Communication method and device

Abstract

The present application provides a communication method and device, which includes a first centralized unit of a network device receiving first information of a terminal device, where the first information is used to indicate the type of the terminal device; and the first centralized unit sending second information to a first distributed unit of the network device, where the first information is used to indicate the type of the terminal device.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on March 4, 2021, with application number 202110240470.5 and application name “A terminal capability indication method, terminal and network device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The embodiments of the present application relate to the field of wireless communication technologies, and in particular to a communication method and device. Background Art

[0004] Currently, in the evolution of LTE Rel-15 and 5G NR, such as Figure 1 As shown in the figure, a new network architecture is proposed. Under this network architecture, the functions of the base station are divided into two units: the central unit (CU) and the distributed unit (DU). The CU handles the functions of the wireless high-level protocol stack, such as the radio resource control (RRC) layer and the packet data convergence protocol (PDCP) layer; the DU handles the physical layer of the baseband processing and some layer 2 protocol stack functions, such as the radio link control (RLC) layer, the media access control (MAC) layer, and the physical layer (PHY). The interface between the CU and DU is the F1 interface.

[0005] Currently, under the CU-DU network architecture, network equipment cannot achieve better scheduling and access management for low-capability (Redcap) terminal devices. Summary of the Invention

[0006] The embodiments of the present application provide a communication method and device, which enable network equipment to better schedule and manage access of low-capability terminal devices.

[0007] In a first aspect, the present application provides a communication method, comprising: a first centralized unit of a network device receives first information of a terminal device, wherein the first information is used to indicate the type of the terminal device; and the first centralized unit sends second information to a first distributed unit of the network device, wherein the first information is used to indicate the type of the terminal device.

[0008] For example, the centralized unit of the network device may be a CU, and the distributed unit of the network device may be a DU. Through the above method, after the terminal device accesses the network device, the first centralized unit of the network device may send second information to the first distributed unit of the network device based on the first information of the terminal device received, so that the first distributed unit of the network device can obtain the type of the terminal device in a timely manner. For example, the type of the terminal device may be a low-capability terminal device (for example, a REDCAP terminal device, or an NB-IoT terminal device, etc.), or the type of the terminal device may be a type of medium- and low-capability terminal device. For example, when the low-capability terminal device is a REDCAP terminal device, the type of the low-capability terminal device may be a terminal device with different capabilities that is further subdivided among the REDCAP terminal devices. For another example, it may also be a terminal device with different antennas that is further subdivided among the REDCAP terminal devices, and so on.

[0009] Thus, the first distributed unit in the network device can schedule corresponding resources and access priorities for the terminal device in a timely manner based on the type of terminal device in the second information obtained from the first centralized unit of the network device during the terminal device access process, or when the terminal device switches to the first distributed unit of the network device, thereby realizing the scheduling management of low-capability terminal devices.

[0010] In a possible implementation manner, the type of the terminal device includes any one of the following: a low-capability terminal device, or a type of a low-capability terminal device.

[0011] In a possible implementation manner, the first centralized unit receives the first information through the first distributed unit.

[0012] Through the above method, when the terminal device accesses the network through the first distributed unit and the first centralized unit, the terminal device can send the first information to the first centralized unit through the first distributed unit in a transparent transmission manner.

[0013] In a possible implementation, the first centralized unit receives the first information through a second distributed unit, where the second distributed unit is a distributed unit to which the terminal device accesses before switching to the first distributed unit.

[0014] Through the above method, when the terminal device accesses the second distributed unit, it can send the first information to the first centralized unit through the second distributed unit, so that the first centralized unit can obtain the type of the terminal device in a timely manner. When switching to the first distributed unit, the first distributed unit can obtain the second information through the second information sent by the first centralized unit to ensure that after switching, the first distributed unit can still schedule the resources of the terminal device in a timely manner.

[0015] In a possible implementation, the first centralized unit receives the first information sent by a second centralized unit, where the second centralized unit is a centralized unit to which the terminal device accesses before switching to the first centralized unit.

[0016] In one possible implementation, the first distributed unit schedules the resources of the terminal device and / or the access priority of the terminal device according to the second information.

[0017] In a possible implementation, the first centralized unit sends the second information to a third distributed unit, where the third distributed unit is the distributed unit to which the terminal device is switched from the first distributed unit.

[0018] Through the above method, the first centralized unit can send the second information to the third distributed unit when the terminal device switches to the third distributed unit, so that the third distributed unit can obtain the type of the terminal device earlier when switching, and can provide the terminal device with resource scheduling corresponding to low-capability terminal devices earlier in the process of the terminal device accessing the third distributed unit.

[0019] In one possible implementation, the first centralized unit sends the first information to a third centralized unit, where the third centralized unit is the centralized unit after the terminal device is switched from the first centralized unit. The first information is used by the third centralized unit to send the second information to a third distributed unit, where the third distributed unit is the distributed unit after the terminal device is switched from the first distributed unit.

[0020] Through the above method, the first centralized unit can send the first information to the third centralized unit when the terminal device switches to the third centralized unit, so that the third centralized unit can obtain the type of the terminal device earlier when switching, and send the second information to the third distributed unit after the terminal device accesses the third centralized unit, so that the third distributed unit can provide the terminal device with resource scheduling corresponding to the low-capability terminal device earlier.

[0021] In a possible implementation, the second information is carried in a first message, and the first message includes a first field, and the first field carries the second information.

[0022] Through the above method, a first field can be added to the first message for the second information to enable the second information to be sent in the first message. For example, the first message can be a message sent by the first centralized unit to the first distributed unit, so that the first distributed unit of the network device can obtain the second information earlier and schedule resources for low-capability terminal devices earlier.

[0023] In second aspect, the present application provides a communication method, including: a first distributed unit of a network device receives first information of a terminal device, the first information is used to indicate the type of the terminal device; the first distributed unit sends second information to a first centralized unit of the network device, the second information is used to indicate the type of the terminal device.

[0024] For example, the centralized unit of the network device may be a CU, and the distributed unit of the network device may be a DU. Through the above method, after the terminal device accesses the network device, the first distributed unit of the network device may send second information to the first centralized unit of the network device based on the first information of the terminal device received, so that the first centralized unit of the network device can obtain the type of the terminal device in a timely manner. For example, the type of the terminal device may be a low-capability terminal device (for example, a REDCAP terminal device, or an NB-IoT terminal device, etc.), or the type of the terminal device may be a type of medium- and low-capability terminal device. For example, when the low-capability terminal device is a REDCAP terminal device, the type of the low-capability terminal device may be a terminal device with different capabilities that is further subdivided among the REDCAP terminal devices. For another example, it may also be a terminal device with different antennas that is further subdivided among the REDCAP terminal devices, and so on.

[0025] Thus, the first centralized unit in the network device can timely control the access of low-capability terminal devices based on the type of terminal device in the second information obtained from the first centralized unit of the network device during the terminal device access process, or when the terminal device switches to the first centralized unit of the network device or the first distributed unit of the network device, thereby improving the utilization rate of network resources.

[0026] In a possible implementation, the first centralized unit controls access of the terminal device according to the second information.

[0027] In a possible implementation, the first centralized unit sends the second information to a third distributed unit, where the third distributed unit is the distributed unit to which the terminal device is switched from the first distributed unit.

[0028] In a possible implementation, the first centralized unit sends the second information to a third centralized unit, and the third centralized unit is the centralized unit after the terminal device is switched from the first centralized unit.

[0029] In a possible implementation, the second information is used to control access of the terminal device.

[0030] In a possible implementation, the second information is carried in a second message, the second message includes a first field, and the first field carries the second information.

[0031] Through the above method, a first field can be added to the second message for the second information to enable the second information to be sent in the second message. For example, the second message can be an initial uplink wireless resource control message transmission message, so that the first centralized unit of the network device can obtain the second information earlier and control the access of low-capability terminal devices earlier.

[0032] In a possible implementation, the first message is any one of the following: a downlink wireless resource control message delivery message, a terminal device context request message; and the second message is an initial uplink wireless resource control message delivery message.

[0033] In a possible implementation manner, the first information is carried by message 1 or message 3.

[0034] In the above manner, after the first information, that is, after message 1 or message 3 in the random access process, the first distributed unit of the network device or the first centralized unit of the network device can be sent to the corresponding first centralized unit or first distributed unit earlier, thereby scheduling or managing the low-capability terminal device earlier.

[0035] In one possible implementation, the first distributed unit and the first centralized unit are separate network elements in a first network device, and the first network device is used for the terminal device to access the network; or, the second distributed unit and the second centralized unit are separate network elements in a second network device, and the second network device is used for the terminal device to access the network; or, the third distributed unit and the third centralized unit are separate network elements in a third network device, and the third network device is used for the terminal device to access the network; or, the second distributed unit and the first centralized unit are separate network elements in a fourth network device, and the fourth network device is used for the terminal device to access the network; or, the third distributed unit and the first centralized unit are separate network elements in a fifth network device, and the fifth network device is used for the terminal device to access the network.

[0036] In a third aspect, the present application provides a communication device, which is applied to a first centralized unit of a network device. The first centralized unit may include a processing module, a sending module and a receiving module.

[0037] A processing module is used to receive first information of a terminal device through a receiving module, wherein the first information is used to indicate the type of the terminal device; and a processing module is used to send second information to a first distributed unit of the network device through a sending module, wherein the first information is used to indicate the type of the terminal device.

[0038] In a possible implementation, the processing module is configured to receive the first information from the terminal device via the first distributed unit through the receiving module.

[0039] In a possible implementation, the processing module is configured to receive the first information from the terminal device via the receiving module via the second distributed unit, where the second distributed unit is the distributed unit to which the terminal device accesses before switching to the first distributed unit.

[0040] In a possible implementation, the processing module is configured to receive, through a receiving module, the first information sent by a second centralized unit, where the second centralized unit is a centralized unit to which the terminal device accesses before switching to the first centralized unit.

[0041] In one possible implementation, the first distributed unit schedules the resources of the terminal device and / or the access priority of the terminal device according to the second information.

[0042] In a possible implementation, the processing module is configured to send the second information to a third distributed unit through a sending module, where the third distributed unit is a distributed unit to which the terminal device is switched from the first distributed unit.

[0043] A possible implementation method is that the processing module is used to send the first information to a third centralized unit through a sending module, and the third centralized unit is the centralized unit after the terminal device is switched from the first centralized unit. The first information is used by the third centralized unit to send the second information to the third distributed unit, and the third distributed unit is the distributed unit after the terminal device is switched from the first distributed unit.

[0044] In a possible implementation, the second information is carried in a first message, and the first message includes a first field, and the first field carries the second information.

[0045] In a fourth aspect, the present application provides a communication device, which is applied to a first distributed unit of a network device. The first distributed unit may include a processing module, a sending module and a receiving module.

[0046] A processing module is used to receive first information of a terminal device through a receiving module, wherein the first information is used to indicate the type of the terminal device; a processing module is used to send second information to a first centralized unit of a network device through a sending module, wherein the second information is used to indicate the type of the terminal device.

[0047] In a possible implementation manner, the type of the terminal device includes any one of the following: a low-capability terminal device, or a type of a low-capability terminal device.

[0048] In a possible implementation, the first centralized unit controls access of the terminal device according to the second information.

[0049] In a possible implementation, the first centralized unit sends the second information to a third distributed unit, where the third distributed unit is the distributed unit to which the terminal device is switched from the first distributed unit.

[0050] In a possible implementation, the first centralized unit sends the second information to a third centralized unit, and the third centralized unit is the centralized unit after the terminal device is switched from the first centralized unit.

[0051] In a possible implementation, the second information is used to control access of the terminal device.

[0052] In a possible implementation, the second information is carried in a second message, the second message includes a first field, and the first field carries the second information.

[0053] In combination with the third aspect or the fourth aspect, the first message is any one of the following: a downlink wireless resource control message delivery message, a terminal device context request message; the second message is: an initial uplink wireless resource control message delivery message.

[0054] In combination with the third aspect or the fourth aspect, a possible implementation method is that the first information is carried by message 1 or message 3.

[0055] In combination with the third aspect or the fourth aspect, a possible implementation method is that the first distributed unit and the first centralized unit are separate network elements in a first network device, and the first network device is used for the terminal device to access the network; or, the second distributed unit and the second centralized unit are separate network elements in a second network device, and the second network device is used for the terminal device to access the network; or, the third distributed unit and the third centralized unit are separate network elements in a third network device, and the third network device is used for the terminal device to access the network; or, the second distributed unit and the first centralized unit are separate network elements in a fourth network device, and the fourth network device is used for the terminal device to access the network; or, the third distributed unit and the first centralized unit are separate network elements in a fifth network device, and the fifth network device is used for the terminal device to access the network.

