A communication method and a communication apparatus

Abstract

The application discloses a communication method and a communication device, relates to the field of communication, and can enable a terminal device to successfully decode a MAC sub-PDU of an OD-SIB1 based on preset length identification information in the case that an UL-WUS configuration message does not include a totalNumberOfRA-Preambles parameter, thereby improving communication efficiency and saving expenses. A communication method is applied to a terminal device and includes the following steps: sending a WUS for requesting a network device to send an OD-SIB1 to the network device; receiving a MAC PDU from the network device; the MAC PDU includes a first MAC sub-PDU and preset length identification information; the first MAC sub-PDU is a MAC sub-PDU of the OD-SIB1, and the preset length identification information is used for indicating that a MAC sub-PDU adjacent to the preset length identification information is the first MAC sub-PDU.

Description

Technical Field

[0001] This application relates to the field of communications, and more particularly to a communication method and a communication device. Background Technology

[0002] In on-demand scenarios, after an R19 UE (User Equipment) in Release 19 (R19) of the technical specification developed by the 3rd Generation Partnership Project (3GPP) standardization organization sends an uplink wake-up signal (UL-WUS) requesting on-demand System Information Block 1 (OD-SIB1) to the network device, it receives a random access response (RAR) message from the network device. This RAR message is encapsulated in the network device using a Medium Access Control Protocol Data Unit (MAC PDU), which includes the MAC sub-PDU of OD-SIB1.

[0003] Currently, the R19 UE decodes the OD-SIB1 MAC sub-PDU by obtaining the totalNumberOfRA-Preambles parameter, which represents the total number of physical random access channel preambles (PRACH preambles). However, since the R19 UE has not yet received the first system information block (SIB1) from the network device when it receives the RAR message, it cannot obtain the totalNumberOfRA-Preambles parameter broadcast by SIB1. Therefore, the R19 UE can only obtain it from the UL-WUS configuration message, which pre-configures the totalNumberOfRA-Preambles parameter. However, this increases the overhead of UL-WUS configuration. Summary of the Invention

[0004] This application provides a communication method and a communication device, which enables a terminal device to successfully decode the MAC sub-PDU of OD-SIB1 based on a preset length of identification information even when the totalNumberOfRA-Preambles parameter is not included in the UL-WUS configuration message, thereby improving communication efficiency and saving overhead.

[0005] To achieve the objective, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, a communication method is provided, applied to a terminal device, the method comprising: sending a wake-up signal WUS to a network device; the WUS being used to request the network device to send an on-demand first system information block OD-SIB1; receiving a Media Access Control Protocol Data Unit (MAC PDU) from the network device; the MAC PDU including a first MAC sub-PDU and identification information of a preset length; the first MAC sub-PDU being a MAC sub-PDU of OD-SIB1, and the identification information of the preset length being used to indicate that the MAC sub-PDU following and adjacent to the identification information of the preset length is the first MAC sub-PDU.

[0007] The aforementioned communication method, applied to a terminal device, involves the following steps: First, the terminal device sends a WUS (Warranty Information Service) to the network device requesting the transmission of OD-SIB1. Second, it receives a MAC PDU from the network device. Finally, the terminal device decodes the identifier information of a preset length preceding and adjacent to the MAC sub-PDU of OD-SIB1 to locate the position of the first MAC sub-PDU (i.e., the MAC sub-PDU of OD-SIB1) within the MAC PDU, thus successfully decoding the first MAC sub-PDU. This communication method allows the terminal device to successfully decode the MAC sub-PDU of OD-SIB1 based on the identifier information of a preset length, even when the totalNumberOfRA-Preambles parameter is not included in the UL-WUS configuration message, thereby improving communication efficiency and saving overhead.

[0008] In one possible implementation of the first aspect, the MAC PDU further includes at least one second MAC sub-PDU, the second MAC sub-PDU being a MAC sub-PDU preceding identification information of a preset length; the first byte of the second MAC sub-PDU includes a first field, the value of which is either a first value or a second value, the first field being a first value indicating that the first byte of the second MAC sub-PDU also includes a second field, the first field being a second value indicating that the first byte of the second MAC sub-PDU does not include the second field; the second field being a third value or a fourth value, the second field being a third value indicating that the MAC PDU includes the first MAC sub-PDU, the second field being a fourth value indicating that the MAC PDU does not include the first MAC sub-PDU; the method further includes: decoding the first byte of the MAC PDU; and continuing to decode the MAC PDU if the first field is a first value and the second field is a third value.

[0009] In this implementation, since the second MAC sub-PDU precedes the identification information of a preset length, and the value of the first field of the first byte of the second MAC sub-PDU is used to indicate whether the first byte of the second MAC sub-PDU includes the second field, and the value of the second field of the first byte of the second MAC sub-PDU is used to indicate whether the MAC PDU includes the first MAC sub-PDU. When the value of the first field of the first byte of the second MAC sub-PDU indicates that the first byte of the second MAC sub-PDU includes the second field, the second MAC sub-PDU is the first MAC sub-PDU in the MAC PDU, and the first byte of the second MAC sub-PDU is also the first byte of the MAC PDU. This allows the terminal device to first attempt to decode the first byte of the MAC PDU to determine whether the MAC PDU includes the first MAC sub-PDU, thereby determining whether to end or continue decoding the MAC PDU. If the first field has the first value and the second field has the third value, the terminal device continues to decode the MAC PDU, indicating that the first byte of the MAC PDU not only includes the second field, but also that the MAC PDU includes the first MAC sub-PDU. Therefore, the MAC PDU continues to be decoded. This communication method allows the terminal device to successfully decode the OD-SIB1 MAC sub-PDU based on a preset length of identification information, even when the totalNumberOfRA-Preambles parameter is not included in the UL-WUS configuration message, thus improving communication efficiency and saving overhead.

[0010] In one possible implementation of the first aspect, the method further includes: ending the decoding of the MAC PDU if the value of the first field is a first value and the value of the second field is a fourth value.

[0011] In this implementation, when the first field takes the first value and the second field takes the fourth value, the terminal device ends decoding the MAC PDU. This indicates that the first byte of the MAC PDU includes the second field, but the MAC PDU does not include the first MAC sub-PDU. If the terminal device continues decoding the MAC PDU at this point, it will incur additional time and power consumption. Therefore, the terminal device ends decoding the MAC PDU, thereby saving decoding time and reducing power consumption.

[0012] In one possible implementation of the first aspect, the method further includes: continuing to decode the MAC PDU if the value of the first field is a second value.

[0013] In this implementation, when the first field takes the second value, the default MAC PDU includes the first MAC sub-PDU. Therefore, the terminal device continues to decode the MAC PDU. This communication method allows the terminal device to successfully decode the OD-SIB1 MAC sub-PDU based on a preset length of identification information, even when the totalNumberOfRA-Preambles parameter is not included in the UL-WUS configuration message, thus improving communication efficiency and saving overhead.

[0014] In one possible implementation of the first aspect, the third field of the first byte of the second MAC sub-PDU adjacent to the identification information of a preset length is set to a target value.

[0015] In this implementation, setting the value of the third field of the first byte of the second MAC sub-PDU adjacent to the preset length of the identification information is to indicate that the second MAC sub-PDU is the last second MAC sub-PDU.

[0016] In one possible implementation of the first aspect, the identifier information of a preset length is at least 6 consecutive bytes all of 1 or at least 7 consecutive bytes all of 0.

[0017] In this implementation, setting the preset length of the identifier information to at least 6 consecutive bytes of all 1s or at least 7 consecutive bytes of all 0s is to distinguish the value range of other fields in the MAC PDU, so that the preset length of the identifier information is unique, that is, uniquely determined, and thus the position of the first MAC sub-PDU in the MAC PDU can be uniquely determined.

[0018] In one possible implementation of the first aspect, the second field is a reserved R field.

[0019] In this implementation, based on the three types of the second MAC sub-PDU, in the first byte of the second MAC sub-PDU, since other fields have specific functions, only the R field is a reserved field. Therefore, custom functions can be performed through the R field, that is, the value of the R field can be used to indicate whether the MAC PDU includes the first MAC sub-PDU.

[0020] Secondly, a communication method is provided, applied to a network device. The method includes: receiving a wake-up signal (WUS) from a terminal device; the WUS is used to request the transmission of an on-demand first system information block (OD-SIB1); sending a Media Access Control Protocol Data Unit (MAC PDU) to the terminal device to trigger the terminal device to decode the MAC PDU; the MAC PDU includes a first MAC sub-PDU and identification information of a preset length; the first MAC sub-PDU is a MAC sub-PDU of OD-SIB1, and the identification information of the preset length is used to indicate that the MAC sub-PDU following and adjacent to the identification information of the preset length is the first MAC sub-PDU.

[0021] The aforementioned communication method, applied to a network device, involves the following steps: First, the network device receives a WUS from a terminal device requesting the transmission of OD-SIB1. Second, it sends a MAC PDU to the terminal device, triggering the terminal device to decode the MAC PDU. The network device identifies the position of the first MAC sub-PDU (i.e., the MAC sub-PDU of OD-SIB1) within the MAC PDU by including a preset length of identification information preceding and adjacent to the MAC sub-PDU of OD-SIB1, thereby enabling the terminal device to successfully decode the first MAC sub-PDU. This communication method allows the terminal device to successfully decode the MAC sub-PDU of OD-SIB1 based on the preset length of identification information, even when the totalNumberOfRA-Preambles parameter is not included in the UL-WUS configuration message, thus improving communication efficiency and saving overhead.

