Communication method and apparatus

Abstract

A communication method and apparatus. In the method, an access network device no longer periodically sends a system message, such as SIB1. The access network device sends the system message upon triggering, for example, the access network device sends the system message upon triggering of receiving a first uplink signal. Compared with periodically sending the system message by the access network device, sending the system message upon triggering can reduce the energy consumption of sending the system message by the access network device.

Description

A communication method and apparatus

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411062451.8, filed on August 2, 2024, entitled "A Communication Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0004] In wireless communication systems, access network devices periodically transmit downlink common signals to manage the mobility of terminal devices. For example, in new radio (NR) systems, the transmission period of the synchronization signal / physical broadcast channel block (SSB) is typically 5 milliseconds (ms), 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms. The periodic transmission of downlink common signals by access network devices results in significant energy consumption. Access network devices cannot achieve energy savings through prolonged sleep cycles. Therefore, reducing the power consumption of access network devices transmitting downlink common signals is a pressing issue that needs to be addressed. Summary of the Invention

[0005] This application provides a communication method and apparatus to reduce the power consumption of access network devices when transmitting downlink common signals (such as system messages).

[0006] In a first aspect, a communication method is provided, which is applied to a terminal device. For example, the execution subject of the method is the terminal device or a device or module (e.g., a chip, chip system, circuit, processor, or others) with corresponding functions within the terminal device, comprising: sending a first uplink signal; receiving a first downlink signal, wherein the first uplink signal is used to trigger the first downlink signal, and the first downlink signal includes a system message.

[0007] With the above design, the terminal device sends a first uplink signal, the first access network device receives the first uplink signal, and the first access network device sends a first downlink signal including system messages under the trigger of the first uplink signal. That is, the first access network device sends system messages based on the trigger. Compared with the first access network device periodically sending system messages, the energy consumption of the first access network device in sending system messages can be reduced.

[0008] In conjunction with the first aspect, in one possible implementation, the first downlink signal originates from a first access network device, and the first uplink signal is used to trigger the first downlink signal. Specifically, the identifier of the first tracking area included in the first uplink signal is different from the identifier of the second tracking area where the first access network device is located, the first uplink signal triggers the first downlink signal, and the second tracking area includes at least the first access network device.

[0009] With the above design, when the terminal device moves to a new tracking area, such as the second tracking area, the terminal device can trigger the first access network device in the second tracking area to send a first downlink signal including system messages by sending a first uplink signal. This allows the terminal device to obtain the system messages of the new second tracking area. Furthermore, the terminal device can perform random access based on the system messages of the second tracking area and then access the access network device of the new second tracking area.

[0010] In conjunction with the first or third aspect, in one possible implementation, the terminal device is in a disconnected state. In this mode, the terminal device performs random access via a system message in the first downlink signal, thereby accessing the network and restoring the connected state.

[0011] In conjunction with the first or third aspect, in one possible implementation, the terminal device is in an idle state or a deactivated state.

[0012] In conjunction with the first aspect, in one possible implementation, prior to sending the first uplink signal, the method further includes receiving a synchronization signal, the synchronization signal including an identifier of the first tracking area.

[0013] In conjunction with the first aspect, in one possible implementation, sending the first uplink signal includes: receiving a synchronization signal, the synchronization signal including an identifier of a first tracking area; the identifier of the first tracking area is different from the identifier of a third tracking area; sending the first uplink signal including the first indication information, the identifier of the third tracking area being the latest tracking area identifier obtained before receiving the synchronization signal, and the first tracking area or the third tracking area including at least one access network device.

[0014] With the above design, the terminal device receives a synchronization signal including the identifier of the first tracking area. Of course, this synchronization signal can be sent by the access network device located in the first tracking area. The terminal device can determine whether the identifier of the first tracking area is the same as the identifier of the previously acquired third tracking area. If the identifier of the first tracking area is the same as the identifier of the third tracking area, it means that the terminal device has not moved to a new tracking area; otherwise, it means that the terminal device has moved to a new tracking area (e.g., the first tracking area). At this time, the terminal device can send a first uplink signal. When the first access network device in the first tracking area receives the first uplink signal, it can send a first downlink signal including system messages, so that the terminal device can receive the system messages of the newly moved first tracking area and access the first access network device of the newly moved first tracking area.

[0015] In conjunction with the first aspect, in one possible implementation, the first uplink signal includes an identifier of the terminal device, which is used to obtain context information of the terminal device.

[0016] With the above design, the identifier of the terminal device is carried in the first uplink signal, and the first access network device can quickly obtain the context information of the terminal device, thereby enabling the terminal device and the first access network device to quickly transmit data.

[0017] In a second aspect, a communication method is provided, which is applied to a first access network device. For example, the execution subject of the method is the first access network device, or the first access network device has a corresponding device or module (e.g., chip, chip system, circuit, processor or others) with corresponding functions. The method includes: receiving a first uplink signal, which is used to trigger a first downlink signal; and sending the first downlink signal, which includes a system message.

[0018] In one possible implementation, in conjunction with the first, second, or third aspect, the first uplink signal includes an identifier of a first tracking area, which includes at least one access network device.

[0019] In conjunction with the second aspect, in one possible implementation, the first downlink signal is sent by the first access network device, and sending the first downlink signal includes: the identifier of the first tracking area included in the first uplink signal is different from the identifier of the second tracking area where the first access network device is located, and the first downlink signal is sent, wherein the second tracking area includes at least the first access network device.

[0020] In one possible implementation, in conjunction with the first, second, or third aspect, the first uplink signal includes first indication information, which is used to indicate the transmission of the first downlink signal.

[0021] In conjunction with the second aspect, in one possible implementation, prior to receiving the first uplink signal, the method further includes: sending a synchronization signal, the synchronization signal including an identifier of a first tracking area, the first tracking area including at least one access network device.

[0022] In conjunction with the first, second, or third aspect, in one possible implementation, the synchronization signal is also used to indicate the time-frequency resources of the first uplink signal.

[0023] In conjunction with the first, second, or third aspect, in one possible implementation, the synchronization signal is further used to indicate the time-frequency resources of the first uplink signal, specifically including: the synchronization signal is further used to indicate M time-frequency resources, the M time-frequency resources being time-frequency resources in M ​​tracking areas used to carry the first uplink signal, where M is an integer greater than 1.

[0024] In one possible implementation, in conjunction with the first, second, or third aspect, the M tracking regions include the first tracking region and M-1 tracking regions adjacent to the first tracking region.

[0025] In one possible implementation, combining the first, second, or third aspects, the transmission period of the synchronization signal is greater than 160 milliseconds.

[0026] In conjunction with the second aspect, in one possible implementation, the first uplink signal includes an identifier of the terminal device, and further includes: determining the context information of the terminal device based on the identifier of the terminal device.

[0027] In one possible implementation, in conjunction with the first, second, or third aspect, the first uplink signal further includes second indication information, which is used to indicate that the terminal device has a data transmission requirement.

[0028] Thirdly, a communication method is provided, comprising: a second access network device sending a synchronization signal to a terminal device; the terminal device receiving the synchronization signal and sending a first uplink signal to a first access network device, the first uplink signal being used to trigger a first downlink signal; the first access network device receiving the first uplink signal and sending a first downlink signal to the terminal device, the first downlink signal including a system message. Optionally, the second access network device and the first access network device may be the same access network device or different access network devices.

[0029] In conjunction with the third aspect, in one possible implementation, the synchronization signal includes an identifier of a first tracking area, which includes at least the second access network device.

[0030] In conjunction with the third aspect, in one possible implementation, the first access network device receives a first uplink signal and sends a first downlink signal to the terminal device, including: the identifier of the first tracking area included in the first uplink signal is different from the identifier of the second tracking area where the first access network device is located, and the first downlink signal is sent, wherein the second tracking area includes at least the first access network device.

[0031] In conjunction with the third aspect, in one possible implementation, the terminal device receives a synchronization signal and sends a first uplink signal to the first access network device, including: the synchronization signal received by the terminal device includes an identifier of a first tracking area; the identifier of the first tracking area is different from the identifier of a third tracking area; the terminal device sends the first uplink signal including the first indication information; the identifier of the third tracking area is the latest tracking area identifier obtained before receiving the synchronization signal; the first tracking area or the third tracking area includes at least one access network device.

[0032] In conjunction with the third aspect, in one possible implementation, the first uplink signal includes the identifier of the terminal device, and further includes: the first access network device determining the context information of the terminal device based on the identifier of the terminal device.

