Data transmission methods and apparatuses, devices, chip and storage medium

Abstract

Provided in the embodiments of the present application are data transmission methods and apparatuses, devices, a chip and a storage medium. A method comprises: a terminal device executes early data transmission (EDT) for uplink data on the basis of a first policy, wherein the first policy comprises one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first contention resolution algorithm; a first resource pool; and a first subcarrier spacing.

Description

A data transmission method, apparatus, device, chip, and storage medium Technical Field

[0001] This application relates to the field of mobile communication technology, specifically to a data transmission method, apparatus, device, chip, and storage medium. Background Technology

[0002] To reduce uplink and downlink signaling overhead and improve system uplink capacity, it is planned to further enhance the Early Data Transmission (EDT) feature, such as introducing Contention Based-msg3 EDT (CB-Msg3 EDT), which transmits Msg3 directly without going through the Msg1 and Msg2 processes.

[0003] While some preliminary conclusions have been published regarding the selection of EDT types across different dimensions, the question of how to combine these different selection dimensions—for example, how to determine the order in which EDT types are selected for each dimension—has not been addressed. Furthermore, different orders will lead to different fallback schemes, requiring the design of corresponding fallback mechanisms for different EDT type selection orders. Summary of the Invention

[0004] This application provides a data transmission method, apparatus, device, chip, and storage medium.

[0005] In a first aspect, embodiments of this application provide a data transmission method, including:

[0006] The terminal device performs Early Data Transmission (EDT) for uplink data based on a first strategy; the first strategy includes one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier spacing.

[0007] Secondly, embodiments of this application provide a data transmission method, including:

[0008] The network device receives uplink data; the uplink data is sent by the terminal device based on a first strategy; the first strategy includes one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier spacing.

[0009] Thirdly, embodiments of this application provide a data transmission apparatus applied to a terminal device, the data transmission apparatus comprising:

[0010] The first transmitting unit is configured to perform Early Data Transmission Technique (EDT) for uplink data based on a first strategy; the first strategy includes one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier spacing.

[0011] Fourthly, embodiments of this application provide a data transmission apparatus applied to a network device, the data transmission apparatus comprising:

[0012] The first receiving unit is configured to receive uplink data; the uplink data is sent by the terminal device based on a first strategy; the first strategy includes one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier spacing.

[0013] Fifthly, embodiments of this application provide a terminal device including a processor and a memory. The memory stores a computer program, and the processor calls and runs the computer program stored in the memory to perform the data transmission method as described in the first aspect.

[0014] Sixthly, embodiments of this application provide a network device including a processor and a memory. The memory stores a computer program, and the processor invokes and runs the computer program stored in the memory to perform the data transmission method as described in the second aspect.

[0015] In a seventh aspect, embodiments of this application provide a chip. The chip includes: a processor for retrieving and running a computer program from a memory, causing a device on which the chip is installed to perform the method described in either the first or second aspect; and a transceiver for receiving and sending information during the exchange of information with the device or the chip.

[0016] Eighthly, embodiments of this application provide a computer-readable storage medium for storing a computer program that causes a computer to perform the methods described in either the first or second aspect.

[0017] Ninthly, embodiments of this application provide a computer program product including computer program instructions that cause a computer to perform the method described in either the first or second aspect.

[0018] In a tenth aspect, embodiments of this application provide a computer program that, when run on a computer, causes the computer to perform the method described in either the first or second aspect.

[0019] This application provides a data transmission method in which a terminal device can perform different EDT transmissions for uplink data according to different strategies. This method can improve the transmission efficiency and communication quality of EDT. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0021] Figure 1 is a schematic diagram of an application scenario of an embodiment of this application;

[0022] Figure 2 is a schematic diagram of a contention-based random access procedure provided in an embodiment of this application;

[0023] Figure 3 is a schematic diagram of a non-contention-based random access procedure provided in an embodiment of this application;

[0024] Figure 4 is a schematic diagram of the EDT process for user plane transmission provided in an embodiment of this application;

[0025] Figure 5 is a schematic diagram of the EDT process for control plane transmission provided in an embodiment of this application;

[0026] Figure 6 is a schematic diagram of coverage enhancement level division provided in an embodiment of this application;

[0027] Figure 7 is a schematic flowchart of a data transmission method provided in an embodiment of this application;

[0028] Figure 8 is a schematic flowchart of a data transmission method provided in an embodiment of this application;

[0029] Figure 9 is a flowchart illustrating an EDT transmission method provided in an embodiment of this application;

[0030] Figure 10 is a structural schematic diagram of a data transmission device 1000 provided in an embodiment of this application;

[0031] Figure 11 is a structural schematic diagram of a data transmission device 1100 provided in an embodiment of this application;

[0032] Figure 12 is a schematic structural diagram of a communication device provided in an embodiment of this application;

[0033] Figure 13 is a schematic structural diagram of a chip provided in an embodiment of this application;

[0034] Figure 14 is a schematic block diagram of a communication system provided in an embodiment of this application. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0036] Figure 1 is a schematic diagram of an application scenario of an embodiment of this application.

[0037] As shown in Figure 1, the communication system 100 may include a terminal device 110 and a network device 120. The network device 120 can communicate with the terminal device 110 via an air interface. Multi-service transmission is supported between the terminal device 110 and the network device 120.

[0038] It should be understood that the embodiments of this application are only illustrated by way of example with communication system 100, but the embodiments of this application are not limited thereto. That is to say, the technical solutions of the embodiments of this application can be applied to various communication systems, such as: Long Term Evolution (LTE) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Internet of Things (IoT) system, Narrow Band Internet of Things (NB-IoT) system, enhanced Machine-Type Communications (eMTC) system, 5G communication system (also known as New Radio (NR) communication system), or future communication systems, etc.

[0039] In the communication system 100 shown in Figure 1, network device 120 may be an access network device that communicates with terminal device 110. The access network device can provide communication coverage for a specific geographical area and can communicate with terminal device 110 (e.g., user equipment (UE)) located within that coverage area.

[0040] Network device 120 may be an evolved Node B (eNB or eNodeB) in a Long Term Evolution (LTE) system, a Next Generation Radio Access Network (NG RAN) device, a base station (gNB) in an NR system, a radio controller in a Cloud Radio Access Network (CRAN), or a relay station, access point, vehicle-mounted device, wearable device, hub, switch, bridge, router, or network device in a future evolved Public Land Mobile Network (PLMN), etc.

[0041] Terminal device 110 can be any terminal device, including but not limited to terminal devices that are connected to network device 120 or other terminal devices via wired or wireless connections.

[0042] For example, the terminal device 110 can refer to an Ambient-Internet of Things (A-IoT) device, access terminal, UE, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. The access terminal can be a cellular phone, cordless phone, Session Initiation Protocol (SIP) phone, IoT device, satellite handheld terminal, Wireless Local Loop (WLL) station, Personal Digital Assistant (PDA), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, in-vehicle device, wearable device, terminal device in a 5G network, or terminal device in a future evolved network, etc.

[0043] Terminal device 110 can be used for device-to-device (D2D) communication.

[0044] The wireless communication system 100 may further include a core network device 130 that communicates with the network device 120. This core network device 130 may be a 5G core network (5G Core, 5GC) device, such as an Access and Mobility Management Function (AMF), an Authentication Server Function (AUSF), a User Plane Function (UPF), or a Session Management Function (SMF). Optionally, the core network device 130 may also be an Evolved Packet Core (EPC) device for an LTE network, such as a Session Management Function + Core Packet Gateway (SMF+PGW-C) device. It should be understood that SMF+PGW-C can simultaneously implement the functions of both SMF and PGW-C. During network evolution, the aforementioned core network device may also be called by other names, or new network entities may be formed by dividing the core network functions; this embodiment does not limit this.

[0045] The various functional units in the communication system 100 can also establish connections through interfaces to achieve communication.

[0046] For example, terminal device 110 establishes an air interface connection with access network equipment through the NR interface for transmitting user plane data and control plane signaling; terminal device 110 can establish a control plane signaling connection with AMF through the N1 interface; access network equipment, such as next-generation radio access base station (gNB), can establish a user plane data connection with UPF through NG-U (i.e., N3 interface); access network equipment can establish a control plane signaling connection with AMF through NG-C (i.e., N2 interface); UPF can establish a control plane signaling connection with SMF through N4 interface; UPF can interact with data network for user plane data through N6 interface; AMF can establish a control plane signaling connection with SMF through N11 interface; SMF can establish a control plane signaling connection with PCF through N7 interface.

[0047] Figure 1 exemplarily illustrates a network device 120, a core network device 130, and two terminal devices 110. Optionally, the wireless communication system 100 may include multiple network devices 120, and the coverage area of ​​each network device 120 may include other numbers of terminal devices 110. This application embodiment does not limit this.

[0048] It should be noted that Figure 1 is merely an example illustrating the system to which this application applies. Of course, the method shown in the embodiments of this application can also be applied to other systems. Furthermore, the terms "system" and "network" are often used interchangeably in this document. The term "and / or" in this document merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. It should also be understood that "instruction" mentioned in the embodiments of this application can be a direct instruction, an indirect instruction, or an indication of a related relationship. For example, A instructing B can mean that A directly instructs B, for example, B can be obtained through A; it can also mean that A indirectly instructs B, for example, A instructs C, B can be obtained through C; or it can mean that there is a related relationship between A and B. It should also be understood that "correspondence" mentioned in the embodiments of this application can indicate a direct or indirect correspondence between two things, or an related relationship between two things, or a relationship of instruction and being instructed, configuration and being configured, etc. It should also be understood that the "predefined" or "predefined rules" mentioned in the embodiments of this application can be implemented by pre-storing corresponding codes, tables, or other means that can be used to indicate relevant information in the device (e.g., including terminal devices and network devices), and this application does not limit the specific implementation method. For example, predefined can refer to those defined in a protocol. It should also be understood that in the embodiments of this application, the "protocol" can refer to standard protocols in the field of communication, such as LTE protocol, NR protocol, and related protocols applied to future communication systems, and this application does not limit this.

[0049] To facilitate understanding of the technical solutions of the embodiments of this application, the relevant technologies of the embodiments of this application are described below. The following relevant technologies are optional solutions and can be combined with the technical solutions of the embodiments of this application in any way, and they all fall within the protection scope of the embodiments of this application.

[0050] LTE random access procedure

[0051] 1. Triggering of the random access procedure

[0052] In LTE and NR, the random access procedure can be primarily triggered by the following events:

[0053] 1) Establishing a radio connection during initial UE access: The UE transitions from the RRC_IDLE state to the RRC_CONNECTED state;

[0054] 2) RRC connection reconstruction process: used by the UE to reconstruct the radio connection after the radio link fails;

[0055] 3) Handover: The UE needs to establish uplink synchronization with the new cell;

[0056] 4) In the RRC_CONNECTED state, downlink (DL) data arrives, and the UL is out of sync at this time;

[0057] 5) In the RRC_CONNECTED state, uplink (UL) data arrives. At this time, the UL is out of sync or there is no physical uplink control channel (PUCCH) resource for sending scheduling requests (SRs).

[0058] 6) SR failed;

[0059] 7) The UE receives a synchronization reconfiguration request from the Radio Resource Control (RRC).

[0060] 2. Random access method

[0061] Currently, two main random access methods are supported: contention-based random access and non-contention-based random access.

[0062] Figure 2 is a schematic diagram of a contention-based random access procedure provided in an embodiment of this application. As shown in Figure 2, the contention-based random access procedure may include the following steps:

[0063] S201, The terminal device sends Msg1 to the network device.

[0064] Msg1 includes the Random Access Preamble (RAP), also known as the preamble.

[0065] The terminal device can select a Physical Random Access Channel (PRACH) resource and transmit a selected preamble on the selected PRACH. Based on the preamble, the network device can estimate the uplink timing and the grant size required for the terminal device to transmit Msg3.

[0066] S202, The network device sends Msg2 to the terminal device.

[0067] Msg2 includes the Random Access Response (RAR).

[0068] After the terminal device sends Msg1, it can open a random access response window (ra-ResponseWindow) and monitor the physical downlink control channel (PDCCH) scrambled with the Random Access-Radio Network Temporary Identifier (RA-RNTI) within the random access response window. In LTE, the calculation formula of RA-RNTI is as shown in formula (1): RA-RNTI=1+t_id+10*f_id (1);

[0069] Where t_id (0≤t_id<10) is the index of the first subframe of PRACH transmission, and f_id (0≤f_id<6) is the frequency domain index of the corresponding PRACH in that subframe. The PRACH resources are numbered sequentially in the frequency domain from low to high.

[0070] For Enhanced Machine Type Communication (eMTC) terminal devices, the calculation formula for RA-RNTI is shown in formula (2): RA-RNTI=1+t_id+10*f_id+60*(SFN_id mod (Wmax / 10)) (2);

[0071] Where t_id (0≤t_id<10) is the index of the first subframe of PRACH transmission, f_id (0≤f_id<6) is the frequency domain index of the corresponding PRACH in that subframe, and PRACH resources are numbered sequentially in the frequency domain from low to high. SFN_id is the index of the first System Frame Numble (SFN) of PRACH transmission, and Wmax is the maximum RAR window length supported by eMTC, with a value of 400 subframes.

[0072] For Narrow Band Internet of Things (NB-IoT) terminal devices, the calculation formula for RA-RNTI is shown in formula (3): RA-RNTI=1+floor(SFN_id / 4)+256*carrier_id (3);

[0073] Here, SFN_id is the index of the first SFN in the PRACH transmission, and carrier_id is the index of the UL carrier corresponding to the PRACH transmission. The carrier_id corresponding to the anchor carrier is 0.

[0074] For NB-IoT terminal devices in Time Division Duplexing (TDD) mode, the calculation formula for RA-RNTI is shown in formula (4): RA-RNTI=1+floor(SFN_id / 4)+256*(H-SFN mod 2) (4);

[0075] Wherein, SFN_id is the index of the first SFN transmitted by PRACH, and H-SFN is the first Hyper System Frame Number (H-SFN) transmitted by PRACH.

[0076] As can be seen from the above RA-RNTI calculation formula, RA-RNTI is related to the PRACH time-frequency resources used by the terminal device to send Msg1.

[0077] After the terminal device successfully receives the RA-RNTI scrambled PDCCH, it can obtain the Physical Downlink Shared Channel (PDSCH) scheduled by the PDCCH, which contains the RAR. The RAR specifically contains the following information:

[0078] The RAR subheader contains a Backoff Indicator (BI), which indicates the backoff time for retransmitting Msg1.

[0079] The random access preamble identifier (RAP Identify, RAPID) in RAR: the preamble index received in the network response;

[0080] The RAR payload contains a TAG used to adjust uplink timing;

[0081] Uplink grant (UL grant): Used to schedule uplink resource indications for Msg3;

[0082] Temporary Cell Radio Network Temporary Identifier (TC-RNTI): Used for scrambling Msg4 in the PDCCH (Initial Access).

[0083] If the terminal device receives a PDCCH scrambled with RAR-RNTI, and the RAR contains the index of the preamble it sent, the terminal device considers it to have successfully received the random access response.

[0084] For non-contention-based random access, the random access process ends after the terminal device successfully receives Msg2. For contention-based random access, after successfully receiving Msg2, the terminal device still needs to transmit Msg3 and receive Msg4.

[0085] S203, The terminal device sends Msg3 (Scheduled Transmission) to the network device.

[0086] Terminal devices can transmit Msg3 on resources scheduled by network devices. Msg3 is mainly used to inform network devices what event triggered the random access procedure. For example, if it is an initial access random procedure, the Msg3 will carry the terminal device's identifier (ID) and establishment cause; if it is an RRC reconstruction, it will carry the connected terminal device's identifier and establishment cause.

[0087] S204. The network device sends Msg4 (Contention Resolution) to the terminal device.

[0088] Msg4 serves two purposes: contention resolution and transmission of RRC configuration messages from network devices to terminal devices. Contention resolution occurs in two ways: First, if the terminal device carries the Cell Radio Network Temporary Identifier (C-RNTI) in Msg3, then Msg4 uses a PDCCH scrambled with the C-RNTI for scheduling. Second, if the terminal device does not carry the C-RNTI in Msg3 (e.g., during initial access), then Msg4 uses a PDCCH scrambled with the TC-RNTI for scheduling. In this case, the terminal device receives the PDSCH from Msg4 and resolves the conflict by matching the Common Control Channel Service Data Unit (CCCH SDU) within the PDSCH.

[0089] Figure 3 is a schematic diagram of a non-contention-based random access procedure provided in an embodiment of this application. As shown in Figure 3, the non-contention-based random access procedure may include the following steps:

[0090] S301. The network device sends a random access preamble assignment (RA) message to the terminal device.

[0091] S302, The terminal device sends Msg1 to the network device.

[0092] Msg1 includes a random access preamble, also known as a preamble. The terminal device can send the preamble specified by the network device on the PRACH resource specified by the network device. Based on the preamble, the network device can estimate the uplink timing and the grant size required for the terminal device to transmit Msg3.

[0093] S303, The network device sends Msg2 to the terminal device.

[0094] This step can be referred to in step S202 above, and will not be repeated here.

[0095] As can be seen from the above random access process, the main purpose of random access is for the terminal device to achieve uplink synchronization with the cell. During random access, the network device can know the time when the terminal device sends the preamble based on the time-frequency resources of the Random Access Channel (RACH) used by the preamble from the terminal device. Therefore, based on the transmission and reception times of the preamble, the network device determines the initial timing advance (TA) of the terminal device and informs the terminal device through RAR.

[0096] EDT

[0097] In traditional LTE systems, if a UE in RRC IDLE state needs to transmit uplink data, it must first initiate an RRC connection establishment process through a random access procedure. Only after establishing an RRC connection with the network can it transmit data. To reduce signaling interactions between the UE and the network caused by data transmission and to save terminal power consumption, 3GPP introduced the EDT mechanism in Release 15 for NB-IoT and eMTC (including BL UEs, UEs in enhanced coverage, and NB-IoT UEs). This feature allows a UE in RRC IDLE state to transmit UL data via Msg3 during the random access procedure. Upon receiving a successful reception response from the base station, the random access procedure is terminated, and the UE remains in RRC IDLE state without entering RRC connected state. The base station configures separate PRACH resources for EDT. When the amount of UL data to be transmitted by the UE does not exceed the data limit configured by the network, the UE can send Msg1 on the separate PRACH resources for EDT to request Msg3 grant from the base station for EDT.

[0098] Taking the user plane transport scheme as an example, referring to Figure 4, the EDT may include the following steps:

[0099] Under the premise that the terminal device sends a random access preamble to the network device, and the network device sends a random access response to the terminal device:

[0100] S401. The terminal device sends an RRC ConnectionResumeRequest message to the network device.

[0101] The RRC ConnectionResumeRequest message may include a resume identifier (resumeID), a resume cause (resumeCause), and a short resume media access control integrity (shortResumeMAC-I). In addition, it may carry uplink data.

[0102] S402. The network device sends a UE ContextResumeRequest message to the mobility management entity.

[0103] The network device sends a UEContextResumeRequest message to the Mobility Management Entity (MME) via the S1 Application Protocol (S1-AP).

[0104] S403, Mobility Management Entity and Service Gateway Interaction Modify Bearer.

[0105] The process of the Mobility Management Entity interacting with the Serving Gateway (S-GW) to modify the Bearer.

[0106] S404. The Mobility Management Entity sends a UE Context Resume Response message to the network device.