[0022] In one possible implementation of the second aspect, the MAC PDU further includes at least one second MAC sub-PDU, the second MAC sub-PDU being a MAC sub-PDU preceding identification information of a preset length; the first byte of the second MAC sub-PDU includes a first field; the first field is a first value or a second value; the first field being a first value indicates that the first byte of the second MAC sub-PDU also includes a second field, the first field being a second value indicates that the first byte of the second MAC sub-PDU does not include a second field; the second field being a third value or a fourth value, the second field being a third value indicates that the MAC PDU includes a first MAC sub-PDU, the second field being a fourth value indicates that the MAC PDU does not include the first MAC sub-PDU.

[0023] In one possible implementation of the second aspect, the third field of the first byte of the second MAC sub-PDU adjacent to the identification information of a preset length is set to a target value.

[0024] In one possible implementation of the second aspect, the preset length of the identification information is at least 6 consecutive bytes of all 1s or at least 7 consecutive bytes of all 0s.

[0025] In one possible implementation of the second aspect, the second field is a reserved R field.

[0026] Thirdly, a communication device is provided, including a processor and a memory, wherein instructions are stored in the memory, and when the processor executes the instructions, the communication device performs a communication method as described in the first aspect and any embodiment thereof, or performs a communication method as described in the second aspect and any embodiment thereof.

[0027] Fourthly, a computer-readable storage medium is provided that stores a computer program or instructions thereon, which, when executed, cause a computer to perform a communication method as described in the first aspect and any embodiment thereof, or to perform a communication method as described in the second aspect and any embodiment thereof.

[0028] The technical effects of the design methods in the third and fourth aspects can be found in the technical effects of the different design methods in the first or second aspects, and will not be repeated here. Attached Figure Description

[0029] Figure 1 This application provides a schematic diagram of the architecture of a wireless communication system.

[0030] Figure 2 A schematic diagram of the structure of a terminal device and a network device provided for related technologies;

[0031] Figure 3 A flowchart of a communication method provided for related technologies;

[0032] Figure 4 A flowchart illustrating a communication method provided in an embodiment of this application;

[0033] Figure 5 This is a schematic diagram of the structure of a MAC PDU provided in an embodiment of this application;

[0034] Figure 6 This application provides a schematic diagram of the structure of a type of MAC sub-PDU.

[0035] Figure 7 This is a schematic diagram illustrating how a second terminal device determines whether the value of the fourth field of the first byte of the second MAC sub-PDU is the same as the target identifier index to be sent, according to an embodiment of this application.

[0036] Figure 8 This is a schematic diagram illustrating how a second terminal device determines whether the value of the third field of the first byte of the second MAC sub-PDU is a target value, as provided in an embodiment of this application. Detailed Implementation

[0037] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0038] First, some concepts involved in this application will be described.

[0039] The terms "first" and "second" used in the embodiments of this application are only used to distinguish features of the same type and should not be construed as indicating relative importance, quantity, order, etc.

[0040] The terms "exemplary" or "for example" used in the embodiments of this application are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0041] The technical solutions provided in this application can be applied to various communication systems, such as: Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, sidelink communication systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, non-terrestrial network (NTN) communication systems, 5th generation (5G) mobile communication systems, new radio access technology (NR), future communication systems, and 5G Advanced communication systems. Among these, 5G mobile communication systems can include non-standalone (NSA) and / or standalone (SA) networking. The technical solutions provided in this application can also be applied to future communication systems. This application does not limit the scope of these applications. The terms "system" and "network" in the embodiments of this application are often used interchangeably, and the described technologies can be used in the systems and radio technologies mentioned above, as well as in other systems and radio technologies.

[0042] Appendix Figure 1 This is a schematic diagram of the architecture of a wireless communication system provided in an embodiment of this application. The wireless communication system 100 may include network devices, such as... Figure 1At least one network device 110 is shown. The wireless communication system 100 may also include terminal devices, such as... Figure 1 The terminal device 120 shown. The network device 110 and the terminal device 120 can communicate with each other via a wireless link.

[0043] Appendix Figure 1 An exemplary network device 110 and a terminal device 120 are shown. Optionally, the wireless communication system 100 may also include multiple network devices 110 and multiple terminal devices 120.

[0044] The network equipment in this application can be network-side equipment such as access network equipment and core network equipment. Access network equipment is sometimes also called an access node. Access network equipment has wireless transceiver capabilities for communicating with terminals. Access network equipment includes, but is not limited to, base stations, evolved NodeBs (eNodeBs), transmission reception points (TRPs) in the aforementioned communication systems, next-generation NodeBs (gNBs) in 5G mobile communication systems, access network equipment or modules of access network equipment in open RAN (ORAN) systems, satellites in NTN communication systems, base stations in future mobile communication systems, or access nodes in WiFi systems. Access network equipment can also be modules or units capable of implementing some of the functions of a base station. Access network equipment can be a macro base station, micro base station, indoor station, relay node, donor node, or a wireless controller in a cloud radioaccess network (CRAN) scenario. Optionally, access network equipment can also be a server, wearable device, or vehicle-mounted equipment, etc. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). Multiple access network devices in a communication system can be base stations of the same type or different types. Base stations can communicate with terminals directly or via relay stations. Terminals can communicate with multiple base stations using different access technologies. The embodiments of this application do not limit the specific technology or device form used in the access network equipment. In this application, the access network equipment is referred to as a network device.

[0045] In this application, the means for implementing the functions of a network device can be a network device itself, or a means capable of supporting the network device in implementing those functions, such as a processor, circuit, chip, or chip system. This means can be installed in or connected to the network device. In the technical solutions provided in this application, the example of a network device being used to implement the functions of a network device is used to describe the technical solutions provided in this application.

[0046] The terminal device in this application can be a wireless terminal device capable of receiving network device scheduling and instruction information. The wireless terminal device can be a device providing voice and / or data connectivity to a user, a handheld device with wireless connectivity, or other processing devices connected to a wireless modem. For example, the terminal device can communicate with one or more core networks or the Internet via a radio access network (RAN). The terminal device can also be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), ultra-reliable low-latency communication (URLLC), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, or satellite communication, etc. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver capabilities, wearable device, vehicle, aircraft (such as drone, helicopter, airplane), hot air balloon, ship, robot, robotic arm, or smart home device, etc. The embodiments of this application do not limit the form of the terminal device.

[0047] In this application, the apparatus for implementing the functions of a terminal device can be the terminal device itself, or any apparatus capable of supporting the terminal device in implementing those functions, such as a processor, circuit, chip, or chip system. This apparatus can be installed in the terminal device or connected to and used with the terminal device. In the technical solutions provided in this application, the example of a terminal device being used to implement the functions of a terminal device is used to describe the technical solutions provided in this application.

[0048] Access network equipment and terminal equipment can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed in the air on aircraft, balloons, and satellites. This application does not limit the application scenarios of the access network equipment and terminal equipment. Access network equipment and terminal equipment can be deployed in the same or different scenarios. For example, access network equipment and terminal equipment can be deployed simultaneously on land; or, access network equipment can be deployed on land and terminal equipment can be deployed on water, etc., and so on.

[0049] In practical applications, multiple network devices can collaborate to assist terminal devices in achieving wireless access, with different network devices each implementing a portion of the base station's functions. For example, network devices can be central units (CUs), distributed units (DUs), CU-control plane (CPs), CU-user plane (UPs), or radio units (RUs), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0050] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (Open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. CU (or CU-CP and CU-UP), DU, and RU can implement different protocol layer functions.

[0051] Figure 2 This is a schematic diagram of the structure of a terminal device and a network device provided in an embodiment of this application. The terminal device 120 includes a first processor 121, a first memory 122, and a first transceiver 123.

[0052] The first processor 121 may include one or more processing units, such as: a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a central processor unit (CPU), a network processor (NP), a microcontroller unit (MCU), a programmable logic device (PLD), an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors.

[0053] The first memory 122 can be volatile memory or non-volatile memory, or it can include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DRRAM).

[0054] The first memory 122 can exist independently and be connected to the first processor 121 via a bus. Alternatively, the first memory 122 can be integrated with the first processor 121. The first memory 122 stores application code that executes the scheme of this application, and its execution is controlled by the first processor 121. The first processor 121 executes the computer program instructions stored in the first memory 122, thereby performing various functional applications and data processing of the terminal device, such as implementing the sensing method described in the embodiments of this application.

[0055] The first processor 121 and the first transceiver 123 are connected via a bus. The first transceiver 123 can be any transceiver-like device used for communication with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area network (WLAN), etc. The first transceiver 123 includes a transmitter Tx and a receiver Rx.

[0056] Network device 110 includes a second processor 111, a second memory 112, and a second transceiver 113. The second processor 111 executes computer program instructions stored in the second memory 112, thereby performing various functional applications and data processing of the network device 110, such as implementing the communication method described in the embodiments of this application. The functions of the second processor 111 are described with reference to the first processor 121, the functions of the second memory 112 are described with reference to the first memory 122, and the functions of the second transceiver 113 are described with reference to the first transceiver 123, and will not be repeated here.