[0056] In a fifth aspect, the present application provides a communication device comprising a processor and a memory, wherein the memory is used to store computer-executable instructions. When the device is running, the processor executes the computer-executable instructions stored in the memory so that the device executes any of the implementation methods of the first aspect mentioned above.

[0057] In the sixth aspect, the present application provides a communication device comprising a processor and a memory, wherein the memory is used to store computer-executable instructions. When the device is running, the processor executes the computer-executable instructions stored in the memory so that the device executes any of the implementation methods of the second aspect mentioned above.

[0058] In the seventh aspect, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores instructions, which, when executed on a computer, enables the computer to execute any of the implementation methods of the first to second aspects above.

[0059] In an eighth aspect, an embodiment of the present application further provides a computer program product, which includes a computer program. When the computer program is run, any of the implementation methods of the first to second aspects above is executed.

[0060] In a ninth aspect, an embodiment of the present application further provides a chip system, comprising: a processor for executing any of the implementation methods of the first to second aspects above.

[0061] In the tenth aspect, an embodiment of the present application also provides a communication system, including a first centralized unit as in the third aspect or the fifth aspect, or including a first distributed unit as in the fourth aspect or the sixth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1A schematic diagram of a network architecture applicable to an embodiment of the present application;

[0063] Figure 2a-2b A schematic diagram of a network architecture applicable to an embodiment of the present application;

[0064] Figure 3 A schematic diagram of a random access method;

[0065] Figure 4 A flow chart of a communication method provided in an embodiment of the present application;

[0066] Figure 5 A flow chart of a communication method provided in an embodiment of the present application;

[0067] Figure 6 A flow chart of a communication method provided in an embodiment of the present application;

[0068] Figure 7 A flowchart of the method for establishing a context;

[0069] Figure 8 A schematic diagram of an application scenario applicable to the embodiments of the present application;

[0070] Figure 9 A flow chart of a communication method provided in an embodiment of the present application;

[0071] Figure 10 A schematic diagram of an application scenario applicable to the embodiments of the present application;

[0072] Figure 11 A flow chart of a communication method provided in an embodiment of the present application;

[0073] Figure 12 A flow chart of a communication method provided in an embodiment of the present application;

[0074] Figure 13 A flow chart of a communication method provided in an embodiment of the present application;

[0075] Figure 14 A schematic diagram of a communication device provided in an embodiment of the present application;

[0076] Figure 15 A schematic diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0077] Below, some terms used in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

[0078] 1) Low-capability terminal devices refer to terminal devices with simplified capabilities designed to improve the battery life of terminal devices in 5G NR networks, including lower data processing capabilities, smaller signal transmission and reception bandwidth, lower battery capacity, and a small number of transmission and reception antennas. For example, REDCAP terminal devices support lower air interface capabilities, such as the ability to support smaller bandwidth, fewer antennas, lower modulation orders, etc. Specifically, REDCAP terminal devices can be divided into different REDCAP terminal device types according to the maximum capabilities supported. For example, REDCAP terminal devices can be further divided into high-capability REDCAP terminal device types (such as supporting a maximum number of receiving antennas of 2, or a maximum bandwidth of 40M) and low-capability REDCAP terminal device types (such as supporting a maximum number of receiving antennas of 1, or a maximum bandwidth of 20M). It should be noted that in the embodiments of the present application, the low-capability terminal device may also be a narrowband internet of things (NB-IoT) terminal device, or a machine type communication (MTC) terminal device, or it may also be other types of terminal devices with simplified capabilities. Here, only REDCAP is used as an example of a low-capability terminal device, and this application does not limit its name.

[0079] 2) The communication system may be various radio access technology (RAT) systems, such as a long term evolution (LTE) system and various systems based on LTE evolution. In addition, the communication system may also be applicable to future-oriented communication technologies, such as fifth generation (5G) systems or new radio (NR).

[0080] Figure 1 A schematic diagram of a network architecture of a communication system applicable to an embodiment of the present application.

[0081] like Figure 1 As shown, the communication system 100 includes a terminal device 101 and a network device 102. The terminal device 101 accesses the network device 102 through a random access process.

[0082] The terminal device 101 can access the wireless network to obtain services of the external network (such as the Internet) through the wireless network, or communicate with other devices through the wireless network, such as communicating with other terminal devices. The access network can be a next generation radio access network (NG-RAN), and the access network can include access network devices, such as base stations (for example, gNBs), and gNBs are connected through interfaces (for example, Xn interfaces). The RAN device is used to access the terminal device 101 to the wireless network, and the gNB and 5GC are connected through interfaces (for example, Ng interfaces). The core network may include multiple core network devices, and the core network devices are used to manage the terminal device and provide a gateway for communicating with the external network. When Figure 1 When the network architecture shown is applicable to a 5G communication system, the core network may be a 5G core network (5G core network, 5GC). 5GC includes one or more functions or devices. For example, the core network device may be an access and mobility management function (AMF) entity, a session management function (SMF) entity or a user plane function (UPF) entity, etc., a session management function (SMF). These functions or devices may be network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform). It is understandable that the names of various core network devices are names in the 5G communication system, and as the communication system evolves, they may be replaced with other names with the same functions. When Figure 1 When the network architecture shown is applicable to an LTE communication system, the core network devices may be a mobility management entity (MME) and a serving gateway (S-GW).

[0083] It should be understood that Figure 1 The number of devices in the communication system shown is for illustration only, and the embodiments of the present application are not limited thereto. In actual applications, the communication system may further include more terminal devices 101, more RAN devices, and other devices.

[0084] RAN can also be called access network equipment or base station, or RAN node (or RAN equipment). Currently, some examples of access network equipment include: gNB / NR-NB, transmission reception point (TRP), evolved Node B (eNB), next generation eNodeB (ng-eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved NodeB, or home Node B, HNB), base band unit (BBU), wireless fidelity (Wi-Fi) access point (AP), or access network equipment in possible future communication systems. It can also be a gNB in a 5G system, such as NR, or a transmission point (TRP or TP), one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or it can also be a network node constituting a gNB or a transmission point, such as a baseband unit (BBU).

[0085] A terminal device, which can also be called a terminal device, user equipment (UE), mobile station (MS), or mobile terminal (MT), is a device that provides voice or data connectivity to users. It can also be an IoT device. For example, a terminal device includes a handheld device with wireless connectivity, an in-vehicle device, and so on. Currently, terminal devices can be: mobile phones, tablet computers, laptop computers, PDAs, mobile internet devices (MIDs), wearable devices (such as smart watches, smart bracelets, pedometers, etc.), vehicle-mounted devices (such as cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed trains, etc.), virtual reality (VR) devices, augmented reality (AR) devices, wireless terminal devices in industrial control, smart home devices (such as refrigerators, TVs, air conditioners, electric meters, etc.), intelligent robots, workshop equipment, wireless terminal devices in self-driving, wireless terminal devices in remote medical surgery, wireless terminal devices in smart grids, wireless terminal devices in transportation safety, wireless terminal devices in smart cities, or wireless terminal devices in smart homes, flying devices (such as intelligent robots, hot air balloons, drones, airplanes), etc. In the embodiments of the present application, the solution is described using UE or terminal devices.

[0086] Figure 2a This is a schematic diagram of a network architecture in a 5G communication system to which the present application is applicable. Figure 2a As shown, the network architecture includes CN devices (e.g., Figure 2a 5GC), RAN equipment and terminal equipment shown.

[0087] Communication between RAN equipment and terminal devices follows a specific protocol layer structure. For example, the control plane protocol layer structure may include the functions of the radio resource control (RRC) layer, packet data convergence protocol (PDCP) layer, radio link control (RLC) layer, media access control (MAC) layer, and physical layer. The user plane protocol layer structure may include the functions of the PDCP layer, RLC layer, MAC layer, and physical layer. In one possible implementation, the service data adaptation protocol (SDAP) layer may also be included above the PDCP layer. The RRC layer primarily functions as the high-level control plane for the UE, related to UE access control, maintenance, release, and configuration. Only the RRC layer can parse RRC messages. The MAC and physical (PHY) layers primarily function as low-level scheduling for the UE, related to data packetization and scheduling. Only the MAC layer can parse MAC control signaling, and only the PHY layer can parse PHY control signaling. The RAN device may implement the functions of protocol layers such as RRC, PDCP, RLC and MAC by one node, or may implement the functions of these protocol layers by multiple nodes.

[0088] In a new network architecture of the 5G NR network, the network equipment can be composed of two logical network elements: a centralized unit and a distributed unit. Part of the functions of the network equipment are deployed in a centralized unit, and the remaining functions are deployed in a distributed unit. Multiple distributed units can share one centralized unit to save costs and facilitate network expansion. Depending on the scenario and needs, they can be deployed in one unit or separately. For example, the centralized unit can be a CU, and the distributed unit can be a DU. The following explanation takes the network architecture including the centralized unit and the distributed unit as an example of a CU-DU separation architecture. With the evolution of the network architecture and the emergence of new business scenarios, as long as the wireless access network equipment of the communication system has a CU-DU separation architecture or an architecture equivalent to the CU-DU separation architecture function, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems.

[0089] In the embodiment of the present application, the CU and DU are connected via an interface (e.g., F1 interface). The CU represents the base station and is connected to the core network via an interface (e.g., Ng interface). In the communication system of the present application, Figure 2aAs shown, the UE can be connected to an access network device (e.g., a gNB). Specifically, the UE can be connected to the DU in the gNB. The CU is connected to the 5GC and DU respectively. In the downlink communication link, the CU is used to receive data from the 5GC and send the data to the DU. In the uplink communication link, the CU is used to receive data from the DU and send it to the 5GC. At the same time, the CU has a centralized control function for the DU. In systems using different wireless access technologies, devices with CU functions may have different names. For the convenience of description, devices with CU functions are collectively referred to as access network central units.

[0090] The DU is connected to the CU and user equipment (UE). In downlink communications, the DU receives data from the CU and sends it to the UE. In uplink communications, the DU receives data from the UE and sends it to the CU. Devices with DU functionality may have different names in systems using different radio access technologies. For ease of description, devices with DU functionality are collectively referred to as access network distributed units.

[0091] In the above network architecture, the signaling generated by the CU can be sent to the terminal device through the DU, or the signaling generated by the terminal device can be sent to the CU through the DU. The DU can directly encapsulate the signaling through the protocol layer and transparently transmit it to the terminal device or CU without parsing it. In the following embodiments, if the transmission of such signaling between the DU and the terminal device is involved, then the sending or receiving of the signaling by the DU includes this scenario. For example, the signaling of the RRC or PDCP layer will eventually be processed into physical layer signaling and sent to the terminal device, or converted from the received physical layer signaling. Under this architecture, the signaling of the RRC or PDCP layer can also be considered to be sent by the DU, or sent by the DU and the RF load.

[0092] The CU and DU of network devices can be divided according to the protocol stack as follows: Figure 2b For example, the RRC layer, SDAP layer, and PDCP layer are deployed in the CU of the network device; and the RLC layer, MAC layer, and physical layer are deployed in the DU of the network device.

[0093] In the embodiment of the present application, when the network device is a device that supports the NR system, the functional division of the CU and DU can be divided according to the protocol stack. The CU of the network device and the DU of the network device are two functional entities. One possible way is to distinguish the functional division based on the real-time nature of the content. Figure 2bAs shown, the RRC, SDAP, and PDCP layers are deployed in the CU. The RLC, MAC, and PHY layers are deployed in the DU. Accordingly, the CU has RRC, PDCP, and SDAP processing capabilities. For network devices with a CU-DU architecture, the CU is responsible for managing the RRC status of terminal devices. The DU has RLC, MAC, and PHY processing capabilities.

[0094] It is worth noting that the above functional division is just an example. Other divisions are possible. For example, the CU includes RRC, PDCP, RLC, and SDAP processing capabilities, while the DU has MAC and PHY processing capabilities. Another example is that the CU includes RRC, PDCP, RLC, SDAP, and partial MAC processing capabilities (such as adding MAC headers), while the DU has PHY and partial MAC processing capabilities (such as scheduling).

[0095] This division of the protocol layer is only an example, and it can also be divided at other protocol layers, such as dividing at the RLC layer, setting the functions of the RLC layer and the protocol layers above it in the CU, and the functions of the protocol layers below the RLC layer in the DU; or, dividing at a certain protocol layer, for example, setting part of the functions of the RLC layer and the functions of the protocol layers above the RLC layer in the CU, and setting the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer in the DU. In addition, it can also be divided in other ways, such as dividing by latency, setting the functions whose processing time needs to meet the latency requirements in the DU, and the functions that do not need to meet the latency requirements in the CU. The division of the protocol layer described above is only an example, and it can also be divided at other protocol layers, and I will not give examples one by one here.