[0107] The network device sends a UE Context Resume Response message to the Mobility Management Entity via the S1 Application Protocol (S1-AP).

[0108] S405. The network device sends uplink data to the service gateway.

[0109] S406, The service gateway sends downlink data to network devices.

[0110] In some cases, the service gateway can also send downlink data to network devices.

[0111] S407a, Mobility Management Entity and Service Gateway Interaction Modify Bearer.

[0112] S407b, Mobility Management Entity and Network Devices execute the suspension procedure of the S1 interface.

[0113] The MME and network devices execute the S1 interface suspend procedure.

[0114] S408. The network device sends an RRC ConnectionRelease message to the terminal device.

[0115] The RRC ConnectionRelease message may include (releaseCause), resumeID, and may also carry downlink data.

[0116] The MO-EDT features used for user plane CIoT EPS optimization are as follows:

[0117] 1. NextHopChainingCount has been provided to the UE in the RRCConnectionRelease message with a suspension indication.

[0118] 2. Uplink user data is sent on the DTCH, which is multiplexed with the UL RRCConnectionResumeRequest message on the CCCH.

[0119] 3. Downlink user data may optionally be sent on the DTCH multiplexed with the DL RRCConnectionRelease message;

[0120] 4. The short recovery MAC-I is reused as the authentication token for the RRCConnectionResumeRequest message and is calculated using the integrity key from the previous connection;

[0121] 5. User data in both the uplink and downlink is encrypted. The key is exported using NextHopChainingCount provided in the RRCConnectionRelease message of the previous RRC connection;

[0122] 6. Use the newly exported key to perform integrity protection and encryption on RRCConnectionRelease messages;

[0123] 7. There is no conversion to RRC connection.

[0124] Taking the control plane transmission scheme as an example, referring to Figure 5, the EDT may include the following steps:

[0125] Under the premise that the terminal device sends a random access preamble to the network device, and the network device sends a random access response to the terminal device:

[0126] S501, The terminal device sends an RRC EarlyDataRequest message to the network device.

[0127] The RRC EarlyDataRequest message may include the System Architecture Evolution Temporary Mobile Subscriber Identity (SAE Temporary Mobile Subscriber Identity, S-TMSI), establishmentCause, and dedicatedInfoNAS.

[0128] S502, The network device sends an Initial UE message to the Mobility Management Entity.

[0129] Network devices send Initial UE message (NAS message) to MME via S1-AP.

[0130] S503, Mobility Management Entity and Service Gateway Interaction Modify Bearer.

[0131] The MME interacts with the S-GW to modify the Bearer process.

[0132] S504. The Mobility Management Entity sends uplink data to the Serving Gateway.

[0133] MME sends Uplink data to S-GW.

[0134] S505, the service gateway sends downlink data to the mobility management entity.

[0135] In some cases, the S-GW can also send downlink data to the MME.

[0136] S506a, Mobility Management Entity performs downlink non-access stratum transmission to network equipment.

[0137] The MME performs download (DL) non-access stratum (NAS) transport to network devices via the S1-AP.

[0138] S506b: The Mobility Management Entity sends a connection establishment instruction to the network device.

[0139] The MME sends a connection establishment indication to the network device via the S1-AP.

[0140] S507. The network device sends an RRC EarlyDataComplete message to the terminal device.

[0141] The RRC EarlyDataComplete message may include dedicatedInfoNAS.

[0142] S508a, the Mobility Management Entity and network devices execute the release procedure of the S1 interface.

[0143] The MME and network devices execute the S1 interface release procedure.

[0144] S508b, Mobility Management Entity and Service Gateway Interaction Modify Bearer.

[0145] The MO-EDT characterization for control plane CIoT EPS optimization is as follows:

[0146] 1. Send uplink user data in the NAS message cascaded in the UL RRCEarlyDataRequest message on CCCH.

[0147] 2. Downlink user data may optionally be sent in a NAS message concatenated in the DL RRCEarlyDataComplete message on the CCCH.

[0148] 3. There is no conversion to RRC connection.

[0149] Preconfigured Uplink Resources (PUR)

[0150] To further reduce signaling overhead and terminal power consumption beyond EDT, 3GPP introduced the PUR feature in Release 16 for NB-IoT and eMTC. This feature allows the base station to configure PUR resources for the UE while releasing it to RRC IDLE state. The UE can then use these PUR resources for uplink transmission in RRC IDLE state without initiating a random access procedure. When configuring the PUR for the UE, the network can also simultaneously configure a DMRS cyclic shift, allowing up to two UEs to share the same PUSCH resource (distinguished by DRMS). By skipping the random access procedure, uplink transmission efficiency and terminal power consumption can be further improved.

[0151] Before performing a PUR transmission, the UE needs to verify the validity of the TA. The validity of the TA is determined based on one or more of the following conditions:

[0152] 1. Has the service area changed?

[0153] 2. Has the TAT timed out?

[0154] 3. Changes in UE RSRP.

[0155] Coverage enhancement (CE)

[0156] One important application of NB-IoT / eMTC is smart meters, which are typically installed in basements, insulated by metal enclosures, or in older, thick-walled buildings. In these situations, path loss between the UE and the base station can be very severe. Another goal of NB-IoT / eMTC is to achieve a 15dB coverage enhancement compared to traditional LTE. Considering the varying distances between different UEs and base stations in the network, the required level of coverage enhancement differs for each UE. Maximizing the coverage for all UEs would lead to resource waste. Therefore, NB-IoT / eMTC defines coverage enhancement levels (CE level) and coverage enhancement modes (CE mode) for BL UEs, UEs in enhanced coverage, and NB-IoT UEs.

[0157] In idle state, up to 4 CE levels, i.e., PRACH coverage enhancement levels, can be configured.

[0158] Referring to Figure 6, for example, four CE levels are configured: CE level 0, CE level 1, CE level 2, and CE level 3. Three RSRP threshold values ​​can be configured for each of these levels: threshold 1 to distinguish between CE level 0 and CE level 1, threshold 2 to distinguish between CE level 1 and CE level 2, and threshold 3 to distinguish between CE level 2 and CE level 3. The UE measures the RSRP and determines which CE level it belongs to based on the RSRP range. It then sends a random access preamble on the corresponding CE level's PRACH resource. Based on this, the network device considers the UE to be in the CE level where it detects the random access preamble on the PRACH resource. Before the RRC connection is established, the correspondence between the CE mode and level used in messages such as Msg2, Msg3, and Msg4 is defined: CE level 0 and CE level 1 use CE mode A, while CE level 2 and CE level 3 use CE mode B.

[0159] After the RRC connection is established, the base station configures the UE to be in CE mode A (no repetition or fewer repetitions) or CE mode B (supports more repetitions of PDSCH and PUSCH) through RRC signaling.

[0160] The main solutions for coverage enhancement include repeating the same information in multiple subframes, frequency hopping, and cross-subframe channel estimation.

[0161] To reduce uplink and downlink signaling overhead and improve system uplink capacity, R19 IoT NTN plans to further enhance EDT features, such as introducing Contention Based-msg3 EDT (CB-Msg3 EDT), which transmits Msg3 directly without going through the Msg1 and Msg2 processes. The research objectives for this feature are as follows:

[0162] If beneficial, investigate and specify the following enhancements to reduce the uplink and downlink signaling required to complete EDT transactions [RAN2]:

[0163] 1. Msg3 transmission without msg1 / RAR.

[0164] 2. Efficient delivery of Msg4 / RRC EarlyDataComplete (reduced overhead).

[0165] In traditional EDT, the UE needs to send Msg1 to request Msg3 grant from the base station for EDT. The base station allocates PUSCH resources for the initial transmission of Msg3 to the UE through Msg2 (i.e., RAR). At the same time, Msg2 will indicate a TC-RNTI, which is used for scrambling the Msg3 PUSCH, indicating the scrambling of the PDCCH for Msg3 retransmission or Msg4 reception, and the scrambling of the Msg4 PDSCH.

[0166] For CB-Msg3 EDT, the UE skips Msg1 and Msg2 and directly transmits Msg3. The network provides cell-specific CB-Msg3 PUSCH transmission resources through system messages, and multiple different UEs need to compete for Msg3 transmission resources in this Msg3 transmission resource pool. In CB-Msg3 EDT, if multiple UEs choose the same PUSCH resource to transmit Msg3 (i.e., multiple UEs have Msg3 conflicts), the base station can only successfully receive the Msg3 of at most one UE. However, in most cases, the Msg3 of all these conflicting UEs cannot be correctly received by the base station. Thus, for UEs that fail to resolve the conflict, they need to retry the Msg3 transmission. Msg3 conflicts in CB-Msg3 EDT waste system PUSCH resources and increase the latency of UE data transmission, thereby affecting the user experience. Therefore, in order to further improve system capacity, the following two features have been agreed upon after discussion:

[0167] 1. Diversity Slotted Aloha (DSA) Technology: In some current satellite communication standards, DSA or Contention Resolution Diversity Slotted Aloha (CRDSA) is used to effectively improve the utilization of random access resources while reducing the probability of collisions between different UEs for random access. Taking CB-Msg3 EDT as an example, the basic idea of ​​DSA is that the UE uses different Msg3 transmissions to send multiple copies of Msg3. As long as the base station can successfully receive one of the Msg3s, the UE can consider the EDT to be successful. Therefore, DSA increases the probability of the UE's Msg3 being successfully received by the base station by increasing the opportunities for Msg3 transmission, thereby improving system capacity.

[0168] 2. Orthogonal Cover Codes (OCC) Technology: Taking CB-Msg3 EDT as an example, OCC technology is used during Msg3 PUSCH transmission, allowing multiple UEs to reuse the same PUSCH time-frequency resources for transmission, with different UEs distinguished by OCC. This is equivalent to extending the PUSCH resources in the code domain, avoiding collisions caused by multiple UEs transmitting on the same PUSCH time-frequency resources.

[0169] The RAN2#128 meeting agreed on the following conclusions:

[0170] 1. System information is only used to provide cell-specific CB-Msg3 PUSCH resources (for 15kHz SCS NB-IoT and eMTC CE mode B, if anything is needed in the dedicated signaling of the TA authentication parameters, then FFS).

[0171] 2. At least for the initial selection, reuse the existing CE level selection process used for CB-Msg3. For FFS, can we reuse the same threshold across layers?

[0172] 3. The UE triggers CB-Msg3 only when the size of the pending UL data is less than the configured maximum TBS (or FFS if the maximum TBS is the same or different for different CE levels).

[0173] 4. There will be an RSRP threshold to determine whether CB-Msg3 can be used (if the RSRP is below such a threshold, then PRACH must be used) (if we need a separate set of thresholds, including different minimum thresholds, then in the case of CB-Msg3 EDT combined with OCC, FFS).

[0174] 5. The number of DSA replicas will be configured by NW: 1 (SA), 2, 3, 4. The replica count configuration is CE-specific.

[0175] Based on existing technology and the above conclusions, there are different types of EDT with the following dimensions, and the basis for their selection:

[0176] 1. Selection of CB-Msg3 EDT or traditional EDT: based on UE capability and / or RSRP threshold and / or maximum TBS.

[0177] 2. CE level selection: based on UE capabilities and / or network configuration and / or RSRP threshold and / or maximum TBS for each CE level.

[0178] 3. Anchor / non-Anchor carrier selection (applicable only to NB-IoT UE): When multiple carriers provide EDT resources at the same CE level, the carrier is selected based on probability, with the aim of load balancing.

[0179] 4. SA or DSA selection: based on UE capabilities and / or network configuration.

[0180] 5. Selection of EDT resource pool based on / not based on OCC: based on UE capabilities and / or network configuration and / or RSRP thresholds.

[0181] Among them, the selection of multiple OCC-based EDT resource pools is based on the set of RSRP thresholds (within an OCC-based EDT resource pool, NW expects all UE UL transmissions to have comparable received power to ensure EDT transmission performance).

[0182] 6. Numerology Selection (applicable only to NB-IoT UEs, i.e., 15kHz SCS or 3.75kHz SCS for CB-Msg3 PUSCH resources): Based on UE capabilities and / or network configuration and / or TA validity (timer / RSRP change) and / or RSRP thresholds. For CB-Msg3 PUSCH resources with 15kHz SCS, dedicated signaling may be required to provide an additional TA validation parameter, which can only be used when the TA is valid.

[0183] While some preliminary conclusions have been published regarding the selection of EDT types across the aforementioned different dimensions, the question of how to combine these different selection dimensions—for example, how to determine the order of EDT type selection for each dimension—has not been addressed. Furthermore, different orders will lead to different fallback schemes, requiring the design of corresponding fallback mechanisms for different EDT type selection orders.

[0184] In view of this, embodiments of this application provide a data transmission method in which a terminal device can perform different EDT transmissions for uplink data according to different strategies. This method can improve the transmission efficiency and communication quality of EDT.

[0185] To facilitate understanding of the technical solutions of the embodiments of this application, the technical solutions of this application are described in detail below through specific embodiments. The above-mentioned related technologies are optional solutions and can be arbitrarily combined with the technical solutions of the embodiments of this application, all of which fall within the protection scope of the embodiments of this application. The embodiments of this application include at least some of the following contents.

[0186] Figure 7 illustrates a data transmission method provided in an embodiment of this application, applied to a terminal device. The method may include:

[0187] S700, the terminal device performs Early Data Transmission (EDT) for uplink data based on a first strategy; the first strategy includes one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier spacing.

[0188] In this embodiment of the application, the terminal device performs Early Data Transmission (EDT) for uplink data based on a first strategy; the first strategy includes one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier spacing.

[0189] In some embodiments, the terminal device may perform EDT transmission for the uplink data based on a first strategy when uplink data arrives and EDT transmission is triggered.

[0190] In some embodiments, the factors considered by the first strategy include one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier spacing.

[0191] In some embodiments, when a terminal device performs EDT transmission for uplink data, it may transmit the uplink data to the network device based on different EDT types, and / or different coverage enhancement levels, and / or different carriers, and / or different conflict resolution algorithms, and / or different resource pools, and / or different subcarrier intervals. The specific first EDT type, and / or first coverage enhancement level, and / or first carrier, and / or first conflict resolution algorithm, and / or first resource pool, and / or first subcarrier interval used need to be determined by the terminal device itself or configured by the network device.

[0192] In some implementations, the first EDT type is any of the following: an EDT based on message 1; an EDT based on contention-based message 3.

[0193] In some embodiments, Message 1-based EDT can be understood as Msg1-based EDT, which is the traditional EDT. Terminal devices can use Msg1-based EDT to perform EDT transmission for uplink data.

[0194] In some embodiments, the contention-based message 3 EDT can be understood as CB-Msg3 EDT, and the terminal device can use CB-Msg3 EDT to perform EDT transmission for uplink data.

[0195] In some implementations, the terminal device may also perform the following steps: the terminal device determines a first EDT type; if the first EDT type is determined, the terminal device determines a first coverage enhancement level.

[0196] In some embodiments, the first strategy includes both a first EDT type and a first coverage enhancement level, thereby allowing the terminal device to first determine the first EDT type to be used and then determine the first coverage enhancement level.

[0197] In some embodiments, if the terminal device first determines the first EDT type and then determines the first coverage enhancement level, then when configuring the coverage enhancement level for the EDT type, it can be selected to set different sets of coverage enhancement levels for different EDT types, i.e. different CE levels and their threshold values.

[0198] For example, assuming the EDT type includes Msg1-based EDT or CB-Msg3 EDT, if the terminal device determines that the first EDT type is CB-Msg3 EDT, then the terminal device can determine the first coverage enhancement level from a set of coverage enhancement levels set for CB-Msg3 EDT; correspondingly, if the terminal device determines that the first EDT type is Msg1-based EDT, then the terminal device can determine the first coverage enhancement level from a set of coverage enhancement levels set for Msg1-based EDT.

[0199] In some embodiments, if the terminal device first determines the first EDT type and then determines the first coverage enhancement level, the same set of coverage enhancement levels, i.e. the same CE level and its threshold value, can also be set for different EDT types.

[0200] For example, assuming the EDT type includes Msg1-based EDT or CB-Msg3 EDT, then regardless of whether the first EDT type determined by the terminal device is CB-Msg3 EDT or Msg1-based EDT, the terminal device determines the first coverage enhancement level from a set of coverage enhancement levels.

[0201] Understandably, the above method of first determining the first EDT type and then determining the first coverage enhancement level allows for the selection of different coverage enhancement levels for different EDT types, which offers a high degree of flexibility.

[0202] In some implementations, the terminal device may also perform the following steps: if a first condition is met, the terminal device determines that the first EDT type is a contention-based message 3 EDT; the first condition includes one or more of the following: the terminal device supports a contention-based message 3 EDT; the reference signal received power currently measured by the terminal device is greater than or equal to a first reference signal received power threshold; the amount of uplink data is less than a first maximum transmission block size.

[0203] In some implementations, the terminal device may also perform the following steps: if the first condition is not met, the terminal device determines that the first EDT type is an EDT based on message 1, or the terminal device does not select an EDT based on contention-based message 3.

[0204] In some embodiments, when determining the first EDT type, the terminal device needs to determine it according to a first condition. If the terminal device meets one or more of the first conditions, the terminal device can choose to use or select to use CB-Msg3 EDT.

[0205] In some embodiments, the terminal device's choice to use CB-Msg3 EDT can be understood as: the terminal device can use either CB-Msg3 EDT or Msg1-based EDT, that is, CB-Msg3 EDT and Msg1-based EDT have the same priority; the terminal device's use of CB-Msg3 EDT can be understood as: the terminal device will only use CB-Msg3 EDT, that is, CB-Msg3 EDT has a higher priority than Msg1-based EDT.

[0206] In some embodiments, if the terminal device's capability supports CB-Msg3 EDT, and / or the RSRP measured by the terminal device is greater than or equal to the first RSRP threshold, and / or the amount of uplink data is less than the first maximum TBS, the terminal device may choose to use CB-Msg3 EDT; otherwise, the terminal device may not choose CB-Msg3 EDT, or may directly choose Msg1-based EDT.

[0207] In some embodiments, if the terminal device supports OCC-based CB-Msg3 EDT, the first reference signal reception power threshold value in the first condition needs to be changed to the reference signal reception power threshold value for the terminal device supporting OCC-based CB-Msg3 EDT. Other conditions do not need to be modified. The terminal device supporting OCC-based CB-Msg3 EDT can select the first EDT type based on the modified first condition.

[0208] In some embodiments, the first reference signal received power threshold, the reference signal received power threshold for supporting the terminal device of the OCC-based CB-Msg3 EDT, and the first maximum transmission block size can be carried in the configuration information sent by the network device to the terminal device, or can be agreed upon by the protocol information; or, if the first maximum transmission block size is not configured or agreed upon, then the maximum value of at least one second maximum transmission block size in the subsequent embodiments can be used as the first maximum transmission block size, which is not limited in this embodiment.

[0209] In some implementations, the terminal device may further perform the following steps: the terminal device determines a first coverage enhancement level based on first information; the first information includes one or more of the following: the amount of uplink data; the reference signal received power currently measured by the terminal device; a first set of coverage enhancement levels supported by the terminal device on a first EDT type; at least one second reference signal received power threshold value for distinguishing the first set of coverage enhancement levels; and at least one second maximum transport block size corresponding to the first set of coverage enhancement levels.