[0033] Fourthly, an apparatus is provided capable of implementing the method described in the first aspect. For example, the apparatus includes modules, units, or components that perform the method described in the first aspect. Specifically, the modules, units, or components can be implemented in hardware, software, or a combination of hardware and software.

[0034] In one design, the device includes a unit that performs the method described in the first aspect.

[0035] In one design, the device includes a processor for implementing the method of the first aspect described above. Optionally, the device further includes a memory, with the processor coupled to the memory, the processor executing computer programs or instructions stored in the memory, such that the device implements the method of the first aspect described above.

[0036] In one design, the device includes a processor and an interface circuit. The interface circuit is used to receive signals from other devices outside the device and transmit them to the processor, or to send signals from the processor to other devices outside the device. The processor implements the method of the first aspect described above through logic circuits or executing code instructions.

[0037] In one design, the device may be the first device, or a module, unit, or component (e.g., a chip, chip system, circuit, or processor, etc.) that corresponds one-to-one with the first device to perform the methods / operations / steps / actions described in the first aspect, or a device that can be used in conjunction with the first device.

[0038] Fifthly, an apparatus is provided capable of implementing the method of the second aspect described above. For example, the apparatus includes modules, units, or components that perform the method described in the second aspect. Specifically, the modules, units, or components can be implemented in hardware, software, or a combination of hardware and software.

[0039] In one design, the device includes a unit that performs the method described in the second aspect.

[0040] In one design, the device includes a processor for implementing the method of the second aspect described above. Optionally, the device further includes a memory, with the processor coupled to the memory, the processor executing computer programs or instructions stored in the memory, such that the device implements the method of the second aspect described above.

[0041] In one design, the device includes a processor and an interface circuit. The interface circuit is used to receive signals from other devices outside the device and transmit them to the processor, or to send signals from the processor to other devices outside the device. The processor implements the method of the second aspect described above through logic circuits or executing code instructions.

[0042] In one design, the device can be a second device, or a module, unit, or component (e.g., a chip, chip system, circuit, or processor, etc.) that corresponds one-to-one with the method / operation / step / action described in the second aspect in the second device, or a device that can be used in conjunction with the second device.

[0043] Sixthly, a computer-readable storage medium is provided, storing a computer program or instructions that, when executed on a computer, cause the computer to implement the methods of the first or second aspect described above.

[0044] In a seventh aspect, a computer program product is provided, comprising a computer program or instructions that, when executed by a computer, cause the methods described in the first or second aspect to be performed.

[0045] Eighthly, a chip is provided, including a processor for implementing the methods of the first or second aspect described above. Optionally, the chip further includes a memory, the processor being coupled to the memory, the processor executing computer programs or instructions stored in the memory, causing the chip to implement the methods of the first or second aspect described above.

[0046] Ninth aspect, a communication system is provided, comprising: a first communication device and a second communication device; wherein the first communication device is used to implement the method of the first aspect; and the second communication device is used to implement the method of the second aspect. Attached Figure Description

[0047] Figure 1 is a schematic diagram of the communication system provided in an embodiment of this application;

[0048] Figure 2 is a flowchart illustrating the communication method provided in an embodiment of this application;

[0049] Figure 3 is a schematic diagram of the application scenario provided in the embodiments of this application;

[0050] Figure 4 is a structural schematic diagram of the device provided in an embodiment of this application;

[0051] Figure 5 is another structural schematic diagram of the device provided in the embodiment of this application. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings. The specific operating methods and functional descriptions in the method embodiments can also be applied to the device embodiments or system embodiments.

[0053] In this application, the number of nouns, unless otherwise specified, refers to "singular nouns or plural nouns," that is, "one or more." "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. In the textual description of this application, the character " / " generally indicates an "or" relationship between the preceding and following related objects; in the formulas of this application, the character " / " indicates a "division" relationship between the preceding and following related objects. "Including at least one of A, B, or C" or similar expressions can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B, and C, where A, B, and C can be singular or plural.

[0054] In the embodiments of this application, the various numerical designations are used for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the process numbers does not imply the order of execution; the execution order of each process should be determined by its function and internal logic. The ordinal numbers such as "first" and "second" used in the embodiments of this application are used to distinguish multiple objects and do not limit the size, order, timing, priority, or importance of the multiple objects.

[0055] Figure 1 illustrates a possible, non-limiting system diagram. As shown in Figure 1, the communication system 1000 includes a radio access network (RAN) 100 and a core network (CN) 200. Optionally, the communication system 1000 also includes an Internet 300.

[0056] RAN100 includes at least one RAN node (110a and 110b in Figure 1, collectively referred to as 110) and at least one terminal device (120a-120j in Figure 1, collectively referred to as 120). RAN100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1).

[0057] Terminal device 120 is connected to RAN node 110 wirelessly. RAN node 110 is connected to core network 200 wirelessly or via wired connection. The core network equipment in core network 200 and RAN node 110 in RAN 100 can be different physical devices, or they can be the same physical device integrating core network logical functions and radio access network logical functions.

[0058] RAN100 can be used for cellular systems related to the 3rd generation partnership project (3GPP), such as 4th generation (4G). th generation, 4G), fifth generation (5 th RAN100 can be a generation (5G) mobile communication system, or a future-oriented evolution system (such as a future communication network). RAN100 can also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. RAN100 can also be a communication system that integrates two or more of the above systems.

[0059] RAN node 110, forming part of the communication system, assists terminal devices in achieving wireless access. Multiple RAN nodes 110 in the communication system 1000 can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal device 120 are relative. For example, network element 120i in Figure 1 can be a helicopter or drone, which can be configured as a mobile base station. For terminal devices 120j accessing RAN 100 through network element 120i, network element 120i is a base station; however, for base station 110a, network element 120i is a terminal device.

[0060] In one possible scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a base station in a future communication network, or an access node in a WiFi system. A RAN node can be a macro base station (as shown in Figure 1, 110a), a micro base station or indoor station (as shown in Figure 1, 110b), a relay node or donor node, or a radio controller in a CRAN scenario. Optionally, a RAN node can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). All or part of the functions of the RAN node in this application embodiment can be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The RAN node in this application embodiment can also be a logical node, logical module, or software capable of implementing all or part of the RAN node functions.

[0061] In another possible scenario, multiple RAN nodes collaborate to assist terminal devices in achieving wireless access, with different RAN nodes each implementing a portion of the base station's functions. For example, RAN nodes can be central units (CUs), distributed units (DUs), CU-control plane (CPs), CU-user plane (UPs), or radio units (RUs), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0062] It is understood that CU (or CU-CP and CU-UP), DU, or RU may have different names in different systems, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called an open-CU (open-CU, O-CU), DU can also be called an open-DU (open-DU, O-DU), CU-CP can also be called an open-CU-CP (open-CU-CP, O-CU-CP), CU-UP can also be called an open-CU-UP (open-CU-UP, O-CU-UP), and RU can also be called an open-RU (open RU, O-RU). For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in the embodiments of this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0063] Terminal device 120 is a device with wireless transceiver capabilities. Terminal device 120 can also be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc. This application embodiment does not limit the device form of the terminal device.

[0064] RAN node 110 and terminal device 120 can be fixed or mobile. RAN node 110 and terminal device 120 can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed in the air on aircraft, balloons, and satellites. This application embodiment does not limit the application scenarios of RAN node 110 and terminal device 120. RAN node 110 and terminal device 120 can be deployed in the same or different scenarios. For example, RAN node 110 and terminal device 120 can be deployed simultaneously on land; or RAN node 110 can be deployed on land and terminal device 120 can be deployed on water, etc., and so on.

[0065] RAN node 110 and terminal device 120 can communicate via licensed spectrum, unlicensed spectrum, or both simultaneously. For example, RAN node 110 and terminal device 120 can communicate via spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0066] RAN node 110 and terminal equipment 120 are sometimes referred to as communication devices. For example, network elements 110a and 110b in Figure 1 can be understood as communication devices with base station functions. For instance, this communication device can be a base station, or a module, unit, or component applied to a base station (e.g., a chip, chip system, processor, circuit, or others). The chip system consists of chips and may also include chips and other discrete devices. Network elements 120a-120j can be understood as communication devices with terminal equipment functions. For instance, this communication device can be a terminal equipment, or a module, unit, or component applied to a terminal equipment.

