Communication method used for random access, terminal, and base station
Embodiments of the present invention provide a communication method used for random access, including: receiving, by a terminal, random access preamble information sent by a base station; and before sending random access to the base station based on the random access preamble information, receiving, by the terminal, a random access response sent by the base station, where the random access response includes an uplink asynchronous hybrid automatic repeat request HARQ process identifier, and the uplink asynchronous HARQ process identifier is used by the terminal to send uplink data to the base station. Compared with the prior art, the communication method provided in the embodiments of the present invention can ensure to some extent that uplink data is transmitted timely and can effectively improve uplink data transmission reliability.
1. A communication method used for random access, wherein carrier aggregation is performed on a licensed assisted access (LAA) cell and a primary cell of a base station, the method is used by a terminal to perform non-contention-based random access based on the LAA cell, the method comprising:
receiving, by a terminal, random access preamble information sent by a base station in a serving cell of the terminal, wherein the serving cell comprises the LAA cell and the primary cell;
sending, in the LAA cell of the base station by the terminal, a first random access preamble to the base station based on the random access preamble information, wherein the first random access preamble is different from a second random access preamble in the primary cell; and
receiving, by the terminal, a random access response sent by the base station in the primary cell, wherein the random access response comprises an uplink asynchronous hybrid automatic repeat request (HARQ) process identifier, and the uplink asynchronous HARQ process identifier is used by the terminal to send uplink data to the base station.
2. The method according to claim 1 , wherein the random access response further comprises listen before talk LBT information, and the LBT information is used by the terminal to obtain an unlicensed-spectrum channel; and
the method further comprises:
performing, by the terminal, uplink transmission in the LAA cell of the base station based on the unlicensed-spectrum channel.
3. The method according to claim 2 , wherein
the random access response further indicates that an uplink resource used by the terminal to perform uplink transmission is located on the unlicensed-spectrum channel of the LAA cell.
4. The method according to claim 1 , wherein
the random access response further comprises a physical cell identifier PCI, wherein the physical cell identifier PCI is used by the terminal to identify whether the random access response is applicable to the terminal.
5. A communication method used for random access, wherein carrier aggregation is performed on a licensed assisted access (LAA) cell and a primary cell of a base station, the method is used by a terminal to perform non-contention-based random access based on the LAA cell, the method comprising:
sending, by a base station, random access preamble information to a terminal in a serving cell of the terminal, wherein the serving cell comprises the LAA cell and the primary cell;
receiving, by the base station, a first random access preamble sent by the terminal in the LAA cell of the base station, wherein the first random access preamble is different from a second random access preamble in the primary cell; and
sending, in the primary cell by the base station, a random access response to the terminal, wherein the random access response comprises an uplink asynchronous hybrid automatic repeat request HARQ process identifier, and the uplink asynchronous HARQ process identifier is used by the terminal to send uplink data to the base station.
6. The method according to claim 5 , wherein the random access response further comprises listen before talk LBT information, and the LBT information is used by the terminal to obtain an unlicensed-spectrum channel; and
the method further comprises:
performing, in the LAA cell of the base station, uplink transmission with the terminal based on the unlicensed-spectrum channel.
7. The method according to claim 6 , wherein
the random access response further indicates that an uplink resource used by the terminal to perform uplink transmission is located on the unlicensed-spectrum channel of the LAA cell.
8. The method according to claim 5 , wherein
the random access response further comprises a physical cell identifier PCI, used to identify whether the random access response is applicable to the terminal.
9. A terminal, wherein carrier aggregation is performed on a licensed assisted access (LAA) cell and a primary cell of a base station, the terminal performs non-contention-based random access based on the LAA cell, the terminal comprising:
a receiver, configured to receive random access preamble information sent by a base station in a serving cell of the terminal, wherein the serving cell comprises the LAA cell and the primary cell; and
a transmitter, configured to send in the LAA cell of the base station a first random access preamble to the base station based on the random access preamble information, wherein the first random access preamble is different from a second random access preamble in the primary cell, wherein
the receiver is further configured to receive a random access response sent by the base station in the primary cell, the random access response comprises an uplink asynchronous hybrid automatic repeat request HARQ process identifier, and the uplink asynchronous HARQ process identifier is used by the terminal to send uplink data to the base station.
10. The terminal according to claim 9 , wherein the random access response further comprises listen before talk LBT information, and the LBT information is used by the terminal to obtain an unlicensed-spectrum channel; and
the terminal further comprises:
a processor, configured to perform uplink transmission in the LAA cell of the base station based on the unlicensed-spectrum channel.
11. The terminal according to claim 10 , wherein
the random access response further indicates that an uplink resource used by the terminal to perform uplink transmission is located on the unlicensed-spectrum channel of the LAA cell.
12. The terminal according to claim 9 , wherein
the random access response further comprises a physical cell identifier PCI, wherein the physical cell identifier PCI is used by the terminal to identify whether the random access response is applicable to the terminal.
13. A base station, wherein carrier aggregation is performed on a licensed assisted access (LAA) cell and a primary cell of the base station, the base station comprising:
a transmitter, configured to send random access preamble information to a terminal in a serving cell of the terminal, wherein the serving cell comprises the LAA cell and the primary cell; and
a receiver, configured to receive a first random access preamble sent by the terminal in the LAA cell of the base station, wherein the first random access preamble is different from a second random access preamble in the primary cell, wherein
the transmitter is further configured to send in the primary cell a random access response to the terminal, the random access response comprises an uplink asynchronous hybrid automatic repeat request HARQ process identifier, and the uplink asynchronous HARQ process identifier is used by the terminal to send uplink data to the base station.
14. The base station according to claim 13 , wherein
the random access response further comprises a physical cell identifier PCI, used to identify whether the random access response is applicable to the terminal.
15. The base station according to claim 13 , wherein the random access response further comprises listen before talk LBT information, and the LBT information is used by the terminal to obtain an unlicensed-spectrum channel; and
the base station further comprises:
a processor, configured to perform, in the LAA cell of the base station, uplink transmission with the terminal based on the unlicensed-spectrum channel.
16. The base station according to claim 15 , wherein
the random access response further indicates that an uplink resource used by the terminal to perform uplink transmission is located on the unlicensed-spectrum channel of the LAA cell.