[0210] In some embodiments, after determining the first EDT type, the terminal device can determine a first coverage enhancement level for the first EDT type. When determining the first coverage enhancement level, the terminal device needs to determine it based on the first information.

[0211] In some embodiments, if the first EDT type is CB-Msg3 EDT, the first coverage enhancement level can be determined from a set of coverage enhancement levels set for CB-Msg3 EDT. This set of coverage enhancement levels can be set separately for CB-Msg3 EDT, i.e., CB-Msg3 EDT is different from Msg1-based EDT, or it can be set simultaneously for CB-Msg3 EDT and Msg1-based EDT, i.e., CB-Msg3 EDT and Msg1-based EDT are the same. This embodiment does not limit this.

[0212] In some embodiments, the first set of coverage enhancement levels may be a portion of a set of coverage enhancement levels set for the first EDT type. For example, a set of coverage enhancement levels set for the first EDT type typically includes CE level0, CE level1, CE level2, and CE level3. The first set of coverage enhancement levels being CE level0, CE level1, and CE level2 indicates that the terminal device only supports CE level0, CE level1, and CE level2, and does not support CE level3.

[0213] In some embodiments, assuming the first set of coverage enhancement levels are CE level0, CE level1, and CE level2, at least one second reference signal received power threshold value can be a threshold value used to distinguish CE level0, CE level1, and CE level2, such as a threshold value used to distinguish CE level0 and CE level1 and a threshold value used to distinguish CE level1 and CE level2.

[0214] In some embodiments, assuming the first set of coverage enhancement levels are CE level0, CE level1, and CE level2, at least one second maximum transport block size may include a second maximum transport block size allocated to CE level0, a second maximum transport block size allocated to CE level1, and a second maximum transport block size allocated to CE level2.

[0215] In some embodiments, the terminal device may simultaneously determine the first coverage enhancement level based on the amount of uplink data, the currently measured reference signal received power, the first set of coverage enhancement levels, at least one second reference signal received power threshold, and at least one second maximum transport block size.

[0216] For example, assuming the first EDT type is CB-Msg3 EDT, and the terminal device supports the first set of coverage enhancement levels on CB-Msg3 EDT as CE level0, CE level1, CE level2, and CE level3, the determination can proceed step by step from CE level3. First, if the terminal device supports CE level3 and is configured with a second reference signal received power threshold (less than the second reference signal received power threshold for CE level2 and CE level3, greater than the second reference signal received power threshold for CE level2), and is configured with the second maximum transmission block size corresponding to CE level3, if the currently measured RSRP of the terminal device is less than the second RSRP threshold used to distinguish CE level2 and CE level3, and the amount of uplink data is less than or equal to the second maximum TBS corresponding to CE level3, then the terminal device can select CE level3 as the first coverage enhancement level; otherwise, if the terminal device supports CE level2 and is configured with a second reference signal received power threshold (less than the second reference signal received power threshold for CE level1 and CE level2), the terminal device can select CE level3 as the first coverage enhancement level. If the terminal device currently measures RSRP (which is greater than the second reference signal received power threshold for CE level 1) and has configured a second maximum transmission block size corresponding to CE level 2, and the uplink data volume is less than or equal to the second maximum TBS corresponding to CE level 2, then the terminal device can select CE level 2 as the first coverage enhancement level. Otherwise, if the terminal device supports CE level 1 and has configured a second reference signal received power threshold (which is less than the second reference signal received power threshold for CE level 1 and greater than the second reference signal received power threshold for CE level 0) and has configured a second maximum transmission block size corresponding to CE level 1, and the terminal device currently measures RSRP (which is less than the second RSRP threshold for CE level 0 and CE level 1) and the uplink data volume is less than or equal to the second maximum TBS corresponding to CE level 1, then the terminal device can select CE level 1 as the first coverage enhancement level. Otherwise, the terminal device selects CE level 0 as the first coverage enhancement level.

[0217] In some embodiments, the terminal device may first determine a candidate first coverage enhancement level based on a first set of coverage enhancement levels, the currently measured reference signal received power, at least one second reference signal received power threshold, and at least one second maximum transport block size, and then determine the availability between the amount of uplink data and the second maximum transport block size corresponding to the candidate first coverage enhancement level.

[0218] For example, suppose the first EDT type is CB-Msg3 EDT, and the first set of coverage enhancement levels supported by the terminal device on CB-Msg3 EDT is CE level3. At the same time, it is determined that the currently measured RSRP is less than the second RSRP threshold corresponding to CE level3. In this case, CE level3 can be selected as the candidate first coverage enhancement level. Then, it is determined whether the amount of uplink data is less than the second maximum TBS corresponding to CE level3. If it is less than or equal to, then CE level3 is determined as the first coverage enhancement level; if it is greater, then the current CB-Msg3 EDT transmission is canceled.

[0219] In some embodiments, for the case where the first EDT type is CB-Msg3 EDT, one or more of the first set of coverage enhancement levels, at least one second reference signal received power threshold value, and at least one second maximum transport block size can be reused not only in the configuration information sent by the network device to the terminal device, but also as agreed upon in the protocol information, but also the CE level and its threshold value and transport block size set by the terminal device on the Msg1-based EDT. For example, each of the first set of coverage enhancement levels, at least one second reference signal received power threshold value, and at least one second maximum transport block size can reuse the Msg1-based EDT. Alternatively, the configuration information sent by the network device to the terminal device can only carry part of the CE level and its threshold value of the CB-Msg3 EDT, and the remaining CE level and its threshold value on the CB-Msg3 EDT can reuse the CE level and its threshold value set on the Msg1-based EDT. This embodiment does not limit this.

[0220] In some implementations, the first EDT type is a contention-based message 3 EDT, and the terminal device may also perform the following steps: if the network device indicates that the uplink data transmission has failed, the terminal device re-executes at least one of the following determination procedures: first carrier; first resource pool; first subcarrier interval.

[0221] In some embodiments, after the terminal device performs an EDT for uplink data based on the first strategy, it can receive a fifth indication information sent by the network device. The fifth indication information is used to indicate whether the transmission was successful or failed. In the case of uplink data transmission failure, considering that it may be a time slot conflict, the terminal device can not change the determined first strategy. It only needs to re-execute the determination process for one or more of the first carrier, the first resource pool and the first subcarrier interval, and then re-execute the EDT for uplink data.

[0222] For example, assuming the first EDT type is CB-Msg3 EDT, after the CB-Msg3 EDT transmission fails, the terminal device can continue to try CB-Msg3 EDT transmission at the first coverage enhancement level. In addition, the terminal device can re-execute one or more of the following determination processes each time it tries: (1) selection of CB-Msg3 EDT resource pool based on / not based on OCC; (2) selection of subcarrier spacing (Numerology) (only applicable to NB-IoT devices); (3) selection of Anchor / non-Anchor carrier (only applicable to NB-IoT devices).

[0223] In some implementations, the first EDT type is a contention-based message 3 EDT, and the terminal device may also perform the following steps: if a second condition is met, the terminal device performs EDT transmission for uplink data using a second coverage enhancement level, where the second coverage enhancement level is a coverage enhancement level higher than the first coverage enhancement level in the first set of coverage enhancement levels.

[0224] In some implementations, the second condition is that the number of times the terminal device fails to transmit based on the first coverage enhancement level reaches a first value.

[0225] In some embodiments, if the terminal device determines the first coverage enhancement level after determining the first EDT type, and rollback is required due to transmission failure, it needs to roll back the first coverage enhancement level first, and then roll back the first EDT type.

[0226] In some embodiments, if the number of transmission failures at the first coverage enhancement level reaches a first value, the terminal device keeps the first EDT type unchanged as a contention-based message 3 EDT, falls back from the first coverage enhancement level to the second coverage enhancement level, and performs EDT transmission for uplink data using the second coverage enhancement level; the second coverage enhancement level is a coverage enhancement level higher than the first coverage enhancement level in the first set of coverage enhancement levels.

[0227] For example, if the first set of coverage enhancement levels supported by the terminal device on the CB-Msg3 EDT is CE level0, CE level1, CE level2 and CE level3, and the first coverage enhancement level is CE level0, then the second coverage enhancement level can be CE level1, CE level2 or CE level3.

[0228] In some implementations, the second coverage enhancement level is the next higher coverage enhancement level in the first set of coverage enhancement levels.

[0229] For example, if the first set of coverage enhancement levels supported by the terminal device on the CB-Msg3 EDT is CE level0, CE level1, CE level2 and CE level3, and the first coverage enhancement level is CE level0, then the second coverage enhancement level can be CE level1. Similarly, if the first coverage enhancement level is CE level1, then the second coverage enhancement level can be CE level2. Similarly, if the first coverage enhancement level is CE level2, then the second coverage enhancement level can be CE level3.

[0230] In some implementations, the second coverage enhancement level is the coverage enhancement level that satisfies the third condition.

[0231] In some embodiments, the second coverage enhancement level is a coverage enhancement level that is higher than the first coverage enhancement level in the first set of coverage enhancement levels and satisfies the third condition.

[0232] For example, if the first set of coverage enhancement levels supported by the terminal device on the CB-Msg3 EDT is CE level0, CE level1, CE level2 and CE level3, and the first coverage enhancement level is CE level0, then the second coverage enhancement level can be any of the coverage enhancement levels among CE level1, CE level2 and CE level3 that satisfy the third condition.

[0233] In some implementations, the second coverage enhancement level is the coverage enhancement level in the first group of coverage enhancement levels that is higher than the first coverage enhancement level and is the first to satisfy the third condition.

[0234] In some embodiments, when the terminal device determines the second coverage enhancement level from the first group of coverage enhancement levels, it may check in order of coverage enhancement level from low to high whether each coverage enhancement level higher than the first coverage enhancement level meets the third condition, and determine the coverage enhancement level in the first group of coverage enhancement levels that is higher than the first coverage enhancement level and is the first to meet the third condition as the second coverage enhancement level.

[0235] For example, if the first set of coverage enhancement levels supported by the terminal device on the CB-Msg3 EDT is CE level0, CE level1, CE level2, and CE level3, and the first coverage enhancement level is CE level0, then the terminal device can check whether CE level1 meets the third condition in the order of CE level1, CE level2, and CE level3. If CE level1 meets the third condition, then CE level1 is the second coverage enhancement level. Otherwise, if CE level1 does not meet the third condition, then check whether CE level2 meets the third condition. If CE level2 meets the third condition, then CE level2 is the second coverage enhancement level. Otherwise, if CE level2 does not meet the third condition, then check whether CE level3 meets the third condition. If CE level3 meets the third condition, then CE level3 is the second coverage enhancement level. Otherwise, cancel the current CB-Msg3 EDT transmission and / or perform a first EDT type rollback, rolling back from the CB-Msg3 EDT to the Msg1-based EDT.

[0236] In some implementations, the third condition includes one or more of the following: the reference signal received power currently measured by the terminal device is less than a third reference signal received power threshold; the third reference signal received power threshold is a threshold value used to distinguish between the second coverage enhancement level and the first coverage enhancement level among at least one second reference signal received power threshold value; the amount of uplink data is less than or equal to the third maximum transport block size; the third maximum transport block size is the maximum transport block size corresponding to the second coverage enhancement level among at least one second maximum transport block size.

[0237] In some embodiments, when the second coverage enhancement level is the next coverage enhancement level higher than the first coverage enhancement level and satisfies the third condition, the next coverage enhancement level higher than the first coverage enhancement level in the first group of coverage enhancement levels can be used as a candidate second coverage enhancement level. Then, check whether the candidate second coverage enhancement level satisfies the third condition. If it does, then the candidate second coverage enhancement level is determined as the second coverage enhancement level. If it does not, the current contention-based message 3 EDT transmission is directly canceled, and / or a first EDT type rollback is performed, rolling back from the contention-based message 3 EDT to the message 1-based EDT. This method only checks once, that is, whether the next coverage enhancement level higher than the first coverage enhancement level in the first group of coverage enhancement levels satisfies the third condition.

[0238] For example, if the first set of coverage enhancement levels supported by the terminal device on the CB-Msg3 EDT is CE level0, CE level1, CE level2 and CE level3, and the first coverage enhancement level is CE level0, then the terminal device can use CE level1 as a candidate second coverage enhancement level, and then determine whether the currently measured RSRP is less than the third RSRP threshold corresponding to CE level1, and / or determine whether the amount of uplink data is less than the third maximum TBS corresponding to CE level1. If one or more conditions are met, then CE level1 is determined as the second coverage enhancement level; if one or more conditions are not met, then the current CB-Msg3 EDT transmission is canceled, and / or a first EDT type fallback is performed, falling back from CB-Msg3 EDT to Msg1-based EDT.

[0239] In some embodiments, for the case where the second coverage enhancement level is higher than the first coverage enhancement level in the first group of coverage enhancement levels and is the first coverage enhancement level to satisfy the third condition, the next coverage enhancement level higher than the first coverage enhancement level in the first group of coverage enhancement levels can be selected as the candidate second coverage enhancement level in order of coverage enhancement level from low to high. Then, it is checked whether the candidate second coverage enhancement level satisfies the third condition. If it does, the candidate second coverage enhancement level is determined as the second coverage enhancement level. If it does not, the current contention-based message 3 EDT transmission is directly canceled, and / or a first EDT type rollback is performed, rolling back from the contention-based message 3 EDT to the message 1-based EDT. This method can be judged multiple times, that is, judging whether each coverage enhancement level higher than the first coverage enhancement level in the first group of coverage enhancement levels satisfies the third condition.

[0240] For example, if the terminal device supports the first set of coverage enhancement levels on the CB-Msg3 EDT as CE level0, CE level1, CE level2, and CE level3, and the first coverage enhancement level is CE level0, then the terminal device can use CE level1 as a candidate second coverage enhancement level. It then determines whether the currently measured RSRP is less than the third RSRP threshold corresponding to CE level1, and / or whether the uplink data volume is less than the third maximum TBS corresponding to CE level1. If one or more conditions are met, CE level1 is determined as the second coverage enhancement level. If one or more conditions are not met, CE level2 is used as a candidate second coverage enhancement level. Then, it determines whether the currently measured RSRP is less than the third RSRP threshold corresponding to CE level2, and / or whether the uplink data volume is less than the third maximum TBS corresponding to CE level2. If one or more conditions are met, CE level2 is determined as the second coverage enhancement level. If one or more conditions are not met, CE level3 is used as a candidate second coverage enhancement level. Then, it determines whether the currently measured RSRP is less than the third RSRP corresponding to CE level3. The threshold is used to determine whether the amount of uplink data is less than the third maximum TBS corresponding to CE level3. If one or more conditions are met, CE level3 is determined as the second coverage enhancement level. If one or more conditions are not met, the current CB-Msg3 EDT transmission is canceled, and / or a first EDT type fallback is performed, falling back from CB-Msg3 EDT to Msg1-based EDT.

[0241] In some implementations, the terminal device may also perform the following steps: if the fourth condition is met, the terminal device performs EDT transmission based on message 1 for the uplink data.

[0242] In some implementations, the fourth condition includes one or more of the following: the number of times the terminal device fails to transmit using the first coverage enhancement level and the second coverage enhancement level reaches a second value; the number of times the terminal device fails to transmit using the second coverage enhancement level reaches a third value; there is no available second coverage enhancement level in the first set of coverage enhancement levels; the terminal device receives a third indication message sent by the network device; the third indication message is used to indicate that the contention-based message 3 EDT has failed or to terminate the current uplink transmission.

[0243] In some embodiments, if the terminal device is still unable to successfully transmit uplink data after performing a fallback for the first coverage enhancement level, then it needs to perform a fallback for the first EDT type.

[0244] For example, assuming the first EDT type is CB-Msg3 EDT, after the fallback of the first coverage enhancement level is completed, if one or more of the fourth conditions are met, the fallback of CB-Msg3 EDT to Msg1-based EDT is performed: (1) the number of times the terminal device performs transmission for CB-Msg3 EDT using the first coverage enhancement level and the second coverage enhancement level (number of failures) is greater than or equal to the second value; (2) the terminal device has no available CE level; (3) the number of times the terminal device performs transmission for CB-Msg3 EDT using the second coverage enhancement level (number of failures) is greater than or equal to the third value; (4) the terminal device receives the third indication information sent by the network device to indicate that CB-Msg3 EDT has failed or terminated this uplink transmission.

[0245] In some embodiments, when calculating the number of times the terminal device fails to transmit at the first coverage enhancement level and the second coverage enhancement level, different calculation methods can be selected for the first conflict resolution algorithm selected in the first strategy.

[0246] For example, if the first conflict resolution algorithm is the slotted Aloha algorithm, then one failure under the slotted Aloha algorithm can be counted as one failure count; if the first conflict resolution algorithm is the diversity slotted Aloha algorithm, then multiple failures under the diversity slotted Aloha algorithm can be counted as one failure count, or one failure under the diversity slotted Aloha algorithm can be counted as one failure count; the specific calculation method can be determined according to the actual situation, and this application embodiment does not limit it here.

[0247] In some implementations, the terminal device may also perform the following steps: the terminal device performs message 1-based EDT transmission for uplink data using a third coverage enhancement level, the third coverage enhancement level being determined according to one or more of the following: a first coverage enhancement level; a second coverage enhancement level; the reference signal received power currently measured by the terminal device; and the amount of uplink data.

[0248] In some embodiments, since different coverage enhancement levels may be configured for different EDT types when the terminal device determines the first coverage enhancement level after determining the first EDT type, the terminal device needs to redetermine the third coverage enhancement level on the message-based EDT after falling back from the contention-based message 3 EDT to the message-based EDT, and send uplink data based on the message-based EDT resources associated with the third coverage enhancement level.

[0249] In some embodiments, the terminal device determines a third coverage enhancement level based on a first coverage enhancement level and / or a second coverage enhancement level.

[0250] For example, if the first coverage enhancement level is CE level 1 and the second coverage enhancement level is CE level 3, then the third coverage enhancement level can be the same as the index of CE level 1 and / or CE level 3. For example, the third coverage enhancement level is CE level 1 and / or CE level 3 on Msg1-based EDT.

[0251] In some embodiments, after the terminal device determines the third coverage enhancement level on the Msg1-based EDT, it needs to check whether the reference signal received power currently measured by the terminal device meets the threshold value corresponding to the third coverage enhancement level, and check whether the amount of uplink data is less than the maximum transmission block size corresponding to the third coverage enhancement level.

[0252] In some embodiments, the terminal device may determine a third coverage enhancement level based on the reference signal received power measured when determining the first coverage enhancement level and / or the second coverage enhancement level, as well as the amount of uplink data. Thus, after determining the third coverage enhancement level, it is no longer necessary to check the threshold value and maximum transport block size corresponding to the third coverage enhancement level.

[0253] In some implementations, the terminal device may also perform the following steps: the terminal device determines a first coverage enhancement level; and if the first coverage enhancement level is determined, the terminal device determines a first EDT type.

[0254] In some embodiments, the first strategy includes both a first EDT type and a first coverage enhancement level, thereby allowing the terminal device to first determine the first coverage enhancement level and then determine the first EDT type to use.

[0255] In some embodiments, if the terminal device first determines the first coverage enhancement level and then determines the first EDT type to be used, then different EDT types can be configured with the same set of coverage enhancement levels, i.e., the same CE level and its threshold value, when configuring the coverage enhancement level for the EDT type in advance.