[0067] The solution of this application embodiment can be applied to the communication system 1000 shown in Figure 1, which can correspond to a terrestrial network (TN). Alternatively, the solution of this application embodiment can also be applied to a non-terrestrial network (NTN). In the NTN communication system, the "RAN node" in Figure 1 can be replaced by "satellite and ground station". The satellite is deployed in space, and the ground station is deployed on the ground. The ground station can be understood as a base station deployed on the ground, and can also be called a gateway station (GW). The link between the satellite and the terminal equipment is called the user link, the link between the satellite and the ground station is called the feeder link, and the link between different satellites is called the inter-satellite link. The satellite's operating modes include transparent and regenerative.

[0068] When the satellite operates in transparent transmission mode, it has signal relay capabilities, and the ground station possesses all or part of the functions of a base station; the ground station can be considered a base station. It is understood that a ground station can be a single device (e.g., a macro base station or a micro base station), or it can consist of multiple RAN nodes (e.g., CU and DU) implementing the corresponding functions; see the preceding explanation for details. Alternatively,

[0069] When a satellite operates in regenerative mode, it has the ability to process digital signals and possesses all or part of the functions of a base station; thus, the satellite can be considered a base station. Furthermore, regenerative mode can be further subdivided into: all base station functions are deployed on the satellite, referred to as "all base station functions (e.g., CU and DU) on satellite"; or, some base station functions are deployed on the satellite, referred to as "partial base station functions (e.g., DU) on satellite," while the remaining base station functions (e.g., CU) are implemented at the ground station.

[0070] Satellites and ground stations are sometimes referred to as communication devices. For example, a satellite can be understood as a communication device with satellite functions, and a ground station can be understood as a communication device with ground station functions.

[0071] It is understood that in a TN communication system, the RAN node is used to help terminal devices achieve wireless access, and it can also be referred to in other different ways, such as RAN entity, access node, access network device, etc.; in an NTN communication system, satellites and ground stations help terminal devices achieve wireless access. In the following description of the embodiments of this application, unless otherwise specified, the nodes or devices that help terminal devices achieve wireless access will be described as "access network devices".

[0072] It is understood that, in the embodiments of this application, the functions of the access network device can also be executed by modules, units, or components (such as chips) within the access network device, or by a control subsystem that includes the functions of the access network device. This control subsystem, including the functions of the access network device, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal device can also be executed by modules, units, or components (such as chips or modems) within the terminal device, or by a device that includes the functions of the terminal device.

[0073] For ease of description, some communication terms or terminology used in this application are explained. It is understood that this explanation is for understanding the embodiments of this application and is not intended to limit the embodiments of this application.

[0074] (1) Tracking area (TA), also known as the tracking area.

[0075] The tracking area includes at least one cell, which may belong to at least one access network device. Through this relationship, the correspondence between the tracking area and the access network device can be determined. In the description of the embodiments of this application, the access network device corresponding to the tracking area can be described as: the access network device included in the tracking area; the tracking area corresponding to the access network device can be described as: the tracking area where the access network device is located, belongs to, or is affiliated with.

[0076] In one possible implementation, the core network device can divide the network into at least one tracking area during network planning. Each tracking area corresponds to an identifier used to uniquely identify a tracking area. For example, this identifier can be called a tracking area identity (TAI). The core network device can notify each access network device of the tracking area identity to which it belongs, thus allowing each access network device to obtain the tracking area identity. It is understood that in one scheme, a tracking area may include multiple access network devices, in which case these multiple access network devices belong to the same tracking area, and their tracking area identities are identical.

[0077] In the embodiments of this application, a tracking area is used to represent a region including at least one access network device. Besides a tracking area, this region can also be described as a service area or other names, without limitation. It is understood that in the embodiments of this application, the concept of a "tracking area" in a new radio (NR) system can be utilized to implement the solutions of the embodiments of this application. Alternatively, in the embodiments of this application, a region can be redefined, which includes at least one access network device, and the at least one access network device corresponds to the same region identifier. For ease of explanation, the tracking area is used as an example in the following description to illustrate the solutions of the embodiments of this application.

[0078] (2) Synchronization signal.

[0079] In one possible implementation, the access network device may periodically send a synchronization signal. When the terminal device detects the synchronization signal, it can synchronize with the access network device based on the synchronization signal. Furthermore, the synchronization signal includes configuration information for system messages, and the terminal device can receive system messages based on the configuration information of the system messages. For an explanation of system messages, please refer to (3) below.

[0080] The synchronization signal can be a synchronization signal / physical broadcast channel block (SSB), or other signals used for synchronization, without restriction. The SSB mainly consists of four parts: the primary synchronization signal (PSS), the secondary synchronization signal (SSS), the physical broadcast channel (PBCH), and the demodulation reference signal (DMRS) of the PBCH.

[0081] (3) System messages.

[0082] The system message includes a system information block (SIB) 1. There are no restrictions on whether the system message includes other types of SIBs. For example, the system message may also include other types of SIBs, such as SIB2 to SIB8. In one description, when the system message only includes SIB1, the system message is also replaced with: SIB1.

[0083] In one possible implementation, SIB1 includes information about the terminal device performing random access. For example, the random access occasion (RO, random access channel, RACH). RO can be understood as the time-frequency resource for the terminal device to send the random access preamble.

[0084] (4) Connected state and disconnected state

[0085] The connected state refers to the state in which a terminal device completes random access and establishes a radio resource control (RRC) connection, and this RRC connection has not been released. In the connected state, the terminal device can perform uplink and / or downlink data transmission.

[0086] The connectionless state includes the idle state and the inactive state. The idle state refers to the state a terminal device is in when it has completed its camp on the cell but has not yet performed random access. Typically, the terminal device enters the idle state upon power-on or when RRC is released. The inactive state is the state between the connected state and the idle state. In the inactive state, the user plane of the air interface between the terminal device and the RAN is suspended, while the user plane and control plane bearers between the RAN and CN are maintained. When the terminal device is paged or initiates a service request, it can activate the air interface user plane bearers, reusing the existing RAN and CN user plane and control plane bearers. Compared to the idle state, the terminal device in the inactive state retains system messages and its context, allowing for rapid data transmission after restoring air interface connectivity.

[0087] In some descriptions, the connected state can be called the RRC connected state, the disconnected state can be called the RRC disconnected state, and the idle state and deactivated state can be called the RRC idle state and the RRC deactivated state, respectively.

[0088] In NR systems, access network devices periodically send system messages. For example, the period for sending system messages by access network devices is usually 160 milliseconds (ms), which results in high power consumption for access network devices when sending system messages.

[0089] Therefore, embodiments of this application provide a communication method and apparatus, in which: the access network device no longer periodically sends system messages, but instead sends system messages based on triggers. Compared to the access network device periodically sending system messages, the energy consumption of the access network device in sending system messages can be reduced, thus meeting the energy-saving requirements of the access network device.

[0090] In the various flowcharts of the embodiments of this application, the executing entity can be a terminal device, an access network device, or a device or module with corresponding functions within the terminal device or access network device (e.g., a chip, chip system, processor, circuit, or others). The following description uses a terminal device and an access network device as examples of executing entities. When the executing entity is a device or module with corresponding functions within the terminal device or access network device, receiving / transmitting can be understood as input / output, meaning that the module communicates with other modules or components of the terminal device or access network device. Furthermore, the processing performed by a single executing entity can also be divided into multiple executing entities, which can be logically and / or physically separated. For example, the processing performed by the access network device can be divided into execution by at least one of CU, DU, RU, etc.

[0091] Figure 2 is a schematic interactive diagram of the communication method 2000 provided in an embodiment of this application. It is understood that steps 200 to 220 are only for illustrating the process of the communication method 2000 and should not be construed as limiting the method 2000. Steps 200 to 220 can be broken down into more steps or combined into fewer steps, and the order of steps 200 to 220 is not limited.

[0092] Step 210: The terminal device sends a first uplink signal, and the first access network device receives the first uplink signal.

[0093] The first uplink signal is used to trigger the first downlink signal, which includes system messages. In one interpretation, the first uplink signal triggering the first downlink signal can be understood as: the first uplink signal triggers the first access network device to send the first downlink signal; or, the first uplink signal indicates that the terminal device has a need to receive the first downlink signal.

[0094] In one possible implementation, the terminal device may be in a disconnected state, such as an idle state or a deactivated state. The first uplink signal may be a random access preamble. For example, the first uplink signal may include an uplink sequence, which is a set of orthogonal sequences. This uplink sequence may be predefined, such as as specified by a protocol, or configured or indicated to the terminal device by the access network device (e.g., the first access network device).