[0057] To facilitate understanding of the embodiments of this application, the terminology used in this application is first briefly explained. Optionally, the explanation of some terms can also refer to the explanations in the 3rd Generation Partnership Project (3GPP) standard protocol. It should be understood that the technical terms in this application are only examples and not limitations. For example, as technology evolves, technical terms may also change; where the technical meaning remains the same, other technical terms should also apply to this application.

[0058] User equipment (UE): UE refers to the user's terminal equipment, such as mobile phones, IoT modules, etc.

[0059] Release 19 (R19) is a technical specification version developed by the 3GPP standardization organization, defining new functions that UEs and network devices must support. It is the second version of 3GPP 5G-Advanced (5G-A) (R18 was the first), and is expected to be frozen (completed standardization) by the end of 2025.

[0060] Next-generation nodeB (gNB) in 5G mobile communication systems: gNB is the core network element of 5G base station, responsible for transmitting and receiving radio signals, resource scheduling, and interaction with terminal equipment (UE) and core network (5GC).

[0061] Network Energy Saving Cell (NES cell): An NES cell refers to a cell that reduces base station energy consumption while ensuring network quality of service (QoS) by dynamically adjusting the cell's operating status (such as activation / dormancy), resource configuration, or coverage. Its core objective is to improve network energy efficiency.

[0062] Wake-up signal (WUS): A dedicated low-power signal that wakes up a device in a sleep state, avoiding continuous network monitoring and significantly extending battery life (such as sensors and wearable devices).

[0063] Uplink wake-up signal (UL-WUS): This is a signal sent by the UE to the base station (gNB / eNodeB) to request network resources or trigger downlink data transmission, thereby avoiding the UE continuously listening to the downlink control channel (such as PDCCH) and saving power.

[0064] Uplink wake-up signal configuration (UL-WUS-Config): Used to carry time offset information and index configuration information, etc.

[0065] Random access response (RAR) message: The RAR message is sent by the base station (gNB) to the terminal (UE) in response to a random access request initiated by the UE. The RAR message is sent at the MAC layer in the form of a Media Access Control Protocol Data Unit (MAC PDU).

[0066] The Medium Access Control Protocol Data Unit (MACPDU) is the core data encapsulation format of the MAC layer in wireless communication systems such as 5G / LTE. It is used to transmit control information and user data between the UE (UE) and the base station (gNB / eNodeB).

[0067] MAC sub-PDU: This is the basic unit for MAC layer data encapsulation in wireless communication systems such as 5G / LTE. It is used to carry different types of control information or user data. A MAC PDU includes multiple MAC sub-PDUs.

[0068] Total Number of RA-Preambles: In the 5G NR random access (RACH) process, totalNumberOfRA-Preambles is a key RRC layer parameter used to define the total number of available random access preambles (PRACH Preambles) in the cell, which directly affects the success rate of contention for access and the efficiency of resource allocation.

[0069] System information (SI) is a key configuration parameter broadcast by network devices to terminal devices (UEs) for processes such as cell access, reselection, and connection establishment.

[0070] System Information Block (SIB): An SIB is a set of key system parameters broadcast by a base station to a terminal in a mobile communication network. It is used for network access, resource configuration, and service control. SIBs include types such as MIB, SIB1, SIB2, SIB3, SIB4, SIB5, SIB6, SIB7, SIB8, and SIB9.

[0071] System Information Block 1 (SIB1): SIB1 is one type of SIB. SIB1 includes key parameters for terminal equipment accessing and camping on the cell, such as the cell's Public Land Mobile Network (PLMN) identifier, Tracking Area Code (TAC), cell reselection priority, minimum received signal level, scheduling information for other SIBs (such as SIB2~SIB9), supported operating frequency bands, and carrier bandwidth. Traditional SIB1 is transmitted periodically, resulting in higher power consumption for network equipment.

[0072] On-demand SIB1 (OD-SIB1): When a terminal device needs to re-access the network (e.g., cell reselection, cell camping failure), the network device is triggered to send a PDCCH via UL WUS. The downlink control information (DCI) in the PDCCH is used to schedule SIB1, so that the terminal device can re-access the network according to SIB1. On-demand SIB1 can reduce invalid SIB1 broadcasts and reduce the power consumption of network devices.

[0073] In related technologies, in on-demand request scenarios, the R19 UE decodes the OD-SIB1 MAC sub-PDU by obtaining the totalNumberOfRA-Preambles parameter. Typically, as exemplified, see the attached... Figure 3 As shown, the communication method 300 includes the following steps S301-S304:

[0074] S301. The second network device sends a UL-WUS configuration message to the terminal device.

[0075] The terminal device is an R19 UE. The second network device (or the network device's base station) sends a UL-WUS configuration message to the terminal device to distribute configuration parameters. The totalNumberOfRA-Preambles parameter can be carried in the UL-WUS configuration message; that is, the UL-WUS configuration message can include the pre-configured totalNumberOfRA-Preambles parameter. The UL-WUS configuration message can also include time offset information and index configuration information. Correspondingly, the R19 UE receives the UL-WUS configuration message from the second network device.

[0076] S302, The terminal device sends a UL-WUS to the first network device to request the first network device to send OD-SIB1.

[0077] First, R19 UE sends a UL-WUS to the first network device (or the network energysaving (NES) cell of the network device) to request the first network device to send OD-SIB1. When R19 UE is in idle state (RRC_IDLE) or inactive state (RRC_INACTIVE), if it re-accesses the network (e.g., cell reselection, cell camping failure), it will send a UL WUS to the first network device to trigger the first network device to send a PDCCH. The DCI in the PDCCH is used to schedule SIB1 so that R19 UE can re-access the network according to SIB1. Accordingly, the first network device receives the UL WUS from R19 UE.

[0078] S303, The first network device sends a RAR message to the terminal device.

[0079] The RAR message is sent in the form of a Media Access Control Protocol Data Unit (MAC PDU). The MAC PDU includes multiple MAC sub-PDUs. In the on-demand request scenario, the MAC PDU includes the MAC sub-PDU of OD-SIB1. After receiving a UL-WUS request for OD-SIB1 from the R19 UE, the first network device sends a RAR message to the R19 UE. Correspondingly, the R19 UE receives the RAR message from the first network device.

[0080] S304. The first network device sends SIB1 to the terminal device.

[0081] The first network device broadcasts the totalNumberOfRA-Preambles parameter to the R19 UE via SIB1. Correspondingly, the R19 UE receives SIB1 from the first network device.

[0082] As described in the communication method 300 of steps S301-S304 above, since the R19 UE has not yet received the execution step S304 when it receives the RAR message, that is, it has not yet received SIB1 from the first network device, it cannot obtain the totalNumberOfRA-Preambles parameter broadcast by SIB1, causing the R19 UE to fail to decode the RAR message. Therefore, the R19 UE can only obtain it from the UL-WUS configuration message that has the totalNumberOfRA-Preambles parameter pre-configured. In other words, the second network device needs to pre-configure the totalNumberOfRA-Preambles parameter in the UL-WUS configuration message and send it to the R19 UE. Then, after receiving the UL-WUS configuration message from the second network device, the R19 UE sends a request for UL-WUS for OD-SIB1 to the first network device, and then receives the RAR message from the first network device. Since the totalNumberOfRA-Preambles parameter was pre-configured in the UL-WUS configuration message, the UL-WUS configuration message now includes the totalNumberOfRA-Preambles parameter, thus successfully decoding the MAC sub-PDU of OD-SIB1. However, this increases the overhead of UL-WUS configuration.

[0083] In view of this, this application provides a communication method. First, the terminal device sends a WUS to the network device to request the transmission of OD-SIB1. Second, the terminal device receives a MAC PDU from the network device. Finally, the terminal device locates the position of the OD-SIB1 MAC sub-PDU within the MAC PDU by decoding the identification information of a preset length that precedes and is adjacent to the OD-SIB1 MAC sub-PDU, thereby successfully decoding the OD-SIB1 MAC sub-PDU. This communication method allows the terminal device to successfully decode the OD-SIB1 MAC sub-PDU based on the preset length of identification information, even when the totalNumberOfRA-Preambles parameter is not included in the UL-WUS configuration message, thus improving communication efficiency and saving overhead.

[0084] The solution provided in this application will be described in detail below with reference to the corresponding flowcharts. It is understood that the illustrative flowcharts provided in this application primarily use different devices (e.g., terminal devices, network devices) as examples of the execution subjects of this interactive illustration to illustrate the method, but this application does not limit the execution subjects of the interactive illustrations. For example, the devices in the illustrative flowcharts (e.g., terminal devices, network devices) can also be chips, chip systems, or processors that support the implementation of this method on the device, or logic modules or software that can implement all or part of the functions of the device.

[0085] As a general statement, the message or signaling interactions involved in the interaction process of this application embodiment can be standard messages or signaling or newly introduced messages or signaling. This application embodiment does not make specific limitations on this.

[0086] Appendix Figure 4 This is a flowchart illustrating a communication method provided in an embodiment of this application. It can be understood that the terminal device involved in this communication method may be an accessory... Figure 1 The term "terminal device" can also refer to a component within that terminal device (such as a processor, chip, or chip system). The network equipment involved in this communication method can be an accessory... Figure 1 Network equipment can also refer to devices within network equipment (such as processors, chips, or chip systems). For example, see attached... Figure 4 As shown, the communication method 400 includes the following steps S401-S416:

[0087] S401, The first terminal device sends WUS to the network device.

