Method and device for transmitting a random access message, and a storage medium

1. A method for transmitting a random access message, comprising:

in a random access process based on an unlicensed channel, performing, by a terminal, random access preamble transmission in a first Rach Occasion (RO) in a Listen Before Talk (LBT) mode before arrival of the first RO, the first RO being a first RO selected in the random access process; and

in response to determining that a Random Access Response (RAR) returned by a base station is not received before arrival of a second RO, performing, by the terminal, random access preamble transmission in the second RO in the LBT mode, the second RO being any RO within a RAR time window corresponding to the random access process, the RAR time window being a period of a predetermined duration starting after the first RO,

wherein performing random access preamble transmission in the first RO in the LBT mode comprises: in response to monitoring that a target frequency domain interval is in an idle state within a preset duration before start of the first RO, sending a random access preamble on one time-frequency unit of at least two time-frequency units corresponding to the first RO; and

wherein the target frequency domain interval is a frequency domain interval including a frequency band in which the at least two time-frequency units are located.

2. The method of claim 1 , further comprising:

in the random access process, monitoring the RAR returned by the base station starting upon a first successful random access preamble transmission.

3. The method of claim 1 , further comprising:

in response to determining that the RAR returned by the base station is received before arrival of the second RO, ending monitoring of the RAR returned by the base station after the RAR returned by the base station has been monitored for a first time within the RAR time window.

4. The method claim 3 , further comprising:

stopping random access preamble transmission in a subsequent RO after the RAR returned by the base station has been monitored for the first time within the RAR time window.

5. The method of claim 1 , wherein performing random access preamble transmission in the first RO in the LBT mode comprises:

performing random access preamble transmission in the first RO in an LBT mode without random backoff.

6. The method of claim 1 ,

wherein the at least two time-frequency units are frequency division multiplexed, or frequency division multiplexed and time division multiplexed, in an unlicensed channel resource pool.

7. A device for transmitting a random access message, applied to a terminal, comprising:

a processor; and

a memory configured to store processor executable instructions,

wherein the processor is configured to implement acts comprising:

in a random access process based on an unlicensed channel, performing random access preamble transmission in a first Rach Occasion (RO) in a Listen Before Talk (LBT) mode before arrival of the first RO, the first RO being a first RO selected in the random access process;

in response to determining that a Random Access Response (RAR) returned by a base station is not received before arrival of a second RO, performing random access preamble transmission in the second RO in the LBT mode, the second RO being any RO within a RAR time window corresponding to the random access process, the RAR time window being a period of a predetermined duration starting after the first RO; and

in response to monitoring that a target frequency domain interval is in an idle state within a preset duration before start of the first RO, sending a random access preamble on one time-frequency unit of at least two time-frequency units corresponding to the first RO so that the device performs random access preamble transmission in the first RO in the LBT mode,

wherein the target frequency domain interval is a frequency domain interval including a frequency band in which the at least two time-frequency units are located.

8. The device of claim 7 , wherein the processor is further configured to implement acts comprising:

in the random access process, monitoring the RAR returned by the base station starting upon a first successful random access preamble transmission.

9. The device of claim 7 , wherein the processor is further configured to implement acts comprising:

in response to determining that the RAR returned by the base station is received before arrival of the second RO, ending monitoring of the RAR returned by the base station after the RAR returned by the base station has been monitored for a first time within the RAR time window.

10. The device of claim 9 , wherein the processor is further configured to implement acts comprising:

stopping random access preamble transmission in a subsequent RO after the RAR returned by the base station has been monitored for the first time within the RAR time window.

11. The device of claim 7 , wherein the processor is configured to perform random access preamble transmission in the first RO in the LBT mode by:

performing random access preamble transmission in the first RO in an LBT mode without random backoff.

12. The device of claim 7 ,

wherein the at least two time-frequency units are frequency division multiplexed, or frequency division multiplexed and time division multiplexed, in an unlicensed channel resource pool.

13. A non-transitory computer-readable storage medium having stored therein instructions which, when executed by a processor in a terminal, implement acts comprising:

in a random access process based on an unlicensed channel, performing random access preamble transmission in a first Rach Occasion (RO) in a Listen Before Talk (LBT) mode before arrival of the first RO, the first RO being a first RO selected in the random access process; and

in response to determining that a Random Access Response (RAR) returned by a base station is not received before arrival of a second RO, performing random access preamble transmission in the second RO in the LBT mode, the second RO being any RO within a RAR time window corresponding to the random access process, the RAR time window being a period of a predetermined duration starting after the first RO,

wherein the instructions are for performing random access preamble transmission in the first RO in the LBT mode by: in response to monitoring that a target frequency domain interval is in an idle state within a preset duration before start of the first RO, sending a random access preamble on one time-frequency unit of at least two time-frequency units corresponding to the first RO,

wherein the target frequency domain interval is a frequency domain interval including a frequency band in which the at least two time-frequency units are located.

14. The storage medium of claim 13 , wherein the instructions are further for:

in the random access process, monitoring the RAR returned by the base station starting upon a first successful random access preamble transmission.

15. The storage medium of claim 13 , wherein the instructions are further for:

in response to determining that the RAR returned by the base station is received before arrival of the second RO, ending monitoring of the RAR returned by the base station after the RAR returned by the base station has been monitored for a first time within the RAR time window.

16. The storage medium of claim 15 , wherein the instructions are further for:

stopping random access preamble transmission in a subsequent RO after the RAR returned by the base station has been monitored for the first time within the RAR time window.

17. The storage medium of claim 13 , wherein the instructions are for performing random access preamble transmission in the first RO in the LBT mode by:

performing random access preamble transmission in the first RO in an LBT mode without random backoff.