Random access method and device

1. A random access method, wherein the method comprises:

sending, by a terminal device, a first message to a network device, wherein the first message comprises a random access preamble and an uplink (UL) message, and the UL message comprises a first identifier;

if the terminal device is in connected, determining, by the terminal device, the first identifier as a cell-radio network temporary identifier, C-RNTI, and determining a first target radio network temporary identifier, RNTI, as the C-RNTI used for blindly detecting a first physical downlink control channel, PDCCH, according to the first. identifier; and if the terminal device is in idle or inactive, determining, by the terminal device, the first identifier as other identifier other than the C-RNTI, and determining the first target RNTI as a random access radio network temporary identifier, RA-RNTI, used for blindly detecting the first PDCCH according to the first identifier:

blindly detecting, by the terminal device, the first PDCCH according to the first target RNTI;

determining, by the terminal device, whether a contention conflict in a random access procedure is resolved according to a blind detection result of the first PDCCH or a first physical downlink shared channel (PDSCH) scheduled bye the first PDCCH.

2. The method according to claim 1 , wherein the method further comprises:

starting, by the terminal device, a first tinier or opening a first window after the terminal device sends the first message to the network device;

the blindly detecting, by the terminal device, the first PDCCH according to the first target RNTI comprises:

blindly detecting, by the terminal device, the first PDCCH according to the first target RNTI within a duration range of the first timer or the first window.

3. The method according to claim 1 , wherein when the first identifier is the C-RNTI and the first target RNTI is the C-RNTI,

the determining, by the terminal device, whether a contention conflict in a random access procedure is resolved according to a blind detection result of the first PDCCH or a first PDSCH scheduled by the first PDCCH comprises:

determining, by the terminal device, that the contention conflict in the random access procedure is resolved if the first PDCCH is blindly detected by the terminal device;

determining, by the terminal device, that the contention conflict in the random access procedure is not resolved if the first PDCCH is not blindly detected by the terminal device.

4. The method according to claim 1 , wherein when the first identifier is the other identifier other the C-RNTI and the first target RNTI is the RA-RNTI),

the RA-RNTI is determined according to at least one of a position of a physical random access channel (PRACH) resource for transmitting the random access preamble, or a position of a physical uplink shared channel (PUSCH) resource for transmitting the UL message.

5. The method according to claim 4 , wherein the determining, by the terminal device, whether a contention conflict in a random access procedure is resolved according to a blind detection result of the first PDCCH or a first physical downlink shared channel PDSCH scheduled by the first PDCCH comprises:

determining, by the terminal device, whether to blindly detect a second PDCCH according to the blind detection result of the first PDCCH;

blindly detecting, by the terminal device, the second PDCCH if the terminal device determines to blindly detect the second PDCCH;

determining, by the terminal device, whether the contention conflict in the random access procedure is resolved according to a blind detection result of the second PDCCH.

6. The method according to claim 5 , wherein the determining, by the terminal device, whether to blindly detect the second PDCCH according to the blind detection result of the first PDCCH comprises:

determining, by the terminal device, whether to blindly detect the second PDCCH according to first instruction information if the first PDCCH is blindly detected by the terminal device, wherein the first PDCCH comprises the first instruction information, or the first PDSCH scheduled by the first PDCCH comprises the first instruction information;

if a value of at least one bit in the first instruction information is a first value, the first instruction information is used to instruct the terminal device to blindly detect the second PDCCH; and

if a value of at least one bit in the first instruction information is a second value, the first instruction information is used to instruct the terminal device not to blindly detect the second PDCCH.

7. The method according to claim 6 , wherein the determining, by the terminal device, whether to blindly detect the second PDCCH according to first instruction information comprises:

determining, by the terminal device, to blindly detect the second PDCCH if the first instruction information is used to instruct the terminal device to blindly detect the second PDCCH;

determining, by the terminal device, not to blindly detect the second PDCCH if the first instruction information is used to instruct the terminal device not to blindly detect the second PDCCH.

8. The method according to claim 6 , wherein the first instruction information is comprised in a random access response (RAR), and a bit position of at least one bit in the RAR is equal to a bit position of a preserved bit in a four-step random access.

9. The method according to claim 5 , Wherein if the terminal device does not blindly detect the second PDCCH, the method further comprises:

sending, by the terminal device, a message 3 in a four-step random access to the network device:

receiving, by the terminal device, a message 4 sent by the network device aiming at the message 3;

determining, by the terminal device, whether the contention conflict in the random access procedure is resolved according to the message 4.

10. The method according to claim 5 , wherein if the terminal device does not blindly detect the second PDCCH, the method further comprises:

retransmitting, by the terminal device, the first message to the network device.