[0088] The first terminal device refers to the terminal device based on the technical specifications developed by the 3GPP standardization organization after 2025. In other words, the first terminal device is a terminal device that can be applied to 5G and future 6G and above technical specifications. For example, the terminal device of R19.

[0089] In one possible implementation, the network device can be a serving cell (e.g., an NES cell) or a base station. This application embodiment does not limit the type of network device.

[0090] In one possible implementation, the first terminal device can be either an R19 UE or an R20 UE. This application embodiment does not limit the protocol version of the first terminal device.

[0091] In this embodiment of the application, WUS is used to request the network device to send OD-SIB1. In this case, WUS can be UL-WUS.

[0092] In one possible implementation, the first terminal device may send one WUS to the network device, or it may send multiple WUS to the network device. The number of WUS is not limited in the embodiments of this application.

[0093] When the first terminal device is in an idle state (RRC_IDLE) or an inactive state (RRC_INACTIVE), if it re-accesses the network (e.g., cell reselection, cell camping failure), it will send a UL WUS to the network device, triggering the network device to send a PDCCH. The DCI in the PDCCH is used to schedule SIB1 so that the terminal device can re-access the network according to SIB1. Accordingly, the network device receives the UL WUS from the first terminal device.

[0094] S402, The second terminal device sends the target identification code to the network device.

[0095] The target identifier can be a preamble. The second terminal device is a terminal device based on a technical specification version developed by the 3GPP standardization organization before 2025, that is, a version prior to R19. For example, a terminal device based on R18.

[0096] In one possible implementation, the second terminal device can be an R18 UE, or any version of the UE from R99 to R4-R18. This application embodiment does not limit the protocol version of the second terminal device.

[0097] In this embodiment of the application, the target identifier code can be used to request the network device to send system information SI.

[0098] In one possible implementation, the second terminal device may send one target identifier code to the network device, or it may send multiple target identifier codes to the network device. The number of target identifier codes is not limited in the embodiments of this application.

[0099] When the second terminal device is in idle state (RRC_IDLE) or inactive state (RRC_INACTIVE), if it is accessing the network for the first time or re-accessing the network (e.g., cell reselection, cell camping failure), it will send a target identifier code to the network device on the random access channel occasion (RO) to trigger the initial connection or resynchronization between the second terminal device and the network device. Accordingly, the network device receives the target identifier code from the second terminal device.

[0100] S403. The network device encapsulates the RAR corresponding to each of the above requests in a MAC sub-PDU to form a RAR MACPDU.

[0101] After receiving the WUS from the first terminal device and the preamble from the second terminal device, the network device, at the MAC layer, encapsulates the RAR corresponding to each request into a MAC sub-PDU in the form of a MAC PDU, forming a RAR MACPDU (or simply MAC PDU). Since the RAR MAC PDU is the MAC layer encapsulation format for RAR messages, it essentially forms a RAR message. Each MAC PDU includes multiple MAC sub-PDUs, which are concatenated according to priority, with each MAC sub-PDU corresponding to one request.

[0102] In the embodiments of this application, exemplarily, as shown in the appendix Figure 5 As shown, the structure of this RAR message includes the following:

[0103] (1) A MAC PDU includes a first MAC sub-PDU and (n-1) second MAC sub-PDUs, and the nth MAC sub-PDU is the first MAC sub-PDU, and (n-1) second MAC sub-PDUs precede the first MAC sub-PDU.

[0104] The first MAC sub-PDU is the MAC sub-PDU of OD-SIB1, and the second MAC sub-PDU is another type of MAC sub-PDU, corresponding to other types of random access requests, such as SI requests, radio resource control (RRC) connection establishment requests, etc. In other words, the second MAC sub-PDU is the MAC sub-PDU of SI or RRC. A MAC PDU includes n MAC sub-PDUs, where n is a positive integer, n>=2. The nth MAC sub-PDU is the first MAC sub-PDU, and the (n-1)th MAC sub-PDU is the second MAC sub-PDU. That is, the MAC sub-PDU of OD-SIB1 is at the end, and the MAC sub-PDUs of SI or RRC are before the MAC sub-PDUs of OD-SIB1.

[0105] In one possible implementation, the order of the SI MAC sub-PDU and the RRC MAC sub-PDU among the n-1 second MAC sub-PDUs can be random or set according to the order of reception. In this application embodiment, the order of the RRC MAC sub-PDU and the SI MAC sub-PDU is not limited.

[0106] In one possible implementation, the MAC PDU may or may not include padding information; the specific structure of the MAC PDU is not limited in this application. For example, see the attached... Figure 5 As shown in (a) above, the MACPDU does not include padding information. For example, see attached... Figure 5As shown in (b) of the diagram, the MAC PDU includes padding information.

[0107] In one possible implementation, the MAC PDU may also include padding information following the first MAC sub-PDU. The padding information is added to align with the size of the transport block (TB). An example is shown in the attached document. Figure 5 As shown in (b), the MAC PDU includes padding information following the first MAC sub-PDU.

[0108] (2) The value of the third field of the first byte of the (n-1)th second MAC sub-PDU is the target value.

[0109] The target value of the third field indicates that the second MAC sub-PDU is the (n-1)th second MAC sub-PDU, i.e., the last second MAC sub-PDU. The third field can take either a fifth or a sixth value. A fifth value indicates that the second MAC sub-PDU is the (n-1)th second MAC sub-PDU. A sixth value indicates that the second MAC sub-PDU is not the (n-1)th second MAC sub-PDU. The fifth and sixth values ​​correspond one-to-one. The fifth value can be 0 or 1. For example, when the fifth value is 0, the sixth value is 1. When the fifth value is 1, the sixth value is 0.

[0110] The second MAC sub-PDU is either an SI or RRC MAC sub-PDU. The second MAC sub-PDU includes the following three types: A1 type, A2 type, and A3 type.

[0111] For example, see attached Figure 6As shown in (a), the second MAC sub-PDU of type A1 includes the E field, T field, R field, and BI field. The E field is a flag indicating whether the second MAC sub-PDU is the last second MAC sub-PDU in the MAC PDU. An E field value of 1 indicates that the second MAC sub-PDU is not the (n-1)th second MAC sub-PDU, i.e., not the last second MAC sub-PDU in the MAC PDU. An E field value of 0 indicates that the second MAC sub-PDU is the (n-1)th second MAC sub-PDU, i.e., the last second MAC sub-PDU in the MAC PDU. The T field is a flag indicating whether the second MAC sub-PDU includes the random access preamble identifier (RAPID) field or the backoff indicator (BI) field. A T field value of 1 indicates that the second MAC sub-PDU includes the RAPID field. A T field value of 0 indicates that the second MAC sub-PDU includes the BI field. The R field is a reserved bit field. The BI field is used to indicate the overload status of the network device and has a length of 4 bits. In the second MAC sub-PDU of type A1, the second MAC sub-PDU includes a BI field, therefore, the T field has a value of 0. The length of the second MAC sub-PDU of type A1 is 1 byte, which includes a 1-bit E field, a 1-bit T field, a 1-bit R field, a 1-bit R field, and a 4-bit BI field.

[0112] For example, see attached Figure 6 As shown in (b), the second MAC sub-PDU of type A2 includes an E field, a T field, and a RAPID field. The E and T fields have already been described in detail in the second MAC sub-PDU of type A1, and will not be repeated here. The RAPID field is used to indicate the index information of the random access preamble detected / received by the network device, i.e., the preamble index, and has a length of 6 bits. In the second MAC sub-PDU of type A2, since it includes the RAPID field, the T field has a value of 1. The second MAC sub-PDU of type A2 is 1 byte long, consisting of a 1-bit E field, a 1-bit T field, and a 6-bit RAPID field.

[0113] For example, see attached Figure 6As shown in (c), the first byte of the second MAC sub-PDU of type A3 is the same as that of the second MAC sub-PDU of type A2, which has been described in detail in the second MAC sub-PDU of type A2 above, and will not be repeated here. In addition to the first byte, the second MAC sub-PDU of type A3 also includes a 7-byte MAC RAR. The MAC RAR includes fields such as transmission identity (TI) or R, timing advance command (TAC), uplink grant (UL Grant), and temporary cell radio network temporary identifier (TC-RNTI). The TI field is used to identify the uniqueness or status of data transmission, for example, distinguishing between initial transmission and retransmission, ensuring that the receiver correctly merges retransmitted data, or identifying new data. The TAC field represents the adjustment amount, which, by adjusting the UE's transmission time, ensures that all UE's uplink data arrives within the base station's expected reception window, avoiding inter-symbol interference (ISI). UL Grant is an uplink resource grant allocated by the base station (gNB / eNB) to the UE via downlink control signaling (such as DCI or RAR). It specifies when, on which frequency band, and in what manner the UE transmits uplink data (such as Msg3, PUSCH data, etc.). The TC-RNTI field is a temporary UE identifier used in 5G (NR) and 4G (LTE) for the Random Access Response (RACH), primarily used during the contention resolution phase. It is allocated to the UE by the gNB (5G) or eNB (4G) via the Random Access Response (RAR, Msg2) and used for scheduling and conflict resolution in subsequent Msg3 / Msg4 interactions. Since the first byte of the second MAC sub-PDU of type A3 is the same as that of the second MAC sub-PDU of type A2, and the first byte of this second MAC sub-PDU includes the RAPID field, the T field value is 1. The length of the second MAC sub-PDU of type A3 is 8 bytes, including a 1-bit E field, a 1-bit T field, a 6-bit RAPID field, and a 7-byte MAC RAR. A MAC RAR contains a 1-byte TI (or R) and TAC, a 1-byte TAC and UL Grant, a 3-byte UL Grant, and a 2-byte TC-RNTI.