[0096] Of course, the embodiments of the present application can also be applied to LTE communication systems. For example, RAN equipment and CN equipment may also be included in the LTE communication system. Among them, the RAN equipment (eNB) includes a baseband device and a radio frequency device, wherein the baseband device can be implemented by one node or by multiple nodes, and the radio frequency device can be independently implemented remotely from the baseband device, or integrated in the baseband device, or partially remotely integrated in the baseband device. The radio frequency device can be arranged remotely relative to the baseband device, for example, the radio frequency remote unit (RRU) is arranged remotely relative to the BBU. In addition, the radio frequency device can be remote and not placed in the DU, or it can be integrated in the DU, or partially remotely integrated in the DU, without any limitation here.

[0097] It should be understood that Figure 2a and Figure 2bThe number and type of UEs included in the communication system shown are merely examples, and the embodiments of the present application are not limited thereto. For example, more UEs communicating with access network devices (such as gNBs) may be included, but for simplicity, they are not described one by one in the accompanying drawings. In addition, in the communication system shown in FIG2 , although a base station and a UE connected to each DU are shown, the communication system may not be limited to including the base station and a UE connected to each DU, and will not be described in detail here.

[0098] In the following embodiments, the network supported by the first DU is the union of the networks supported by all logical CUs. This means that the first DU supports the networks supported by each connected logical CU. For ease of description, the first logical CU is referred to as the "first CU" and the second logical CU is referred to as the "second CU."

[0099] It should be understood that Figures 1 to 2b The figure only illustrates several functions or devices involved in the embodiments of the present application, and the communication system architecture may also include more or fewer functions or devices. For example, Figure 1 The 5GC equipment in the 5GC may also include unified data management (UDM) or data network (DN), etc. The DU shown in Figure 2 may also be configured with more logical cells, etc.

[0100] The communication system architecture applicable to the embodiments of the present application is not limited to Figures 1 to 2b As shown, it is possible to achieve Figures 1 to 2b The communication system architecture of the functions of each device shown is applicable to this application.

[0101] The terms "system" and "network" in the embodiments of the present application can be used interchangeably. "At least one" refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, a and b, a and c, b and c, or a and b and c.

[0102] Furthermore, unless otherwise indicated, ordinal numbers such as "first" and "second" in the embodiments of this application are used to distinguish between multiple objects and are not used to define the order, timing, priority, or importance of multiple objects. For example, the first priority criterion and the second priority criterion are only used to distinguish different criteria and do not indicate differences in the content, priority, or importance of the two criteria.

[0103] In addition, the terms "including" and "having" in the embodiments, claims, and drawings of this application are not exclusive. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the listed steps or modules and may also include steps or modules that are not listed.

[0104] exist Figure 1 、 Figure 2a or Figure 2b In the illustrated network architecture, the terminal device 101 establishes a connection with the network device 102 and requests the network device 102 to allocate corresponding dedicated resources to the terminal device 101 for normal service transmission. The terminal device can establish uplink synchronization with the network device through a random access process and obtain a unique terminal device identifier, such as a cell radio network temporary identifier (C-RNTI), so that the terminal device can perform uplink transmission with the network device.

[0105] The following explains the relevant technical features of the random access process involved in the embodiments of the present application.

[0106] 1. Triggering the Random Access Process

[0107] The random access process refers to the process from the time the terminal device sends a random access signal to try to access the network to the time before a basic signaling connection is established with the network device. The random access signal can be used to initiate the random access process. For example, the random access signal can be a random access preamble. Optionally, the random access signal can also be a demodulation reference signal (DMRS). The terminal device can exchange information with the network device through the random access process to achieve uplink time synchronization with the communication system. Optionally, it can also request resources or transmit data through the random access process. In the embodiment of the present application, the random access process may also be referred to as random access or random access channel process or random access method. This application does not distinguish between them and they can be used interchangeably in the following description.

[0108] Exemplarily, there may be multiple events (or scenarios) that trigger the random access process. For example, in an LTE communication system, the random access process may be triggered by the following scenarios:

[0109] Scenario 1: Initial access of the terminal device. Initial RRC connection establishment of the terminal device. When the terminal device changes from the RRC idle (RRC_IDLE) state to the RRC connected (RRC_CONNECTED) state, the terminal device initiates random access.

[0110] Scenario 2: RRC connection re-establishment procedure of the terminal device. When the wireless connection fails and the terminal device needs to re-establish the RRC connection, the terminal device will initiate random access.

[0111] Scenario 3: When the terminal device performs cell handover, the terminal device initiates random access in the target cell.

[0112] Scenario 4: Downlink data arrives. When the terminal device is in a connected state, the network device has downlink data to transmit to the terminal device, but finds that the terminal device is out of sync in the uplink. In the RRC_CONNECTED state, when the downlink data arrives (at this time, a reply confirmation (ACK) / non-confirmation (NACK) is required), the uplink is in an "out of sync" state; the network device will control the terminal device to initiate random access. Among them, the network device side maintains an uplink timer. If the uplink timer times out and the network device does not receive a response signal from the terminal device, the network device considers that the terminal device is out of sync in the uplink.

[0113] Scenario 5: Uplink data arrives. When the terminal device is in a connected state, the terminal device has uplink data to transmit to the network device, but it is found to be in an uplink out-of-sync state. In the RRC_CONNECTED state, when uplink data arrives (for example, a measurement report needs to be reported or user data needs to be sent), the uplink is in an "out-of-sync" state or there are no available physical uplink control channel (PUCCH) resources for scheduling request (SR) transmission (at this time, uplink synchronized terminal devices are allowed to use random access channels (RACH) instead of SR). The terminal device will initiate random access, in which the terminal device side maintains an uplink timer. If the uplink timer times out and the terminal device does not receive a command from the network device to adjust the maximum time advance (TA) value, the terminal device considers that the uplink is out of sync.

[0114] For example, in a 5G communication system, the random access process can also be triggered by the following scenarios:

[0115] (1) Uplink (UL) data arrives in the inactive state, and the uplink is in an "out-of-sync" state; (2) Downlink (DL) data arrives in the inactive state, and the uplink is in an "out-of-sync" state; (3) Requesting on-demand system information (SI) (In the 5G communication system, system information is divided into two categories: minimum SI and on-demand SI, where minimum SI is required to be accepted by all terminal devices, and on-demand SI can be requested according to the needs of the terminal device itself); (4) Beam failure recovery (BFR).

[0116] The above is an event that triggers the random access process. It can be seen that no matter it is an LTE system or an NR system, the terminal device needs to go through the random access process to access the network device. There are two different ways of random access process: contention based random access and non-contention based random access. For example, according to whether the preamble sent by the terminal device is selected by the terminal device itself, the random access process can be divided into a contention based random access process and a non-contention based random access process. Among them, in the contention based random access process, the preamble can be selected by the terminal device; when the event that triggers the random access process is other events other than switching and beam failure recovery described above, the contention based random access process can be adopted. In the non-contention based random access process, the network device can allocate a preamble to the terminal device; when the event that triggers the random access process is the switching and beam failure recovery events described above, the non-contention based random access process can be adopted.

[0117] The following takes the random access process based on contention as an example, combined with Figure 3 Describe the steps involved in the random access procedure. Figure 3 A schematic diagram of a random access process provided in an embodiment of the present application. Figure 3 As shown, the random access process provided in the embodiment of the present application includes the following steps.

[0118] Step 300: The network device sends random access configuration information to the terminal device, and the terminal device can receive the random access configuration information from the network device, and the random access configuration information is used to configure random access parameters. This step can be used for preparation before performing the random access process and is not included in the steps of the random access process.

[0119] Exemplarily, the random access parameters may include one or more of the following: a physical random access channel (PRACH) resource set used to transmit a random access preamble; a random access preamble set; a maximum number of random access preamble transmissions; an initial transmit power of a random access preamble; a size of a random access response window; a maximum number of hybrid automatic repeat request (HARQ) retransmissions of a third message; and a contention resolution timer duration. Furthermore, the random access parameters may also include a power ramp step size.

[0120] Among them, the PRACH resource set may include the time-frequency resources that the terminal device can use to send the preamble, which can be indicated by the field rach-ConfigGeneric. The maximum number of transmissions of the random access preamble can be indicated by the field totalNumberOfRA-Preambles. The initial transmit power of the random access preamble can be indicated by the field reambleInitialReceivedTargetpower. The size of the random access response window is used to indicate the number of subframes included in the random access response window, which can be indicated by the field ra-ResponsewindowSize. The random access response window starts at the third subframe after the subframe in which the terminal device sends the preamble (if the preamble spans multiple subframes in the time domain, it is calculated based on the last subframe) and lasts for ra-ResponseWindowSize subframes. The maximum number of HARQ retransmissions of the third message can be indicated by the field maxHARQ-Msg3. The duration of the contention resolution timer can be indicated by the field mac-ContentionResolutionTimer.

[0121] It should be noted that: (1) Each of the above-described "PRACH resource set, preamble set, maximum number of transmissions of the random access preamble, initial transmit power of the random access preamble, size of the random access response window, maximum number of HARQ retransmissions of the third message, and duration of the contention resolution timer" can be preset with a corresponding default value. For example, when the random access configuration information sent by the network device configures the RACH resource set but does not configure the maximum number of transmissions of the random access preamble (for example, the random access configuration information includes the field rach-ConfigGeneric but does not include the field totalNumberOfRA-Preambles), the value of the maximum number of transmissions of the random access preamble can be the default value.

[0122] (2) The above is an exemplary description of the contents included in the random access parameters. In other possible embodiments, the random access parameters may also include other contents related to the random access process, such as time indication information.

[0123] Step 301: The terminal device sends a preamble to the network device, and the network device receives the preamble from the terminal device, wherein the preamble is also called the first message or message 1 (MSG1) in the random access process.

[0124] The preamble sent by the terminal device to the network device in step 401 may be a random access request sent by the terminal device to the network device. The preamble may be a preamble selected by the terminal device from the preamble set for random access obtained in step 400. Optionally, the network device may estimate the transmission delay between itself and the terminal device based on the preamble and calibrate the uplink timing accordingly.

[0125] Step 302: After detecting the preamble sent by the terminal device, the network device sends a random access response (RAR) message to the terminal device.

[0126] Correspondingly, the terminal device receives a RAR message from the network device, wherein the RAR message is also referred to as the second message or message 2 (MSG2) in the random access process. Message 2 includes a MAC protocol data unit (PDU) consisting of a media access control MAC header (subheader) and a MACRAR. Message 2 may include one or more of the following information: an identifier or index of the detected preamble, uplink time synchronization information, uplink resources and BI allocated for the terminal device to send message 3. Of course, message 2 may also include other information. The identifier of the preamble is, for example, a random access preamble identifier (RAPID). It should be noted that if the network device does not receive the preamble sent by the terminal device, the message 2 sent by the network device does not include the identifier of the preamble corresponding to the terminal device.

[0127] Exemplarily, the MAC RAR may include a timing advance (TA) command, where the TA is used to specify the time adjustment required for uplink synchronization of the terminal device; or, it may also include uplink resources allocated to message 3; or, it may also include a temporary cell radio network temporary identifier (TC-RNTI) allocated to the terminal device, where the TC-RNTI is used for subsequent transmissions between the terminal device and the network device. After the conflict is resolved, the TC-RNTI may become a cell radio network temporary identifier (C-RNTI).

[0128] After the terminal device sends Message 1, it will receive Message 2 within the RAR time window (RA response window). If the network device does not receive Message 2 in response within this RAR time window, the random access process is considered to have failed. For the terminal device whose random access failed, the network device may send a backoff indication to it. The backoff indication may be used to indicate a time value, which is used to determine a backoff time range. When the random access process fails, the terminal device may select a backoff time within the backoff time range and may only use the random access resources configured for it by the network device in step 400 after the selected backoff time expires.

[0129] Step 303: The terminal device sends uplink data to the network device according to message 2.

[0130] Correspondingly, the network device receives the uplink data from the terminal device, wherein the uplink data is also referred to as the third message or message 3 (MSG3) in the random access process.