11. The method according to claim 5 , wherein if the terminal device determines to blindly detect the second PDCCH, the blindly detecting, by the terminal device, the second PDCCH comprises:

blindly detecting, by the terminal device, the second PDCCH by using a second target RNTI; and

wherein the determining, by the terminal device, whether the contention conflict in the random access procedure is resolved according to a blind detection result of the second PDCCH comprises:

determining, by the terminal device, that the contention conflict in the random access procedure is resolved if the second PDCCH is detected by the terminal device and the first identifier successfully matches with a second identifier, wherein the second identifier is a conflict resolution identifier carried by the second PDCCH, or the second identifier is a conflict resolution identifier carried by a second PDSCH scheduled by the second PDCCH.

12. The method according to claim 11 , wherein the second target RNTI is the C-RNTI or a temporary cell-radio network temporary identifier (TC-RNTI).

13. The method according to claim 5 , wherein the second PDCCH is used to instruct parameters used by the terminal device for data transmission after the terminal device resolves the contention conflict; and

wherein the parameters used by the terminal device for data transmission comprises parameters in a random access response (RAR) sent by the network device aiming at the first message.

14. The method according to claim 4 , wherein the first PDSCH comprises a medium access control (MAC) protocol data unit (PDU), the MAC PDU at least comprises downlink (DL) resource assignment instruction information, and the DL resource assignment instruction information is used to instruct the terminal device to receive a time-frequency resource of a second PDSCH; and

wherein the determining, by the terminal device, whether a contention conflict in a random access procedure is resolved according to a blind detection result of the first PDCCH or a first physical downlink shared channel (PDSCH) scheduled by the first PDCCH comprises:

determining, by the terminal device, that the contention conflict in the random access procedure is resolved if the first identifier successfully matches with a fourth identifier, wherein the fourth identifier is a conflict resolution identifier carried by the first PDCCH or the first PDSCH.

15. The method according to claim 14 , wherein the MAC PDU comprises fifth instruction information, and the fifth instruction information is used to instruct whether the MAC PDU comprised in the first PDSCH comprises the DL resource assignment instruction information.

16. The method according to claim 15 , wherein a bit position of a bit in the fifth instruction information is equal to a position of a preserved bit in a random access response (RAR) in a fourth-step random access.

17. The method according to claim 4 , wherein the other identifier other than the C-RNTI comprises at least one of the following: a random number, a 5G-service temporary mobile subscriber identifier (5G-S-TMSI), an identifier radio network temporary identifier (I-RNTI), a short identifier radio network temporary identifier Short (I-RNTI).

18. A random access method, wherein the method comprises:

receiving, by a network device, a first message sent by a terminal device, wherein the first message comprises a random access preamble and an uplink (UL) message, and the UL message comprises a first identifier;

decoding, by the network device, the first message;

determining, by the network device, a response message to be sent to the terminal device according to a decoding situation of the first message;

wherein the determining, by the network device, a response :message to be sent to the terminal device according to a decoding situation of the first message comprises:

sending by the network device a first physical downlink control channel, PDCCH, scrambled by a first target radio network temporary identifier, RNTI, to the terminal device if the random access preamble is decoded successfully and the first identifier is decoded successfully, wherein

if the terminal device is in connected, the first identifier is a cell-radio network temporary identifier, C-RNTI, and the first target RNTI is the C-RNTI;

if the terminal device is in idle or inactive, the first identifier is other identifier other than the C-RNTI, and the first target RNTI is a random access radio network temporary identifier, RA-RNTI.

19. A terminal device, comprising:

a processor, a memory and a transceiver, wherein the memory is configured to store a computer program, and the processor is configured to call and run the computer program stored in the memory to:

control the transceiver to send a first message to a network device, wherein the first message comprises a random access preamble and an uplink (UL) message, and the UL message contains a first identifier;

if the terminal device is in connected, determining the first identifier as a cell-radio network temporary identifier, C-RNTI, and determining a first target radio network temporary identifier, RNTI, as the C-RNTI used for blindly detecting a first physical downlink control channel, PDCCH, according to the first identifier; and if the terminal device is in idle or inactive, determining the first identifier as other identifier other than the C-RNTI, and determining the first target RNTI as a random access radio network temporary identifier, RA-RNTI, used for blindly detecting the first PDCCH according to the first identifier;

blindly detect the first PDCCH according to the first target radio network temporary identifier (RNTI);

determine whether a contention conflict in a random access procedure is resolved according to a blind detection result of the first PDCCH or a first physical downlink shared channel (PDSCH) scheduled by the first PDCCH.

20. A non-transitory computer-readable storage medium, configured to store a computer program, wherein the computer program causes a computer to execute the method according to claim 1 .