[0095] In one possible implementation, the terminal device can transmit a first uplink signal on a time-frequency resource. For example, the time-frequency resource for transmitting the first uplink signal (which may be simply referred to as the time-frequency resource of the first uplink signal) can be one time-frequency resource or multiple time-frequency resources. For instance, these multiple time-frequency resources can be represented as M time-frequency resources, where M is an integer greater than 1. The time-frequency resource of the first uplink signal can be predefined, such as as specified by a protocol, or configured or indicated to the terminal device by the access network device (e.g., a first access network device or a second access network device). In one possible implementation, the time-frequency resource of the first uplink signal is indicated to the terminal device by the second access network device through a synchronization signal. In this approach, optionally, the method shown in Figure 2 further includes:

[0096] Step 200: The second access network device sends a synchronization signal, and the terminal device receives the synchronization signal.

[0097] In one possible implementation, the synchronization signal is used to indicate the time-frequency resources of the first uplink signal. For example, the synchronization signal may indicate M time-frequency resources, which are time-frequency resources in M ​​tracking areas used to carry the first uplink signal, where M is an integer greater than 1. Further, the M tracking areas include a first tracking area and M-1 tracking areas adjacent to the first tracking area. See the description below for the first tracking area. For example, when the terminal device receives the synchronization signal, it obtains indication information of the M time-frequency resources from the synchronization signal; in step 210, the terminal device transmits the first uplink signal on each of the M time-frequency resources. At this time, the access network devices located in the M tracking areas can receive the first uplink signal on the time-frequency resources. Alternatively, the synchronization signal may indicate a time-frequency resource, and the terminal device transmits the first uplink signal on that time-frequency resource, allowing the access network devices in the M tracking areas to receive the first uplink signal on that time-frequency resource.

[0098] In one possible implementation, the second access network device transmits a synchronization signal on time-frequency resources, and the terminal device receives the synchronization signal on the same time-frequency resources. The time-frequency resources for the synchronization signal can be predefined, such as those specified by a protocol, or they can be configured or indicated to the terminal device by the access network device (e.g., the second access network device). Alternatively, the terminal device may not know the specific time-frequency resources for the synchronization signal, and it may detect or blindly detect the synchronization signal on a segment of time-frequency resources or multiple preset time-frequency resources. Of course, the aforementioned segment or multiple time-frequency resources include the time-frequency resources for the synchronization signal.

[0099] In one possible implementation, the second access network device may periodically transmit a synchronization signal. To reduce the power consumption of the access network device, the period for transmitting the synchronization signal can be longer than the transmission period of the synchronization signal in the NR. For example, the period for transmitting the synchronization signal can be greater than 160ms; for instance, the period could be 320ms, 640ms, or 1 second.

[0100] Step 220: The first access network device sends a first downlink signal, and the terminal device receives the first downlink signal.

[0101] In one interpretation, the first uplink signal is used to trigger the first downlink signal. This can be understood as follows: when the first access network device receives the first uplink signal, it sends the first downlink signal. In other words, the first access network device can send the first downlink signal based on the triggering of the first uplink signal.

[0102] In one interpretation, the first downlink signal includes system messages. For example, this system message may only include SIB1. In this case, including system messages in the first downlink signal can be described as: the first downlink information includes SIB1, or the first downlink signal is SIB1. Alternatively, the first downlink information may include other types of SIBs besides SIB1, such as SIB2 to SIB8. SIB1 includes information related to random access performed by non-connected terminal equipment, such as RO.

[0103] In another interpretation, the first downlink signal includes a system message containing information related to random access performed by the non-connected terminal, such as RO. There are no restrictions on the name of this system message. For example, it could be SIB1 in NR, or it could have other names as the system evolves; there are no limitations.

[0104] In one possible implementation, the first access network device may broadcast a first downlink signal, and the second access network device may broadcast a synchronization signal. Terminal devices within the broadcast range can then receive both the first downlink signal and the synchronization signal. It is understood that the terminal devices in this embodiment are located within the aforementioned broadcast range. The terminal devices may also broadcast a first uplink signal, and the first access network device, being within the broadcast range, can receive the first uplink signal.

[0105] It is understood that the second access network device that sends the synchronization signal in step 200 can be the same access network device as the first access network device in steps 210 and 220, or they can be different access network devices. In the flowchart of Figure 2, the example is given where the first access network device and the second access network device are the same access network device, and both are represented as the first access network device.

[0106] For example, in one possible implementation, the first access network device and the second access network device are different access network devices: for example, in Example 1 below, the first access network device and the second access network device are different access network devices, specifically: the first access network device and the second access network device are located in different tracking areas, the second access network device belongs to the first tracking area, and the first access network device belongs to the first tracking area. Alternatively, the first access network device and the second access network device are the same access network device. For example, in Example 2 below, the first access network device and the second access network device are the same access network device, and this access network device is located in the first tracking area.

[0107] The following section continues to explain the process by which the first uplink signal triggers the first downlink signal. Specifically, the following two examples will illustrate this.

[0108] Example 1: Consider the following scenario, as shown in Figure 3: The "second access network device" in this embodiment is located in the first tracking area. The second access network device sends a synchronization signal, which includes the identifier of the first tracking area. When the terminal device is within the coverage area of ​​the first tracking area, it receives the synchronization signal and obtains the identifier of the first tracking area. When the terminal device moves from the first tracking area to the second tracking area: when the terminal device is within the coverage area of ​​the second tracking area, it sends a first uplink signal carrying the identifier of the first tracking area. When the first access network device in the second tracking area receives the first uplink signal, it finds that the identifier of the first tracking area it carries is different from the identifier of its own second tracking area (i.e., the identifier of the second tracking area), and then sends a first downlink signal including system messages. Of course, if the terminal device has not moved and is still within the coverage area of ​​the first tracking area, when any access network device in the first tracking area receives the first uplink signal, it finds that the identifier of the first tracking area it carries is the same as the identifier of its own first tracking area (i.e., the identifier of the first tracking area), and then does not send a first downlink signal including system messages.

[0109] The above process can be summarized as follows: the first uplink signal sent by the terminal device includes an identifier of the tracking area. When the access network device receives the first uplink signal, it determines whether to send a first downlink signal including system messages based on the identifier of the tracking area included in the first uplink signal. In some descriptions, the access network device's decision to send the first downlink signal including system messages may be referred to as the access network device updating the system messages, or as the access network device updating the system messages based on the tracking area, etc. The specific process is as follows:

[0110] 1. The second access network device in the first tracking area periodically sends a synchronization signal, which includes the identifier of the first tracking area.

[0111] In one possible implementation, all access network devices in the first tracking area (including the second access network device) can periodically transmit synchronization signals. Alternatively, one or more access network devices (including the second access network device) in the first tracking area can be selected to periodically transmit synchronization signals. For other access network devices in the first tracking area besides the aforementioned one or more access network devices, the transmission of synchronization signals can be disabled, meaning these other access network devices no longer periodically transmit synchronization signals, thus reducing the power consumption of the access network devices throughout the first tracking area. In the above possible implementations, the period for the access network devices in the first tracking area to transmit synchronization signals can be greater than 160ms.

[0112] Understandably, for the method by which some access network devices in the first tracking area send synchronization signals, it is necessary to ensure that the signal strength of the synchronization signals sent by these access network devices can cover the entire first tracking area. In other words, the signal strength of the synchronization signals sent by these access network devices should be sufficient to ensure that the terminal device can receive the synchronization signal regardless of its location within the first tracking area.

[0113] In one possible implementation, the synchronization signal further includes: time-frequency resources of a first uplink signal. The time-frequency resources of the first uplink signal can be one time-frequency resource, or M time-frequency resources, which are time-frequency resources of M tracking regions, including at least the second tracking region described below.

[0114] Furthermore, the synchronization signal may also include configuration information for system messages. When the terminal device is within the coverage area of ​​the first tracking area, it can receive the synchronization signal sent by the second access network device in the first tracking area. If the terminal device is in an idle state, it can receive system messages based on the configuration information of the system messages included in the synchronization signal. Further, based on the system messages, it performs random access and connects to the second access network device in the first tracking area. If the terminal device is in a deactivated state, since it saved the system messages when switching from the connected state to the deactivated state, it can directly utilize the saved system messages to perform random access for the deactivated terminal device.