[0131] Among them, message 3 may include identifiers of different scenario information, which will be used for contention resolution in step 404. The content of message 3 may also be different depending on the terminal device status and application scenarios. For example, the identifier of the terminal device (such as UE-ID). For example, for the initial access scenario, message 3 is an RRC setup request (RRCSetupRequest) message, and the unique identifier of the terminal device or a random number carried in message 3 at this time; for the scenario in which the terminal device reestablishes the RRC connection, message 3 is an RRC reestablishment request (RRCReestablishmentRequest) message, and the identifier of the corresponding scenario information is C-RNTI; for the RRC connection recovery scenario, message 3 is an RRC recovery request (RRCResumeRequest) message, and the identifier of the corresponding scenario information may be C-RNTI. For other scenarios in which the terminal device is in the RRC connected state, the unique identifier of the terminal device carried in message 3 may be C-RNTI. For example, message 2 may carry uplink resources and TA commands, so that after receiving message 2, the terminal device uses the TA value indicated by the TA command to send message 3 on the uplink resources indicated by message 2.

[0132] Step 304: When the network device detects message 3, it sends a contention resolution message to the terminal device, and the terminal device receives the contention resolution message from the network device.

[0133] The contention resolution message is also referred to as the fourth message or message 4 (MSG4). Message 4 may include part of message 3 or a physical downlink control channel (PDCCH) containing the C-RNTI, i.e., message 4 includes the C-RNTI carried by the PDCCH.

[0134] Message 4 is used for contention resolution. In this mechanism, the network device carries a unique identifier in Message 4 (the unique identifier of the terminal device is included in Message 3) to specify the terminal device that successfully accesses the network. Other terminal devices that did not successfully resolve the contention will re-initiate random access.

[0135] For example, if the network device receives uplink data sent by the terminal device, message 4 may carry the identification of the terminal device; if the network device does not receive the uplink data sent by the terminal device, the message 4 sent by the network device does not include the identification of the terminal device; when the terminal device receives the message 4, it can determine whether it has successfully accessed the network device based on whether the identification of the terminal device carried in the message 4 is consistent with its own identification, wherein, if the two are consistent, it is determined that the terminal device has successfully accessed the network device; if the two are inconsistent, it is determined that the terminal device has failed to access.

[0136] Optionally, after message 4, a message 5 may be included that is sent by the terminal device to the network device. The message 5 may be used to send the capability information of the terminal device. For details, see the following section. Figure 7 , I will not go into details here.

[0137] It should be noted that the above description is the implementation process of the contention-based random access process. The implementation of the non-contention random access process can refer to it. The difference is that for the non-contention random access process, the random access parameters include powerRampingStepHighPriority and scalingFactorBI in addition to the parameters described above.

[0138] Taking the 5G communication system as an example, terminal devices may be some special terminal devices, such as REDCAP terminal devices, NB-IoT terminal devices, or MTC terminal devices. For these low-capability terminal devices, resources and access methods need to be allocated accordingly to meet their requirements such as narrow bandwidth and low energy consumption. Based on this, when such devices access the network equipment, the network equipment needs to know whether the accessed terminal device is a low-capability terminal device as soon as possible so that the access network equipment can schedule corresponding resources for the low-capability terminal device earlier or perform access control for the low-capability terminal device.

[0139] Based on the above architecture, the embodiment of the present application provides a communication method for implementing the access process of the terminal device after applying the above architecture provided by the embodiment of the present application. Figure 4 , the method may include the following steps:

[0140] Step 401: A first unit of a network device obtains first information of a terminal device.

[0141] In some embodiments, the first unit may be a DU of the network device, and the second unit may be a CU of the network device. In this case, the network device may obtain the first information via the first information sent by the terminal device. Alternatively, the first unit may be the CU of the network device, and the second unit may be the DU of the network device. In this case, the network device may receive the first information from the terminal device via the DU of the network device. In other embodiments, the first unit may be the target DU of the network device, and the second unit may be the target CU of the network device. This means that the terminal switches from a source CU to a target CU, or vice versa, due to reasons such as mobility. In this case, the first unit may be the target DU of the network device. Therefore, during the switching process, the CU of the network device may send the first information of the terminal device to the target DU of the network device, so that the target DU of the network device obtains the first information of the terminal device. Alternatively, the CU may switch from the source DU to the target DU without switching. In this case, the first unit may be the target DU of the network device, and the second unit may be the target CU of the network device. Therefore, during the switching process, the network device may first send the first information of the terminal device to the target CU of the network device via the source CU of the network device, and then send the first information of the terminal device to the target DU of the network device via the target CU of the network device, so that the target DU of the network device obtains the first information of the terminal device.

[0142] The first information is used to indicate the type of the terminal device, and the type of the terminal device includes that the terminal device is a low-capability terminal device, or the type of the terminal device is a low-capability terminal device type.

[0143] For specific instruction methods, please refer to Method 1 to Method 3 below, which will not be repeated here.

[0144] Step 402: The first unit of the network device sends second information to the second unit of the network device.

[0145] The second information is used to indicate the type of the terminal device, and the type of the terminal device includes: the terminal device is a low-capability terminal device, or the type of the terminal device is a type of low-capability terminal device.

[0146] In some embodiments, the second information is used to indicate that the terminal device is a low-capability terminal device. For example, the second information can identify the type of the terminal device through the identifier of the terminal device. For example, the second information is the identifier of the terminal device, where identifier = 0 indicates that the terminal device is not configured with any type; identifier = 1 indicates that the terminal device is a REDCAP terminal device; identifier = 2 indicates that the terminal device is an NB-IoT terminal device; identifiers = 3 to 10 are reserved for future use; identifier = 11 indicates that the terminal device is a terminal device corresponding to access level 11, and so on.

[0147] For another example, the second information can also be used to indicate that the terminal device is a low-capability terminal device that supports a maximum number of receiving antennas of 2, or to indicate that the terminal device is a low-capability terminal device that supports a maximum number of receiving antennas of 1, or to indicate that the terminal device is a low-capability terminal device that supports a maximum bandwidth of 40M, or to indicate that the terminal device is a low-capability terminal device that supports a maximum bandwidth of 20M, etc. The specific second information can also be divided according to the identifier of the terminal device, and the details can be referred to the above examples.

[0148] In other embodiments, the second information may be used to indicate the type of the low-capability terminal device. Compared to the way the second information indicates the low-capability terminal device, the second information indicates the type of the low-capability terminal device, and more bits may be set accordingly. For example, the type of the low-capability terminal device may be a low-capability terminal device with 2 receiving antennas, a low-capability terminal device with 1 receiving antenna, and so on. In this case, the type of the low-capability terminal device may be indicated by 2 bits of the second information. For example, a high-capability terminal device is indicated by 00 in the second information, a low-capability terminal device with 2 receiving antennas is indicated by 11 in the second information, and a low-capability terminal device with 1 receiving antenna is indicated by 01 in the second information.

[0149] Through the above method, after the CU of the network device or the DU of the network device obtains the first information of the terminal device, it can share the information of whether the terminal device is a low-capability terminal device, so that the CU of the network device can timely control the access of the low-capability terminal device, and the DU of the network device can timely reasonably schedule the resources of the low-capability terminal device or reasonably divide the access priority of the low-capability terminal device, thereby improving the earlier and more timely management of the low-capability terminal device and optimizing the network performance of the low-capability terminal device.

[0150] The following is an example to illustrate the solution of the embodiment of the present application.

[0151] Example 1

[0152] Based on the above architecture, the embodiment of the present application provides a communication method for implementing the access process of the terminal device after applying the above architecture provided by the embodiment of the present application. Figure 5 , the method may include the following steps:

[0153] Step 501: The terminal device sends first information to the first DU.

[0154] The first information is used to indicate the type of the terminal device, and the type of the terminal device includes that the terminal device is a low-capability terminal device, or the type of the terminal device is a low-capability terminal device type.

[0155] In some embodiments, when accessing the network device, the terminal device may send first information to the DU of the network device through message 1 or message 3 of the random access process. Correspondingly, the DU of the network device receives the first information sent by the terminal device through message 1 or message 3 of the random access process, thereby enabling the type of the UE to be identified.

[0156] The following examples illustrate Mode 1 and Mode 2 in which the DU of the network device receives the first information sent by the UE through Message 1 or Message 3 of the random access process.

[0157] Method 1: Determine the first information through the resource information carried in message 1.

[0158] Alternatively, the first information is determined through resource information corresponding to message 1.

[0159] For example, consider configuring a specific PRACH time-frequency resource or a specific preamble code sequence for a low-capability terminal device. After the terminal device selects a specific time-frequency resource or a specific code sequence, the terminal device can send the corresponding time-frequency resource or code sequence through message 1. Thus, the DU of the network device can use the time-frequency resource or code sequence sent by message 1 as the first information, so that the DU of the network device determines that the terminal device is a low-capability terminal device based on the time-frequency resource or code sequence of the terminal device.

[0160] For another example, consider configuring a specific initial bandwidth part (BWP) for a low-capability terminal device. After the terminal device selects a specific initial BWP, the terminal device uses the time-frequency resources corresponding to the specific initial BWP or sends a codeword sequence message 1. Thus, the DU of the network device can use the initial BWP corresponding to message 1 as the first information to determine that the UE is a low-capability terminal device.

[0161] In mode 1, the first information is determined through information of the PHY layer. Therefore, the DU equipped with the PHY layer can obtain the first information, thereby determining that the terminal device is a low-capability terminal device.

[0162] Through method 1, the base station can more reasonably schedule subsequent messages 2, 3, 4, and subsequent messages. In addition, through method 1, the base station can prioritize the access of non-low-capability terminal devices and REDCAP UEs, such as giving priority to access to non-low-capability terminal devices. Alternatively, if the base station is a base station that preferentially configures corresponding resources for low-capability UEs, it will give priority to allowing REDCAP UEs to access the network. Thus, it can also be set that the random access process initiated by the low-capability terminal device and the random access process triggered by the switching event (or BFR event) can have the same priority, or different priorities.

[0163] Method 2: The first information is carried by using the second field in message 1 or message 3 of the random access process.

[0164] The second field may be introduced in message 1 or message 3. For example, the second field may be a MAC control element (MAC CE), or the second field may be a new logical channel ID (LCID) field in the MAC header. The second field may include the first information.

[0165] In some embodiments, the terminal device may carry the first information in the second field, for example, REDCAP information and REDCAP type information, to indicate that the terminal device is a REDCAP UE. For another example, the terminal device may carry the first information in the second field to indicate the type of the terminal device, for example, indicating that the terminal device is a default terminal device, or indicating that the terminal device is a terminal device that sends emergency messages, etc.

[0166] In Method 2, the first information is determined using MAC layer information. Therefore, a DU with a MAC layer can obtain this information and determine that the terminal device is a low-capability terminal device. Method 2 enables the base station to more effectively schedule subsequent Message 4 and subsequent messages. Furthermore, the base station can prioritize access between standard UEs and REDCAP UEs, for example, prioritizing access to non-low-capability terminal devices. Furthermore, the base station can more effectively manage contention between low-capability and non-low-capability terminal devices.

[0167] Similarly, in a two-step non-contention random access process, the base station can determine that the terminal device is a low-capability terminal device through message A of the random access process (message A of the two-step random access process includes messages 1 and 3 of the four-step random access process, that is, message A is a message combined with message 1 and message 3). For specific methods, please refer to the above methods 1 and 2, which will not be repeated here.

[0168] Step 502: A first DU of the network device sends a second message to a first CU of the network device.

[0169] The second message includes second information, where the second information is used to indicate the type of the terminal device, and the type of the terminal device includes that the terminal device is a low-capability terminal device, or the terminal device is a type of low-capability terminal device.

[0170] Specifically, the second message may be an initial UL RRC message transfer message. The second message may include: a newly added first field, where the first field is used to indicate the second information.

[0171] Table 1 shows the fields that may be included in an initial uplink RRC message transmission. For example, it includes the message type field (Message Type); the F1 interface application identification field of the DU and UE (gNB-DU UE F1AP ID); the NR configuration authorization information field (NR (configured grant information, CGI)); the terminal device identification field C-RNTI, which is used by the terminal device to locate the network device DU; the RRC container field (RRC-Container), which may include: the uplink message field (UL-CCCH-Message IE or UL-CCCH1-Message IE); the RRC container field sent by the DU to the CU (DU to CU RRCContainer); the SUL access identification field (Access Indication); the service identification field (Transaction ID); the RAN and UE identification field (RAN UE ID); the RRC container setup field (RRC-Container-RRCSetupComplete), which carries the uplink control information unit (UL-DCCH-Message IE) through the RRC setup message (RRCSetupComplete message); and the terminal device type field (UE type).

