Data transmission method and apparatus

1. A data transmission method comprising:

sending, by a terminal device, a random access preamble to a first network device,

wherein the random access preamble is useable by the first network device to send a random access response (RAR) to the terminal device upon successful detection of the random access preamble by the first network device:

receiving, by the terminal device, downlink control information (DCI) and the RAR scheduled by the DCI from the first network device,

wherein the RAR comprises downlink data,

wherein the DCI and/or the RAR comprise/comprises first information for scheduling transmission of acknowledgement (ACK)/negative acknowledgement (NACK) feedback information by the terminal device in response to receipt of the RAR, and

wherein the first information comprises (a) first indication information for determining subcarrier spacing of subcarriers for transmitting the ACK/NACK feedback information and/or (b) second indication information for determining a repetition quantity of the ACK/NACK feedback information;

determining, by the terminal device, a time-frequency resource, the subcarrier spacing, and/or the repetition quantity of the ACK/NACK feedback information; and

sending, by the terminal device, the ACK/NACK feedback information to the first network device based on the time-frequency resource, the subcarrier spacing, and/or the repetition quantity.

2. The method according to claim 1 , wherein the DCI comprises time-frequency resource information of the ACK/NACK feedback information, and

in response to the first information comprising only the first indication information, the repetition quantity of the ACK/NACK feedback information is indicated by a system message or is set; and

in response to the first information comprising only the second indication information, the subcarrier spacing of the subcarriers for transmitting the ACK/NACK feedback information is indicated by a system message or is set.

3. The method according to claim 1 , wherein in response to the RAR comprising only the first information, the first information further comprises one or more of the following:

third indication information for use in determining a location of the subcarrier for transmitting the ACK/NACK feedback information;

fourth indication information for use in determining a scheduling delay of the ACK/NACK feedback information;

fifth indication information for use in determining target receive power of the ACK/NACK feedback information;

sixth indication information for use in determining a path loss compensation factor for transmitting the ACK/NACK feedback information; and

seventh indication information for use in determining a timing advance for transmitting the ACK/NACK feedback information.

4. The method according to claim 1 , wherein both the DCI and the RAR comprise the first information, wherein the DCI comprises the first indication information and the RAR comprises the second indication information.

5. The method according to claim 1 , wherein before sending the random access preamble to the first network device, the method further comprises:

receiving, by the terminal device, a first paging message from the first network device,

wherein the first paging message comprises resource indication information,

wherein the resource indication information indicates a random access channel (RACH) resource allocated to the terminal device, and

wherein the RACH resource is used to carry the random access preamble; and

the RACH resource is allocated based on second information that comprises paging-related capability information possessed by the terminal device.

6. The method according to claim 5 , wherein the second information comprises one or more of the following:

first capability information indicating whether the terminal device supports initiating random access on a non-anchor carrier;

second capability information indicating whether the terminal device supports using a preamble format 2; and

third capability information indicating whether the terminal device supports early data transmission (EDT) for user plane cellular internet of things (CIOT) evolved packet system (EPS) optimization.

7. A data transmission method comprising:

receiving, by a first network device, a random access preamble from a terminal device, wherein the random access preamble is useable by the first network device to send a random access response (RAR) to the terminal device upon successful detection of the random access preamble by the first network device;

sending, by the first network device, downlink control information (DCI) and the RAR scheduled by the DCI to the terminal device,

wherein the RAR comprises downlink data,

wherein the DCI and/or the RAR comprise/comprises first information for scheduling transmission of acknowledgement (ACK)/negative acknowledgement (NACK) feedback information by the terminal device in response to receipt of the RAR, and

wherein the first information comprises (a) first indication information for use by the terminal device to determine subcarrier spacing of subcarriers for transmitting the ACK/NACK feedback information and/or (b) second indication information for use by the terminal device to determine a repetition quantity of the ACK/NACK feedback information; and

receiving, by the first network device, the ACK/NACK feedback information from the terminal device based on a time-frequency resource, a subcarrier spacing, and/or a repetition quantity determined by the terminal device from the first information.

8. The method according to claim 7 , wherein in response to the message 2 comprising the first information, the first information further comprises one or more of the following:

third indication information used for determining a location of the subcarrier for transmitting the ACK/NACK feedback information;

fourth indication information used for determining a scheduling delay of the ACK/NACK feedback information;

fifth indication information used for determining target receive power of the ACK/NACK feedback information;

sixth indication information used for determining a path loss compensation factor for transmitting the ACK/NACK feedback information; and

seventh indication information used for determining a timing advance for transmitting the ACK/NACK feedback information.