[0114] In one possible implementation, each second MAC sub-PDU can be of type A1, A2, or A3. The embodiments of this application do not limit the type of each second MAC sub-PDU.

[0115] Based on the type of the second MAC sub-PDU described above, in this embodiment of the application, the third field is the E field, the fifth value is 0, the sixth value is 1, and the target value is the fifth value.

[0116] The value of the third field of the first byte of the (n-1)th second MAC sub-PDU is the target value, which is to indicate that the second MAC sub-PDU is the (n-1)th second MAC sub-PDU.

[0117] (3) The preset length of the identification information is between the first MAC sub-PDU and the (n-1)th second MAC sub-PDU.

[0118] Since the UL-WUS configuration message does not include the totalNumberOfRA-Preambles parameter, identification information is needed to identify the position of the first MAC sub-PDU in the MAC PDU, so that the first terminal device can successfully decode the received RAR message.

[0119] As described above for the second MAC sub-PDUs of types A1, A2, and A3, the MAC RAR includes two fields with value ranges: TAC and TC-RNTI. The TAC field ranges from 0 to 3846 (0 to 1111 00000110 0000). The TC-RNTI field ranges from 0001 to FFF2 (0000 0000 0000 0001 to 1111 11111111 0010). In the TAC and TC-RNTI fields of the MAC RAR, bytes 1 through 7 are not all 1s, and bytes 6 and 7 cannot both be all 0s simultaneously. That is, a MAC PDU can contain at most 6 consecutive bytes of all 0s (bytes 1 through 6 of the MAC RAR) or 5 consecutive bytes of all 1s (bytes 2 through 6 of the MAC RAR).

[0120] To distinguish between the two fields mentioned above, the TAC field and the TC-RNTI field, and to ensure that the preset length of the identification information is unique, i.e., uniquely identifiable, the position of the first MAC sub-PDU within the MAC PDU can be uniquely determined. In one possible implementation, the preset length of the identification information can be at least 6 consecutive bytes all of 1 or at least 7 consecutive bytes all of 0.

[0121] For example, see attached Figure 5As shown, the preset length of the identifier information is located between the first MAC sub-PDU (i.e., the nth MAC sub-PDU) and the (n-1)th second MAC sub-PDU (i.e., the (n-1)th MAC sub-PDU). This preset length of identifier information is located between the first MAC sub-PDU and the (n-1)th second MAC sub-PDU to pinpoint the position of the first MAC sub-PDU within the MAC PDU. After decoding the preset length of identifier information, the first MAC sub-PDU can be decoded.

[0122] (4) The first field of the first byte of the MAC PDU can be either a first value or a second value; the first value indicates that the first byte of the MAC PDU includes the second field, and the second value indicates that the first byte of the MAC PDU does not include the second field.

[0123] The first byte of the MAC PDU is the first byte of the first second MAC sub-PDU. The first field indicates whether the first byte of this second MAC sub-PDU includes the second field. The value of the first field is either a first value or a second value. A first value indicates that the first byte of the second MAC sub-PDU includes the second field. A second value indicates that the first byte of the second MAC sub-PDU does not include the second field. The first and second values ​​correspond one-to-one. The first value can be 0 or 1. For example, when the first value is 0, the second value is 1. When the first value is 1, the second value is 0.

[0124] From the above description of the second MAC sub-PDUs of types A1, A2, and A3, we can see that: 1) Only the second MAC sub-PDU whose first byte includes the BI field has an R field in its first byte. 2) In the first byte of the second MAC sub-PDU, since all other fields have specific functions, only the R field is a reserved field. Therefore, custom functions can be performed through the R field.

[0125] Furthermore, in the communication method 400 described above, if the network device fails to receive the WUS from the first terminal device, or if the network device successfully receives the WUS from the first terminal device but does not send the first MAC sub-PDU to the first terminal device, the first terminal device still needs to decode the MAC PDU that does not include the first MAC sub-PDU. This results in additional time and power consumption, and in this case, the preset length of the identification information is also unnecessary. Therefore, to avoid the above situation, save decoding time and reduce power consumption, the value of the R field in the first byte of the MAC PDU can be used to indicate whether the MAC PDU includes the first MAC sub-PDU. To indicate whether the MAC PDU includes the first MAC sub-PDU through the R field in the first byte of the MAC PDU, it is first necessary to determine whether the first byte of the MAC PDU includes the R field, i.e., the type of the first second MAC sub-PDU.

[0126] The T field indicates whether the second MAC sub-PDU includes the RAPID field or the BI field. Only second MAC sub-PDUs whose first byte includes the BI field have an R field in their first byte. Therefore, the value of the T field in the first byte of the MAC PDU can be used to determine whether the first byte of the MAC PDU includes the R field. To determine whether the first byte of the MAC PDU includes the second field, the value of the first field in the first byte of the MAC PDU can be either a first value or a second value. Determining the value of the first field in the first byte of the MAC PDU is to determine whether the first byte includes the BI field, thereby determining whether the first byte includes the R field, and ultimately determining whether the MAC PDU includes the first MAC sub-PDU. In this embodiment, the first field is the T field, with a first value of 0 and a second value of 1.

[0127] If the first field has the first value, then the first byte of the second MAC sub-PDU includes the second field, and it can be further determined whether the second field has the third or fourth value. If the first field has the second value, it can be assumed that the MAC PDU includes the first MAC sub-PDU.

[0128] (5) If the first byte of the MAC PDU includes a second field, the value of the second field of the first byte of the MAC PDU shall be a third value or a fourth value; if the second field is a third value, it indicates that the MAC PDU includes a first MAC sub-PDU. If the second field is a fourth value, it indicates that the MAC PDU does not include the first MAC sub-PDU.

[0129] Similarly, the first byte of the MAC PDU is the first byte of the first second MAC sub-PDU. The second field indicates whether the MAC PDU includes the first MAC sub-PDU. The value of the second field can be either a third or a fourth value. A third value indicates that the MAC PDU includes the first MAC sub-PDU. A fourth value indicates that the MAC PDU does not include the first MAC sub-PDU. The third and fourth values ​​correspond one-to-one. The third value can be 0 or 1. For example, when the third value is 0, the fourth value is 1. When the third value is 1, the fourth value is 0.

[0130] Since the R field can be customized, it can be used to indicate whether the MAC PDU includes the first MAC sub-PDU. Therefore, in this embodiment, the second field is the R field, the third value is 0, and the fourth value is 1.

[0131] In one possible implementation, the first R field can be used to indicate whether the MAC PDU includes the first MAC sub-PDU, or the second R field can be used to indicate whether the MAC PDU includes the first MAC sub-PDU, or both R fields can be used to indicate whether the MAC PDU includes the first MAC sub-PDU. The type and number of R fields are not limited in the embodiments of this application.

[0132] When the first byte of the MAC PDU includes a second field, the value of the second field of the first byte of the MAC PDU is either a third or a fourth value. This is to determine whether the MAC PDU includes a first MAC sub-PDU. Thus, the first terminal device can end the decoding of the MAC PDU if the MAC PDU does not include the first MAC sub-PDU, thereby saving decoding time and reducing power consumption.

[0133] (6) The value of the fourth field of the first byte of the MAC PDU is the target identifier index.

[0134] The fourth field is the RAPID field. Based on the type of the second MAC sub-PDU described above, the RAPID field is used to indicate the index information of the random access preamble detected / received by the network device, i.e., the preamble index. Therefore, in this embodiment, the fourth field is the RAPID field.

[0135] The value of the fourth field is the target identifier index, which is used to locate the position of the second MAC sub-PDU corresponding to the request sent by the second terminal device in the MAC PDU. That is, after the network device receives the target identifier from the second terminal device, the value of the fourth field of one of the second MAC sub-PDUs is the received target identifier index, so that the second terminal device can subsequently locate the position of the second MAC sub-PDU in the MAC PDU, thereby ending the decoding of the MAC PDU.

[0136] The structure of the RAR message described above includes a first MAC sub-PDU and n-1 second MAC sub-PDUs, with the nth MAC sub-PDU preceding the first MAC sub-PDU and the n-1 second MAC sub-PDUs. The third field of the first byte of the (n-1)th second MAC sub-PDU is the target value. A preset length of identification information is located between the first MAC sub-PDU and the (n-1)th second MAC sub-PDU. The first field of the first byte of the MAC PDU is either a first or a second value, indicating whether the first byte of the MAC PDU includes a second field. If the first byte of the MAC PDU includes a second field, the second field of the first byte of the MAC PDU is either a third or a fourth value, indicating whether the MAC PDU includes the first MAC sub-PDU. The fourth field is the target identifier index. Finally, the MAC PDU is encapsulated to form the RAR message. This approach not only enables the first terminal device to successfully decode the OD-SIB1 MAC sub-PDU based on a preset length of identification information, even when the UL-WUS configuration message does not include the totalNumberOfRA-Preambles parameter, thus improving communication efficiency and saving overhead, but also allows the first terminal device to terminate decoding of the MAC PDU based on the value of the R field, even if the network device fails to receive the WUS from the first terminal device, or even if the network device successfully receives the WUS but does not send the first MAC sub-PDU to the first terminal device, thereby saving decoding time and reducing power consumption. Furthermore, it enables the second terminal device to successfully decode the second MAC sub-PDU corresponding to the sent request, thus allowing the terminal device to be compatible with decoding both OD-SIB1 MAC sub-PDUs and SI (or RRC) MAC sub-PDUs.