[0172] Table 1

[0173]

[0174]

[0175] Exemplarily, as shown in Table 2, the first field may be used to indicate the type of terminal equipment (UE type), and the second information of the first field may include any one of the following: REDCAP, REDCAP type, or other UE types.

[0176] For example, the type of the terminal device can be identified by the terminal device's identifier. For example, identifier = 0 indicates that the terminal device is not configured with any type; identifier = 1 indicates that the terminal device is a REDCAP terminal device; identifier = 2 indicates that the terminal device is an NB-IoT terminal device; identifiers = 3 to 10 are reserved for future use; identifier = 11 indicates that the terminal device is a terminal device corresponding to access level 11, and so on.

[0177] In an embodiment of the present application, there may be multiple ways for the type information to indicate the type of the terminal device. In one example, the type information may include 4 bits, and there are 16 values for UE type. For example, when the value of the 4 bits is 0000, it indicates UE type = 0, corresponding to a type of terminal device, for example, a high-capability terminal device with 4 antennas. When the value of the 4 bits is 0001, it indicates UE type = 1, corresponding to a type of terminal device, for example, a low-capability terminal device with 1 antenna. When the value of the 4 bits is 0010, it indicates UE type = 2, corresponding to a type of terminal device, for example, a low-capability terminal device with 2 antennas, and so on. In this way, the second network device can determine the type of the terminal device according to the UE type indicated by the type information. For example, if UE type = 1, it can be determined that the terminal device is a first type terminal device. In another example, the type information may include 1 bit. If the value of the bit is 1, it indicates that the terminal device is a first type terminal device. If the value of the bit is 0, it indicates that the terminal device is not a first type terminal device. In another example, considering that the terminal device in the embodiment of the present application may be a REDCAP terminal device or a NB-IoT terminal device, the type information may include 2 bits, wherein the value of 1 bit is used to indicate whether the terminal device is a REDCAP terminal device (for example, if the value is 1, it indicates that the terminal device is a REDCAP terminal device, and if the value is 0, it indicates that the terminal device is not a REDCAP terminal device), and the other bit is used to indicate whether the terminal device is a NB-IoT terminal device (for example, if the value is 1, it indicates that the terminal device is a NB-IoT terminal device, and if the value is 0, it indicates that the terminal device is not a NB-IoT terminal device). Alternatively, the type information may include 2 bits, and the type of the terminal device is jointly indicated by the value of the 2 bits, for example, 00 indicates that the terminal device is a REDCAP terminal device, 01 indicates that the terminal device is a NB-IoT terminal device, 10 indicates that the terminal device is neither a REDCAP terminal device nor a NB-IoT terminal device, and 11 is reserved for future use.

[0178] Table 2

[0179] IE / Group Name Presence Range IE type and reference Semantics description UE type O ENUMERATED(REDCAP,...) UE type information

[0180] It should be noted that in an embodiment of the present application, the second message may also be a message sent by other DUs to the CU during the random access process, for example, a newly added message used to carry the first field, so that the DU can notify the CU whether the terminal device is a low-capability terminal device by sending a second message to the CU.

[0181] Step 503: The first CU may control the terminal device to access the network according to the second information.

[0182] For example, if the CU of the network device determines that the current network load is large, the first CU of the network device may deny access to the low-capability terminal device; or if the first CU of the network device determines that the current network resources are sufficient, the first CU of the network device may allow access to the low-capability terminal device. It should be noted that step 503 is an optional step.

[0183] Example 2

[0184] Based on the above architecture, the embodiment of the present application provides a communication method for implementing the access process of the terminal device after applying the above architecture provided by the embodiment of the present application. Figure 6 , the method may include the following steps:

[0185] Step 601: The terminal device sends first information to the first CU of the network device through the first DU of the network device.

[0186] The first information is used to indicate the type of the terminal device, and the type of the terminal device includes that the terminal device is a REDCAP terminal device, or that the terminal device is a low-capability terminal device.

[0187] In some embodiments, when accessing the network device, the terminal device may send first information to the CU of the network device via the DU of the network device through Message 3 of the random access process. Specifically, the DU of the network device first receives Message 3 sent by the UE but does not parse the content of the RRC message in Message 3, and then sends the RRC message in Message 3 to the CU of the network device. Accordingly, the CU of the network device receives the first information sent by the terminal device through Message 3 of the random access process, thereby enabling the identification of the type of the UE.

[0188] The following describes by way of example a method 3 in which the CU of the network device receives the first information sent by the UE through the message 3 of the random access process.

[0189] Method 3: Determine that the terminal device is a low-capability terminal device through the RRC message in message 3 of the random access process.

[0190] In some embodiments, the terminal device may use a reserved field in the RRC message (such as an RRCSetupRequest message) carried in message 3 as the first field, that is, the RRC message carried in message 3 includes a first field, wherein the first field includes first information for indicating whether the UE is a REDCAP UE.

[0191] In other embodiments, the terminal device may extend the size of the RRC message carried in message 3, for example, by adding a new field of the RRC message as the first field, that is, the RRC message carried in message 3 includes a first field, wherein the first field includes first information for indicating whether the UE is a REDCAP UE.

[0192] In some other embodiments, the terminal device may introduce a new common control channel and a new RRC message as the RRC message in message 3, wherein the new RRC message includes a first field including first information for indicating whether the UE is a REDCAP UE.

[0193] Through mode 3, the base station can control the access of REDCAP UE earlier, for example, denying REDCAP UE access to the network when network resources are tight, or allowing REDCAP UE access to the network when network resources are abundant.

[0194] Considering that the information identified in method 3 is RRC layer information, only the CU with the RRC layer can obtain this information and determine that the terminal device is a low-capability terminal device. The DU with the PHY layer and MAC layer does not know the identification information of the REDCAP UE and cannot reasonably schedule subsequent messages or prioritize the UE's access.

[0195] Similarly, in a two-step non-contention random access process, the base station can determine that the terminal device is a low-capability terminal device based on message A of the random access process (message A of the two-step random access process includes messages 1 and 3 of the four-step random access process, i.e., message A is a message that combines messages 1 and 3). The specific method can refer to the above method 3 and will not be repeated here.

[0196] Step 602: A first CU of a network device sends a first message to a first DU of the network device.

[0197] The first message includes second information. The second information is used to indicate the type of the UE, and the type of the terminal device includes that the terminal device is a REDCAP terminal device.

[0198] In some embodiments, the first message may be a downlink RRC message transfer (DL RRC message transfer) message sent by the CU of the network device to the DU of the network device. In this case, the first message may include a newly added first field, and the first field carries the second information.

[0199] Table 3 shows the fields that may be included in a downlink RRC message. For example, it includes the message type field (Message Type); the F1 interface application identification field between the CU and UE (gNB-CU UE F1AP ID); the F1 interface application identification field between the DU and UE (gNB-DU UE F1AP ID); the old DU and UE F1 interface application identification field (old gNB-DUUE F1AP ID), which is used when the RRC container includes information about RRC connection establishment; the new DU and UE F1 interface application identification field (old gNB-DU UE F1AP ID); and the SRB identification field (SRB ID).

[0200] Execute duplication field (Execute Duplication); RRC container field (RRC-Container), which may include: downlink message field (DL-DCCH-Message IE); RAT frequency authorization information field (RAT-FrequencyPriority Information); RRC delivery status request field (RRC Delivery Status Request); terminal device context not retrieved field (UE Context not retrievable); redirected RRC message field (redirectedRRC message); access PLMN network sharing information field (PLMN Assistance Info for NetworkSharing); the first field, for example, the terminal device type field (UE type).

[0201] Table 3

[0202]

[0203] Exemplarily, in combination with Table 3 and Table 2, the first field carried in the first message can be used to indicate the type of terminal device (UE type), and its value range may include: REDCAP, REDCAP type, or other UE types. For example, the type of terminal device can be identified by the identifier of the terminal device, identifier = 0 indicates that the terminal device is not configured with any parameters; identifier = 1 indicates that the terminal device is a REDCAP terminal device; identifier = 2 indicates that the terminal device is an NB-IoT terminal device; identifier = 3 to 10 is reserved for future use; identifier = 11 indicates that the terminal device is a terminal device corresponding to access level 11, and so on. Of course, you can also refer to the method of setting the type of terminal device in the above example. For example, the type of low-capability terminal device set accordingly includes a low-capability terminal device with 2 antennas, corresponding identifier = 3, and a low-capability terminal device with 1 antenna, corresponding identifier = 4, which will not be repeated here.

[0204] In other embodiments, the first message may also be a terminal device context setup request (UE context setup request) message. In this case, a first field may be added to the terminal device context setup request message so that the first field carries second information for indicating whether the terminal device is a low-capability terminal device.

[0205] It should be noted that in an embodiment of the present application, the first message may also be a message sent by other CUs to the DU during the random access process, or a newly added message used to carry the first field, so that the CU can notify the DU whether the terminal device is a low-capability terminal device by sending the first message to the DU.

[0206] Step 603: The first DU may schedule subsequent random access messages or other messages for the low-capability terminal device according to the second information.

[0207] It should be noted that step 603 is an optional step. For example, the first DU of the network device schedules the subsequent message 4 or message 5 within the range supported by the capability of the low-capability terminal device. Specifically, the first DU can configure the corresponding resources for the low-capability terminal device. The specific configured resources can be referred to Figure 4 The introduction of the random access process in will not be repeated here.

[0208] Optionally, the first CU of the network device may determine the access priority of the low-capability terminal device for the low-capability terminal device according to the second information.

[0209] For example, the first CU of the network device can set the access priority of low-capability terminal devices to low priority and set the access priority of non-low-capability terminal devices to low priority, so that when low-capability terminal devices and non-low-capability terminal devices access the network at the same time, non-low-capability terminal devices are given priority to access the network.

[0210] After completing the access process of the above-mentioned terminal device, the terminal device may need to be switched due to reasons such as poor signal quality of the current cell caused by the movement of the terminal device, too many terminal devices accessed by the base station and the current congestion of the cell. The CU of the network device can initiate a switching process based on the context of the terminal device to ensure that during the switching process, the terminal device can establish an RRC connection without re-initiating the random access process, thereby reducing latency and saving signaling overhead. In addition, consider a new RRC state: inactive state, where the terminal device and the network suspend the RRC connection to achieve the same power saving effect as the idle state. Different from the idle state: in the inactive state, the terminal device and the access network device save the context of the terminal device. When the terminal device needs to enter the connected state, for example, the terminal device has uplink data to send, or the network device pages the terminal device to enter the connected state, the terminal device enters the connected state based on the saved terminal device context, thereby reducing latency and saving signaling overhead. The following example introduces the process of establishing the context of the terminal device. For details, please refer to Figure 7 shown.

[0211] Step 701: The terminal device sends capability information to the CU of the network device.

[0212] The capability information is used to indicate the capability of the terminal device.

[0213] Optionally, the capability information is used to indicate that the terminal device has the ability to transmit data in an inactive state, which means that when the terminal device is in an inactive state, it has the ability to transmit uplink information in a configuration authorization or a scheduling authorization. The uplink information includes but is not limited to uplink signaling and uplink data. The uplink signaling can be uplink RRC signaling, etc., and the uplink data can be uplink service data, such as video data, audio data, etc.

[0214] It should be noted that a scheduling grant refers to resources allocated by a network device to a terminal device based on a resource request sent by the terminal device. For example, a resource request can be a preamble during random access or an uplink scheduling request. A configuration grant refers to resources pre-configured by the network device without the terminal device sending a resource request, and is characterized by one-time allocation and multiple uses.

[0215] It should be noted that the terminal device has multiple capabilities, and the capability information can also indicate other capabilities of the terminal device, which is not limited in the embodiments of the present application.

[0216] It should be noted that the CU of the network device can also obtain the capability information of the terminal device from the core network device. If the CU of the network device obtains the capability information of the terminal device from the core network device, the CU of the network device does not need to obtain the capability information of the terminal device from the terminal device, that is, the terminal device does not need to send the capability information to the CU of the network device.

[0217] Step 702: The CU of the network device sends a UE context establishment request message to the DU of the network device.

[0218] The UE context establishment request message may be used to request establishment of a context for a terminal device.

[0219] Optionally, the UE context establishment request message may include the capability information.

[0220] Step 703: The DU of the network device establishes a context for the terminal device and sends a UE context establishment response message to the CU of the network device.

[0221] It should be noted that, in the embodiment of the present application, the context may include an air interface context and an F1 context.