[0256] For example, assuming the EDT type includes Msg1-based EDT or CB-Msg3 EDT, if the terminal device determines that the first coverage enhancement level is CE level 1, then the terminal device can determine the first EDT type from Msg1-based EDT or CB-Msg3 EDT. If it is determined to be CB-Msg3 EDT, then the terminal device uses CB-Msg3 EDT and CE level 1 to perform EDT transmission for uplink data.

[0257] Understandably, the above method of first determining the first coverage enhancement level and then determining the first EDT type, with different EDT types configured with the same coverage enhancement level, can save signaling.

[0258] In some implementations, the terminal device may further perform the following steps: the terminal device determines a first coverage enhancement level based on second information; the second information includes one or more of the following: the amount of uplink data; the reference signal received power currently measured by the terminal device; a second set of coverage enhancement levels supported by the terminal device; at least one fourth reference signal received power threshold value for distinguishing the second set of coverage enhancement levels; and at least one fourth maximum transport block size corresponding to the second set of coverage enhancement levels.

[0259] In some embodiments, since different EDT types share the same set of coverage enhancement levels in the scheme where the terminal device first determines the first coverage enhancement level, the terminal device can determine the first coverage enhancement level from the set of coverage enhancement levels based on the second information, without considering the EDT type.

[0260] In some embodiments, the second set of coverage enhancement levels may be a portion of the same set of coverage enhancement levels set for different EDT types. For example, a set of coverage enhancement levels typically includes CE level0, CE level1, CE level2, and CE level3. The second set of coverage enhancement levels may be CE level0, CE level1, and CE level2, indicating that the terminal device only supports CE level0, CE level1, and CE level2, and does not support CE level3.

[0261] In some embodiments, assuming the second set of coverage enhancement levels are CE level0, CE level1, and CE level2, at least one fourth reference signal received power threshold can be a threshold used to distinguish CE level0, CE level1, and CE level2, such as a threshold used to distinguish CE level0 and CE level1 and a threshold used to distinguish CE level1 and CE level2.

[0262] In some embodiments, assuming the second set of coverage enhancement levels are CE level0, CE level1, and CE level2, at least one fourth maximum transport block size may include a fourth maximum transport block size allocated to CE level0, a fourth maximum transport block size allocated to CE level1, and a fourth maximum transport block size allocated to CE level2.

[0263] In some embodiments, the terminal device may simultaneously determine the first coverage enhancement level based on the amount of uplink data, the currently measured reference signal received power, the second set of coverage enhancement levels, at least one fourth reference signal received power threshold, and at least one fourth maximum transport block size.

[0264] For example, assuming the terminal device supports the second set of coverage enhancement levels as CE level 0, CE level 1, CE level 2, and CE level 3, the determination can proceed step by step from CE level 3 downwards. First, if the terminal device supports CE level 3 and is configured with a fourth reference signal received power threshold (less than the fourth reference signal received power threshold for CE level 3, greater than the fourth reference signal received power threshold for CE level 2), and is configured with the fourth maximum transmission block size corresponding to CE level 3, if the currently measured RSRP of the terminal device is less than the fourth RSRP threshold used to distinguish CE level 2 and CE level 3, and the amount of uplink data is less than or equal to the fourth maximum TBS corresponding to CE level 3, then the terminal device can select CE level 3 as the first coverage enhancement level; otherwise, if the terminal device supports CE level 2 and is configured with a fourth reference signal received power threshold (less than the fourth reference signal received power threshold for CE level 2, greater than the fourth reference signal received power threshold for CE level 1), and is configured with CE level 3, then the terminal device can select CE level 3 as the first coverage enhancement level. If the terminal device's currently measured RSRP is less than the fourth RSRP threshold used to distinguish between CE level 1 and CE level 2, and the amount of uplink data is less than or equal to the fourth maximum TBS corresponding to CE level 2, then the terminal device can select CE level 2 as the first coverage enhancement level. Otherwise, if the terminal device supports CE level 1, and is configured with a fourth reference signal received power threshold value used to distinguish between CE level 0 and CE level 1 (less than the fourth reference signal received power threshold value for CE level 1, and greater than the fourth reference signal received power threshold value for CE level 0), and is configured with the fourth maximum transmission block size corresponding to CE level 1, then if the terminal device's currently measured RSRP is less than the fourth RSRP threshold used to distinguish between CE level 0 and CE level 1, and the amount of uplink data is less than or equal to the fourth maximum TBS corresponding to CE level 1, then the terminal device can select CE level 1 as the first coverage enhancement level. Otherwise, the terminal device selects CE level 0 as the first coverage enhancement level.

[0265] In some embodiments, the terminal device may first determine a candidate first coverage enhancement level based on the second set of coverage enhancement levels, the currently measured reference signal received power, at least one fourth reference signal received power threshold, and at least one fourth maximum transport block size, and then determine the availability between the amount of uplink data and the fourth maximum transport block size corresponding to the candidate first coverage enhancement level.

[0266] For example, suppose the terminal device supports the second set of coverage enhancement levels as CE level 3, and it is determined that the currently measured RSRP is less than the fourth RSRP threshold corresponding to CE level 3. In this case, CE level 3 can be selected as the first alternative coverage enhancement level. Then, it is determined whether the amount of uplink data is less than the fourth maximum TBS corresponding to CE level 3. If it is less than or equal to, then CE level 3 is determined as the first coverage enhancement level; if it is greater than, then the current CB-Msg3 EDT transmission is canceled.

[0267] In some embodiments, one or more of the second set of coverage enhancement levels, at least one fourth reference signal received power threshold value, and at least one fourth maximum transport block size may be reused, in addition to being carried in the configuration information sent by the network device to the terminal device, or as agreed in the protocol information, by reusing the CE level and its threshold value and transport block size set by the terminal device on the Msg1-based EDT. For example, each of the second set of coverage enhancement levels, at least one second reference signal received power threshold value, and at least one second maximum transport block size may reuse the Msg1-based EDT. Alternatively, the configuration information sent by the network device to the terminal device may only carry part of the CE level and its threshold value of the enhancement levels that need to be changed, and the remaining CE levels and their threshold values ​​may reuse the CE level and its threshold value set on the Msg1-based EDT. This embodiment does not limit this.

[0268] In some implementations, the terminal device may also perform the following steps: if a fifth condition is met, the terminal device determines that the first EDT type is a contention-based message 3 EDT; the fifth condition includes one or more of the following: the terminal device supports a contention-based message 3 EDT; the reference signal received power currently measured by the terminal device is greater than or equal to the fifth reference signal received power threshold; the amount of uplink data is less than the fifth maximum transmission block size.

[0269] In some implementations, the terminal device may also perform the following steps: if the fifth condition is not met, the terminal device determines that the first EDT type is an EDT based on message 1, or the terminal device does not select an EDT based on contention-based message 3.

[0270] In some embodiments, when determining the first EDT type, the terminal device needs to determine it according to the fifth condition. If the terminal device meets one or more of the fifth conditions, the terminal device can choose to use or select to use CB-Msg3 EDT.

[0271] In some embodiments, the terminal device's choice to use CB-Msg3 EDT can be understood as: the terminal device can use either CB-Msg3 EDT or Msg1-based EDT, that is, CB-Msg3 EDT and Msg1-based EDT have the same priority; the terminal device's use of CB-Msg3 EDT can be understood as: the terminal device will only use CB-Msg3 EDT, that is, CB-Msg3 EDT has a higher priority than Msg1-based EDT.

[0272] In some embodiments, if the terminal device's capability supports CB-Msg3 EDT, and / or the RSRP measured by the terminal device is greater than or equal to the fifth RSRP threshold, and / or the amount of uplink data is less than the fifth maximum TBS, the terminal device may choose to use CB-Msg3 EDT; otherwise, the terminal device may not choose CB-Msg3 EDT, or may directly choose Msg1-based EDT.

[0273] In some embodiments, if the terminal device supports OCC-based CB-Msg3 EDT, the fifth reference signal received power threshold value in the fifth condition needs to be changed to the reference signal received power threshold value for the terminal device supporting OCC-based CB-Msg3 EDT. Other conditions do not need to be modified. The terminal device supporting OCC-based CB-Msg3 EDT can select the first EDT type based on the modified fifth condition.

[0274] In some embodiments, the fifth reference signal received power threshold, the reference signal received power threshold for supporting the terminal device of the OCC-based CB-Msg3 EDT, and the fifth maximum transport block size can be carried in the configuration information sent by the network device to the terminal device, or can be agreed upon by the protocol information; or, if the fifth maximum transport block size is not configured or agreed upon, then the maximum value of at least one of the fourth maximum transport block sizes in the previous embodiments can be used as the fifth maximum transport block size, which is not limited in this embodiment.

[0275] In some implementations, the first EDT type is a contention-based message 3 EDT, and the terminal device may also perform the following steps: if the network device indicates that the uplink data transmission has failed, the terminal device re-executes at least one of the following determination procedures: first carrier; first resource pool; first subcarrier interval.

[0276] In some embodiments, after the terminal device performs an EDT for uplink data based on the first strategy, it can receive a fifth indication information sent by the network device. The fifth indication information is used to indicate whether the transmission was successful or failed. In the case of uplink data transmission failure, considering that it may be a time slot conflict, the terminal device can not change the determined first strategy. It only needs to re-execute the determination process for one or more of the first carrier, the first resource pool and the first subcarrier interval, and then re-execute the EDT for uplink data.

[0277] For example, assuming the first EDT type is CB-Msg3 EDT, after the CB-Msg3 EDT transmission fails, the terminal device can continue to try CB-Msg3 EDT transmission at the first coverage enhancement level. In addition, the terminal device can re-execute one or more of the following determination processes each time it tries: (1) selection of CB-Msg3 EDT resource pool based on / not based on OCC; (2) selection of subcarrier spacing (Numerology) (only applicable to NB-IoT devices); (3) selection of Anchor / non-Anchor carrier (only applicable to NB-IoT devices).

[0278] In some implementations, the first EDT type is a contention-based message 3 EDT, and the terminal device may also perform the following steps: if the sixth condition is met, the terminal device performs message 1-based EDT transmission for uplink data using the first coverage enhancement level.

[0279] In some implementations, the sixth condition includes one or more of the following: the number of times the terminal device fails to transmit using the first coverage enhancement level reaches a fourth value; the terminal device receives a fourth indication message sent by the network device; the fourth indication message is used to indicate that the contention-based message 3 EDT has failed or to terminate the current uplink transmission.

[0280] In some embodiments, if the terminal device determines the first EDT type after determining the first coverage enhancement level, and rollback is required due to transmission failure, it needs to roll back to the first EDT type first, and then roll back to the first coverage enhancement level.

[0281] In some embodiments, if the number of times the terminal device fails to transmit the contention-based message 3 EDT at the first coverage enhancement level reaches a fourth value, and / or receives a fourth indication message from the network device indicating that the contention-based message 3 EDT has failed or the current uplink transmission has been terminated, the terminal device maintains the first coverage enhancement level unchanged, falls back from the contention-based message 3 EDT to the message-based EDT, and performs the message-based EDT transmission at the first coverage enhancement level.

[0282] For example, if the second set of coverage enhancement levels supported by the terminal device is CE level0, CE level1, CE level2 and CE level3, and the first EDT type is CB-Msg3 EDT, and the first coverage enhancement level is CE level0, then, if the sixth condition is met, the terminal device performs Msg1-based EDT on CE level0.

[0283] In some embodiments, when calculating the number of times the terminal device fails to transmit at the first coverage enhancement level, different calculation methods can be selected for the first conflict resolution algorithm selected in the first strategy.

[0284] For example, if the first conflict resolution algorithm is the slotted Aloha algorithm, then one failure under the slotted Aloha algorithm can be counted as one failure count; if the first conflict resolution algorithm is the diversity slotted Aloha algorithm, then multiple failures under the diversity slotted Aloha algorithm can be counted as one failure count, or one failure under the diversity slotted Aloha algorithm can be counted as one failure count; the specific calculation method can be determined according to the actual situation, and this application embodiment does not limit it here.

[0285] In some implementations, the first coverage enhancement level satisfies a seventh condition, which includes one or more of the following: the reference signal received power currently measured by the terminal device is less than a sixth reference signal received power threshold; the sixth reference signal received power threshold is a threshold value corresponding to the first coverage enhancement level among at least one fourth reference signal received power threshold; the amount of uplink data is less than or equal to a sixth maximum transport block size; and the sixth maximum transport block size is the maximum transport block size corresponding to the first coverage enhancement level among at least one fourth maximum transport block size.

[0286] In some embodiments, when the terminal device performs message 1-based EDT transmission on the first coverage enhancement level, since the EDT type has been changed, it is necessary to check whether the first coverage enhancement level meets the seventh condition, that is, to determine whether the reference signal received power currently measured by the terminal device is less than the sixth reference signal received power threshold and / or whether the amount of uplink data is less than or equal to the sixth maximum transmission block size. If one or more of these conditions are met, it can be determined that the first coverage enhancement level on message 1-based EDT is available, and message 1-based EDT transmission for uplink data is performed using the first coverage enhancement level.

[0287] In some implementations, the terminal device may also perform the following steps: if the eighth condition is met, the terminal device performs contention-based EDT transmission of message 3 or message 1 based EDT transmission for uplink data using the fourth coverage enhancement level; the fourth coverage enhancement level is a coverage enhancement level in the second set of coverage enhancement levels that is higher than the first coverage enhancement level.

[0288] In some implementations, the eighth condition is that the number of times the terminal device fails to transmit using the first coverage enhancement level reaches a fifth value.

[0289] In some embodiments, if the terminal device is still unable to successfully transmit uplink data after performing a fallback for the first EDT type, then it needs to perform a fallback for the first coverage enhancement level.

[0290] In some embodiments, if the number of transmission failures at the first coverage enhancement level reaches a fifth value (including performing EDT transmission based on message 1 and performing EDT transmission based on contention-based message 3), the terminal device may choose to fall back to the first coverage enhancement level. When falling back to the first coverage enhancement level, it may fall back on performing EDT transmission based on contention-based message 3, that is, using EDT resource transmission based on contention-based message 3 associated with the fourth coverage enhancement level, or it may fall back on performing EDT transmission based on message 1, that is, using EDT resource transmission based on message 1 associated with the fourth coverage enhancement level.

[0291] In some implementations, the fourth coverage enhancement level is the next higher coverage enhancement level in the second set of coverage enhancement levels than the first coverage enhancement level.

[0292] For example, if the second set of coverage enhancement levels supported by the terminal device is CE level0, CE level1, CE level2 and CE level3, and the first coverage enhancement level is CE level0, then the fourth coverage enhancement level can be CE level1. Similarly, if the first coverage enhancement level is CE level1, then the fourth coverage enhancement level can be CE level2. Similarly, if the first coverage enhancement level is CE level2, then the fourth coverage enhancement level can be CE level3.

[0293] In some implementations, the fourth coverage enhancement level is the coverage enhancement level that satisfies the ninth condition.

[0294] In some embodiments, the fourth coverage enhancement level is a coverage enhancement level in the second set of coverage enhancement levels that is higher than the first coverage enhancement level and satisfies the ninth condition.

[0295] For example, if the second set of coverage enhancement levels supported by the terminal device is CE level0, CE level1, CE level2 and CE level3, and the first coverage enhancement level is CE level0, then the fourth coverage enhancement level can be any of the coverage enhancement levels among CE level1, CE level2 and CE level3 that satisfy the ninth condition.

[0296] In some implementations, the fourth coverage enhancement level is the coverage enhancement level in the second set of coverage enhancement levels that is higher than the first coverage enhancement level and is the first to satisfy the ninth condition.

[0297] In some embodiments, when the terminal device determines the fourth coverage enhancement level from the second group of coverage enhancement levels, it may check in order of coverage enhancement level from low to high whether each coverage enhancement level higher than the first coverage enhancement level satisfies the ninth condition, and determine the coverage enhancement level in the second group of coverage enhancement levels that is higher than the first coverage enhancement level and is the first to satisfy the ninth condition as the fourth coverage enhancement level.

[0298] For example, if the second set of coverage enhancement levels supported by the terminal device is CE level0, CE level1, CE level2, and CE level3, and the first coverage enhancement level is CE level0, then the terminal device can check whether CE level1 meets the ninth condition in the order of CE level1, CE level2, and CE level3. If CE level1 meets the ninth condition, then CE level1 is the fourth coverage enhancement level. Otherwise, if CE level1 does not meet the ninth condition, then check whether CE level2 meets the ninth condition. If CE level2 meets the ninth condition, then CE level2 is the fourth coverage enhancement level. Otherwise, if CE level2 does not meet the ninth condition, then check whether CE level3 meets the ninth condition. If CE level3 meets the ninth condition, then CE level3 is the fourth coverage enhancement level. Otherwise, cancel the current EDT transmission (including Msg1-based EDT transmission and CB-Msg3 EDT transmission).

[0299] In some implementations, the ninth condition includes one of the following: the reference signal received power currently measured by the terminal device is less than the seventh reference signal received power threshold; the seventh reference signal received power threshold is a threshold value used to distinguish between the fourth coverage enhancement level and the first coverage enhancement level among at least one fourth reference signal received power threshold value; the amount of uplink data is less than or equal to the seventh maximum transmission block size; the seventh maximum transmission block size is the maximum transmission block size corresponding to the fourth coverage enhancement level among at least one fourth maximum transmission block size.

[0300] In some embodiments, when the fourth coverage enhancement level is the next coverage enhancement level that is higher than the first coverage enhancement level and satisfies the ninth condition, the next coverage enhancement level higher than the first coverage enhancement level in the second group of coverage enhancement levels can be used as a candidate fourth coverage enhancement level. Then, check whether the candidate fourth coverage enhancement level satisfies the ninth condition. If it does, then the candidate fourth coverage enhancement level is determined as the fourth coverage enhancement level. If it does not, the current EDT transmission (including Msg1-based EDT transmission and CB-Msg3 EDT transmission) is directly cancelled. This method only checks once, that is, whether the next coverage enhancement level higher than the first coverage enhancement level in the second group of coverage enhancement levels satisfies the ninth condition.

[0301] For example, if the second set of coverage enhancement levels supported by the terminal device is CE level0, CE level1, CE level2 and CE level3, and the first coverage enhancement level is CE level0, then the terminal device can use CE level1 as a candidate fourth coverage enhancement level, and then determine whether the currently measured RSRP is less than the seventh RSRP threshold corresponding to CE level1, and / or determine whether the amount of uplink data is less than the seventh maximum TBS corresponding to CE level1. If one or more conditions are met, then CE level1 is determined as the fourth coverage enhancement level; if one or more conditions are not met, then the current EDT transmission (including Msg1-based EDT transmission and CB-Msg3 EDT transmission) is canceled.

[0302] In some embodiments, for the case where the fourth coverage enhancement level is the first coverage enhancement level in the second group of coverage enhancement levels that is higher than the first coverage enhancement level and is the first to satisfy the ninth condition, the next coverage enhancement level in the second group of coverage enhancement levels that is higher than the first coverage enhancement level can be selected as the candidate fourth coverage enhancement level in order of coverage enhancement level from low to high. Then, it is checked whether the candidate fourth coverage enhancement level satisfies the ninth condition. If it does, the candidate fourth coverage enhancement level is determined as the fourth coverage enhancement level. If it does not, the current EDT transmission (including Msg1-based EDT transmission and CB-Msg3 EDT transmission) is directly cancelled. This method can be checked multiple times, that is, checking whether each coverage enhancement level in the second group of coverage enhancement levels that is higher than the first coverage enhancement level satisfies the ninth condition.