[0115] In one possible implementation, when the "terminal device" in this embodiment is within the coverage area of ​​the first tracking area: the terminal device can receive the aforementioned synchronization signal, and further, the terminal device obtains the identifier of the first tracking area and the time-frequency resources of the first uplink signal from the synchronization signal. When the terminal device moves from the first tracking area to the second tracking area: when the terminal device is within the coverage area of ​​the second tracking area, the terminal device sends a first uplink signal, which carries or includes the identifier of the first tracking area. For example, the first uplink signal consists of an uplink sequence and the identifier of the first tracking area. The terminal device sends the first uplink signal on the aforementioned time-frequency resources of the first uplink signal, and the first access network device in the second tracking area receives the first uplink signal and sends a first downlink signal.

[0116] 2. The terminal device sends a first uplink signal, which includes the identifier of the first tracking area.

[0117] In one possible implementation, the time-frequency resource for the first uplink signal is a single time-frequency resource, meaning the synchronization signal includes a time-frequency resource. The terminal device transmits the first uplink signal on this time-frequency resource. In another possible implementation, the time-frequency resource used to carry the first uplink signal is the same in multiple tracking areas (e.g., M tracking areas). When the terminal device is within the coverage area of ​​a certain tracking area (e.g., a second tracking area), the access network equipment in that tracking area can receive the first uplink signal on the aforementioned time-frequency resource.

[0118] In another possible implementation, the time-frequency resources of the first uplink signal are multiple time-frequency resources, such as M time-frequency resources. That is, the synchronization signal includes multiple time-frequency resources. For example, taking M time-frequency resources as an example, the terminal device can send M uplink signals on M time-frequency resources.

[0119] In one example, the M time-frequency resources are the time-frequency resources carrying the first uplink signal in the M tracking areas; that is, each tracking area has one time-frequency resource carrying the uplink signal. The terminal device transmits M uplink signals on the M time-frequency resources. When the terminal device is located within the coverage area of ​​a certain tracking area (e.g., the second tracking area), the access network device in that tracking area can receive the first uplink signal because the terminal device is close to the access network device in that tracking area. Whether access network devices in other tracking areas can receive the first uplink signal is not limited. For example, if the access network devices in other tracking areas are far from the terminal device, they may not receive the first uplink signal. In one possible implementation, the M tracking areas are the first tracking area and M-1 tracking areas adjacent to the first tracking area; that is, when the second access network device in the first tracking area transmits a synchronization signal, it carries not only the time-frequency resources for transmitting the first uplink signal in the first tracking area, but also the time-frequency resources for transmitting the first uplink signal in the M-1 adjacent tracking areas.

[0120] In one example, the M time-frequency resources are the time-frequency resources carrying the first uplink signal in N tracking areas, where N is an integer less than M. For example, one or more tracking areas in the N tracking areas may have multiple time-frequency resources carrying the first uplink signal; that is, at least one of the N tracking areas may have multiple time-frequency resources carrying the first uplink signal.

[0121] For example, if M is 10 and N is 5, then each of the 10 tracking areas includes 2 time-frequency resources carrying the first uplink signal. Alternatively, if M is 10 and N is 9, then one of the 9 tracking areas includes 2 time-frequency resources carrying the first uplink signal, and the remaining 8 tracking areas each include 1 time-frequency resource carrying the first uplink signal.

[0122] In one possible implementation, time-frequency resources carrying the first uplink signal can be allocated to each tracking area based on the number of access network devices included in the tracking area. For example, if a tracking area includes X access network devices, then X time-frequency resources carrying the first uplink signal can be allocated to that tracking area, where X is a positive integer. That is, each access network device in a tracking area is allocated one time-frequency resource carrying the first uplink signal. When a terminal device is within the coverage area of ​​a tracking area (e.g., a second tracking area), the terminal device transmits the first uplink signal using multiple time-frequency resources in the second tracking area, and multiple access network devices in the second tracking area can receive the first uplink signal. Which access network device responds to the first uplink signal and transmits the first downlink signal can be determined by a higher-level node. For example, multiple access network devices that have received the first uplink signal can request a higher-level node to determine which access network device should respond to the first uplink signal. For example, this higher-level node could be a core network node. Alternatively, when the access network equipment adopts a CU and DU separate architecture, the multiple access network equipment receiving the first uplink signal can be replaced by multiple DUs receiving the first uplink signal. In this case, the CU can determine which DU specifically responds to the first uplink signal.

[0123] 3. When the first access network device in the second tracking area receives the first uplink signal, and the identifier of the first tracking area included in the first uplink signal is different from the identifier of the second tracking area (the identifier of the second tracking area) where the first access network device is located, the first access network device in the second tracking area sends the first downlink signal.

[0124] When the terminal device is in a disconnected state: Upon receiving the first downlink signal, the terminal device obtains system messages from the first downlink signal. Based on the system messages, the terminal device performs random access and connects to the first access network device in the second tracking area. Afterwards, the terminal device can establish an RRC connection with the first access network device, restoring the connected state. In the connected state, the terminal device can perform uplink and / or downlink data transmission.

[0125] With the above design, when the terminal device moves to a new tracking area (e.g., a second tracking area), the terminal device can trigger the access network device in the new tracking area to send a first downlink signal, including system messages, by sending a first uplink signal. For a terminal device in a disconnected state, random access can be performed according to the system messages of the new tracking area, and the terminal device can connect to the access network device in the new tracking area, thus restoring the connected state.

[0126] Example 2: First, in Example 2, the second access network device in step 200 of the flowchart in Figure 2 and the first access network device in steps 210 and 220 are the same access network device, and this access network device is referred to as the first access network device. The following scenario is set: the first tracking area includes the first access network device, and the first access network device in the first tracking area periodically sends a synchronization signal, which includes the identifier of the first tracking area. When the terminal device is within the coverage area of ​​the first tracking area, the terminal device can receive the aforementioned synchronization signal and obtain the identifier of the first tracking area from the synchronization signal; the terminal device compares the identifier of the first tracking area with the identifier of a previously obtained tracking area (e.g., the identifier of a third tracking area) to determine whether to send a first uplink signal. When the first access network device in the first tracking area receives the first uplink signal, it sends a first downlink signal including system messages.

[0127] 1. The first access network device in the first tracking area periodically sends a synchronization signal, which includes the identifier of the first tracking area.

[0128] In one possible implementation, all access network devices in the first tracking area may periodically transmit synchronization signals; alternatively, one or more access network devices may be selected within the first tracking area to periodically transmit synchronization signals. Of course, the one or more access network devices transmitting synchronization signals may include at least the aforementioned first access network device. The period for transmitting synchronization signals by the access network devices in the first tracking area may be greater than 160 ms.

[0129] 2. The terminal device determines whether to send the first uplink signal based on the identifier of the first tracking zone included in the synchronization signal.

[0130] For example, when the terminal device receives a synchronization signal, it obtains the identifier of the first tracking area included in the synchronization signal; the terminal device compares whether the identifier of the first tracking area is the same as the identifier of the third tracking area.

[0131] In one possible implementation, if the identifier of the first tracking area is the same as the identifier of the third tracking area, the terminal device no longer sends the first uplink signal; if the identifier of the first tracking area is different from the identifier of the third tracking area, the terminal device sends the first uplink signal. In this case, the terminal device can be considered to be within the coverage area of ​​the first tracking area, and the first access network device in the first tracking area can receive the first uplink signal. The first access network device in the first tracking area then sends a first downlink signal including system messages. Further, optionally, the first uplink signal includes first indication information, which is used to indicate the transmission of the first downlink signal. The first access network device can then send the first downlink signal according to the indication of the first indication information.

[0132] In another possible implementation, if the identifier of the first tracking area is the same as the identifier of the third tracking area, the terminal device sends a first uplink signal including third indication information (referred to here as the third indication information for ease of distinction from the "second indication information" hereinafter), which indicates that the first downlink signal should not be transmitted. Alternatively, if the identifier of the first tracking area is different from the identifier of the third tracking area, the terminal device sends a first uplink signal including the first indication information, which indicates that the first downlink signal should be transmitted. For example, the first and third indication information can be represented by 1 bit of binary data; for instance, the first indication information can be represented by a binary bit "1" and the third indication information by a binary bit "0," or vice versa, without limitation.

[0133] The identifier of the third tracking zone can be understood as the latest tracking zone identifier obtained by the terminal device before receiving the synchronization signal of the first tracking zone. The third tracking zone may include at least one access network device.