[0222] The air interface context may refer to the terminal device's RLC layer configuration, MAC layer configuration, physical layer configuration information, I-RNTI, C-RNTI, etc. It may also include "configuration authorization for inactive data transmission," PDCCH configuration information for sending physical layer feedback information, and RNTI for scrambling the PDCCH. The F1 context may refer to the F1AP ID, transport layer address information for F1 data transmission, etc. The transmission of a terminal device's DRB data between the CU and DU of a network device is also referred to as F1 data transmission.

[0223] In the embodiment of the present application, the context established by the DU of the network device for the terminal device may include one or more of the following:

[0224] 1. Configuration information of the physical downlink control channel (PDCCH) configured for the terminal device; the configuration information of the PDCCH can be used to send feedback information of uplink data or schedule PUSCH transmission, schedule physical downlink shared control channel (PDSCH) transmission, etc.

[0225] The configuration information of the PDCCH includes but is not limited to the resource location information, period, starting position, etc. of the PDCCH.

[0226] In an embodiment of the present application, the PDCCH may schedule the transmission of physical layer signaling, such as at least one of Acknowledgement (ACK) or Negative Acknowledgement (NACK) signaling, uplink authorization for initial transmission, and uplink authorization for retransmission. The PDCCH may also schedule the transmission of the PDSCH, and the information carried in the PDSCH includes but is not limited to one or more of downlink RRC signaling, downlink data, and timing advance commands. The terminal device can perform uplink and downlink transmissions according to the scheduling of the PDCCH.

[0227] 2. A temporary identifier for scrambling the PDCCH; the temporary identifier is a 32-bit radio network temporary identity (RNTI) for scrambling the PDCCH. For example, the temporary identifier may be a cell radio network temporary identity (C-RNTI) of the terminal device.

[0228] 3. Configuration information of the RLC layer of the radio bearer configured for the terminal device.

[0229] 4. Configuration information of the MAC layer configured for the terminal device.

[0230] 5. An inactive radio network temporary identity (I-RNTI) configured for the terminal device.

[0231] 6. A configuration authorization configured for the terminal device; the configuration authorization may be used to indicate uplink resources allocated to the terminal device, wherein the configuration authorization may include but is not limited to one or more of a physical uplink shared channel (PUSCH) frequency domain resources, period, starting position, and data demodulation reference information.

[0232] Optionally, the configuration authorization may be configured for a terminal device in an inactive state, and the terminal device in the inactive state may use the configuration authorization to send one or more of uplink RRC signaling and uplink data.

[0233] Optionally, the time-frequency resources configured by the configuration authorization can be time-frequency resources dedicated to the terminal device, that is, time-frequency resources not shared with other terminal devices. In this case, the DU of the network device can establish a mapping relationship between the configuration authorization and the context of the terminal device and the data transmission channel of the terminal device.

[0234] Optionally, the time-frequency resources configured by the configuration authorization may be time-frequency resources shared by the terminal device with other terminal devices. In this case, when the CU of the network device determines that the terminal device enters an inactive state, an inactive state I-RNTI may be sent to the DU of the network device. The DU of the network device may establish a mapping relationship between the configuration authorization and the I-RNTI of the terminal device. The I-RNTI may be a unique identifier of an inactive terminal device within a wireless network notification area (RAN-based notification area, RNA).

[0235] It should be noted that the above is only an example, and the context of the terminal device may also include other information, which is not limited in the embodiments of the present application and will not be illustrated one by one here. For example, the UE context establishment response message sent by the CU of the network device may include the context of the terminal device.

[0236] Figure 7 The process shown only describes the main steps. There may be other steps in the process of establishing a context for the terminal device, which will not be described here. Figure 7 The process shown establishes the context of the terminal device.

[0237] Considering that after the terminal device leaves the coverage of the access network device that originally saved the context, it is necessary to initiate the RRC recovery process to the new access network device. The following is an example using a specific scenario.

[0238] Scene 1

[0239] like Figure 8 As shown, the terminal device moves from cell 1 to the adjacent cell 2. At this time, the CU can remain unchanged, and the terminal device switches from the DU of the source network device to the DU of the target network device. In this case, the source network device (e.g., the fourth network device) includes a first CU and a second DU, and the target network device (e.g., the first network device) includes a first CU and a first DU.

[0240] For network devices with a CU-DU architecture, the CU of the network device is responsible for managing the RRC state of the terminal device. The CU of the network device stores the context of the terminal device (including terminal device capability information and other terminal device configuration information). In the scenario where the CU of the network device remains unchanged and the DU of the network device switches, the CU of the network device can send the context of the terminal device to the DU of the target network device. The DU of the target network device initiates a random access process for the terminal device based on the received context of the terminal device and allocates the preamble and C-RNTI used by the DU of the target network device, so that the terminal device can access the CU of the network device through the DU of the target network device. This completes the random access process for the terminal device.

[0241] During the handover process, consider that the CU of the network device may not carry the second information indicating whether the terminal device is a low-capability terminal device. For example, when a handover occurs, the UE capability information carried in the terminal device context cannot determine that the UE is a low-capability terminal device. In this case, the DU of the target network device cannot allocate a matching preamble or C-RNTI to the low-capability terminal device. In this case, the DU of the target network device cannot reasonably schedule subsequent messages or prioritize the UE's access.

[0242] Based on the above problems, the present invention provides a communication method. Figure 9 As shown, the following steps are included:

[0243] Step 901: The first CU initiates an initial switching process to the first DU.

[0244] The specific switching manner may be that the first CU initiates a switching request to switch to the first DU.

[0245] For example, taking the first DU as the target DU and the second DU as the source DU, the switching request can be used to request that the terminal device be switched to the target DU; after receiving the switching request, the target DU triggers the switching process of the terminal device according to the switching request.

[0246] In some embodiments, the first CU may determine that the terminal device needs to be switched based on the measurement report after receiving the measurement report of the terminal device. Specifically, when the first CU determines that the current communication quality of the terminal device is poor based on the received measurement report, the terminal device may be switched, and a switching request may be sent to the first entity.

[0247] Furthermore, the measurement reporting process of the terminal device can be triggered by the first CU. Alternatively, the terminal device can actively report. Optionally, the handover request includes one or more of the following information: the identifier of the terminal device to be switched, the identifier of the target cell, and the target frequency information.

[0248] In one possible implementation, the first CU may also receive a cell congestion status report sent by the second DU. If the report indicates that the cell is currently in a congested state, the CU of the network device may accordingly determine a mitigation strategy to alleviate the cell congestion state (such as: release of low-priority GBR, release of edge users, etc.), and send a cell congestion relief request to the first entity, which includes the determined mitigation strategy; the first entity may then perform relief processing according to the mitigation strategy. The cell congestion status report includes one or more of the following information: cell identification, bearer type (such as: GBR or non-GBR), ARP, congestion type (such as: GBR congestion or non-GBR congestion), congestion level (such as: severe, general, non-congested, etc.), etc.

[0249] Step 902: The first CU sends a first message to the first DU.

[0250] The first message may include: second information. The second information is used to indicate the type of the terminal device, where the type of the terminal device includes that the terminal device is a low-capability terminal device, or that the type of the terminal device is a type of a low-capability terminal device.

[0251] In some embodiments, the first message may be a terminal device context request (UE context setup request) message sent by the first CU to the first DU. The first message may include a first field, which may be a newly added field in the UE context request message. The first field is used to indicate or identify UE information, or to indicate or identify UE type information. For example, the first field may be in the CU to DU RRC information field in the UE context request message.

[0252] Table 4 shows the fields that a UE context request message may include. For example, it includes a configuration authorization confirmation information field (CG-ConfigInfo); a configuration authorization confirmation field (CG-Config); a terminal equipment capability RAT list field (UE-capabilityRAT-containerLis); a measurement information field (MeasConfig); a handover preparation information field (handover preparation information); a cell group information field (CellGroupConfig); a measurement timing confirmation field (measurement timing configuration); and a first field, for example, a terminal equipment type field (UEtype).

[0253] Table 4

[0254]

[0255]

[0256] Exemplarily, in combination with Table 4 and Table 2, the first field carried in the first message can be used to indicate the type of terminal device (UE type), and its value range may include: REDCAP, REDCAP type, or other UE types. For example, the type of terminal device can be identified by the identifier of the terminal device, where identifier = 0 indicates that the terminal device is not configured with any parameters; identifier = 1 indicates that the terminal device is a REDCAP terminal device; identifier = 2 indicates that the terminal device is an NB-IoT terminal device; identifier = 3 to 10 is reserved for future use; identifier = 11 indicates that the terminal device is a terminal device corresponding to access level 11, and so on.

[0257] Step 903: The first DU may schedule subsequent random access messages or other messages for the low-capability terminal device according to the second information.

[0258] It should be noted that step 603 is an optional step. For example, the DU of the network device schedules the messages (e.g., message 4 or message 5) in the subsequent random access process within the range supported by the low-capability terminal device. Specifically, the first DU may configure the corresponding resources for the low-capability terminal device. The specific configured resources can be referred to Figure 4 The introduction of the random access process in will not be repeated here.

[0259] Optionally, the first CU may determine the access priority of the low-capability terminal device for the low-capability terminal device according to the second information.

[0260] For example, the first CU can set the access priority of low-capability terminal devices to low priority and set the access priority of non-low-capability terminal devices to low priority, so that when low-capability terminal devices and non-low-capability terminal devices access the network at the same time, non-low-capability terminal devices are given priority to access the network.

[0261] Scene 2

[0262] like Figure 10 As shown, the terminal device moves from cell 1 to cell 3. At this time, the terminal device switches from the CU of the source network device to the CU of the target network device, and the terminal device switches from the DU of the source network device to the DU of the target network device. At this time, the source network device (e.g., the second network device) includes the second CU and the second DU, and the target network device (e.g., the first network device) includes the first CU and the first DU.

[0263] The present application embodiment provides a communication method, such as Figure 11 As shown, the following steps are included:

[0264] Step 1101: The second CU initiates a switching process to the first CU.

[0265] For example, the CU of the source network device is the second CU, the CU of the target network device is the first CU, the DU of the source network device is the second DU, and the DU of the target network device is the first DU. At this time, the second CU stores the context of the terminal device. During the handover process, the second CU can send the context of the terminal device (for example, including terminal device capability information) to the CU of the target network device through the UE context request message. The specific handover process can be referred to step 901 and will not be repeated here.

[0266] The context request message of the UE may include second information, and the second information indicates whether the UE is a low-capability terminal device.

[0267] Step 1102: The first CU initiates a handover process to the first DU.

[0268] The context of the terminal device (for example, including terminal device capability information) is sent to the DU of the target network device through the CU of the target network device. The DU of the target network device allocates the preamble and C-RNTI used by the terminal device to access the DU of the target network device based on the received context of the terminal device. This completes the random access process for the terminal device. The specific switching process can be referred to step 901 and will not be repeated here.

[0269] Step 1103: The first CU sends a first message to the first DU.

[0270] The first message may include: second information. The second information is used to indicate the type of the terminal device. The type of the terminal device includes that the terminal device is a low-capability terminal device, or the type of the terminal device is a type of a low-capability terminal device.

[0271] In some embodiments, the first message may be a UE context setup request message sent by the first CU to the first DU. The first message may include a first field, which may be a newly added field in the UE context setup request message. The first field is used to indicate or identify UE information, or to indicate or identify UE type information. For another example, the first field may be in the CU to DU RRC information field in the UE context setup request message.

[0272] Step 1104: The first DU may schedule subsequent random access messages or other messages for the low-capability terminal device according to the second information.

[0273] It should be noted that step 603 is an optional step. For example, the first DU schedules the messages (e.g., message 4 or message 5) in the subsequent random access process within the range supported by the low-capability terminal device. Specifically, the first DU may configure corresponding resources for the low-capability terminal device. The specific configured resources can be referred to Figure 4 The introduction of the random access process in will not be repeated here.

[0274] Optionally, the first CU may determine the access priority of the low-capability terminal device for the low-capability terminal device according to the second information.

[0275] For example, the first CU can set the access priority of low-capability terminal devices to low priority and set the access priority of non-low-capability terminal devices to low priority, so that when low-capability terminal devices and non-low-capability terminal devices access the network at the same time, non-low-capability terminal devices are given priority to access the network.

[0276] It should be noted that not all of the above steps 1101-1104 must be performed. In some embodiments, only some of the steps 1101-1104 may be performed, for example, only step 1101, step 1103, and step 1104, or only step 1102, step 1103, and step 1104. This is not limited here.