[0303] For example, if the terminal device supports a second set of coverage enhancement levels of CE level 0, CE level 1, CE level 2, and CE level 3, and the first coverage enhancement level is CE level 0, then the terminal device can use CE level 1 as a candidate fourth coverage enhancement level. It then determines whether the currently measured RSRP is less than the seventh RSRP threshold corresponding to CE level 1, and / or whether the uplink data volume is less than the seventh maximum TBS corresponding to CE level 1. If one or more conditions are met, CE level 1 is determined as the fourth coverage enhancement level. If one or more conditions are not met, CE level 2 is used as a candidate fourth coverage enhancement level. Then, it determines whether the currently measured RSRP is less than the seventh RSRP threshold corresponding to CE level 2, and / or whether the uplink data volume is less than the seventh maximum TBS corresponding to CE level 2. If one or more conditions are met, CE level 2 is determined as the fourth coverage enhancement level. If one or more conditions are not met, CE level 3 is used as a candidate fourth coverage enhancement level. Then, it determines whether the currently measured RSRP is less than the seventh RSRP threshold corresponding to CE level 3, and / or whether the uplink data volume is less than the seventh maximum TBS corresponding to CE level 3. If TBS meets one or more of the criteria, CE level3 will be designated as the fourth coverage enhancement level; if it does not meet one or more of the criteria, the current EDT transmission (including Msg1-based EDT transmission and CB-Msg3 EDT transmission) will be cancelled.

[0304] In some implementations, the terminal device is an NB-IoT device, and the terminal device may also perform the following steps: the terminal device determines a first carrier from a plurality of carriers corresponding to a first coverage enhancement level according to a first parameter; the plurality of carriers includes anchored carriers and non-anchored carriers.

[0305] In some embodiments, the first parameter is a first probability parameter used for selecting the anchor carrier and the non-anchor carrier.

[0306] For example, when the first EDT type is CB-Msg3 EDT, for the same CE level, if multiple carriers provide CB-Msg3 EDT resource pools, the terminal device selects one carrier from the multiple carriers according to the first Probability parameter. In one implementation, the selection probability of the CB-Msg3 EDT resource pool of the Anchor carrier is the first Probability parameter, and the selection probability of the CB-Msg3 EDT resource pool of all remaining non-Anchor carriers is the same, which is (1 - first Probability parameter) / number of non-anchor carriers. In another implementation, a first Probability parameter can be configured for each carrier, that is, multiple carriers correspond to multiple first Probability parameters, and the sum of the first Probability parameters of all carriers is 1.

[0307] In some embodiments, the first parameter may be carried in the configuration information sent by the network device to the terminal device, or it may be agreed upon in the protocol information; this embodiment does not limit this.

[0308] In some implementations, the terminal device may also perform the following steps: the terminal device determines a first conflict resolution algorithm based on the fifth information; the first conflict resolution algorithm is any one of the following: slotted Aloha algorithm; diversity slotted Aloha algorithm.

[0309] In some implementations, the fifth information includes one or more of the following: first capability information of the terminal device; the first capability information includes capability information supporting the slotted Aloha algorithm and / or capability information supporting the diversity slotted Aloha algorithm; and second parameters.

[0310] In some embodiments, the terminal device may select either the time-slot Aloha algorithm or the diversity time-slot Aloha algorithm based on the terminal device's first capability information and / or second parameters.

[0311] In some embodiments, the slotted Aloha algorithm is (Slotted Aloha, SA), and the diversity slotted Aloha algorithm is (Diversity Slotted Aloha, DSA).

[0312] In some embodiments, the second parameter is the number of Msg3 replicas, which includes values ​​1 / 2 / 3 / 4, where 1 is SA, and 2 / 3 / 4 are DSA and the number of Msg3 replicas.

[0313] For example, when the first EDT type is CB-Msg3 EDT, for the same CE level, if the first capability information of the terminal device indicates that the terminal device supports DSA and a second parameter exists, the terminal device performs CB-Msg3 EDT transmission based on SA (with 1 Msg3 copy) when the second parameter is 1, and performs CB-Msg3 EDT transmission based on DSA (with 2 / 3 / 4 Msg3 copies) when the second parameter is 2 / 3 / 4; otherwise, if the capability information of the terminal device indicates that the terminal device does not support DSA (supports SA) and / or the second parameter does not exist, the terminal device can perform CB-Msg3 EDT transmission based on SA (with 1 Msg3 copy).

[0314] In some embodiments, the second parameter may be carried in the configuration information sent by the network device to the terminal device, or may be agreed upon in the protocol information; this embodiment does not impose any limitations on this.

[0315] In some implementations, the first resource pool is any one of the following: an OCC-based contention-based message 3EDT resource pool; or an OCC-free contention-based message 3EDT resource pool.

[0316] In some implementations, the terminal device may further perform the following steps: if a ninth condition is met, the terminal device determines the first resource pool as an OCC-based contention-based message 3EDT resource pool; the ninth condition includes one or more of the following: the terminal device supports OCC-based contention-based message 3EDT transmission; the network device configures at least one OCC-based contention-based message 3EDT resource pool; the reference signal received power currently measured by the terminal device is located in the first reference signal received power range corresponding to any one of the at least one OCC-based contention-based message 3EDT resource pools.

[0317] In some embodiments, the OCC-based contention-based message 3EDT resource pool is an OCC-based CB-Msg3 EDT resource pool, and the non-OCC-based contention-based message 3EDT resource pool is a non-OCC-based CB-Msg3 EDT resource pool.

[0318] In some embodiments, for the same CE level, each OCC-based CB-Msg3 EDT resource pool can be configured with a reference signal received power range, i.e., an RSRP threshold range. The RSRP threshold range includes an upper threshold and a lower threshold, or an upper threshold and a range, or a lower threshold and a range, to distinguish different RSRP threshold ranges.

[0319] For example, when the first EDT type is CB-Msg3 EDT, for the same CE level, if the terminal device supports contention-based message 3EDT transmission using OCC, and the network device is configured with a non-OCC-based CB-Msg3 EDT resource pool and one or more OCC-based CB-Msg3 EDT resource pools, the terminal device can determine whether to use an OCC-based CB-Msg3 EDT resource pool or a non-OCC-based CB-Msg3 EDT resource pool based on the currently measured RSRP. Specifically: if the terminal device's currently measured RSRP is within the first reference signal received power range corresponding to an OCC-based CB-Msg3 EDT resource pool, then the terminal device can choose to use the resources in that OCC-based CB-Msg3 EDT resource pool; if the terminal device's currently measured RSRP is not within the first reference signal received power range corresponding to any OCC-based CB-Msg3 EDT resource pool, then the terminal device chooses to use a non-OCC-based CB-Msg3 EDT resource pool. Resources in the EDT resource pool: In other words, the terminal device cannot select resources in the OCC-based CB-Msg3 EDT resource pool. Alternatively, if the terminal device does not support OCC-based contention-based 3EDT transmission, and the network device is configured with a non-OCC-based CB-Msg3 EDT resource pool and one or more OCC-based CB-Msg3 EDT resource pools, then the terminal device will choose to use resources in the non-OCC-based CB-Msg3 EDT resource pool. That is, the terminal device cannot choose to use resources in the OCC-based CB-Msg3 EDT resource pool.

[0320] In some embodiments, at least one first reference signal received power range corresponding to at least one OCC-based contention message 3EDT resource pool can be carried in the configuration information sent by the network device to the terminal device, or agreed upon by the protocol information; this embodiment does not limit this.

[0321] In some implementations, the terminal device is an NB-IoT device, and the terminal device may also perform the following steps: the terminal device determines a first subcarrier interval based on seventh information; the seventh information includes one or more of the following: second capability information of the terminal device; the second capability information includes at least one subcarrier interval supported by the terminal device; first indication information sent by the network device; the first indication information is used to indicate the first subcarrier interval; and TA validity information of the terminal device.

[0322] In some embodiments, if the second capability information of the terminal device indicates that the terminal device supports uplink transmission using the first subcarrier spacing, and / or the network device indicates that the first subcarrier spacing is available, then the terminal device may use the first subcarrier spacing.

[0323] For example, in the case where the first EDT type is CB-Msg3 EDT and the first subcarrier spacing is 3.75kHz SCS, if the terminal device supports 3.75kHz SCS NPUSCH and / or the network device indicates that 3.75kHz SCS is available, then the terminal device can use 3.75kHz SCS for CB-Msg3 NPUSCH transmission.

[0324] In some embodiments, if the second capability information of the terminal device indicates that the terminal device supports uplink transmission using the first subcarrier interval, and / or the network device indicates that the first subcarrier interval is available, and / or the TA validity information of the terminal device identifies that the current TA of the terminal device is valid, then the terminal device may use the first subcarrier interval.

[0325] For example, in the case where the first EDT type is CB-Msg3 EDT and the first subcarrier spacing is 15kHz SCS, if the terminal device supports 15kHz SCS NPUSCH, and / or the network device indicates that 15kHz SCS is available, and / or the terminal device's current TA is valid (timer is running and / or RSRP change is less than the RSRP change threshold), then the terminal device can use 15kHz SCS for CB-Msg3 NPUSCH transmission.

[0326] In some embodiments, if it is determined from the seventh information that multiple subcarrier intervals are available, then the subcarrier interval to be used can be determined based on a set reference signal received power threshold.

[0327] For example, if both 3.75kHz SCS and 15kHz SCS are available, the terminal device can determine which subcarrier interval to use by comparing the currently measured RSRP with a set RSRP threshold. If the currently measured RSRP is less than the set RSRP threshold, the terminal device can choose 3.75kHz SCS, meaning it cannot choose 15kHz SCS. If the currently measured RSRP is not less than the set RSRP threshold, the terminal device can choose either 15kHz SCS or 3.75kHz SCS.

[0328] In some implementations, one or more of the following are determined based on predefined information or configuration information sent by the network device: a first reference signal received power threshold; a fifth reference signal received power threshold; a first maximum transmission block size; a fifth maximum transmission block size; a first set of coverage enhancement levels; a second set of coverage enhancement levels; at least one second reference signal received power threshold; at least one fourth reference signal received power threshold; at least one second maximum transmission block size; at least one fourth maximum transmission block size; a first value; a second value; a third value; a fourth value; a fifth value; a first parameter; a second parameter; and a first reference signal received power range.

[0329] In some embodiments, the network device may send EDT configuration information to the terminal device, which carries one or more of the following: a first reference signal received power threshold; a fifth reference signal received power threshold; a first maximum transmission block size; a fifth maximum transmission block size; a first set of coverage enhancement levels; a second set of coverage enhancement levels; at least one second reference signal received power threshold; at least one fourth reference signal received power threshold; at least one second maximum transmission block size; at least one fourth maximum transmission block size; a first value; a second value; a third value; a fourth value; a fifth value; a first parameter; a second parameter; and a first reference signal received power range.

[0330] In summary, according to the data transmission method of the embodiments of this application, the terminal device can perform different EDT transmissions for uplink data according to different strategies, which can improve the transmission efficiency and communication quality of EDT.

[0331] The data transmission method of this embodiment of the invention has been described in detail above from the perspective of the terminal device with reference to Figure 7. The data transmission method of this embodiment of the invention will now be described in detail below from the perspective of the network device with reference to Figure 8. It should be understood that the steps performed by the network device correspond to the steps performed by the terminal device. For the sake of brevity, repeated descriptions will be omitted appropriately below.

[0332] Figure 8 illustrates a data transmission method provided in an embodiment of this application, which may include:

[0333] S800, The network device receives uplink data; the uplink data is sent by the terminal device based on a first strategy; the first strategy includes one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier interval.

[0334] In this embodiment of the application, the network device receives uplink data; the uplink data is sent by the terminal device based on a first strategy; the first strategy includes one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier spacing.

[0335] In some embodiments, the terminal device may perform EDT transmission for the uplink data based on a first strategy when uplink data arrives and EDT transmission is triggered.

[0336] In some implementations, the network device may also perform the following steps: sending a fifth indication message to the terminal device; the fifth indication message is used to indicate that the uplink data transmission failed.

[0337] In some embodiments, if the network device indicates that uplink data transmission has failed, the terminal device re-executes the determination process of at least one of the following: a first carrier; a first resource pool; and a first subcarrier interval.

[0338] In some implementations, the first EDT type is a contention-based message 3 EDT, and the network device may also perform the following steps: the network device receives the uplink data sent by the terminal device using the second coverage enhancement level.

[0339] In some implementations, the second condition is that the number of times the terminal device fails to transmit based on the first coverage enhancement level reaches a first value.

[0340] In some implementations, the second coverage enhancement level is the next higher coverage enhancement level in the first set of coverage enhancement levels.

[0341] In some implementations, the second coverage enhancement level is the coverage enhancement level that satisfies the third condition.

[0342] In some implementations, the second coverage enhancement level is the coverage enhancement level in the first set of coverage enhancement levels that is higher than the first coverage enhancement level and is the first to satisfy the third condition.

[0343] In some implementations, the third condition includes one or more of the following: the reference signal received power currently measured by the terminal device is less than a third reference signal received power threshold; the third reference signal received power threshold is a threshold value used to distinguish between the second coverage enhancement level and the first coverage enhancement level among at least one second reference signal received power threshold value; the amount of uplink data is less than or equal to the third maximum transport block size; the third maximum transport block size is the maximum transport block size corresponding to the second coverage enhancement level among at least one second maximum transport block size.

[0344] In some implementations, the first EDT type is a message-1 based EDT, and the network device may also perform the following steps: the network device receives the uplink data sent by the terminal device using a third coverage enhancement level.

[0345] In some implementations, the terminal device may also perform the following steps: if the fourth condition is met, the terminal device performs EDT transmission based on message 1 for the uplink data.

[0346] In some implementations, the fourth condition includes one or more of the following: the number of times the terminal device fails to transmit using the first coverage enhancement level and the second coverage enhancement level reaches a second value; the number of times the terminal device fails to transmit using the second coverage enhancement level reaches a third value; there is no available second coverage enhancement level in the first set of coverage enhancement levels; the terminal device receives a third indication message sent by the network device; the third indication message is used to indicate that the contention-based message 3 EDT has failed or to terminate the current uplink transmission.

[0347] In some implementations, the terminal device may also perform the following steps: the terminal device performs message 1-based EDT transmission for uplink data using a third coverage enhancement level, the third coverage enhancement level being determined according to one or more of the following: a first coverage enhancement level; a second coverage enhancement level; the reference signal received power currently measured by the terminal device; and the amount of uplink data.

[0348] In some implementations, the terminal device may also perform the following steps: the terminal device determines a first coverage enhancement level; and if the first coverage enhancement level is determined, the terminal device determines a first EDT type.

[0349] In some implementations, the terminal device may further perform the following steps: the terminal device determines a first coverage enhancement level based on second information; the second information includes one or more of the following: the amount of uplink data; the reference signal received power currently measured by the terminal device; a second set of coverage enhancement levels supported by the terminal device; at least one fourth reference signal received power threshold value for distinguishing the second set of coverage enhancement levels; and at least one fourth maximum transport block size corresponding to the second set of coverage enhancement levels.

[0350] In some implementations, the terminal device may also perform the following steps: if a fifth condition is met, the terminal device determines that the first EDT type is a contention-based message 3 EDT; the fifth condition includes one or more of the following: the terminal device supports a contention-based message 3 EDT; the reference signal received power currently measured by the terminal device is greater than or equal to the fifth reference signal received power threshold; the amount of uplink data is less than the fifth maximum transmission block size.

[0351] In some implementations, the terminal device may also perform the following steps: if the fifth condition is not met, the terminal device determines that the first EDT type is an EDT based on message 1, or the terminal device does not select an EDT based on contention-based message 3.

[0352] In some implementations, the first EDT type is a contention-based message 3 EDT, and the terminal device may also perform the following steps: if the network device indicates that the uplink data transmission has failed, the terminal device re-executes at least one of the following determination procedures: first carrier; first resource pool; first subcarrier interval.

[0353] In some implementations, the first EDT type is a contention-based message 3 EDT, and the terminal device may also perform the following steps: if the sixth condition is met, the terminal device performs message 1-based EDT transmission for uplink data using the first coverage enhancement level.

[0354] In some implementations, the sixth condition includes one or more of the following: the number of times the terminal device fails to transmit using the first coverage enhancement level reaches a fourth value; the terminal device receives a fourth indication message sent by the network device; the fourth indication message is used to indicate that the contention-based message 3 EDT has failed or to terminate the current uplink transmission.

[0355] In some implementations, the first coverage enhancement level satisfies a seventh condition, which includes one or more of the following: the reference signal received power currently measured by the terminal device is less than a sixth reference signal received power threshold; the sixth reference signal received power threshold is a threshold value corresponding to the first coverage enhancement level among at least one fourth reference signal received power threshold; the amount of uplink data is less than or equal to a sixth maximum transport block size; and the sixth maximum transport block size is the maximum transport block size corresponding to the first coverage enhancement level among at least one fourth maximum transport block size.

[0356] In some implementations, the first EDT type is either message-1 based EDT or contention-based message-3 based EDT, and the network device may also perform the following steps: the network device receives the uplink data sent by the terminal device using the fourth coverage enhancement level.

[0357] In some implementations, the terminal device may also perform the following steps: if the eighth condition is met, the terminal device performs contention-based EDT transmission of message 3 or message 1 based EDT transmission for uplink data using the fourth coverage enhancement level; the fourth coverage enhancement level is a coverage enhancement level in the second set of coverage enhancement levels that is higher than the first coverage enhancement level.

[0358] In some implementations, the eighth condition is that the number of times the terminal device fails to transmit using the first coverage enhancement level reaches a fifth value.

[0359] In some implementations, the fourth coverage enhancement level is the next higher coverage enhancement level in the second set of coverage enhancement levels than the first coverage enhancement level.

[0360] In some implementations, the fourth coverage enhancement level is the coverage enhancement level that satisfies the ninth condition.

[0361] In some implementations, the fourth coverage enhancement level is the coverage enhancement level in the second set of coverage enhancement levels that is higher than the first coverage enhancement level and is the first to satisfy the ninth condition.

[0362] In some implementations, the ninth condition includes one of the following: the reference signal received power currently measured by the terminal device is less than the seventh reference signal received power threshold; the seventh reference signal received power threshold is a threshold value used to distinguish between the fourth coverage enhancement level and the first coverage enhancement level among at least one fourth reference signal received power threshold value; the amount of uplink data is less than or equal to the seventh maximum transmission block size; the seventh maximum transmission block size is the maximum transmission block size corresponding to the fourth coverage enhancement level among at least one fourth maximum transmission block size.

[0363] In some implementations, the terminal device is an NB-IoT device, and the terminal device may also perform the following steps: the terminal device determines a first carrier from a plurality of carriers corresponding to a first coverage enhancement level according to a first parameter; the plurality of carriers includes anchored carriers and non-anchored carriers.

[0364] In some implementations, the terminal device may also perform the following steps: the terminal device determines a first conflict resolution algorithm based on the fifth information; the first conflict resolution algorithm is any one of the following: slotted Aloha algorithm; diversity slotted Aloha algorithm.

[0365] In some implementations, the fifth information includes one or more of the following: first capability information of the terminal device; the first capability information includes capability information supporting the slotted Aloha algorithm and / or capability information supporting the diversity slotted Aloha algorithm; and second parameters.

[0366] In some implementations, the first resource pool is any one of the following: an OCC-based contention-based message 3EDT resource pool; or an OCC-free contention-based message 3EDT resource pool.