9. The method according to claim 7 , wherein the DCI comprises time-frequency resource information of the ACK/NACK feedback information, and

in response to the first information comprising only the first indication information, the repetition quantity of the ACK/NACK feedback information is indicated by a system message or is set; and

in response to the first information comprising only the second indication information, the subcarrier spacing of the subcarriers for transmitting the ACK/NACK feedback information is indicated by a system message or is set.

10. The method according to claim 7 , wherein both the DCI and the RAR comprise the first information, wherein the DCI comprises the first indication information and the RAR comprises the second indication information.

11. The method according to claim 7 , wherein before receiving the random access preamble from the terminal device, the method further comprises:

receiving, by the first network device, a second paging message from a second network device,

wherein the second paging message comprises second information, and wherein the second information comprises paging-related capability information possessed by the terminal device:

allocating, by the first network device, a random access channel (RACH) resource to the terminal device based on the second information, and determining, based on the second paging message, a first paging message to be sent to the terminal device,

wherein the first paging message comprises resource indication information which indicates the RACH resource; and

sending, by the first network device, the first paging message to the terminal device.

12. The method according to claim 11 , wherein the second information comprises one or more of the following:

first capability information indicating whether the terminal device supports initiating random access on a non-anchor carrier;

second capability information indicating whether the terminal device supports using a preamble format 2; and

third capability information indicating whether the terminal device supports early data transmission (EDT) for user plane cellular internet of things (CIoT) evolved packet system (EPS) optimization.

13. A communication apparatus comprising:

a transceiver configured to cooperate with a processor to:

send a random access preamble to a first network device,

wherein the random access preamble useable by the first network device to send a random access response (RAR) to the communication apparatus upon successful detection of the random access preamble by the first network device; and

receive downlink control information (DCI) and the RAR scheduled by the DCI from the first network device,

wherein the RAR comprises downlink data,

wherein the DCI and/or the RAR comprise/comprises first information for scheduling transmission of acknowledgement (ACK)/negative acknowledgement (NACK) feedback information in response to receipt of the RAR, and

wherein the first information comprises (a) first indication information for determining subcarrier spacing of subcarriers for transmitting the ACK/NACK feedback information and (b) second indication information for determining a repetition quantity of the ACK/NACK feedback information;

the processor is configured to determine a time-frequency resource, the subcarrier spacing, and/or the repetition quantity of the ACK/NACK feedback information based on the first information; and

the transceiver is further configured to cooperate with the processor to send the ACK/NACK feedback information to the first network device based on the determined time-frequency resource, the subcarrier spacing, and/or the repetition quantity.

14. The apparatus according to claim 5 , wherein the DCI comprises time-frequency resource information of the ACK/NACK feedback information,

upon the first information comprising only the first indication information, the repetition quantity of the ACK/NACK feedback information is indicated by a system message or is set; and

upon the first information comprising only the second indication information, the subcarrier spacing of the subcarriers for transmitting the ACK/NACK feedback information is indicated by a system message or is set.

15. The apparatus according to claim 5 , wherein in response to the RAR comprising the first information, the first information comprises one or more of the following:

third indication information used for determining a location of the subcarrier for transmitting the ACK/NACK feedback information;

fourth indication information used for determining a scheduling delay of the ACK/NACK feedback information;

fifth indication information used for determining target receive power of the ACK/NACK feedback information;

sixth indication information used for determining a path loss compensation factor for transmitting the ACK/NACK feedback information; and

seventh indication information used for determining a timing advance for transmitting the ACK/NACK feedback information.

16. The apparatus according to claim 13 , wherein both the DCI and the RAR comprise the first information, wherein the DCI comprises the first indication information and the RAR comprises the second indication information.

17. The apparatus according to claim 13 , wherein before the transceiver sends the random access preamble to the first network device, the transceiver is further configured to receive a first paging message from the first network device,

wherein the first paging message comprises resource indication information, which that indicates a random access channel (RACH) resource allocated to the terminal device,

wherein the RACH resource is used to carry the random access preamble, and is allocated based on second information, and the second information comprises paging-related capability information possessed by the terminal device.

18. The method according to claim 1 , wherein the DCI comprises the second indication information and the RAR comprises the first indication information.

19. The method according to claim 7 , wherein the DCI comprises the second indication information and the RAR comprises the first indication information.

20. The apparatus according to claim 13 , the DCI comprises the second indication information and the RAR comprises the first indication information.