[0277] Scene 3

[0278] When the RRC state of the terminal device changes, the CU of the network device needs to notify the DU of the network device to perform linked context processing. Specifically, when the terminal device transitions from the RRC connected state to the inactive state, the CU of the network device notifies the DU of the network device to release the context of the terminal device, which includes all dedicated F1 transmission resources and air interface configuration information. If the DU of the network device releases the context of the terminal device, when the inactive terminal device sends uplink data to the DU of the network device, the DU of the network device cannot immediately send the data to the CU of the network device.

[0279] When the terminal device moves during the inactive state, for example, from cell 1 to cell 3, the terminal device needs to re-initiate an RRC state recovery request. During the process of completing the handover from the DU of the source network device to the DU of the target network device, or from the CU of the source network device to the CU of the target network device, and from the DU of the source network device to the DU of the target network device, if the UE capability information cannot directly identify the UE as a REDCAP UE, the DU of the network device does not know that the UE is a REDCAP UE when allocating the preamble or C-RNTI, and the DU of the network device cannot know that the UE is a REDCAP UE through the preamble in message 1 or the C-RNTI in message 3, then it is impossible to reasonably schedule subsequent messages or prioritize the access of the UE. The following is an example in which the source network device (e.g., the second network device) includes the second CU and the second DU, and the target network device (e.g., the first network device) includes the first CU and the first DU. The embodiment can be referred to in the case in which the source network device (e.g., the third network device) includes the first CU and the second DU, and the target network device (e.g., the first network device) includes the first CU and the first DU.

[0280] Based on the above problems, the present invention provides a communication method. Figure 12 As shown, the following steps are included:

[0281] Step 1201: The terminal device initiates an RRC connection recovery process to the second CU through the second DU.

[0282] For example, the second DU may be the DU of the source network device, and the second CU may be the CU of the source network device. The first DU may be the DU of the target network device, and the first CU may be the CU of the target network device. In this case, the terminal device initiates an RRC connection recovery request to the CU of the source network device through the DU of the source network device. The RRC connection recovery request is used to request the restoration of the RRC connection state.

[0283] Step 1202: The second CU initiates a switching process to the first CU.

[0284] At this time, the CU of the source network device determines that the terminal device needs to be switched based on the RRC connection recovery request of the terminal device and the saved context of the terminal device. Therefore, the CU of the source network device can send the context of the terminal device (for example, including terminal device capability information) to the CU of the target network device through the UE's context request message.

[0285] The context request message of the UE may include second information, and the second information indicates whether the UE is a low-capability terminal device.

[0286] Step 1203: The first CU initiates a handover process to the first DU.

[0287] The CU of the target network device sends the context of the terminal device (for example, including terminal device capability information) to the DU of the target network device. The DU of the target network device allocates the preamble and C-RNTI for the terminal device to access the DU of the target network device based on the received context of the terminal device. This completes the random access process for the terminal device.

[0288] Step 1204: The first CU sends a first message to the first DU.

[0289] The first message may include: second information. The second information is used to indicate the type of the terminal device. The type of the terminal device includes that the terminal device is a low-capability terminal device, or the type of the terminal device is a type of a low-capability terminal device.

[0290] In some embodiments, the first message may be a UE context setup request message sent by the first CU to the first DU. The first message may include a first field, which may be a newly added field in the UE context setup request message. The first field is used to indicate or identify UE information, or to indicate or identify UE type information. For another example, the first field may be in the CU to DU RRC information field in the UE context setup request message.

[0291] Step 1205: The first DU may schedule subsequent random access messages or other messages for the low-capability terminal device according to the second information.

[0292] It should be noted that step 1205 is an optional step. For example, the DU schedules the subsequent random access messages (e.g., message 4 or message 5) within the range supported by the low-capability terminal device. Specifically, the DU may configure the corresponding resources for the low-capability terminal device. The specific configured resources can be referred to Figure 4 The introduction of the random access process in will not be repeated here.

[0293] Optionally, the CU may determine the access priority of the low-capability terminal device for the low-capability terminal device based on the second information. For example, the CU may set the access priority of the low-capability terminal device to be low priority and set the access priority of the non-low-capability terminal device to be low priority, so that when both the low-capability terminal device and the non-low-capability terminal device access the network at the same time, the non-low-capability terminal device is given priority to access the network.

[0294] It should be noted that not all of the above steps 1201-1205 must be executed. In some embodiments, only some of the steps 1201-1205 may be executed, for example, only steps 1202, 1204, and 1205, or only steps 1203, 1204, and 1205. This is not limited here.

[0295] Based on the above problem, an embodiment of the present application provides a communication method, in which the terminal device initially accesses the network through the second distributed unit and the first centralized unit (for example, the fourth network device), and then accesses the network through the first distributed unit and the first centralized unit (for example, the first network device), and then instructs to access the network through the third distributed unit and the first centralized unit (for example, the fifth network device), such as Figure 13 As shown, the following steps are included:

[0296] Step 1301a: The terminal device sends first information to the second distributed unit.

[0297] In step 1301a, the terminal device can access the network through the second distributed unit and the first centralized unit. Figure 5 The method in which the terminal device sends the first information to the first distributed unit.

[0298] Step 1302a: The second distributed unit sends a second message 1 to the first centralized unit.

[0299] Among them, the second message 1 can refer to Figure 5 The terminal device sends a second message to the first distributed unit.

[0300] Step 1301b: The terminal device sends first information to the first centralized unit.

[0301] Among them, in step 1301b, the terminal device can access the network through the second distributed unit and the first centralized unit. At this time, you can refer to Figure 6 The terminal device sends the first information to the centralized unit through the distributed unit.

[0302] It should be noted that step 1301a and step 1302a are one possible implementation manner, and step 1301b is one possible implementation manner.

[0303] Step 1303: The first distributed unit and the first centralized unit initiate an initial switching process of the terminal device.

[0304] Optionally, the terminal device may initiate an initial handover from the second distributed unit to the first distributed unit to access the first distributed unit. Figure 9 The implementation method of switching to the first distributed unit in step 901 in FIG.

[0305] Step 1304: The first centralized unit sends a first message a to the first distributed unit.

[0306] In step 1304, the first centralized unit sends the first message a to the first distributed unit in a manner similar to the manner in which the first centralized unit sends the first message to the first distributed unit in step 902. Here, the first message a may be the same as the first message.

[0307] Step 1305: The first distributed unit schedules resources of the terminal device according to the second information.

[0308] It should be noted that step 1305 is an optional step.

[0309] Step 1306: The third distributed unit and the first centralized unit initiate an initial handover process of the terminal device.

[0310] Optionally, the terminal device may initiate an initial handover from the first distributed unit to the third distributed unit to access the third distributed unit. Figure 9 The implementation method of switching to the first distributed unit in step 901 in FIG.

[0311] Step 1307: The first centralized unit sends a first message b to the third distributed unit.

[0312] In step 1304, the first centralized unit sends the first message b to the third distributed unit in a manner similar to the manner in which the first centralized unit sends the first message to the first distributed unit in step 902. Here, the first message b may be the same as the first message.

[0313] Step 1308: The third distributed unit schedules resources of the terminal device according to the second information.

[0314] It should be noted that step 1308 is an optional step.

[0315] The above method is only described by taking the first centralized unit not switching as an example. In the case where switching also occurs in the first centralized unit, the method can be combined with Figure 13 and Figure 12 For example, the terminal device first accesses the second centralized unit through the second distributed unit, and then switches to the first centralized unit and the first distributed unit. After that, the terminal device can also switch from the first centralized unit to the third centralized unit, and from the first distributed unit to the third distributed unit, that is, access the third network device (including the third centralized unit and the third distributed unit).

[0316] Of course, other combined methods are also possible. The specific method of sending the first information and the second information during the switching can refer to the above embodiment and will not be described in detail here.

[0317] It should be noted that not all of the above steps 1301a-1308 must be executed and are not limited here. Figures 9-13 This is just an example. In the actual process, there may be other steps, which will not be detailed here.

[0318] The various embodiments described herein may be independent solutions or may be combined according to internal logic, and all of these solutions fall within the scope of protection of this application.

[0319] In the embodiments provided in the present application above, the methods provided in the embodiments of the present application are introduced from the perspective of interaction between various devices. In order to implement the various functions in the methods provided in the embodiments of the present application above, the CU of the network device or the DU of the network device may include a hardware structure and / or a software module to implement the above functions in the form of a hardware structure, a software module, or a hardware structure plus a software module. Whether one of the above functions is executed in the form of a hardware structure, a software module, or a hardware structure plus a software module depends on the specific application and design constraints of the technical solution.

[0320] The division of modules in the embodiments of the present application is illustrative and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the present application may be integrated into a single processor, or may exist physically separately, or two or more modules may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or software functional modules.

[0321] like Figure 14As shown, the present application provides a communication device.

[0322] In some embodiments, the communication device 1400 may be applied to a first centralized unit of a network device. In this case, the first centralized unit may include a processing module 1410 , and optionally, a sending module 1420 and a receiving module 1430 .

[0323] The processing module 1410 is used to receive first information of the terminal device through the receiving module 1430, and the first information is used to indicate the type of the terminal device. The processing module 1410 is used to send second information to the first distributed unit of the network device through the sending module 1420, and the first information is used to indicate the type of the terminal device.

[0324] In a possible implementation, the processing module 1410 is configured to receive the first information from the terminal device via the first distributed unit through the receiving module 1430 .

[0325] In a possible implementation, the processing module 1410 is configured to receive the first information from the terminal device via the second distributed unit through the receiving module 1430, where the second distributed unit is the distributed unit to which the terminal device accesses before switching to the first distributed unit.

[0326] In a possible implementation, the processing module 1410 is configured to receive, through the receiving module 1430, the first information sent by a second centralized unit, where the second centralized unit is the centralized unit to which the terminal device accesses before switching to the first centralized unit.

[0327] In one possible implementation, the first distributed unit schedules the resources of the terminal device and / or the access priority of the terminal device according to the second information.

[0328] In a possible implementation, the processing module 1410 is configured to send the second information to a third distributed unit through the sending module 1420 , where the third distributed unit is the distributed unit to which the terminal device is switched from the first distributed unit.

[0329] A possible implementation method is that the processing module 1410 is used to send the first information to a third centralized unit through the sending module 1420, and the third centralized unit is the centralized unit after the terminal device is switched from the first centralized unit. The first information is used by the third centralized unit to send the second information to the third distributed unit, and the third distributed unit is the distributed unit after the terminal device is switched from the first distributed unit.

[0330] In a possible implementation, the second information is carried in a first message, and the first message includes a first field, and the first field carries the second information.

[0331] In some embodiments, the communication device 1400 can be applied to a first distributed unit of a network device. In this case, the first distributed unit may include a processing module 14101410, and optionally, may also include a sending module 14201420 and a receiving module 1430.

[0332] The processing module 1410 is used to receive first information of the terminal device through the receiving module, and the first information is used to indicate the type of the terminal device; the processing module 1410 is used to send second information to the first centralized unit of the network device through the sending module 1420, and the second information is used to indicate the type of the terminal device.

[0333] In a possible implementation manner, the type of the terminal device includes any one of the following: a low-capability terminal device, or a type of a low-capability terminal device.

[0334] In a possible implementation, the first centralized unit controls access of the terminal device according to the second information.

[0335] In a possible implementation, the first centralized unit sends the second information to a third distributed unit, where the third distributed unit is the distributed unit to which the terminal device is switched from the first distributed unit.

[0336] In a possible implementation, the first centralized unit sends the second information to a third centralized unit, and the third centralized unit is the centralized unit after the terminal device is switched from the first centralized unit.

[0337] In a possible implementation, the second information is used to control access of the terminal device.

[0338] In a possible implementation, the second information is carried in a second message, the second message includes a first field, and the first field carries the second information.

[0339] In a possible implementation, the first message is any one of the following: a downlink wireless resource control message delivery message, a terminal device context request message; and the second message is an initial uplink wireless resource control message delivery message.

[0340] In a possible implementation manner, the first information is carried by message 1 or message 3.

[0341] In one possible implementation, the first distributed unit and the first centralized unit are separate network elements in a first network device, and the first network device is used for the terminal device to access the network; or, the second distributed unit and the second centralized unit are separate network elements in a second network device, and the second network device is used for the terminal device to access the network; or, the third distributed unit and the third centralized unit are separate network elements in a third network device, and the third network device is used for the terminal device to access the network; or, the second distributed unit and the first centralized unit are separate network elements in a fourth network device, and the fourth network device is used for the terminal device to access the network; or, the third distributed unit and the first centralized unit are separate network elements in a fifth network device, and the fifth network device is used for the terminal device to access the network.