[0367] In some implementations, the terminal device may further perform the following steps: if a ninth condition is met, the terminal device determines the first resource pool as an OCC-based contention-based message 3EDT resource pool; the ninth condition includes one or more of the following: the terminal device supports OCC-based contention-based message 3EDT transmission; the network device configures at least one OCC-based contention-based message 3EDT resource pool; the reference signal received power currently measured by the terminal device is located in the first reference signal received power range corresponding to any one of the at least one OCC-based contention-based message 3EDT resource pools.

[0368] In some implementations, the terminal device is an NB-IoT device, and the terminal device may also perform the following steps: the terminal device determines a first subcarrier interval based on seventh information; the seventh information includes one or more of the following: second capability information of the terminal device; the second capability information includes at least one subcarrier interval supported by the terminal device; first indication information sent by the network device; the first indication information is used to indicate the first subcarrier interval; and TA validity information of the terminal device.

[0369] In some implementations, the configuration information sent by the network device to the terminal device includes one or more of the following: a first reference signal received power threshold; a fifth reference signal received power threshold; a first maximum transmission block size; a fifth maximum transmission block size; a first set of coverage enhancement levels; a second set of coverage enhancement levels; at least one second reference signal received power threshold; at least one fourth reference signal received power threshold; at least one second maximum transmission block size; at least one fourth maximum transmission block size; a first value; a second value; a third value; a fourth value; a fifth value; a first parameter; a second parameter; and a first reference signal received power range.

[0370] In summary, according to the data transmission method of the embodiments of this application, the terminal device can perform different EDT transmissions for uplink data according to different strategies, which can improve the transmission efficiency and communication quality of EDT.

[0371] The data transmission method provided in the embodiments of this application has been described above. To facilitate understanding of the embodiments of this application, the following describes possible implementation schemes of the random access method applicable to the embodiments of this application based on the interaction process between the UE (terminal device) and the network (network device).

[0372] Example 1: First select CB-Msg3 EDT (the contention-based message 3 EDT in the above examples) or traditional EDT (the message 1-based EDT in the above examples), then select CE level.

[0373] The UE first selects CB-Msg3 EDT / traditional EDT, then selects CE level, and finally selects carrier (if the UE is NB-IoT).

[0374] If you choose CB-Msg3 EDT, you need to select the CB-Msg3 EDT resource pool based on OCC / the CB-Msg3 EDT resource pool not based on OCC, the numberology, and SA / DSA;

[0375] Set different CE levels for the traditional EDT and CB-Msg3 EDT respectively. The traditional EDT and CB-Msg3 EDT may have some of the same CE levels.

[0376] The specific implementation process of this embodiment is as follows:

[0377] Step 1: The UE receives EDT configuration information from the network. The EDT configuration information includes first configuration information for EDT type selection, for example:

[0378] (1) A first RSRP threshold (the first reference signal received power threshold in the above embodiment) and / or a first maximum TBS (the first maximum transmission block size in the above embodiment) for the selection of CB-Msg3 EDT or conventional EDT (i.e., Rel-15 PRACH-based EDT).

[0379] In some embodiments, the first maximum TBS may not be configured. In this case, the first maximum TBS is the maximum value among a plurality of second maximum TBSs (at least one second maximum transport block size in the above embodiments).

[0380] In some embodiments, when an OCC-based EDT resource pool is configured, an additional dedicated first RSRP threshold (i.e., fifth RSRP threshold) is configured to support the selection of CB-Msg3 EDT or traditional EDT for OCC-based UEs.

[0381] (2) Multiple second RSRP thresholds (at least one second reference signal received power threshold in the above embodiments) (the number of which is the number of CE levels minus 1) and / or multiple second maximum TBSs (the number of which corresponds to the number of CE levels), per-CE level configuration, for the selection of CE levels.

[0382] In some embodiments, the CB-Msg3 EDT can reuse the CE level definition and threshold for PRACH in the traditional EDT (Legacy EDT), which means no additional signaling is required; alternatively, the Legacy EDT and CB-Msg3 EDT can be configured separately, which means that the two EDTs have different CE level definitions and thresholds.

[0383] In some embodiments, a dedicated second maximum TBS may not be configured for some or all CE levels. If no TBS is configured for some CE levels, the first maximum TBS is used. If no TBS is configured for all CE levels, further TBS determination is not required during CE level selection.

[0384] (3) The first Probability parameter is used for Anchor / non-Anchor carrier selection (only applicable to NB-IoT UE).

[0385] (4) Number of Msg3 replicas: 1 (SA) / 2 / 3 / 4, configured for each CE level, used by the UE to determine SA (Slot Aloha) or DSA (Diversity Slot Aloha).

[0386] (5) Multiple third RSRP thresholds for a single CE level configuration for selecting an OCC-based / non-OCC-based EDT resource pool and for selecting between multiple OCC-based EDT resource pools.

[0387] In some embodiments, two third RSRP thresholds (one upper threshold and one lower threshold) are configured for each OCC-based EDT resource pool (the first reference signal received power range in the above embodiments).

[0388] (6) The fourth RSRP threshold and / or TA validity parameters (TA validity information in the above embodiments) are used for subcarrier spacing (Numerology) selection (only applicable to NB-IoT UE, i.e., 15kHz SCS or 3.75kHz SCS for CB-Msg3 PUSCH resources). The TA validity parameters (timer, RSRP change threshold) need to be provided additionally via dedicated signaling.

[0389] Step 2: When uplink data arrives at the UE and triggers EDT transmission, the UE selects the EDT type based on the first configuration information. The selection process is as follows.

[0390] (1) First, select between CB-Msg3 EDT and traditional EDT, based on UE capabilities and / or the first RSRP threshold and / or the first maximum TBS, for example:

[0391] In some embodiments, the UE may select / choose CB-Msg3 EDT if at least one of the following conditions is met: (a) the UE is capable of supporting it; (b) the RSRP measured by the UE's Serving Cell is greater than or equal to the first RSRP threshold; (c) the amount of uplink data of the UE is less than the first maximum TBS.

[0392] Otherwise, the UE selects the traditional EDT or does not select CB-Msg3 EDT.

[0393] In some embodiments, if the UE supports OCC-based CB-Msg3 EDT and a fifth RSRP threshold is configured, condition (b) is changed to the RSRP measured by the UE's Serving Cell being greater than or equal to the fifth RSRP threshold.

[0394] (2) Then perform CE level selection: For CB-Msg3 EDT CE level selection (the traditional EDT CE level selection is existing technology and will not be elaborated here), based on UE capabilities and / or network configuration and / or multiple second RSRP thresholds and / or multiple second maximum TBSs, for example (taking 4 CE levels as an example):

[0395] In some embodiments, if the UE is capable of supporting CE level 3, and the network is configured with a second RSRP threshold and a second maximum TBS for CE level 3, and the RSRP measured by the UE's Serving Cell is less than the second RSRP threshold for CE level 3, and the amount of uplink data for the UE is less than the second maximum TBS for CE level 3, then the UE selects CE level 3.

[0396] Otherwise, if the UE is capable of supporting CE level 2, and the network is configured with a second RSRP threshold and a second maximum TBS for CE level 2, and the RSRP measured by the UE's Serving Cell is less than the second RSRP threshold for CE level 2, and the amount of uplink data for the UE is less than the second maximum TBS for CE level 2, then the UE selects CE level 2.

[0397] Otherwise, if the UE is capable of supporting CE level 1, and the network is configured with a second RSRP threshold and a second maximum TBS for CE level 1, and the RSRP measured by the UE's Serving Cell is less than the second RSRP threshold for CE level 1, and the amount of uplink data for the UE is less than the second maximum TBS for CE level 1, then the UE selects CE level 1.

[0398] Otherwise, the UE selects CE level 0.

[0399] In some embodiments, the above only illustrates the case based on UE capabilities, network configuration, multiple second RSRP thresholds, and multiple second maximum TBSs. Optionally, TBS can be determined without first selecting a CE level, for example: first select a CE level based on UE capabilities, network configuration, and multiple second RSRP thresholds; after selecting a CE level, further determine if the amount of uplink data from the UE is greater than the second maximum TBS of the selected CE level, then cancel the CB-Msg3 EDT transmission.

[0400] The following selection dimensions are performed after steps (1) and (2) in step 2. The selection dimensions can be freely arranged or combined without restriction:

[0401] (3) If the terminal device is an NB-IoT device, then an Anchor / non-Anchor carrier selection is performed based on the first Probability parameter (the first parameter in the above embodiment), for example:

[0402] In some embodiments, if multiple carriers provide CB-Msg3 EDT resource pools for the same CE level, the UE randomly selects one of the carriers using the following selection probabilities: the selection probability of the CB-Msg3 EDT resource pool for the Anchor carrier is the first Probability parameter; the selection probability of the CB-Msg3 EDT resource pool for all non-anchor carriers is equal, which is (1 - the first Probability parameter) / the number of non-anchor carriers.

[0403] In some embodiments, there may be multiple first probability parameters, each corresponding to a carrier, and the sum of the first probability parameters of all carriers is 1.

[0404] (4) Perform SA / DSA selection based on UE capabilities and / or network configuration (i.e., the number of Msg3 replicas, including values ​​1 / 2 / 3 / 4, where 1 represents SA, and 2 / 3 / 4 represent DSA and the number of Msg3 replicas), for example:

[0405] In some embodiments, for a CE level, if the UE supports DSA and the network is configured with a number of Msg3 replicas, the UE performs CB-Msg3 transmission based on SA (configured with 1 Msg3 replica) or DSA (configured with 2 / 3 / 4 Msg3 replicas) according to the number of Msg3 replicas configured by the network.

[0406] Otherwise, if the UE does not support DSA or the network does not configure the number of Msg3 replicas, the UE performs SA-based CB-Msg3 transmission, i.e., the number of Msg3 replicas is 1.

[0407] (5) Select the CB-Msg3 EDT resource pool based on / not based on OCC, according to UE capabilities and / or network configuration and / or multiple third RSRP thresholds (e.g., configure two third RSRP thresholds for each OCC-based EDT resource pool (one upper threshold and one lower threshold, or one upper threshold and one range, or one lower threshold and one range)). For example:

[0408] In some embodiments, if the UE capability supports OCC-based CB-Msg3 EDT transmission, and the network is configured with a non-OCC-based CB-Msg3 EDT resource pool and one or more OCC-based CB-Msg3 EDT resource pools: the UE determines whether to use OCC-based EDT resources or non-OCC-based EDT resources based on RSRP measurement results. Specifically, if the UE's RSRP measurement value is within the RSRP range corresponding to an OCC-based EDT resource pool, the UE selects / can choose to use resources in that OCC-based EDT resource pool; otherwise, the UE selects to use resources in a non-OCC-based EDT resource pool, or in other words, the UE cannot choose to use resources in an OCC-based EDT resource pool.

[0409] Otherwise, the UE chooses to use resources in the EDT resource pool that are not based on OCC transmission; in other words, the UE cannot choose to use resources in the EDT resource pool that are based on OCC transmission.

[0410] (6) If the terminal device is an NB-IoT device, select the Numerology (subcarrier spacing) (i.e., 15kHz SCS or 3.75kHz SCS), based on the UE capabilities and / or network configuration and / or the fourth RSRP threshold and / or TA validity parameters:

[0411] In some embodiments, a UE may use 3.75kHz SCS for CB-Msg3 NPUSCH transmission if one or more of the following conditions are met: (a) the UE is capable of supporting 3.75kHz SCS NPUSCH; or (b) the network configuration indicates that 3.75kHz SCS is available.

[0412] In some embodiments, a UE may use 15kHz SCS for CB-Msg3 NPUSCH transmission if one or more of the following conditions are met: (a) the UE is capable of supporting 15kHz SCS NPUSCH; (b) the network configuration indicates that 15kHz SCS is available; or (c) the UE's current TA is valid (timer is running and / or RSRP change is less than the RSRP change threshold).

[0413] In some embodiments, if both 3.75kHz and 15kHz SCS are available, the UE selects the SCS based on the RSRP measurement value. Specifically, if the UE's RSRP measurement value is less than the fourth RSRP threshold, the UE selects the 3.75kHz SCS (or the UE cannot select the 15kHz SCS); otherwise, the UE selects / can select the 15kHz SCS.

[0414] Steps 3 / 4: The UE performs EDT transmission according to the selected EDT type and EDT resources, and receives the response.

[0415] Step 5: UE rollback behavior in case of EDT transmission failure (e.g., contention resolution timer timeout). For CB-Msg3 EDT, rollback is performed first at the CE level, followed by rollback for both CB-Msg3 EDT and traditional EDT.

[0416] (1) After the CB-Msg3 EDT transmission fails, the UE continues to attempt CB-Msg3 transmission at the current CE level until the number of CB-Msg3 transmission attempts reaches (greater than or equal to) the first maximum number of attempts (the first value in the above embodiment).

[0417] In some embodiments, the first maximum number of attempts corresponds to the maximum number of attempts the UE makes for this CB-Msg3 transmission at the current CE level (first CE level), and is configured by the network, such as through system messages.

[0418] In some embodiments, the UE re-executes at least one of the following selections each time a CB-Msg3 attempt is made: (a) selection of CB-Msg3 EDT resource pool based on / not based on OCC; (b) Numerology selection (only applicable to NB-IoT UEs, i.e., 15kHz SCS or 3.75kHz SCS for CB-Msg3 PUSCH resources); (c) Anchor / non-anchor carrier selection (only applicable to NB-IoT UEs).

[0419] (2) For CB-Msg3 EDT, after the number of times the UE performs CB-Msg3 transmission in the current CE level (first CE level) is greater than or equal to the first maximum number of attempts, the UE performs CE level backoff, that is, the UE backoffs to the second CE level (for example, backoffs to the next CE level, such as from CE level 1 to CE level 2), that is, the UE uses the CB-Msg3 transmission resources associated with the second CE level to attempt retransmission;

[0420] In some embodiments, when calculating the number of CB-Msg3 transmissions, N transmissions of Msg3 replicas in DSA mode are counted as one CB-Msg3 transmission (Msg3 transmissions in SA mode are counted as one CB-Msg3 transmission).

[0421] In some embodiments, when calculating the number of CB-Msg3 transmissions, N Msg3 replica transmissions in DSA mode are counted as N CB-Msg3 transmissions (Msg3 transmissions in SA mode are counted as 1 CB-Msg3 transmission).

[0422] In some embodiments, when the UE falls back to the second CE level, the UE re-checks the TBS and / or RSRP. In one implementation, the second CE level is the next CE level (i.e., the first CE level plus one CE level as the second CE level, such as from CE level 1 to CE level 2). The UE determines that the second CE level is available based on the second maximum TBS (the third maximum transport block size in the above embodiments) and / or the second RSRP threshold (the third reference signal received power threshold in the above embodiments) of the second CE level (uplink data is less than or equal to the second maximum TBS and / or the RSRP measurement value of the serving cell measured by the UE is less than the second RSRP threshold). If the second CE level is available, the UE falls back to the second CE level; otherwise, the UE cancels the CB-Msg3 EDT transmission, and / or the UE falls back to the legacy EDT.

[0423] In some embodiments, when the UE falls back to the second CE level, the UE rechecks the TBS and / or RSRP. In another implementation, the second CE level is the next available CE level, which is determined by the UE based on the second maximum TBS and the second RSRP threshold. (For example, if the UE's first CE level is CE level 0, CE level 1 is not possible due to unmet TBS and / or RSRP conditions, but CE level 2 meets the conditions, then the second CE level is CE level 2.) If no CE level is available, the UE cancels the CB-Msg3 EDT transmission, and / or, the UE falls back to the legacy EDT.

[0424] (3) For CB-Msg3 EDT, after the CE level rollback is completed, the CB-Msg3 EDT rollback to the traditional EDT is performed based on one of the following conditions: the UE attempts data transmission using the traditional EDT resources configured by the network, which are related to the third CE level: (a) The number of times the UE performs this CB-Msg3 transmission is greater than or equal to the third maximum number of attempts (the second value in the above embodiment), which is the maximum number of attempts for the total number of CB-Msg3 transmissions (which may include attempts at one or more CE levels), configured by the network through system messages; (b) The UE has no available CE level (as before); (c) The number of attempts by the UE on the second CE level reaches the second maximum number of attempts for the second CE level (the third value in the above embodiment), configured by the network through system messages; (d) The UE receives a network indication that the CB-Msg3 transmission has failed or terminated.

[0425] In some embodiments, the third CE level is determined based on either the first CE level or the second CE level.

[0426] In some embodiments, the third CE level has the same index as the first / second CE level. For example, in the case where the first CE level of CB-Msg3 EDT transmission is CE level 1, the third CE level of conventional EDT transmission is determined to be CE level 1.

[0427] In some embodiments, the third CE level is determined based on the RSRP currently measured by the UE and / or the current uplink data volume, i.e., the UE rechecks the TBS and / or RSRP.

[0428] In some embodiments, the third CE level is determined based on the RSRP and / or uplink data volume when the first CE level or the second CE level is determined, meaning the UE does not need to recheck the TBS and / or RSRP.

[0429] It is understandable that in Example 2, the method of first selecting CB-Msg3 or legacy EDT and then selecting CE level allows for setting different CE levels and thresholds for PRACH and CB-Msg3 PUSCH respectively. Compared to the method where PRACH and CB-Msg3 PUSCH share the same CE level and threshold, this method is more flexible.

[0430] Example 2: First select CE level, then select CB-Msg3 EDT or traditional EDT.

[0431] The UE first selects the CE level, then selects the CB-Msg3 EDT / traditional EDT, and finally selects the carrier (if the UE is NB-IoT).

[0432] If you choose CB-Msg3 EDT, you need to select the CB-Msg3 EDT resource pool based on OCC / the CB-Msg3 EDT resource pool not based on OCC, the numberology, and SA / DSA;

[0433] Set the same CE level for both traditional EDT and CB-Msg3 EDT.

[0434] The specific implementation process of this embodiment is as follows:

[0435] Step 1: The UE receives EDT configuration information from the network. The EDT configuration information includes first configuration information for EDT type selection, for example:

[0436] (1) Multiple second RSRP thresholds (at least one fourth reference signal received power threshold in the above embodiments) and / or multiple second maximum TBSs (at least one fourth maximum transmission block size in the above embodiments), per-CE level configuration, for CE level selection.

[0437] In some embodiments, the CB-Msg3 EDT reuses the CE level definition and thresholds for PRACH in the Legacy EDT, which means that no additional signaling is required.

[0438] In some embodiments, a dedicated second maximum TBS may not be configured for some or all CE levels. If no TBS is configured for some CE levels, the first maximum TBS is used. If no TBS is configured for all CE levels, further TBS determination is not required during CE level selection.

[0439] (2) The first RSRP threshold (the fifth reference signal received power threshold in the above embodiment) and / or the first maximum TBS (the fifth maximum transmission block size in the above embodiment), per-CE level configuration, are used for the selection of CB-Msg3 EDT or conventional EDT.

[0440] In some embodiments, the first maximum TBS may not be configured. In this case, for a CE level, the first maximum TBS is the same as the second maximum TBS.

[0441] In some embodiments, when an OCC-based EDT resource pool is configured, an additional dedicated first RSRP threshold (i.e., fifth RSRP threshold) is configured to support the selection of CB-Msg3 EDT or traditional EDT for OCC-based UEs.