[0134] In one possible scenario, when the terminal device is within the coverage area of ​​a third tracking area, it receives a synchronization signal from an access network device in the third tracking area, which includes the identifier of the third tracking area. Subsequently, the terminal device initiates a move, moving from the third tracking area to a first tracking area: when the terminal device is within the coverage area of ​​the first tracking area, it receives a synchronization signal from a first access network device in the first tracking area, which carries the identifier of the first tracking area. The terminal device determines that the identifier of the first tracking area is different from the previously acquired identifier of the third tracking area, indicating that the terminal device has moved to a new tracking area. The terminal device needs to obtain system messages for the new tracking area (i.e., the first tracking area). The terminal device can send a first uplink signal. Upon receiving the first uplink signal, the first access network device in the first tracking area sends a first downlink signal including the system message. For a terminal device in a disconnected state, it can access the first access network device in the first tracking area based on the system message.

[0135] Understandably, if the identifier of the first tracking area is the same as the identifier of the most recently acquired tracking area (as mentioned earlier, the identifier of the third tracking area), it indicates that the terminal device has not sent a movement signal, or even if the terminal device moves, it remains within the coverage area of ​​a tracking area. For example, if the terminal device remains within the coverage area of ​​the first tracking area, since the first access network device in the first tracking area can periodically send synchronization signals, the terminal device can receive multiple synchronization signals. Each time a synchronization signal is received, the terminal device acquires the identifier of the first tracking area carried in that signal and saves it as the identifier of its most recently acquired tracking area. Thus, whenever the terminal device receives a synchronization signal, it can compare the identifier of the tracking area carried in that signal with the identifier of its most recently acquired tracking area. Continuing with the above explanation, since the terminal device remains within the coverage area of ​​the first tracking area, the identifier of the tracking area acquired by the terminal device in the synchronization signal is the same, which is the identifier of the first tracking area. That is, the identifier of the first tracking area acquired by the terminal device in the synchronization signal is the same as the most recently acquired tracking area identifier, and the terminal device will not send a first uplink signal in this case. Optionally, if the terminal device is in a disconnected state, the above synchronization signal includes a system message for the first tracking area. Based on the system message, the terminal device can perform random access and access the access network device of the first tracking area.

[0136] With the above design, the synchronization signal carries the identifier of the tracking area. When the terminal device receives the synchronization signal, it compares the identifier of the tracking area carried in the synchronization signal with the previously acquired identifier of the tracking area to determine whether to send the first uplink signal. The terminal device does not need to periodically send the first uplink signal, saving the energy consumption of the terminal device in sending the first uplink signal.

[0137] In one possible implementation, in the schemes of Example 1 or Example 2 above, the synchronization signal further includes the identifier of the second access network device. The descriptions of Examples 1 and 2 above are based on a scenario where a "tracking zone" exists. The schemes of the embodiments of this application can also be applied to scenarios where a "tracking zone" does not exist, for example:

[0138] In Example 1, the synchronization signal sent by the second access network device includes the identifier of the second access network device. The terminal is located within the coverage area of ​​the second access network device and can receive the synchronization signal, obtaining the identifier of the second access network device from it. The terminal moves, and after the move, the terminal is located within the coverage area of ​​the first access network device. The terminal sends a first uplink signal carrying or bearing the identifier of the second access network device. Since the terminal is located within the coverage area of ​​the first access network device, the first access network device can receive the first uplink signal. Upon receiving the first uplink signal, the first access network device discovers that the identifier of the second access network device carried in the first uplink signal is different from the identifier of the first access network device. The first access network device then sends a first downlink signal including system messages to the terminal. The terminal is in a disconnected state and can perform random access to connect to the first access network device based on the system messages included in the first downlink signal.

[0139] In Example 2, the synchronization signal sent by the first access network device includes the identifier of the first access network device. The terminal device is located within the coverage area of ​​the first access network device and can receive the synchronization signal. The terminal device retrieves the identifier of the first access network device from the synchronization signal and determines whether the identifier of the first access network device is the same as the identifier of the most recently acquired third access network device. If the identifiers of the first and third access network devices are the same, meaning they are essentially the same access network device, it indicates that the terminal device has not moved out of the coverage area of ​​that access network device, and the terminal device no longer sends the first uplink signal. If the identifiers of the first and third access network devices are different, the terminal device sends the first uplink signal. Upon receiving the first uplink signal, the first access network device sends a first downlink signal including system messages. The terminal device is in a disconnected state and can perform random access and connect to the first access network device based on the system messages included in the first downlink signal. Alternatively, the terminal device may send a first uplink signal carrying first indication information if the identifier of the first access network device is the same as the identifier of the third access network device; or send a first uplink signal carrying third indication information if the identifier of the first access network device is different from the identifier of the third access network device. The first indication information or the third indication information is used to instruct the first access network device to send or not send a first downlink signal.

[0140] In one possible implementation, the "first uplink signal" mentioned above may further include an identifier for the terminal device. This identifier is used by the first access network device to quickly locate the context of the terminal device, thereby enabling rapid data transmission between the terminal device and the first access network device. In this embodiment, the above process is illustrated using an example where both the terminal device and the access network device have data transmission requirements.

[0141] Example 1: The terminal device has a data transmission requirement (which can be simply referred to as a data transmission requirement). The specific solution is as follows:

[0142] 1. The access network equipment in the first tracking area periodically sends a synchronization signal, which includes the identifier of the first tracking area.

[0143] Understandably, in Example 1 above, specifically: the second access network device in the first tracking area sends a synchronization signal. In Example 2 above, specifically: the first access network device in the first tracking area sends a synchronization signal.

[0144] 2. The terminal device sends the first uplink signal.

[0145] In one possible implementation, the first uplink signal includes at least one of the following, second indication information, fourth indication information, and an identifier of the terminal device. Of course, in the scheme of Example 1 above, the first uplink signal also includes: an identifier of the first tracking area. In the scheme of Example 2 above, the first uplink signal may further include: first indication information.

[0146] The second indication information indicates that there is a data transmission requirement on the terminal device side. For example, the second indication information can be represented by 1 bit of binary data. For example, binary bit "1" indicates that there is a data transmission requirement on the terminal device side. The fourth information indicates that there is no data transmission requirement on the terminal device side. For example, the fourth indication information can be represented by 1 bit of binary data. For example, binary bit "0" or the missing 1 bit indicates that there is no data transmission requirement on the terminal device side. The terminal device identifier is used to enable the first access network device that receives the above-mentioned first uplink signal to quickly find the context of the terminal device.

[0147] In one possible implementation, when the first access network device receives a first uplink signal, it obtains second indication information and the identifier of the terminal device from the first uplink signal. Based on the identifier of the terminal device, the first access network device obtains the context of the terminal device to ensure that the context of the terminal device is ready when the first access network device performs data transmission. For example, when the terminal device is in a deactivated state, the access network device stores the context of the terminal device. Therefore, the first access network device can search for the context of the terminal device in the saved or stored context based on the identifier of the terminal device. Alternatively, when the terminal device is in an idle state, the first access network device can establish the context of the terminal device based on the identifier of the terminal device.

[0148] In one possible implementation, multiple access network devices in a tracking area can all receive the first uplink signal sent by the terminal device. Of course, these multiple access network devices include at least the first access network device mentioned above. Among the multiple access network devices, an access network device that meets certain conditions can be selected to obtain the context of the terminal device. For example, among the multiple access network devices, the access network device with the best reception quality of the first uplink signal can be selected to obtain the context of the terminal device. For instance, in a CU and DU separation architecture, multiple DUs can all receive the first uplink signal. The CU can determine and select the DU with the best reception quality of the first uplink signal to obtain the context of the terminal device. It is understood that, in the description of this application, the first access network device obtaining the context of the terminal device can be considered as the first access network device meeting certain conditions, for example, the first access network device having the best signal quality in receiving the first uplink signal. Afterwards, the first access network device sends a first downlink signal, and the terminal device in a disconnected state accesses the first access network device according to the system message included in the first downlink signal.

[0149] 3. The first access network device sends the first downlink signal.