[0342] Optionally, the communication device 1400 may further include a storage unit for storing data or instructions (also referred to as code or program). The aforementioned units may interact or couple with the storage unit to implement corresponding methods or functions. For example, the processing module 1410 may read data or instructions in the storage unit to enable the communication device to implement the method in the above embodiment.

[0343] It should be understood that the division of units in the above device is merely a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or physically separated. Moreover, the units in the device can all be implemented in the form of software called through processing elements; or all be implemented in the form of hardware; or some units can be implemented in the form of software called through processing elements, and some units can be implemented in the form of hardware. For example, each unit can be a separately established processing element, or it can be integrated into a certain chip of the device. In addition, it can also be stored in the form of a program in a memory, called by a certain processing element of the device and perform the function of the unit. In addition, all or part of these units can be integrated together, or they can be implemented independently. The processing element described here can also be a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each unit above can be implemented by the integrated logic circuit of the hardware in the processor element, or it can be implemented in the form of software called through the processing element.

[0344] In one example, the unit in any of the above devices may be one or more integrated circuits configured to implement the above method, such as one or more application specific integrated circuits (ASICs), or one or more digital singnal processors (DSPs), or one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms. For another example, when the unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processor that can call a program. For another example, these units can be integrated together and implemented in the form of a system-on-a-chip (SOC).

[0345] The above-mentioned unit for receiving (e.g., receiving unit) is an interface circuit of the device, which is used to receive signals from other devices. For example, when the device is implemented as a chip, the receiving unit is the interface circuit of the chip used to receive signals from other chips or devices. The above-mentioned unit for sending (e.g., sending unit) is an interface circuit of the device, which is used to send signals to other devices. For example, when the device is implemented as a chip, the sending unit is the interface circuit of the chip used to send signals to other chips or devices.

[0346] refer to Figure 15 , which is a structural diagram of a communication device provided in an embodiment of the present application. The communication device is used to implement the operation of the first centralized unit of the network device or the first distributed unit in the network device in the above embodiment. Figure 15 As shown, taking the communication device as a first centralized unit or the first distributed unit in a network device as an example, the communication device includes: an antenna 1510, a radio frequency device 1520, and a signal processing unit 1530. Antenna 1510 is connected to radio frequency device 1520. In the downlink direction, radio frequency device 1520 receives information sent by a network device or other terminal device via antenna 1510, and sends the information sent by the network device or other terminal device to signal processing unit 1530 for processing. In the uplink direction, signal processing unit 1530 processes the information of the terminal device and sends it to radio frequency device 1520. Radio frequency device 1520 processes the information of the terminal device and sends it to the network device or other terminal device via antenna 1510.

[0347] Taking the communication device as a network device as an example, the communication device includes: an antenna 1510, a radio frequency device 1520, and a signal processing unit 1530. Antenna 1510 is connected to radio frequency device 1520. In the uplink direction, radio frequency device 1520 receives information sent by a first terminal or other terminal device via antenna 1510 and sends the information sent by the first terminal or other terminal device to signal processing unit 1530 for processing. In the downlink direction, signal processing unit 1530 processes the information sent by the network device and sends it to radio frequency device 1520. Radio frequency device 1520 then processes the information sent by the network device and sends it to the first terminal or other terminal device via antenna 1510.

[0348] Signal processing unit 1530 is used to process data at various communication protocol layers. While signal processing unit 1530 may be a subsystem of the communication device, the communication device may also include other subsystems, such as a central processing subsystem for processing the communication device's operating system and application layers; or a peripheral subsystem for connecting to other devices. Signal processing unit 1530 may be a separate chip. Optionally, the aforementioned devices may be located within signal processing unit 1530.

[0349] The signal processing section 1530 may include one or more processing elements 1531, for example, a main control CPU and other integrated circuits, and an interface circuit 1533. Furthermore, the signal processing section 1530 may also include a storage element 1532. The storage element 1532 is used to store data and programs. The program used to execute the method performed by the communication device in the above method may or may not be stored in the storage element 1532. For example, it may be stored in a memory outside the signal processing section 1530. When in use, the signal processing section 1530 loads the program into a cache for use. The interface circuit 1533 is used to communicate with devices. The above devices may be located in the signal processing section 1530. The signal processing section 1530 may be implemented by a chip comprising at least one processing element and an interface circuit. The processing element is used to execute the various steps of any of the methods performed by the above communication device, and the interface circuit is used to communicate with other devices. In one implementation, the unit implementing each step of the above method can be implemented in the form of a processing element scheduling program. For example, the device includes a processing element and a storage element, and the processing element calls a program stored in the storage element to execute the method performed by the communication device in the above method embodiment. The storage element can be a storage element on the same chip as the processing element, that is, an on-chip storage element.

[0350] In another implementation, the program for executing the method performed by the communication device in the above method may be stored in a memory element on a different chip from the processing element, i.e., an off-chip memory element. In this case, the processing element calls or loads the program from the off-chip memory element to the on-chip memory element to call and execute the method performed by the communication device (the first centralized unit or the first distributed unit in the network device) in the above method embodiment.

[0351] In another implementation, the unit of the communication device that implements each step of the above method may be configured as one or more processing elements, which are provided on the signal processing portion 1530. The processing elements here may be integrated circuits, such as one or more ASICs, one or more DSPs, one or more FPGAs, or a combination of these types of integrated circuits. These integrated circuits may be integrated together to form a chip.

[0352] The units implementing the various steps of the above method can be integrated together and implemented in the form of a system-on-a-chip (SOC), and the SOC chip is used to implement the above method. The chip can integrate at least one processing element and a storage element, and the method performed by the above communication device can be implemented by the processing element calling the program stored in the storage element; or the chip can integrate at least one integrated circuit to implement the method performed by the above communication device; or, the above implementation methods can be combined, with the functions of some units being implemented by the processing element calling the program, and the functions of some units being implemented by the integrated circuit.

[0353] As can be seen, the above apparatus may include at least one processing element and an interface circuit, wherein the at least one processing element is configured to execute any of the methods provided in the above method embodiments. The processing element may execute some or all of the steps executed by the communication device in a first manner, namely, by invoking a program stored in a storage element; or in a second manner, namely, by combining hardware integrated logic circuits in the processor element with instructions to execute some or all of the steps executed by the communication device. Of course, the first and second manners may also be combined to execute some or all of the steps executed by the communication device.

[0354] The processing element herein, as described above, may be a general-purpose processor, such as a CPU, or one or more integrated circuits configured to implement the above method, such as one or more ASICs, one or more microprocessors (DSPs), one or more FPGAs, or a combination of at least two of these integrated circuit forms. The storage element may be a single memory or a collective term for multiple storage elements.

[0355] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0356] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a computer, the method described in any one of the method embodiments corresponding to the first centralized unit or the first distributed unit in the network device is implemented.

[0357] An embodiment of the present application further provides a computer program product, which, when executed by a computer, implements the method described in any one of the above method embodiments applied to the first centralized unit or the first distributed unit in the network device.

[0358] It should be pointed out that the words "first" and "second", for example, "first indication information, second indication information", etc., are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. "At least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a, b and c, where a, b, c can be single or plural.

[0359] The above embodiments can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs. When the computer program is loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer program can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer program can be transmitted from one website, computer, server or data center to another website, computer, server or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. Available media may be magnetic media (eg, floppy disks, hard disks, tapes), optical media (eg, high-density digital video discs (DVDs)), or semiconductor media (eg, solid state disks (SSDs)).

[0360] An embodiment of the present application also provides a processing device, including a processor and an interface; the processor is used to execute the method described in any method embodiment applied to the first centralized unit or the first distributed unit in the network device.

[0361] It should be understood that the above-mentioned processing device can be a chip, and the processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading the software code stored in the memory. The memory can be integrated in the processor or located outside the processor and exist independently.

[0362] The above are only specific embodiments of the present application, but the scope of protection of the embodiments of the present application is not limited thereto. Any person skilled in the art can easily conceive of changes or substitutions within the technical scope disclosed in the embodiments of the present application, and such changes or substitutions should be included in the scope of protection of the embodiments of the present application. Therefore, the scope of protection of the embodiments of the present application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: include: A first distributed unit of a network device receives first information of a terminal device, where the first information is used to indicate a type of the terminal device; wherein the first information is carried by message 1 or message 3, and the first information is determined by a time-frequency resource or a preamble codeword sequence corresponding to message 1, or the first information is determined by a logical channel identifier LCID field in a MAC header corresponding to message 3; The first distributed unit sends second information to the first centralized unit of the network device, where the second information is used to indicate the type of the terminal device; The type of the terminal device includes any one of the following: a low-capability terminal device, or a type of a low-capability terminal device.

2. The method according to claim 1, wherein The first centralized unit controls access of the terminal device according to the second information.

3. The method according to claim 1, wherein The method further comprises: The first centralized unit sends the second information to a third distributed unit, where the third distributed unit is a distributed unit after the terminal device is switched from the first distributed unit.

4. The method according to claim 1, wherein The method further comprises: The first centralized unit sends the second information to a third centralized unit, where the third centralized unit is the centralized unit to which the terminal device is switched from the first centralized unit.

5. The method according to claim 1, wherein The second information is used to control access of the terminal device.

6. The method according to claim 1, wherein The second information is carried in a second message, the second message includes a first field, and the first field carries the second information.

7. The method according to claim 6, wherein The second message is: an initial uplink radio resource control message delivery message.

8. The method according to any one of claims 1 to 7, wherein: The first distributed unit and the first centralized unit are separate network elements in a first network device, and the first network device is used for the terminal device to access the network; or, The second distributed unit and the second centralized unit are separate network elements in a second network device, and the second network device is used for the terminal device to access the network; or, The third distributed unit and the third centralized unit are separate network elements in a third network device, and the third network device is used for the terminal device to access the network; or, The second distributed unit and the first centralized unit are separate network elements in a fourth network device, and the fourth network device is used for the terminal device to access the network; or, The third distributed unit and the first centralized unit are separate network elements in a fifth network device, and the fifth network device is used for the terminal device to access the network.

9. A communication method, characterized in that: include: A first centralized unit of a network device receives second information from a first distributed unit of the network device, where the second information indicates a type of the terminal device indicated by the first information sent by the terminal device to the first distributed unit; wherein the first information is carried by message 1 or message 3, and the first information is determined by the time-frequency resources or preamble codeword sequence corresponding to message 1, or the first information is determined by the logical channel identifier LCID field in the MAC header corresponding to message 3; The first centralized unit controls access of the terminal device according to the second information; The type of the terminal device includes any one of the following: a low-capability terminal device, or a type of a low-capability terminal device.

10. The method according to claim 9, wherein The method further comprises: The first centralized unit sends the second information to a third distributed unit, where the third distributed unit is a distributed unit after the terminal device is switched from the first distributed unit.

11. The method according to claim 9, wherein The method further comprises: The first centralized unit sends the second information to a third centralized unit, where the third centralized unit is the centralized unit to which the terminal device is switched from the first centralized unit.

12. The method according to claim 9, wherein The second information is carried in a second message, the second message includes a first field, and the first field carries the second information.

13. The method according to claim 12, wherein: The second message is: an initial uplink radio resource control message delivery message.

14. The method according to any one of claims 9 to 13, wherein: The first distributed unit and the first centralized unit are separate network elements in a first network device, and the first network device is used for the terminal device to access the network; or, The second distributed unit and the second centralized unit are separate network elements in a second network device, and the second network device is used for the terminal device to access the network; or, The third distributed unit and the third centralized unit are separate network elements in a third network device, and the third network device is used for the terminal device to access the network; or, The second distributed unit and the first centralized unit are separate network elements in a fourth network device, and the fourth network device is used for the terminal device to access the network; or, The third distributed unit and the first centralized unit are separate network elements in a fifth network device, and the fifth network device is used for the terminal device to access the network.

15. A communication device, characterized in that: include: A processor and a communication interface, wherein the communication interface is used for the device to communicate, the processor is coupled to a memory, and the memory is used to store programs or instructions. When the program or instructions are executed by the processor, the device executes the method according to any one of claims 1 to 8.

16. A communication device, characterized in that: include: A processor and a communication interface, wherein the communication interface is used for the device to communicate, the processor is coupled to a memory, and the memory is used to store programs or instructions. When the program or instructions are executed by the processor, the device executes the method according to any one of claims 9 to 14.

17. A network device, characterized in that: include: The communication device according to claim 15 and the communication device according to claim 16.

18. A computer-readable storage medium, characterized in that The computer-readable storage medium stores instructions, and when the instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 14.

19. A computer program product, characterized in that The computer product includes a computer program, and when the computer program is run, the method according to any one of claims 1 to 14 is executed.

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