[0442] (3) The first Probability parameter is used for Anchor / non-Anchor carrier selection (only applicable to NB-IoT UE).

[0443] (4) Number of Msg3 replicas: 1 (SA) / 2 / 3 / 4, configured for each CE level, used by the UE to determine SA or DSA.

[0444] (5) Multiple third RSRP thresholds for a single CE level configuration for selecting an OCC-based / non-OCC-based EDT resource pool and for selecting between multiple OCC-based EDT resource pools.

[0445] In some embodiments, two third RSRP thresholds (one upper threshold and one lower threshold) are configured for each OCC-based EDT resource pool.

[0446] (6) The fourth RSRP threshold and / or TA validity parameters are used for Numerology selection (only applicable to NB-IoT UEs, i.e., 15kHz SCS or 3.75kHz SCS for CB-Msg3 PUSCH resources). The TA validity parameters (timer, RSRP change threshold) need to be provided additionally via dedicated signaling.

[0447] Step 2: When the UE uplink data arrives and triggers EDT transmission, the UE selects the EDT type according to the first configuration information. The selection process is as follows.

[0448] (1) First, select the CE level: For CB-Msg3 EDT and traditional EDT, the CE level selection is based on UE capabilities and / or network configuration and / or multiple second RSRP thresholds and / or multiple second maximum TBSs, for example (taking 4 CE levels as an example):

[0449] In some embodiments, if the UE is capable of supporting CE level 3, and the network is configured with a second RSRP threshold and a second maximum TBS for CE level 3, and the RSRP measured by the UE's Serving Cell is less than the second RSRP threshold for CE level 3, and the amount of uplink data for the UE is less than the second maximum TBS for CE level 3, then the UE selects CE level 3.

[0450] Otherwise, if the UE is capable of supporting CE level 2, and the network is configured with a second RSRP threshold and a second maximum TBS for CE level 2, and the RSRP measured by the UE's Serving Cell is less than the second RSRP threshold for CE level 2, and the amount of uplink data for the UE is less than the second maximum TBS for CE level 2, then the UE selects CE level 2.

[0451] Otherwise, if the UE is capable of supporting CE level 1, and the network is configured with a second RSRP threshold and a second maximum TBS for CE level 1, and the RSRP measured by the UE's Serving Cell is less than the second RSRP threshold for CE level 1, and the amount of uplink data for the UE is less than the second maximum TBS for CE level 1, then the UE selects CE level 1.

[0452] Otherwise, the UE selects CE level 0.

[0453] In some embodiments, the above only illustrates the case based on UE capabilities, network configuration, multiple second RSRP thresholds, and multiple second maximum TBSs. Optionally, TBS can be omitted initially, such as based on UE capabilities, network configuration, and multiple second RSRP thresholds. In this case, after selecting the CE level, a further determination is made: if the amount of uplink data from the UE exceeds the second maximum TBS of the selected CE level, then CB-Msg3 EDT and traditional EDT transmissions are cancelled.

[0454] (2) For a given CE level, the choice between CB-Msg3 EDT and traditional EDT is made based on UE capabilities and / or the first RSRP threshold and / or the first maximum TBS, for example:

[0455] In some embodiments, the UE may select / choose CB-Msg3 EDT if at least one of the following conditions is met: (a) the UE is capable of supporting it; (b) the RSRP measured by the UE's Serving Cell is greater than or equal to the first RSRP threshold; (c) the amount of uplink data of the UE is less than the first maximum TBS.

[0456] Otherwise, the UE selects the traditional EDT or does not select CB-Msg3 EDT.

[0457] In some embodiments, if the UE supports OCC-based CB-Msg3 EDT and a fifth RSRP threshold is configured, condition (b) is changed to the RSRP measured by the UE's Serving Cell being greater than or equal to the fifth RSRP threshold.

[0458] The following selection dimensions are performed after steps (1) and (2) in step 2. The selection dimensions can be freely arranged or combined without restriction:

[0459] (3) If the terminal device is an NB-IoT device, then an Anchor / non-Anchor carrier selection is performed based on the first Probability parameter (the first parameter in the above embodiment), for example:

[0460] In some embodiments, if multiple carriers provide CB-Msg3 EDT resource pools for the same CE level, the UE randomly selects one of the carriers using the following selection probabilities: the selection probability of the CB-Msg3 EDT resource pool for the Anchor carrier is the first Probability parameter; the selection probability of the CB-Msg3 EDT resource pool for all non-anchor carriers is equal, which is (1 - the first Probability parameter) / the number of non-anchor carriers.

[0461] In some embodiments, there may be multiple first probability parameters, each corresponding to a carrier, and the sum of the first probability parameters of all carriers is 1.

[0462] (4) Perform SA / DSA selection based on UE capabilities and / or network configuration (i.e., the number of Msg3 replicas, including values ​​1 / 2 / 3 / 4, where 1 represents SA, and 2 / 3 / 4 represent DSA and the number of Msg3 replicas), for example:

[0463] In some embodiments, for a CE level, if the UE supports DSA and the network is configured with a number of Msg3 replicas, the UE performs CB-Msg3 transmission based on SA (configured with 1 Msg3 replica) or DSA (configured with 2 / 3 / 4 Msg3 replicas) according to the number of Msg3 replicas configured by the network.

[0464] Otherwise, if the UE does not support DSA or the network does not configure the number of Msg3 replicas, the UE performs SA-based CB-Msg3 transmission, i.e., the number of Msg3 replicas is 1.

[0465] (5) Select the CB-Msg3 EDT resource pool based on / not based on OCC, according to UE capabilities and / or network configuration and / or multiple third RSRP thresholds (e.g., configure two third RSRP thresholds for each OCC-based EDT resource pool (one upper threshold and one lower threshold, or one upper threshold and one range, or one lower threshold and one range)). For example:

[0466] In some embodiments, if the UE capability supports OCC-based CB-Msg3 EDT transmission, and the network is configured with a non-OCC-based CB-Msg3 EDT resource pool and one or more OCC-based CB-Msg3 EDT resource pools: the UE determines whether to use OCC-based EDT resources or non-OCC-based EDT resources based on RSRP measurement results. Specifically, if the UE's RSRP measurement value is within the RSRP range corresponding to an OCC-based EDT resource pool, the UE selects / can choose to use resources in that OCC-based EDT resource pool; otherwise, the UE selects to use resources in a non-OCC-based EDT resource pool, or in other words, the UE cannot choose to use resources in an OCC-based EDT resource pool.

[0467] Otherwise, the UE chooses to use resources in the EDT resource pool that are not based on OCC transmission; in other words, the UE cannot choose to use resources in the EDT resource pool that are based on OCC transmission.

[0468] (6) If the terminal device is an NB-IoT device, select the Numerology (subcarrier spacing) (i.e., 15kHz SCS or 3.75kHz SCS), based on the UE capabilities and / or network configuration and / or the fourth RSRP threshold and / or TA validity parameters:

[0469] In some embodiments, a UE may use 3.75kHz SCS for CB-Msg3 NPUSCH transmission if one or more of the following conditions are met: (a) the UE is capable of supporting 3.75kHz SCS NPUSCH; or (b) the network configuration indicates that 3.75kHz SCS is available.

[0470] In some embodiments, a UE may use 15kHz SCS for CB-Msg3 NPUSCH transmission if one or more of the following conditions are met: (a) the UE is capable of supporting 15kHz SCS NPUSCH; (b) the network configuration indicates that 15kHz SCS is available; or (c) the UE's current TA is valid (timer is running and / or RSRP change is less than the RSRP change threshold).

[0471] In some embodiments, if both 3.75kHz and 15kHz SCS are available, the UE selects the SCS based on the RSRP measurement value. Specifically, if the UE's RSRP measurement value is less than the fourth RSRP threshold, the UE selects the 3.75kHz SCS (or the UE cannot select the 15kHz SCS); otherwise, the UE selects / can select the 15kHz SCS.

[0472] Steps 3 / 4: The UE performs EDT transmission according to the selected EDT type and EDT resources, and receives the response.

[0473] Step 5: UE rollback behavior in case of EDT transmission failure (e.g., contention resolution timer timeout). Within a CE level, rollback occurs first between CB-Msg3 EDT and traditional EDT, followed by rollback between CE levels.

[0474] (1) After the CB-Msg3 EDT transmission fails, the UE continues to attempt CB-Msg3 transmission at the current CE level (first CE level) until the number of CB-Msg3 transmission attempts reaches (greater than or equal to) the fourth maximum number of attempts (the fourth value in the above embodiment).

[0475] In some embodiments, the fourth maximum number of attempts is the maximum number of attempts for CB-Msg3 transmission under the current CE level (first CE level) of the UE, configured by the network, such as through system messages.

[0476] In some embodiments, the UE re-executes at least one of the following selections each time a CB-Msg3 attempt is made: (a) selection of CB-Msg3 EDT resource pool based on / not based on OCC; (b) Numerology selection (only applicable to NB-IoT UEs, i.e., 15kHz SCS or 3.75kHz SCS for CB-Msg3 PUSCH resources); (c) Anchor / non-Anchor carrier selection (only applicable to NB-IoT UEs).

[0477] In some embodiments, when calculating the number of CB-Msg3 transmissions, N Msg3 replica transmissions in DSA mode are counted as one CB-Msg3 transmission (Msg3 transmissions in SA mode are counted as one CB-Msg3 transmission).

[0478] In some embodiments, when calculating the number of CB-Msg3 transmissions, N Msg3 replica transmissions in DSA mode are counted as N CB-Msg3 transmissions (Msg3 transmissions in SA mode are counted as 1 CB-Msg3 transmission).

[0479] (2) For CB-Msg3 EDT, the UE performs a fallback from CB-Msg3 EDT to traditional EDT at the current CE level (first CE level) based on one of the following conditions. That is, at the first CE level, the UE attempts to transmit data using traditional EDT resources configured by the network based on one of the following conditions, where the traditional EDT resources are associated with the first CE level (i.e., the network configures associated CB-Msg3 EDT and traditional EDT resources for the first CE level simultaneously): (a) the number of attempts for CB-Msg3 transmission reaches (greater than or equal to) the fourth maximum number of attempts; (b) the UE receives a network indication that CB-Msg3 transmission has failed or terminated.

[0480] In some embodiments, the availability of legacy EDT resources at the first CE level is determined based on the RSRP currently measured by the UE and / or the current uplink data volume, i.e., the UE re-examines the TBS and / or RSRP.

[0481] (3) After the number of times the UE performs CB-Msg3 EDT and / or traditional EDT transmission in the current CE level (first CE level) reaches the fifth maximum number of attempts (the fifth value in the above embodiment), the UE performs a CE level backoff, that is, the UE backoffs to the second CE level (for example, backoffs to the next CE level, such as from CE level 1 to CE level 2), that is, the UE uses the CB-MSG3 EDT and / or traditional EDT transmission resources associated with the second CE level to attempt retransmission.

[0482] In some embodiments, the fifth maximum number of attempts is the maximum number of attempts for the traditional EDT, configured by the network and is a parameter of the prior art. In this case, the UE uses different COUNT counts for the number of attempts in CB-Msg3 EDT and traditional EDT within a CE level; or, when falling back from CB-Msg3 EDT to traditional EDT, the UE clears the COUNT count.

[0483] In some embodiments, the fifth maximum number of attempts is the sum of the maximum number of attempts for the traditional EDT and the maximum number of attempts for the CB-Msg3 EDT (the fourth maximum number of attempts), and either the fifth maximum number of attempts or the maximum number of attempts for the traditional EDT is configured by the network. In this case, for a CE level, the UE uses the same COUNT to count the number of attempts for both the CB-Msg3 EDT and the traditional EDT.

[0484] In some embodiments, when the UE falls back to the second CE level, the UE re-checks the TBS and / or RSRP. In one implementation, the second CE level is the next CE level (i.e., the first CE level plus one CE level as the second CE level, such as from CE level 1 to CE level 2). The UE determines whether the second CE level is available based on the second maximum TBS and / or the second RSRP threshold of the second CE level (uplink data is less than or equal to the second maximum TBS and / or the serving cell RSRP measured by the UE is less than the second RSRP threshold). If the second CE level is available, the UE falls back to the second CE level; otherwise, the UE cancels EDT transmissions (CB-Msg3 EDT and legacy EDT).

[0485] In some embodiments, when the UE falls back to the second CE level, the UE rechecks the TBS and / or RSRP. In another implementation, the second CE level is the next available CE level, which is determined by the UE based on the second maximum TBS and the second RSRP threshold. (For example, if the UE's first CE level is CE level 0, and CE level 1 is not possible due to unmet TBS and / or RSRP conditions, but CE level 2 meets the conditions, then the second CE level is CE level 2.) If no CE level is available, the UE cancels EDT transmissions (CB-Msg3 EDT and legacy EDT).

[0486] In some embodiments, when the UE falls back to the second CE level, the selection of CB-Msg3 EDT and traditional EDT and subsequent EDT type selection are re-executed (as in step 2); alternatively, when the UE falls back to the second CE level, the UE only performs the selection of traditional EDT.

[0487] It is understandable that in Example 2, the method of selecting the CE level first and then selecting CB-Msg3 or legacy EDT allows PRACH and CB-Msg3 PUSCH to share the same CE level and its threshold, eliminating the need to configure the CE level and its threshold separately for PRACH and CB-Msg3 PUSCH, thereby saving signaling.

[0488] The preferred embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solutions of this application, and these simple modifications all fall within the protection scope of this application. For example, the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this application will not describe the various possible combinations separately. Furthermore, various different embodiments of this application can also be arbitrarily combined, as long as they do not violate the spirit of this application, they should also be considered as the content disclosed in this application. Moreover, without conflict, the various embodiments and / or the technical features in the various embodiments described in this application can be arbitrarily combined with the prior art, and the resulting technical solutions should also fall within the protection scope of this application.

[0489] It should also be understood that in the various method embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. Furthermore, in the embodiments of this application, the terms "downlink," "uplink," and "sidelink" are used to indicate the transmission direction of signals or data. "Downlink" indicates that the transmission direction of signals or data is a first direction from the site to the user equipment in the cell; "uplink" indicates that the transmission direction of signals or data is a second direction from the user equipment in the cell to the site; and "sidelink" indicates that the transmission direction of signals or data is a third direction from user equipment 1 to user equipment 2. For example, "downlink signal" indicates that the transmission direction of the signal is the first direction. Additionally, in the embodiments of this application, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. Specifically, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0490] Figure 10 is a schematic diagram of the structure of a data transmission device 1000 provided in an embodiment of this application, applied to a terminal device. As shown in Figure 10, the data transmission device 1000 includes:

[0491] The first transmitting unit 1001 is configured to perform Early Data Transmission (EDT) for uplink data based on a first strategy; the first strategy includes one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier spacing.

[0492] In some embodiments, the data transmission apparatus 1000 further includes: a determining unit configured to determine the first EDT type; and, if the first EDT type is determined, to determine the first coverage enhancement level.

[0493] In some embodiments, the determining unit is further configured to, when a first condition is met, determine that the first EDT type is a contention-based message 3 EDT; the first condition includes one or more of the following: the terminal device supports the contention-based message 3 EDT; the reference signal received power currently measured by the terminal device is greater than or equal to a first reference signal received power threshold; the data volume of the uplink data is less than a first maximum transmission block size.

[0494] In some embodiments, the determining unit is further configured to determine that the first EDT type is an EDT based on message 1, or that the terminal device does not select the EDT based on contention-based message 3, if the first condition is not met.

[0495] In some embodiments, the determining unit is further configured to determine the first coverage enhancement level based on first information; the first information includes one or more of the following: the amount of uplink data; a first set of coverage enhancement levels supported by the terminal device on the first EDT type; at least one second reference signal received power threshold for distinguishing the first set of coverage enhancement levels; and at least one second maximum transport block size corresponding to the first set of coverage enhancement levels.

[0496] In some embodiments, the determining unit is further configured to, in the event that the network device indicates that the uplink data transmission has failed, the terminal device re-executes a determining process for at least one of the following: the first carrier; the first resource pool; the first subcarrier interval.

[0497] In some embodiments, the first transmitting unit 1001 is further configured to perform EDT transmission for the uplink data using a second coverage enhancement level when a second condition is met, wherein the second coverage enhancement level is a coverage enhancement level higher than the first coverage enhancement level in a first set of coverage enhancement levels.

[0498] In some embodiments, the first sending unit 1001 is further configured to perform message 1-based EDT transmission on the uplink data if a fourth condition is met.

[0499] In some embodiments, the first transmitting unit 1001 is further configured to perform message-1-based EDT transmission of the uplink data using a third coverage enhancement level, the third coverage enhancement level being determined according to one or more of the following: the first coverage enhancement level; the second coverage enhancement level; the reference signal received power currently measured by the terminal device; and the data volume of the uplink data.

[0500] In some embodiments, the determining unit is further configured to determine the first coverage enhancement level; and, if the first coverage enhancement level is determined, to determine the first EDT type.

[0501] In some embodiments, the determining unit is further configured to determine the first coverage enhancement level based on second information; the second information includes one or more of the following: the amount of uplink data; a second set of coverage enhancement levels supported by the terminal device; at least one fourth reference signal received power threshold for distinguishing the second set of coverage enhancement levels; and at least one fourth maximum transport block size corresponding to the second set of coverage enhancement levels.

[0502] In some embodiments, the determining unit is further configured to determine that the first EDT type is a contention-based message 3 EDT if a fifth condition is met; the fifth condition includes one or more of the following: the terminal device supports the contention-based message 3 EDT; the reference signal received power currently measured by the terminal device is greater than or equal to a fifth reference signal received power threshold; the data volume of the uplink data is less than a fifth maximum transmission block size.

[0503] In some embodiments, the determining unit is further configured to determine that the first EDT type is an EDT based on message 1, or that the terminal device does not select the EDT based on contention-based message 3, if the fifth condition is not met.

[0504] In some embodiments, the first sending unit 1001 is further configured to perform message 1-based EDT transmission of the uplink data using a first coverage enhancement level if a sixth condition is met.

[0505] In some embodiments, the first sending unit 1001 is further configured to perform contention-based EDT transmission of message 3 or message 1 based on the uplink data using a fourth coverage enhancement level when an eighth condition is met; the fourth coverage enhancement level is a coverage enhancement level in the second set of coverage enhancement levels that is higher than the first coverage enhancement level.

[0506] In some embodiments, the determining unit is further configured to determine the first carrier from a plurality of carriers corresponding to the first coverage enhancement level based on a first parameter; the plurality of carriers includes anchored carriers and non-anchored carriers.

[0507] In some embodiments, the determining unit is further configured to determine the first conflict resolution algorithm based on third information; the first conflict resolution algorithm is any one of the following: slotted Aloha algorithm; diversity slotted Aloha algorithm.

[0508] In some embodiments, the determining unit is further configured to determine the first resource pool as an OCC-based EDT resource pool if a tenth condition is met; the tenth condition includes one or more of the following: the terminal device supports OCC-based EDT transmission; the network device configures at least one OCC-based EDT resource pool; and the reference signal received power currently measured by the terminal device is located in the first reference signal received power range corresponding to any one of the at least one OCC-based EDT resource pools.

[0509] In some embodiments, the determining unit is further configured to determine the first subcarrier interval based on fourth information; the fourth information includes one or more of the following: second capability information of the terminal device; the second capability information includes at least one subcarrier interval supported by the terminal device; first indication information sent by the network device; the first indication information is used to indicate the first subcarrier interval; and TA validity information of the terminal device.