[0137] S404. The network device sends a RAR message to the first terminal device.

[0138] After encapsulating the MAC PDU, the network device sends the RAR message to the first terminal device in the form of a MAC PDU. Correspondingly, the first terminal device receives the RAR message from the network device.

[0139] S405, The network device sends a RAR message to the second terminal device.

[0140] Similarly, after encapsulating the MAC PDU, the network device sends the RAR message to the second terminal device in the form of a MAC PDU. The second terminal device then receives the RAR message from the network device.

[0141] S406. The first terminal device decodes the first byte of the MAC PDU.

[0142] As can be seen from the structure of the RAR message described above, the first byte of the MAC PDU is the first byte of the first second MAC sub-PDU.

[0143] Since the first terminal device sends a WUS requesting the network device to send OD-SIB1, the first terminal device only needs to decode the first MAC sub-PDU from this MAC PDU. After the first terminal device sends the WUS, the network device may or may not successfully receive it. The network device may also send the first MAC sub-PDU to the first terminal device, or it may not. Only when the network device successfully receives the WUS from the first terminal device and sends the first MAC sub-PDU will the first terminal device receive the RAR message from the network device containing the first MAC sub-PDU, and only then can the first terminal device successfully decode the first MAC sub-PDU. If the network device fails to receive the WUS from the first terminal device, or if the network device successfully receives the WUS but does not send the first MAC sub-PDU to the first terminal device, the first terminal device will not receive the first MAC sub-PDU in the RAR message from the network device. In this case, the first terminal device cannot successfully decode the first MAC sub-PDU. If the first terminal device still fully decodes the MAC PDU, it will incur additional time and power consumption. Therefore, the first terminal device must first determine whether the MAC PDU in the received RAR message from the network device includes the first MAC sub-PDU. According to the structure of the RAR message described above, the value of the second field of the first byte of the MAC PDU can be used to determine whether the MAC PDU includes the first MAC sub-PDU. Therefore, after receiving the RAR message from the network device, the first terminal device can first attempt to decode the first byte of the MAC PDU to determine whether the MAC PDU includes the first MAC sub-PDU.

[0144] S407. The first terminal device determines whether the value of the first field is the first value.

[0145] To determine whether a MAC PDU includes a first MAC sub-PDU, the value of the second field in the first byte of the MAC PDU must be checked. First, it's necessary to determine if the first byte of the MAC PDU contains the second field. Therefore, after the first terminal device decodes the first byte of the MAC PDU, it can determine whether the MAC PDU includes a first MAC sub-PDU by checking if the value of the first field is the first value.

[0146] The first field is the T field, with a first value of 0 and a second value of 1. A first value indicates that the first byte of the second MAC sub-PDU includes the second field. A second value indicates that the first byte of the second MAC sub-PDU does not include the second field. The content of the first field has been described in detail in the structure of the RAR message above and will not be repeated here. When the first field has the first value, it indicates that the first byte of the MAC PDU includes the second field, and step S408 is executed. When the first field has the second value, it indicates that the first byte of the MAC PDU does not include the second field, and step S409 is executed.

[0147] S408. The first terminal device determines whether the value of the second field is the third value.

[0148] If the first field has the first value, it indicates that the first byte of the MAC PDU includes the second field. Then, the value of the second field of the first byte of the MAC PDU is used to determine whether the MAC PDU includes the first MAC sub-PDU.

[0149] The second field is the R field. The third value of the second field is 0, and the fourth value is 1. A third value in the second field indicates that the MAC PDU includes the first MAC sub-PDU. A fourth value in the second field indicates that the MAC PDU does not include the first MAC sub-PDU. The content of the second field has been described in detail in the RAR message structure above and will not be repeated here. When the second field has a third value, it indicates that the MAC PDU includes the first MAC sub-PDU, and step S409 is executed. When the second field has a fourth value, it indicates that the MAC PDU does not include the first MAC sub-PDU, and step S412 is executed.

[0150] S409, The first terminal device continues to decode the MAC PDU.

[0151] Since the first field takes the second value, it is assumed that the MAC PDU includes the first MAC sub-PDU. If the first field takes the first value and the third field takes the third value, it means that the first byte of the MAC PDU includes the R field, and the value of the R field indicates that the MAC PDU includes the first MAC sub-PDU.

[0152] If the first field is the second value, or if the first field is the first value and the third field is the third value, it indicates that the MAC PDU includes a first MAC sub-PDU. That is, the MAC PDU includes the first MAC sub-PDU sent by the network device to the first terminal device, namely the MAC sub-PDU of OD-SIB1. At this time, the MAC PDU can be decoded further, and step S410 can be executed.

[0153] S410, The first terminal device determines whether the preset length of identification information has been decoded.

[0154] As described above regarding the structure of the RAR message, the MAC PDU includes identification information of a preset length for locating the first MAC sub-PDU. This preset length identification information is adjacent to and precedes the first MAC sub-PDU. Therefore, after determining that the MAC PDU includes the first MAC sub-PDU, the first terminal device can determine the position of the first MAC sub-PDU by checking whether the preset length identification information is decoded during the MAC PDU decoding process.

[0155] The content of the preset length identification information has been described in detail in the structure of the RAR message above, and will not be repeated here. If the first terminal device decodes the preset length identification information, it indicates that the next MAC sub-PDU is the first MAC sub-PDU, and step S411 is executed. If the first terminal device has not yet decoded the preset length identification information, it indicates that the next MAC sub-PDU is not the first MAC sub-PDU, and MAC PDU decoding needs to continue, returning to step S409, until the preset length identification information is decoded.

[0156] S411, The first terminal device decodes the first MAC sub-PDU.

[0157] When the first terminal device decodes the identifier information of the preset length, it indicates that the next MAC sub-PDU is the first MAC sub-PDU. At this time, the first terminal device decodes the first MAC sub-PDU, which is the first MAC sub-PDU sent by the network device to the first terminal device, i.e., the MAC sub-PDU of OD-SIB1.

[0158] S412, The first terminal device finishes decoding the MAC PDU.

[0159] If the first field is the first value and the third field is the fourth value, it indicates that the MAC PDU does not include the first MAC sub-PDU. In other words, the MAC PDU does not include the first MAC sub-PDU sent by the network device to the first terminal device, i.e., the OD-SIB1 MAC sub-PDU. Continuing to decode this MAC PDU in this case would result in additional time and power consumption, and the preset length of the identification information is also unnecessary. Therefore, the first terminal device can stop decoding the MAC PDU, thereby saving decoding time and reducing power consumption.

[0160] If the first terminal device decodes the first MAC sub-PDU, it indicates that the first terminal device has decoded the first MAC sub-PDU corresponding to the request sent to the network device, i.e., the MAC sub-PDU of OD-SIB1. At this time, the first terminal device can end the decoding of the MAC PDU.

[0161] In the communication method 400 described in steps S401-S412 above, the first terminal device and the second terminal device first send a WUS message to the network device requesting the network device to send a MAC sub-PDU of OD-SIB1, and a preamble to the MAC sub-PDU requesting the network device to send SI (or RRC). Based on the above requests, the network device encapsulates the RAR corresponding to each request into a MAC sub-PDU, forming a RAR MAC PDU, and then sends the RAR message to the first terminal device and the second terminal device respectively. After receiving the above RAR message, the first terminal device first decodes the first byte of the MAC PDU, and first determines the value of the first field of the first byte of the MAC PDU, thereby determining whether the first byte of the MAC PDU includes the second field. If the first byte of the first byte of the MAC PDU is the second value, that is, the first byte of the MAC PDU does not include the second field, it is assumed that the MAC PDU includes the first MAC sub-PDU, and the first terminal device continues to decode the MAC PDU. If the first byte of the MAC PDU's first byte is a first value (meaning the first byte of the MAC PDU includes a second field), the first terminal device continues to determine the value of the second field of the first byte of the MAC PDU to ascertain whether the MAC PDU includes a first MAC sub-PDU. If the second byte of the MAC PDU's first byte is a third value (meaning the MAC PDU includes a first MAC sub-PDU), the first terminal device continues decoding the MAC PDU. If the second byte of the MAC PDU's first byte is a fourth value (meaning the MAC PDU does not include a first MAC sub-PDU), the first terminal device ends decoding the MAC PDU. During the continued decoding of the MAC PDU, the first terminal device determines whether a preset length of identification information has been decoded. If the first terminal device decodes the preset length of identification information, it ends decoding the MAC PDU after decoding the first MAC sub-PDU. If the first terminal device does not decode the preset length of identification information, it continues decoding the MAC PDU until the first MAC sub-PDU is decoded. This communication method 400 not only enables the first terminal device to successfully decode the MAC sub-PDU of OD-SIB1 based on the preset length of identification information, even when the totalNumberOfRA-Preambles parameter is not included in the UL-WUS configuration message, thus improving communication efficiency and saving overhead, but also allows the first terminal device to terminate the decoding of the MAC PDU based on the value of the R field, even when the network device fails to receive the WUS from the first terminal device, or even when the network device successfully receives the WUS from the first terminal device but does not send the first MAC sub-PDU to the first terminal device, thereby saving decoding time and reducing power consumption.

