third indication information is carried in an RRC resume cause information element of the RRC resume request message.

14. A communication method, comprising: The communication method applied to a third node comprises: determining a radio access network notification area (RNA) corresponding to a wireless access backhaul (WAB) node; sending a first message to the WAB node, the first message comprising information of the RNA and a node list, the node list comprising information of one or more nodes, the first message instructing the WAB node to establish an Xn interface with the one or more nodes.

15. The communication method according to claim 14, wherein, The communication method further comprises: when an update condition of the RNA is met, sending a second message to the WAB node, the second message being used to update the node list and the information of the RNA.

16. A method of communication, comprising: The communication method applied to a wireless access backhaul (WAB) node comprises: receiving a first message from a third node, the first message comprising information of an RNA corresponding to the WAB node and a node list, the node list comprising information of one or more nodes, the first message instructing the WAB node to establish an Xn interface with the one or more nodes; sending a radio resource control (RRC) release message to a terminal device, the RRC release message comprising information of the RNA, the RRC release message being used to instruct the terminal device to switch to an RRC inactive state.

17. The communication method of claim 16, wherein, The communication method further comprises: receiving a second message from the third node, the second message being used to update the node list and the information of the RNA.

18. A communications device, characterized by The apparatus comprises a module for performing the method according to any one of claims 1-17.

19. A communications device, characterized by The apparatus comprises a processor configured to cause the apparatus to perform the method according to any one of claims 1-17.

20. A communications device, characterized by The apparatus comprises a logic circuit and an interface, the interface being used to input and / or output information, and the logic circuit being used to cause the apparatus to perform the method according to any one of claims 1-17.

21. A computer-readable storage medium, characterized in that, The computer readable storage medium is used to store a computer program, and the computer program is executed by a computer to perform the method according to any one of claims 1-17.

22. A computer program product, characterised in that, The computer program product is executed by a computer to perform the method according to any one of claims 1-17.

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