[0510] Figure 11 is a schematic diagram of the structure of a data transmission device 1100 provided in an embodiment of this application, which is applied to a network device. As shown in Figure 11, the data transmission device 1100 includes:

[0511] The first receiving unit 1101 is configured to receive uplink data; the uplink data is sent by the terminal device based on a first strategy; the first strategy includes one or more of the following: a first EDT type; a first coverage enhancement level; a first carrier; a first conflict resolution algorithm; a first resource pool; and a first subcarrier spacing.

[0512] In some embodiments, the data transmission apparatus 1000 further includes: a second sending unit configured to send fifth indication information to the terminal device; the fifth indication information is used to indicate that the uplink data transmission failed.

[0513] In some embodiments, the first receiving unit 1101 is further configured to receive the uplink data transmitted by the terminal device using a second coverage enhancement level.

[0514] In some embodiments, the first receiving unit 1101 is further configured to receive the uplink data transmitted by the terminal device using a third coverage enhancement level.

[0515] In some embodiments, the first receiving unit 1101 is further configured to receive the uplink data transmitted by the terminal device using a fourth coverage enhancement level.

[0516] Figure 12 is a schematic structural diagram of a communication device provided in an embodiment of this application. This communication device can be a terminal device or a network device. The communication device 1200 shown in Figure 12 includes a processor 1201, which can call and run computer programs from memory to implement the methods in the embodiments of this application.

[0517] Optionally, as shown in FIG12, the communication device 1200 may further include a memory 1202. The processor 1201 can retrieve and run computer programs from the memory 1202 to implement the methods in the embodiments of this application.

[0518] The memory 1202 can be a separate device independent of the processor 1201, or it can be integrated into the processor 1201.

[0519] Optionally, as shown in FIG10, the communication device 1200 may further include a transceiver 1203, and the processor 1201 may control the transceiver 1203 to communicate with other devices. Specifically, it may send information or data to other devices or receive information or data sent by other devices.

[0520] The transceiver 1203 may include a transmitter and a receiver. The transceiver 1203 may further include an antenna, and the number of antennas may be one or more.

[0521] Optionally, the communication device 1200 may specifically be a network device in the embodiments of this application, and the communication device 1200 may implement the corresponding processes implemented by the network device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0522] Optionally, the communication device 1200 may specifically be a terminal device in the embodiments of this application, and the communication device 1200 may implement the corresponding processes implemented by the terminal device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0523] Figure 13 is a schematic structural diagram of a chip provided in an embodiment of this application. The chip 1300 shown in Figure 13 includes a processor 1301, which can call and run computer programs from memory to implement the methods in the embodiments of this application.

[0524] Optionally, as shown in FIG13, chip 1300 may further include memory 1302. Processor 1301 can call and run computer programs from memory 1302 to implement the methods in the embodiments of this application.

[0525] The memory 1302 can be a separate device independent of the processor 1301, or it can be integrated into the processor 1301.

[0526] Optionally, the chip 1300 may also include an input interface 1303. The processor 1301 can control the input interface 1303 to communicate with other devices or chips, specifically, to acquire information or data sent by other devices or chips.

[0527] Optionally, the chip 1300 may also include an output interface 1304. The processor 1301 can control the output interface 1304 to communicate with other devices or chips, specifically, to output information or data to other devices or chips.

[0528] Optionally, the chip can be applied to the network device in the embodiments of this application, and the chip can implement the corresponding processes implemented by the network device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0529] Optionally, the chip can be applied to the terminal device in the embodiments of this application, and the chip can implement the corresponding processes implemented by the terminal device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0530] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0531] This application also provides a computer storage medium storing one or more programs, which can be executed by one or more processors to implement the methods in this application.

[0532] Figure 14 is a schematic block diagram of a communication system provided in an embodiment of this application. As shown in Figure 14, the communication system 1400 includes a terminal device 1401 and a network device 1402.

[0533] The terminal device 1401 can be used to implement the corresponding functions implemented by the terminal device in the above method, and the network device 1402 can be used to implement the corresponding functions implemented by the network device that interacts with the terminal device in the above method. For the sake of brevity, these will not be elaborated here.

[0534] It should be understood that the processor in the embodiments of this application may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method embodiments can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor described above can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0535] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may 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 DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0536] It should be understood that the above-described memory is exemplary and not a limiting description. For example, the memory in the embodiments of this application may also be 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 link dynamic random access memory (SLDRAM), and direct memory bus RAM (DR RAM), etc. That is to say, the memory in the embodiments of this application is intended to include, but is not limited to, these and any other suitable types of memory.

[0537] This application also provides a computer-readable storage medium for storing computer programs.

[0538] Optionally, the computer-readable storage medium can be applied to the network device in the embodiments of this application, and the computer program causes the computer to execute the corresponding processes implemented by the network device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0539] Optionally, the computer-readable storage medium can be applied to the terminal device in the embodiments of this application, and the computer program causes the computer to execute the corresponding processes implemented by the terminal device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0540] This application also provides a computer program product, including computer program instructions.

[0541] Optionally, the computer program product can be applied to the network device in the embodiments of this application, and the computer program instructions cause the computer to execute the corresponding processes implemented by the network device in the various methods of the embodiments of this application. For the sake of brevity, they will not be described in detail here.

[0542] Optionally, the computer program product can be applied to the terminal device in the embodiments of this application, and the computer program instructions cause the computer to execute the corresponding processes implemented by the terminal device in the various methods of the embodiments of this application. For the sake of brevity, they will not be described in detail here.

[0543] This application also provides a computer program.

[0544] Optionally, the computer program can be applied to the network device in the embodiments of this application. When the computer program is run on the computer, it causes the computer to execute the corresponding processes implemented by the network device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0545] Optionally, the computer program can be applied to the terminal device in the embodiments of this application. When the computer program is run on the computer, it causes the computer to execute the corresponding processes implemented by the terminal device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0546] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software 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, but such implementation should not be considered beyond the scope of this application.

[0547] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0548] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units 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 system, 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 apparatuses or units may be electrical, mechanical, or other forms.

[0549] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0550] In addition, 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.

[0551] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) 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.

[0552] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology 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 data transmission method, the method comprising: The terminal device performs Early Data Transmission Techniques (EDT) for uplink data based on a first strategy; the first strategy includes one or more of the following: First EDT type; First level of coverage enhancement; First carrier wave; First conflict resolution algorithm; First resource pool; First subcarrier spacing.

2. The method according to claim 1, wherein the first EDT type is any one of the following: EDT based on message 1; EDT based on competing message 3.

3. The method according to claim 1 or 2, further comprising: The terminal device determines the first EDT type; Upon determining the first EDT type, the terminal device determines the first coverage enhancement level.

4. The method according to claim 3, further comprising: If the first condition is met, the terminal device determines that the first EDT type is a contention-based message 3 EDT; the first condition includes one or more of the following: The terminal device supports the contention-based message 3 EDT; The reference signal received power currently measured by the terminal device is greater than or equal to the first reference signal received power threshold. The amount of data in the uplink is less than the first maximum transmission block size.

5. The method according to claim 4, further comprising: If the first condition is not met, the terminal device determines that the first EDT type is an EDT based on message 1, or the terminal device does not select the EDT based on contention-based message 3.

6. The method according to any one of claims 3-5, further comprising: The terminal device determines the first coverage enhancement level based on first information; the first information includes one or more of the following: The amount of data in the upstream data; The reference signal received power currently measured by the terminal device; The terminal device supports a first set of coverage enhancement levels on the first EDT type; At least one second reference signal received power threshold value used to distinguish the first group of coverage enhancement levels; The first set of coverage enhancement levels corresponds to at least one second maximum transport block size.

7. The method according to any one of claims 3-6, wherein the first EDT type is a contention-based message 3 EDT, and the method further comprises: If the network device indicates that the uplink data transmission has failed, the terminal device shall re-execute at least one of the following determination procedures: The first carrier; The first resource pool; The first subcarrier interval.

8. The method according to any one of claims 3-7, wherein the first EDT type is a contention-based message 3 EDT, and the method further comprises: If the second condition is met, the terminal device performs EDT transmission for the uplink data using the second coverage enhancement level.

9. The method according to claim 8, wherein the second condition is that the number of times the terminal device fails to transmit based on the first coverage enhancement level reaches a first value.

10. The method according to claim 8 or 9, wherein the second coverage enhancement level is the next higher coverage enhancement level in the first set of coverage enhancement levels.

11. The method according to any one of claims 8-10, wherein the second coverage enhancement level is a coverage enhancement level that satisfies the third condition.

12. The method according to claim 8 or 9, wherein the second coverage enhancement level is the first coverage enhancement level in the first group of coverage enhancement levels that is higher than the first coverage enhancement level and satisfies the third condition.

13. The method according to claim 11 or 12, wherein the third condition includes one or more of the following: The reference signal received power currently measured by the terminal device is less than the third reference signal received power threshold value; the third reference signal received power threshold value is the threshold value used to distinguish the second coverage enhancement level from the first coverage enhancement level among the at least one second reference signal received power threshold value. The amount of uplink data is less than or equal to the third maximum transport block size; the third maximum transport block size is the maximum transport block size corresponding to the second coverage enhancement level among the at least one second maximum transport block size.

14. The method according to any one of claims 8-13, wherein the method further comprises: If the fourth condition is met, the terminal device performs EDT transmission based on message 1 for the uplink data.

15. The method of claim 14, wherein the fourth condition comprises one or more of the following: The number of times the terminal device failed to send using the first coverage enhancement level and the second coverage enhancement level reached a second value; The number of times the terminal device failed to transmit using the second coverage enhancement level reached a third value; There is no second coverage enhancement level available in the first group of coverage enhancement levels; The terminal device receives a third indication message sent by the network device; the third indication message is used to indicate that the contention-based message 3 EDT has failed or to terminate the current uplink transmission.

16. The method according to claim 14 or 15, further comprising: The terminal device performs message 1-based EDT transmission of the uplink data using a third coverage enhancement level, the third coverage enhancement level being determined according to one or more of the following: The first coverage enhancement level; The second coverage enhancement level; The reference signal received power currently measured by the terminal device; The amount of data in the upstream data.

17. The method according to claim 1 or 2, further comprising: The terminal device determines the first coverage enhancement level; Upon determining the first coverage enhancement level, the terminal device determines the first EDT type.

18. The method according to claim 17, further comprising: The terminal device determines the first coverage enhancement level based on second information; the second information includes one or more of the following: The amount of data in the upstream data; The reference signal received power currently measured by the terminal device; The terminal device supports a second set of coverage enhancement levels; At least one fourth reference signal received power threshold value used to distinguish the second group of coverage enhancement levels; The second set of coverage enhancement levels corresponds to at least one fourth maximum transport block size.

19. The method according to claim 18, further comprising: If the fifth condition is met, the terminal device determines that the first EDT type is a contention-based message 3 EDT; the fifth condition includes one or more of the following: The terminal device supports the contention-based message 3 EDT; The reference signal received power currently measured by the terminal device is greater than or equal to the fifth reference signal received power threshold. The amount of data in the uplink is less than the fifth maximum transmission block size.

20. The method of claim 19, further comprising: If the fifth condition is not met, the terminal device determines that the first EDT type is an EDT based on message 1, or the terminal device does not select the EDT based on contention-based message 3.

21. The method according to any one of claims 17-20, wherein the first EDT type is a contention-based message 3 EDT, and the method further comprises: If the network device indicates that the uplink data transmission has failed, the terminal device shall re-execute at least one of the following determination procedures: The first carrier; The first resource pool; The first subcarrier interval.

22. The method according to claims 17-21, wherein the first EDT type is a contention-based message 3 EDT, and the method further comprises: If the sixth condition is met, the terminal device performs message 1-based EDT transmission for the uplink data using the first coverage enhancement level.

23. The method of claim 22, wherein the sixth condition comprises one or more of the following: The number of times the terminal device failed to send using the first coverage enhancement level reached a fourth value; The terminal device receives a fourth indication message sent by the network device; the fourth indication message is used to indicate that the EDT based on contention message 3 has failed or to terminate the current uplink transmission.

24. The method according to claim 22 or 23, wherein the first coverage enhancement level satisfies a seventh condition, said seventh condition including one or more of the following: The reference signal received power currently measured by the terminal device is less than the sixth reference signal received power threshold; the sixth reference signal received power threshold is the threshold value corresponding to the first coverage enhancement level among the at least one fourth reference signal received power threshold. The amount of uplink data is less than or equal to the sixth maximum transport block size; the sixth maximum transport block size is the maximum transport block size corresponding to the first coverage enhancement level among the at least one fourth maximum transport block size.

25. The method according to any one of claims 22-24, further comprising: If the eighth condition is met, the terminal device performs contention-based EDT transmission of message 3 or message 1 based EDT transmission for the uplink data using the fourth coverage enhancement level; the fourth coverage enhancement level is a coverage enhancement level in the second set of coverage enhancement levels that is higher than the first coverage enhancement level.

26. The method of claim 25, wherein the eighth condition is that the number of times the terminal device fails to transmit using the first coverage enhancement level reaches a fifth value.

27. The method according to claim 25 or 26, wherein the fourth coverage enhancement level is the next higher coverage enhancement level in the second set of coverage enhancement levels than the first coverage enhancement level.

28. The method according to any one of claims 25-27, wherein the fourth coverage enhancement level is a coverage enhancement level that satisfies the ninth condition.

29. The method according to claim 25 or 26, wherein the fourth coverage enhancement level is the coverage enhancement level in the second group of coverage enhancement levels that is higher than the first coverage enhancement level and is the first to satisfy the ninth condition.

30. The method according to claim 28 or 29, wherein the ninth condition includes one of the following: The reference signal received power currently measured by the terminal device is less than the seventh reference signal received power threshold; the seventh reference signal received power threshold is the threshold value used to distinguish the fourth coverage enhancement level from the first coverage enhancement level among the at least one fourth reference signal received power threshold; The amount of uplink data is less than or equal to the seventh maximum transport block size; the seventh maximum transport block size is the maximum transport block size corresponding to the fourth coverage enhancement level among the at least one fourth maximum transport block size.

31. The method according to any one of claims 1-6 or 17-20, wherein the terminal device is an NB-IoT device, and the method further comprises: The terminal device determines the first carrier from multiple carriers corresponding to the first coverage enhancement level according to the first parameter; The plurality of carriers includes anchored carriers and non-anchored carriers.

32. The method according to any one of claims 1-6, 17-20 or 31, wherein the method further comprises: The terminal device determines the first conflict resolution algorithm based on the third information; the first conflict resolution algorithm is any one of the following: Slotted Aloha algorithm; Diversity Slotted Aloha Algorithm.

33. The method of claim 32, wherein the third information includes one or more of the following: The terminal device's first capability information; the first capability information includes capability information supporting the slotted Aloha algorithm, and / or capability information supporting the diversity slotted Aloha algorithm; The second parameter.

34. The method according to any one of claims 1-6, 17-20, or 31-33, wherein the first resource pool is any one of the following: OCC-based competitive message 3EDT resource pool; Message 3EDT resource pool that is not based on OCC competition.

35. The method according to claim 34, further comprising: If the tenth condition is met, the terminal device determines that the first resource pool is a contention-based message 3EDT resource pool based on OCC. The tenth condition includes one or more of the following: The terminal device supports contention-based 3EDT message transmission using OCC. The network device is configured with at least one OCC-based contention-based message 3EDT resource pool; The reference signal received power currently measured by the terminal device is located within the first reference signal received power range corresponding to any resource pool in the at least one OCC-based contention message 3EDT resource pool.

36. The method according to any one of claims 1-6, 17-20, or 31-34, wherein the terminal device is an NB-IoT device, and the method further comprises: The terminal device determines the first subcarrier interval based on fourth information; the fourth information includes one or more of the following: The second capability information of the terminal device; the second capability information includes at least one subcarrier interval supported by the terminal device; The first indication information sent by the network device; The first indication information is used to indicate the first subcarrier interval; The TA validity information of the terminal device.

37. The method according to any one of claims 4, 6, 15, 18, 19, 23, 26, 31, 33 or 36, wherein one or more of the following are determined based on predefined information or configuration information sent by the network device: First reference signal received power threshold; Fifth reference signal received power threshold; First maximum transfer block size; Fifth, the maximum transfer block size; First group of coverage enhancement levels; Second group of coverage enhancement levels; At least one second reference signal received power threshold; At least one fourth reference signal received power threshold; At least one second maximum transport block size; At least one fourth maximum transport block size; First value; Second value; Third value; The fourth value; The fifth value; First parameter; Second parameter; First reference signal received power range.

38. A data transmission method, the method comprising: The network device receives uplink data; the uplink data is sent by the terminal device based on a first strategy; the first strategy includes one or more of the following: First EDT type; First level of coverage enhancement; First carrier wave; First conflict resolution algorithm; First resource pool; First subcarrier spacing.

39. The method according to claim 38, further comprising: The network device sends a fifth instruction message to the terminal device; The fifth indication information is used to indicate that the uplink data transmission failed.

40. The method according to claim 39, wherein the first EDT type is a contention-based message 3 EDT, and the method further comprises: The network device receives the uplink data sent by the terminal device using the second coverage enhancement level.

41. The method according to claim 40, wherein the first EDT type is an EDT based on message 1, and the method further comprises: The network device receives the uplink data sent by the terminal device using the third coverage enhancement level.

42. The method according to claim 39, wherein the first EDT type is an EDT based on message 1 or an EDT based on contention-based message 3, and the method further comprises: The network device receives the uplink data sent by the terminal device using the fourth coverage enhancement level.

43. A data transmission apparatus, applied to a terminal device, the apparatus comprising: The first transmitting unit is configured to perform Early Data Transmission Techniques (EDT) for uplink data based on a first strategy; the first strategy includes one or more of the following: First EDT type; First level of coverage enhancement; First carrier wave; First conflict resolution algorithm; First resource pool; First subcarrier spacing.

44. A data transmission apparatus, applied to a network device, the apparatus comprising: The first receiving unit is configured to receive uplink data; The uplink data is sent by the terminal device based on a first strategy; the first strategy includes one or more of the following: First EDT type; First level of coverage enhancement; First carrier wave; First conflict resolution algorithm; First resource pool; First subcarrier spacing.

45. A terminal device, comprising: Memory is used to store executable instructions for a computer; A processor, connected to the memory, is configured to implement the method of any one of claims 1 to 37 by executing the computer-executable instructions.

46. ​​A network device, comprising: Memory is used to store executable instructions for a computer; A processor, connected to the memory, is configured to implement the method of any one of claims 38 to 42 by executing the computer-executable instructions.

47. A chip, the chip comprising: A processor for retrieving and running a computer program from memory, causing a device having the chip mounted to perform the method as described in any one of claims 1 to 37, or to perform the method as described in any one of claims 38 to 42.

48. A computer-readable storage medium storing a computer program that, when executed by at least one processor, implements the method as claimed in any one of claims 1 to 37, or performs the method as claimed in any one of claims 38 to 42.

49. A computer program product comprising a computer storage medium storing a computer program, the computer program comprising instructions executable by at least one processor, wherein when the instructions are executed by the at least one processor, the method of any one of claims 1 to 37 is implemented, or the method of any one of claims 38 to 42 is performed.

50. A computer program that causes a computer to perform the method as claimed in any one of claims 1 to 37, or to perform the method as claimed in any one of claims 38 to 42.

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