[0162] S413, the second terminal device decodes the second MAC PDU.

[0163] Since the second terminal device sends a target identifier code (e.g., a preamble) to the network device to request the network device to send an SI or RRC, the second terminal device cannot identify the preset-length identifier information following the second MAC PDU and the first MAC PDU in the MAC PDU. Therefore, it will mask the preset-length identifier information following the second MAC PDU and the first MAC PDU. Thus, the second terminal device only needs to decode the preceding second MAC PDU. After receiving the RAR message from the network device, the second terminal device can begin decoding the MAC PDU, that is, it begins decoding the second MAC PDU. In this embodiment, the second terminal device decodes the MAC PDU sequentially according to the order of the second MAC sub-PDUs.

[0164] S414. The second terminal device determines whether the value of the fourth field of the first byte of the second MAC sub-PDU is the same as the target identifier index to be sent.

[0165] Since the second terminal device sends a target identifier code (e.g., a preamble) to the network device to request the network device to send an SI or RRC, the value of the fourth field (i.e., the RAPID field) of the first byte of the second MAC sub-PDU corresponds to the target identifier code index sent by the second terminal device to the network device. Therefore, the second terminal device only needs to decode the second MAC sub-PDU whose fourth field value is the same as the sent target identifier code index from the MAC PDU. Thus, during the decoding process of the MAC PDU, the second terminal device can determine whether the second MAC sub-PDU corresponds to the request sent by the second terminal device by checking the value of the fourth field of the first byte of the second MAC sub-PDU, thereby ending the decoding of the MAC PDU.

[0166] The content of the fourth field has been described in detail in the RAR message structure above, and will not be repeated here. If the value of the fourth field in the first byte of the second MAC sub-PDU is the same as the target identifier index, it indicates that the second MAC sub-PDU corresponds to the request sent by the second terminal device, and step S416 is executed. If the value of the fourth field in the first byte of the second MAC sub-PDU is different from the target identifier index, it indicates that the second MAC sub-PDU does not correspond to the request sent by the second terminal device, and step S415 is executed.

[0167] S415. The second terminal device determines whether the value of the third field of the first byte of the second MAC sub-PDU is the target value.

[0168] The content of the third field has been described in detail in the RAR message structure above, and will not be repeated here. If the value of the fourth field in the first byte of the second MAC sub-PDU differs from the target identifier index, it is necessary to further determine whether the second MAC sub-PDU is the (n-1)th second MAC sub-PDU, i.e., whether it is the last second MAC sub-PDU. The second terminal device determines whether the value of the third field in the first byte of the second MAC sub-PDU is the target value in order to determine whether the second MAC sub-PDU is the (n-1)th second MAC sub-PDU.

[0169] If the value of the third field of the first byte of the second MAC sub-PDU is the target value, it indicates that the second MAC sub-PDU is the (n-1)th second MAC sub-PDU, and step S416 is executed. If the value of the third field of the first byte of the second MAC sub-PDU is not the target value, it indicates that the second MAC sub-PDU is not the (n-1)th second MAC sub-PDU, and there is at least one more second MAC sub-PDU following it. In this case, return to step S413 and continue decoding the second MAC PDU.

[0170] S416, The second terminal device finishes decoding the MAC PDU.

[0171] If the value of the fourth field of the first byte of the second MAC sub-PDU is the same as the target identifier index, the second terminal device has already decoded the second MAC sub-PDU corresponding to the sent request. At this point, the second terminal device does not need to decode the next second MAC sub-PDU, and therefore can end the decoding of the MAC PDU. For example, see attached... Figure 7 As shown, the second terminal device sends a preamble with index 32 to the network. When decoding the second MAC sub-PDU, if the first byte of the first second MAC sub-PDU includes the BI field but not the RAPID field, the second terminal device continues decoding the next second MAC sub-PDU. If the RAPID field value of the first byte of the second second MAC sub-PDU is 50, which is different from the preamble index 32, the second terminal device continues decoding the next second MAC sub-PDU. If the RAPID field value of the first byte of the third second MAC sub-PDU is 32, which is the same as the preamble index 32, the second terminal device stops decoding the MAC PDU.

[0172] Similarly, the network device may successfully receive the target identifier code from the second terminal device and send a RAR message. In this case, the second terminal device can decode the second MAC sub-PDU corresponding to the request sent by the second terminal device by determining whether the value of the fourth field of the first byte of the second MAC sub-PDU is the same as the index of the sent target identifier code, that is, by following steps S414-S415 described above. The decoding of the MAC PDU ends after decoding the second MAC sub-PDU. Alternatively, the network device may fail to receive the target identifier code from the second terminal device, or although the network device successfully receives the target identifier code from the second terminal device, it may not send the corresponding second MAC sub-PDU to the second terminal device. In this case, the second terminal device will continue decoding until the (n-1)th second MAC sub-PDU. According to the description in step S413 above, the second terminal device cannot identify the preset length identifier information following the second MAC PDU and the first MAC PDU in the MAC PDU, and will therefore mask the preset length identifier information following the second MAC PDU and the first MAC PDU (as shown in the attached figure). Figure 7 - Appendix Figure 8 (The dashed box in the image) In this case, if decoding cannot be completed, the second terminal device will report an error, which may cause a malfunction. Therefore, to avoid the above situation, the decoding of the MAC PDU by the second terminal device can be terminated by checking whether the value of the third field is the target value.

[0173] When the value of the third field is the target value, this second MAC sub-PDU is the (n-1)th second MAC sub-PDU. In this case, regardless of whether the value of the fourth field of the first byte of the second MAC sub-PDU is the same as the target identifier index sent (i.e., whether the second MAC sub-PDU corresponding to the request sent by the second terminal device is decoded), the second terminal device does not need to decode the MAC PDU again. Therefore, the decoding of the MAC PDU can be terminated. For example, see attached... Figure 8As shown, when the second terminal device decodes the second MAC sub-PDU, if the E field of the first byte of the first second MAC sub-PDU is 1, the second terminal device continues decoding the next second MAC sub-PDU. The same applies to the second, third, and so on. The E field of the first byte of the (n-2)th second MAC sub-PDU is 1, and so on. This continues until the (n-1)th second MAC sub-PDU is decoded, at which point the E field of the first byte of the (n-1)th second MAC sub-PDU is 0, indicating it is the last MAC sub-PDU, at which point the second terminal device stops decoding the MAC PDU.

[0174] In the communication method 400 described in steps S401-S405 and S413-S416 above, the first terminal device and the second terminal device first send a WUS message requesting the network device to send a MAC sub-PDU for OD-SIB1 and a preamble requesting the network device to send a MAC sub-PDU for SI (or RRC). Based on the above requests, the network device encapsulates the RAR corresponding to each request into a MAC sub-PDU, forming a RAR MAC PDU, and then sends the RAR message to the first terminal device and the second terminal device respectively. After receiving the above RAR message, the second terminal device starts decoding the MAC PDU (i.e., the second MAC sub-PDU), first determining whether the value of the fourth field of the first byte of the second MAC sub-PDU is the same as the target identifier index to be sent. If the value of the fourth field of the first byte of the second MAC sub-PDU is the same as the target identifier index to be sent, the second terminal device ends the decoding of the MAC PDU. If the value of the fourth field of the first byte of the second MAC sub-PDU differs from the target identifier index, the system continues to determine if the value of the third field of the first byte of the second MAC sub-PDU is the target value, thereby determining whether this second MAC sub-PDU is the last second MAC sub-PDU. If the value of the third field of the first byte of the second MAC sub-PDU is the target value, the second terminal device ends decoding the MAC PDU. If the value of the third field of the first byte of the second MAC sub-PDU is not the target value, the second terminal device continues decoding the next second MAC PDU until the value of the third field of the first byte of the second MAC sub-PDU is the target value. This communication method 400 also enables the second terminal device to successfully decode the second MAC sub-PDU corresponding to the sent request, thus allowing the terminal device to be compatible with decoding OD-SIB1 MAC sub-PDUs and SI (or RRC) MAC sub-PDUs.