[0150] In one possible implementation, the first downlink signal includes a system message. This implementation can be considered an unoptimized solution. In this case, the first uplink signal may not include the terminal device's identifier and second indication information. The data transmission process of the terminal device includes:

[0151] The terminal device obtains a system message from the first downlink signal and, based on the system message, performs random access to connect to the first access network device. The terminal device establishes an RRC connection with the first access network device: for example, the terminal device sends an RRC establishment request to the first access network device, which includes the terminal device's identifier. The first access network device obtains the terminal device's context based on the identifier; the first access network device establishes an RRC connection between the terminal device and the first access network device based on the terminal device's context. For example, it configures air interface transmission resources between the terminal device and the access network device. The first access network device sends an RRC establishment response (or completion) to the terminal device. At this point, the RRC connection between the terminal device and the first access network device is established. Afterwards, the terminal device sends an uplink scheduling request to the first access network device, and the first access network device sends scheduling information (e.g., first scheduling information) to the terminal device based on the uplink scheduling request. The terminal device then performs data transmission based on the scheduling information.

[0152] In another possible implementation, the first downlink signal includes system messages and first scheduling information. This possible implementation can be considered an optimized solution. In this case, the first uplink signal may include the context of the terminal device and second indication information. The data transmission process of the terminal device includes:

[0153] The first access network device can obtain the context of the terminal device based on the terminal device's identifier. Based on the second indication information, the first access network device can determine that the terminal device has a data request. The first access network device can generate first scheduling information to schedule the terminal device to perform data processing. The first downlink signal sent by the first access network device includes the first scheduling information in addition to the system message.

[0154] When the terminal device receives the first downlink signal, it performs random access and connects to the first access network device based on the system messages included in the first downlink signal. Upon successful connection, the first access network device establishes an RRC connection between the terminal device and the first access network device based on the acquired context of the terminal device. The terminal device and the first access network device can then use this RRC connection for data transmission. After the RRC connection is successfully established, the terminal device directly transmits data based on the first scheduling information included in the first downlink signal.

[0155] As can be seen, in the first possible implementation, the terminal device needs to first perform random access, then send an RRC establishment request carrying the terminal device's identifier to the first access network device to establish an RRC connection with the first access network device; afterwards, it sends a data transmission request to the first access network device, which then sends scheduling information to the terminal device, allowing the terminal device to perform data transmission. In the second possible implementation, the first uplink signal sent by the terminal device carries second indication information and the terminal device's identifier. The access network device obtains the terminal device's context based on the identifier; based on the second indication information, it can determine that the terminal device has a data transmission requirement and determine the first scheduling information for scheduling the terminal device's data transmission. The first downlink signal sent by the access network device carries system messages and the first scheduling information. The terminal device performs random access based on the system messages. After successful random access, the terminal device does not need to send an RRC establishment request; the access network device can establish an RRC connection between the terminal device and the access network device based on the terminal device's context. Afterward, the terminal device can directly transmit data according to the scheduling information in the first scheduling information. Comparing the two data transmission processes described above, it can be seen that in the second possible implementation, the terminal device does not need to send an RRC establishment request carrying the terminal device identifier to the access network device, and after the terminal device successfully accesses the network, the terminal device does not need to send a data transmission scheduling request to the access network device, nor does the access network device send special scheduling information to the terminal device. In the second possible implementation, data transmission between the terminal device and the first access network device can be performed quickly.

[0156] Example 2: The access network equipment has data transmission requirements. The specific solution is as follows:

[0157] 1. The access network equipment in the first tracking area periodically sends a synchronization signal, which includes the identifier of the first tracking area.

[0158] Understandably, in Example 1 above, specifically: the second access network device in the first tracking area sends a synchronization signal. In Example 2 above, specifically: the first access network device in the first tracking area sends a synchronization signal.

[0159] 2. The terminal device sends the first uplink signal.

[0160] In one possible implementation, the first uplink signal also includes the identifier of the terminal device. For example, when the first access network device receives the first uplink signal, it can obtain the identifier of the terminal device from the first uplink signal; based on the identifier of the terminal device, it can obtain the context of the terminal device, thus preparing the context of the terminal device before the data transmission of the terminal device. Furthermore, after the terminal device successfully accesses the network, the first access network device can establish an RRC connection between the terminal device and the first access network device based on the context of the terminal device. Of course, in the above Example 1, the first uplink signal also includes: the identifier of the first tracking area. In the above Example 2, the first uplink signal may also include: first indication information.

[0161] 3. The first access network device sends a first downlink signal, which includes a system message.

[0162] In one possible implementation, the first uplink signal carries the identifier of the terminal device. This possible implementation can be considered an optimization scheme proposed in the embodiments of this application: the terminal device performs random access based on the system message included in the first downlink signal. After the terminal device successfully accesses the network, the first access network device can establish an RRC connection between the terminal device and the first access network device based on the previously acquired context of the terminal device. Subsequently, when data from the terminal device arrives at the first access network device, the first access network device sends second scheduling information to the terminal device for scheduling the terminal device's data.

[0163] In another possible implementation, the first uplink signal may not carry the terminal device's identifier. This possible implementation can be considered an unoptimized solution. The entire solution is implemented as follows: The terminal device performs random access based on the systematic message included in the first downlink signal, and the terminal device successfully accesses the first access network device. The terminal device sends an RRC establishment request to the first access network device, which includes the terminal device's identifier. The first access network device obtains the terminal device's context based on the terminal device's identifier and establishes an RRC connection between the terminal device and the first access network device. Subsequently, when data from the terminal device arrives at the first access network device, the first access network device sends second scheduling information to the terminal device to schedule the terminal device's data.

[0164] It is understood that the first scheduling information or the second scheduling information in the embodiments of this application can be Layer 1 signaling. The first scheduling information or the second scheduling information is used to schedule the data transmission of the terminal device. Furthermore, it can also indicate the modulation and coding method used by the terminal device.

[0165] As can be seen from the above comparison, in the optimized scheme of this application embodiment, when the terminal device successfully accesses the network based on the system message, the access network device can directly establish an RRC connection between the terminal device and the access network device based on the previously obtained context of the terminal device. The terminal device does not need to send an RRC establishment request including the identifier of the terminal device to the access network device, thereby speeding up the data transmission process of the terminal device.

[0166] In the embodiments provided above, the methods provided by the embodiments of this application are described from the perspective of the interaction between the terminal device and the access network device. To implement the functions of the methods provided by the embodiments of this application, the terminal device and the access network device may include hardware structures and / or software modules, implementing the above functions in the form of hardware structures, software modules, or a combination of hardware structures and software modules. Whether a particular function is executed in the form of hardware structures, software modules, or a combination of hardware structures and software modules depends on the design constraints of the specific application of the technical solution.

[0167] Based on the same conceptual framework as the above-described method embodiments, Figures 4 and 5 are schematic diagrams of possible communication devices provided in the embodiments of this application. These communication devices can implement the functions of terminal devices or first access network devices in the above-described method embodiments, and therefore may achieve the beneficial effects of the above-described method embodiments. In the embodiments of this application, the communication device may be a terminal device or a first access network device, or a unit, module, or component (such as a chip, chip system, circuit, processor, or others) applied in the terminal device or the first access network device. In the following description, the term "unit" will be used as an example. For example, in the following description, the communication device includes a processing unit and a transceiver unit as an example. The processing unit in the following description can also be replaced by: processing module or processing component, etc. The transceiver unit can also be replaced by: transceiver unit or transceiver component. For example, the transceiver component may refer to a communication module.

[0168] As shown in Figure 4, the communication device 4000 includes a processing unit 410 and a transceiver unit 420. The communication device 4000 is used to implement the functions of the terminal device or the first access network device in Figure 2.

[0169] Optionally, the transceiver unit 420 may also be referred to as an output unit, an interface unit, or a communication unit, etc. In one possible implementation, the transceiver unit 420 includes at least one of a transmitting unit or a receiving unit. The transmitting unit and the receiving unit may be integrated together, or they may be two independent units, etc.

[0170] When the communication device 4000 is used to implement the functions of the terminal device in Figure 2, specifically: optionally, the processing unit 410 is used to generate a first uplink signal; the transceiver unit 420 is used to send the first uplink signal; the transceiver unit 420 is also used to receive a first downlink signal, the first uplink signal being used to trigger the first downlink signal, the first downlink signal including a system message.

[0171] When the communication device 4000 is used to implement the function of the first access network device in Figure 2, specifically: the transceiver unit 420 is used to receive a first uplink signal, which is used to trigger a first downlink signal; optionally, the processing unit 410 is used to generate the first downlink signal; the transceiver unit 420 is also used to send the first downlink signal, which includes a system message.