[0175] In the communication method 400 described in steps S401-S416 above, the first terminal device and the second terminal device first send a preamble of the WUS and SI (or RRC) MAC sub-PDU to the network device, respectively, to request the network device to send the OD-SIB1 MAC sub-PDU. Based on the above request, the network device encapsulates the RAR corresponding to each request into a MAC sub-PDU, forming a RAR MAC PDU, and then sends the RAR message to the first terminal device and the second terminal device respectively. The first terminal device and the second terminal device decode the MAC PDU respectively. Since the MAC PDU includes the values ​​of the first field, the second field, the third field, and the fourth field, and also includes identification information of a preset length between the first MAC sub-PDU and the (n-1)th second MAC sub-PDU. Therefore, this communication method 400 can ensure that, even when the UL-WUS configuration message does not include the totalNumberOfRA-Preambles parameter, when the network device successfully receives the WUS from the first terminal device, the first terminal device can successfully decode the OD-SIB1 MAC sub-PDU based on the values ​​of the first field, the second field, and the preset length of identification information, thus improving communication efficiency and saving overhead. Furthermore, even when the UL-WUS configuration message does not include the totalNumberOfRA-Preambles parameter, the first terminal device can, based on the value of the second field, stop decoding the MAC PDU if the network device fails to receive the WUS from the first terminal device, or if the network device successfully receives the WUS but does not send the first MAC sub-PDU to the first terminal device, thereby saving decoding time and reducing power consumption. Furthermore, it enables the second terminal device to successfully decode the sent second MAC sub-PDU corresponding to the request based on the value of the fourth field when the network device successfully receives the WUS from the first terminal device and sends the request to the second terminal device. This allows the terminal device to be compatible with decoding MAC sub-PDUs of OD-SIB1 and SI (or RRC). It also enables the second terminal device to stop decoding the MAC PDU based on the value of the third field when the network device fails to receive the WUS from the first terminal device, or when the network device successfully receives the target identifier code from the second terminal device but does not send the request to the second terminal device. This prevents the second terminal device from malfunctioning.

[0176] In one possible implementation, the first terminal device may also send a preamble to the network device to request the transmission of SI or RRC. In this case, another network device needs to send the totalNumberOfRA-Preambles parameter to the first terminal device in advance to indicate the purpose of the preamble. Based on the totalNumberOfRA-Preambles parameter and the preamble, the first terminal device decodes the MAC sub-PDU corresponding to the sent request. At this time, the RAR message in this embodiment can also successfully decode the MAC sub-PDU. Its communication method is the same as the principle of communication method 400 described in steps S413-S416, and will not be repeated here.

[0177] The communication method and apparatus provided in this application embodiment involve the first terminal device and the second terminal device first sending a preamble of the WUS and SI (or RRC) MAC sub-PDUs to the network device, respectively, to request the network device to send the OD-SIB1 MAC sub-PDU. Based on the above request, the network device encapsulates the RAR corresponding to each request into a MAC sub-PDU, forming a RAR MAC PDU, and then sends the RAR message to the first terminal device and the second terminal device respectively. The first terminal device and the second terminal device decode the MAC PDU respectively. Since the MAC PDU includes the values ​​of the first field, the second field, the third field, and the fourth field, and also includes identification information of a preset length between the first MAC sub-PDU and the (n-1)th second MAC sub-PDU. Therefore, this communication method 400 can ensure that, even when the UL-WUS configuration message does not include the totalNumberOfRA-Preambles parameter, when the network device successfully receives the WUS from the first terminal device, the first terminal device can successfully decode the OD-SIB1 MAC sub-PDU based on the values ​​of the first field, the second field, and the preset length of identification information, thus improving communication efficiency and saving overhead. Furthermore, even when the UL-WUS configuration message does not include the totalNumberOfRA-Preambles parameter, the first terminal device can, based on the value of the second field, stop decoding the MAC PDU if the network device fails to receive the WUS from the first terminal device, or if the network device successfully receives the WUS but does not send the first MAC sub-PDU to the first terminal device, thereby saving decoding time and reducing power consumption. Furthermore, it enables the second terminal device to successfully decode the sent second MAC sub-PDU corresponding to the request based on the value of the fourth field when the network device successfully receives the WUS from the first terminal device and sends the request to the second terminal device. This allows the terminal device to be compatible with decoding MAC sub-PDUs of OD-SIB1 and SI (or RRC). It also enables the second terminal device to stop decoding the MAC PDU based on the value of the third field when the network device fails to receive the WUS from the first terminal device, or when the network device successfully receives the target identifier code from the second terminal device but does not send the request to the second terminal device. This prevents the second terminal device from malfunctioning.

[0178] It is understood that, in order to achieve the above functions, the electronic device includes hardware and / or software modules that perform the respective functions. Based on the algorithmic steps of the examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is implemented in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application in conjunction with the embodiments, but such implementation should not be considered beyond the scope of this application.

[0179] This embodiment can divide the electronic device into functional modules according to the above method example. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0180] This application also provides a computer-readable storage medium storing computer program code. When the processor executes the computer program code, the electronic device executes the relevant method steps in the above method embodiments.

[0181] This application also provides a computer program product that, when run on a computer, causes the computer to execute the relevant method steps described in the above method embodiments.

[0182] The electronic devices, computer storage media, or computer program products provided in this application are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0183] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0184] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0185] The units described above as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0186] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The functions of the integrated unit can be implemented in hardware or as software functional units.

[0187] If the integrated units described above are implemented as software functional units and sold or used as independent products, they can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, in essence, or the contributing parts, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0188] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, Applied to a terminal device, the method includes: Send a wake-up signal (WUS) to the network device; the WUS is used to request the network device to send the on-demand first system information block (OD-SIB1); The terminal device receives a Media Access Control Protocol Data Unit (MAC PDU) from the network device. The MAC PDU includes a first MAC sub-PDU and an identification information of a preset length. The first MAC sub-PDU is the MAC sub-PDU of the OD-SIB1, and the identification information of the preset length is used to indicate that the MAC sub-PDU following and adjacent to the identification information of the preset length is the first MAC sub-PDU, so that the terminal device can successfully decode the first MAC sub-PDU.

2. The communication method according to claim 1, characterized in that, The MAC PDU further includes at least one second MAC sub-PDU, which is the MAC sub-PDU preceding the identification information of the preset length; the first byte of the second MAC sub-PDU includes a first field, the value of which is either a first value or a second value. The first field being the first value indicates that the first byte of the second MAC sub-PDU also includes a second field, and the first field being the second value indicates that the first byte of the second MAC sub-PDU does not include the second field; the second field being the third value or a fourth value, the second field being the third value indicates that the MAC PDU includes the first MAC sub-PDU, and the second field being the fourth value indicates that the MAC PDU does not include the first MAC sub-PDU; The method further includes: Decode the first byte of the MAC PDU; If the first field is the first value and the second field is the third value, continue decoding the MAC PDU.

3. The communication method according to claim 2, characterized in that, The method further includes: If the first field is the first value and the second field is the fourth value, the decoding of the MAC PDU ends.

4. The communication method according to claim 3, characterized in that, The method further includes: If the first field takes the value of the second value, continue decoding the MAC PDU.

5. The communication method according to claim 2 or 4, characterized in that, The method further includes: If the preset length of identification information is not decoded, continue decoding the MAC PDU.

6. The communication method according to claim 5, characterized in that, The method further includes: If the identifier information of the preset length is decoded, the first MAC sub-PDU is decoded.

7. The communication method according to any one of claims 2-4, characterized in that, The third field of the first byte of the second MAC sub-PDU adjacent to the preset length of the identification information is set to the target value.

8. The communication method according to any one of claims 1-4 and 6, characterized in that, The preset length of the identification information is at least 6 consecutive bytes of all 1s or at least 7 consecutive bytes of all 0s.

9. The communication method according to any one of claims 2-4 and 6, characterized in that, The second field is a reserved R field.

10. A communication method, characterized in that, Applied to network devices, the method includes: Receive a wake-up signal WUS from the terminal device; the WUS is used to request the transmission of the on-demand first system information block OD-SIB1. The terminal device is sent a Media Access Control Protocol Data Unit (MAC PDU) to trigger the terminal device to decode the MAC PDU. The MAC PDU includes a first MAC sub-PDU and identification information of a preset length. The first MAC sub-PDU is the MAC sub-PDU of the OD-SIB1. The identification information of the preset length is used to indicate that the MAC sub-PDU following and adjacent to the identification information of the preset length is the first MAC sub-PDU, so that the terminal device can successfully decode the first MAC sub-PDU.

11. The communication method according to claim 10, characterized in that, The MAC PDU further includes at least one second MAC sub-PDU, which is the MAC sub-PDU preceding the identification information of the preset length; the first byte of the second MAC sub-PDU includes a first field; the first field is a first value or a second value; the first field being the first value indicates that the first byte of the second MAC sub-PDU also includes a second field, and the first field being the second value indicates that the first byte of the second MAC sub-PDU does not include the second field; the second field being a third value or a fourth value, the second field being the third value indicates that the MAC PDU includes the first MAC sub-PDU, and the second field being the fourth value indicates that the MAC PDU does not include the first MAC sub-PDU.

12. The communication method according to claim 11, characterized in that, The third field of the first byte of the second MAC sub-PDU adjacent to the preset length of the identification information is set to the target value.

13. The communication method according to any one of claims 10-12, characterized in that, The preset length of the identification information is at least 6 consecutive bytes of all 1s or at least 7 consecutive bytes of all 0s.

14. The communication method according to claim 11 or 12, characterized in that, The second field is a reserved R field.

15. A communication device, characterized in that, The device includes a processor and a memory, wherein the memory stores instructions, and when the processor executes the instructions, the communication device performs the communication method as described in any one of claims 1-9, or performs the communication method as described in any one of claims 10-14.

16. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed, the computer performs the communication method as described in any one of claims 1-9, or performs the communication method as described in any one of claims 10-14.

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