[0172] A more detailed description of the transceiver unit 420 and the processing unit 410 can be obtained directly from the relevant description in the method embodiment shown in Figure 2, and will not be repeated here.

[0173] It is understood that the division of units in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods. In addition, the functional units in this application embodiment can be integrated into a physical device (e.g., in a processor), or each functional unit can be a separate physical device, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional module, etc.

[0174] As shown in Figure 5, the communication device 5000 includes a processor 510 and an interface circuit 520. The processor 510 and the interface circuit 520 are coupled to each other. It is understood that the interface circuit 520 can be a transceiver or an input / output interface. Optionally, the communication device 5000 may also include a memory 530 for storing instructions executed by the processor 510, or storing input data required by the processor 510 to execute instructions, or storing data generated after the processor 510 executes instructions.

[0175] When the communication device 5000 is used to implement the method shown in FIG2, the processor 510 is used to implement the function of the processing unit 410, and the interface circuit 520 is used to implement the function of the transceiver unit 420.

[0176] When the aforementioned communication device is a chip applied to a terminal device, the chip implements the functions of the terminal device in the above method embodiments. The chip receives information sent to the terminal device by the first access network device through other modules (such as a radio frequency module or antenna) in the terminal device; or, the chip sends information to other modules (such as a radio frequency module or antenna) in the terminal device, which is information sent by the terminal device to the first access network device.

[0177] When the aforementioned communication device is a module applied to a first access network device, the module implements the functions of the first access network device in the above method embodiments. This module receives information from other modules (such as radio frequency modules or antennas) in the first access network device, which is information sent by the terminal device to the first access network device; or, the module sends information to other modules (such as radio frequency modules or antennas) in the first access network device, which is information sent by the first access network device to the terminal device. Here, the module of the first access network device can be a chip of the first access network device, or a DU or other modules. Here, the DU can be a DU under the O-RAN architecture.

[0178] This application embodiment also provides a communication device, which includes a processor for implementing the functions of the terminal device or the first access network device in FIG2. Optionally, the communication device further includes a memory, with the processor coupled to the memory. The processor is used to execute computer programs or instructions stored in the memory to implement the functions of the terminal device or the first access network device in FIG2. Optionally, the communication device may be a chip or a chip system.

[0179] This application embodiment also provides a communication device, including a processor and an interface circuit. The interface circuit is used to receive signals from other devices outside the device and transmit them to the processor, or to send signals from the processor to other devices outside the device. The processor is used to implement the functions of the terminal device or the first access network device in FIG2 above through logic circuits or execution code instructions.

[0180] This application also provides a computer-readable storage medium storing instructions, which may also be referred to as computer programs, computer program code, etc. These instructions, when executed on a computer, cause the computer to perform the functions of the terminal device or the first access network device shown in Figure 2.

[0181] This application also provides a computer program product, including a computer program or instructions, which, when run on a computer, implement the functions of the terminal device or the first access network device in FIG2 above.

[0182] It is understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0183] The memory in the embodiments of this application may be random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), register, hard disk, portable hard disk, CD-ROM, or any other form of storage medium known in the art.

[0184] The method steps in the embodiments of this application can be implemented in hardware or in software instructions executable by a processor. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. The storage medium can also be a component of the processor. The processor and the storage medium can reside in an ASIC.

[0185] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. This computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center integrating one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0186] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

Claims

1. A communication method, characterized in that, Applied to terminal devices, including: Send the first uplink signal; A first downlink signal is received, wherein the first uplink signal is used to trigger the first downlink signal, and the first downlink signal includes a system message.

2. The method as described in claim 1, characterized in that, The first uplink signal includes an identifier of a first tracking area, which includes at least one access network device.

3. The method as described in claim 2, characterized in that, The first downlink signal originates from the first access network device, and the first uplink signal is used to trigger the first downlink signal, specifically including: The identifier of the first tracking area included in the first uplink signal is different from the identifier of the second tracking area where the first access network device is located. The first uplink signal triggers the first downlink signal, and the second tracking area includes at least the first access network device.

4. The method as described in claim 2 or 3, characterized in that, Before sending the first uplink signal, the method further includes: A synchronization signal is received, the synchronization signal including an identifier of the first tracking area.

5. The method as described in claim 1, characterized in that, The first uplink signal includes first indication information, which is used to indicate the transmission of the first downlink signal.

6. The method as described in claim 5, characterized in that, Sending the first uplink signal includes: Receive a synchronization signal, the synchronization signal including an identifier of a first tracking area; The identifier of the first tracking area is different from the identifier of the third tracking area. The first uplink signal including the first indication information is sent. The identifier of the third tracking area is the latest tracking area identifier obtained before receiving the synchronization signal. The first tracking area or the third tracking area includes at least one access network device.

7. The method as described in claim 4 or 6, characterized in that, The synchronization signal is also used to indicate the time-frequency resources of the first uplink signal.

8. The method as described in claim 7, characterized in that, The synchronization signal is also used to indicate the time-frequency resources of the first uplink signal, specifically including: the synchronization signal is also used to indicate M time-frequency resources, the M time-frequency resources being time-frequency resources in M ​​tracking areas used to carry the first uplink signal, where M is an integer greater than 1.

9. The method as described in claim 8, characterized in that, The M tracking regions include the first tracking region and M-1 adjacent tracking regions.

10. The method according to any one of claims 4, 6 to 9, characterized in that, The transmission period of the synchronization signal is greater than 160 milliseconds.

11. The method according to any one of claims 1 to 10, characterized in that, The first uplink signal includes the identifier of the terminal device, which is used to obtain the context information of the terminal device.

12. The method according to any one of claims 1 to 11, characterized in that, The first uplink signal also includes second indication information, which is used to indicate that the terminal device has a data transmission requirement.

13. A communication method, characterized in that, Applied to first access network equipment, including: Receive a first uplink signal, which is used to trigger a first downlink signal; Send the first downlink signal, which includes a system message.

14. The method as described in claim 13, characterized in that, The first uplink signal includes an identifier of a first tracking area, which includes at least one access network device.

15. The method as described in claim 14, characterized in that, The first downlink signal is sent by the first access network device, and sending the first downlink signal includes: The identifier of the first tracking area included in the first uplink signal is different from the identifier of the second tracking area where the first access network device is located, and the first downlink signal is sent, wherein the second tracking area includes at least the first access network device.

16. The method as described in claim 13, characterized in that, The first uplink signal includes first indication information, which is used to indicate the transmission of the first downlink signal.

17. The method as described in claim 16, characterized in that, Before receiving the first uplink signal, the method further includes: A synchronization signal is sent, the synchronization signal including an identifier of a first tracking area, the first tracking area including at least one access network device.

18. The method as described in claim 17, characterized in that, The synchronization signal is also used to indicate the time-frequency resources of the first uplink signal.

19. The method as described in claim 18, characterized in that, The synchronization signal is also used to indicate the time-frequency resources of the first uplink signal, specifically including: the synchronization signal is also used to indicate M time-frequency resources, the M time-frequency resources being time-frequency resources in M ​​tracking areas used to carry the first uplink signal, where M is an integer greater than 1.

20. The method as described in claim 19, characterized in that, The M tracking regions include the first tracking region and M-1 adjacent tracking regions.

21. The method according to any one of claims 17 to 20, characterized in that, The transmission period of the synchronization signal is greater than 160 milliseconds.

22. The method according to any one of claims 13 to 21, characterized in that, The first uplink signal includes the identifier of the terminal device, and also includes: The context information of the terminal device is determined based on the identifier of the terminal device.

23. The method according to any one of claims 13 to 22, characterized in that, The first uplink signal also includes second indication information, which is used to indicate that the terminal device has a data transmission requirement.

24. A communication device, characterized in that, Includes units for implementing the method as described in any one of claims 1 to 12.

25. A communication device, characterized in that, Includes a processor configured to cause the communication device to perform the method as described in any one of claims 1 to 12.

26. A communication device, characterized in that, Includes units for implementing the method as described in any one of claims 13 to 23.

27. A communication device, characterized in that, Includes a processor configured to cause the communication device to perform the method as described in any one of claims 13 to 23.

28. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed, cause the communication device to perform the method as described in any one of claims 1 to 12, or the method as described in any one of claims 13 to 23.

29. A computer program product, characterized in that, The computer program product includes instructions that, when executed, cause the communication device to perform the method as described in any one of claims 1 to 12, or to perform the method as described in any one of claims 13 to 23.

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