Communication method and apparatus

1. A communication method, comprising:

sending, by a terminal device, a random access request to a network device, wherein the random access request comprises a random access preamble and uplink data;

receiving, by the terminal device, a random access response sent by the network device, and

performing, by the terminal device, a state transition AND/OR operation determined according to a message format of the random access response, wherein the message format of the random access response is a format of a plurality of formats comprising:

a first message format, wherein the random access response in the first message format comprises fields having the following information: a connection identifier, an uplink timing advance and a cell radio network temporary identifier;

a second message format, wherein the random access response in the second message format comprises fields having the following information: a random access preamble sequence identifier, an uplink timing advance, uplink scheduling information and a cell radio network temporary identifier; and

a third message format, wherein the random access response in the third message format comprises a backoff indication;

wherein each format of the plurality of formats corresponds to a different AND/OR operation.

2. The method according to claim 1 , further comprising:

determining, by the terminal device, the message format of the random access response according to a message format field in the random access response.

3. The method according to claim 1 , wherein the performing the state transition AND/OR operation comprises performing at least one of:

switching, by the terminal device, to a connected state in response to the random access response being in a first message format;

sending, by the terminal device, a radio resource control (RRC) connection request to the network device in response to the random access response being in a second message format; or

resending, by the terminal device, the random access request to the network device in response to the random access response being in a third message format.

4. The method according to claim 1 , wherein the uplink data comprises a connection identifier.

5. A communication method, comprising:

receiving, by a network device, a random access request sent by a terminal device, wherein the random access request comprises a random access preamble and uplink data; and

sending, by the network device, a random access response to the terminal device, wherein the random access response has a message format that is at least one of at least three message formats, wherein each message format of the at least three message formats indicates a different state transition AND/OR operation, and wherein the at least three message formats comprise:

a first message format, wherein the random access response in the first message format comprises fields having the following information: a connection identifier, an uplink timing advance and a cell radio network temporary identifier;

a second message format, wherein the random access response in the second message format comprises fields having the following information: a random access preamble sequence identifier, an uplink timing advance, uplink scheduling information and a cell radio network temporary identifier; and

a third message format, wherein the random access response in the third message format comprises a backoff indication.

6. The method according to claim 5 , wherein the random access response comprises a message format field, and wherein the message format field indicates the message format of the random access response.

7. The method according to claim 5 , wherein the uplink data comprises a connection identifier.

8. The method according to claim 7 , wherein the connection identifier identifies at least one of a radio resource control connection before the terminal device switches from a connected state to an inactive state, or access stratum context information that is of a radio resource control connection and that is saved when the terminal device switches from the connected state to the inactive state.

9. A communications apparatus, comprising:

a transmitter, configured to send a random access request to a network device, wherein the random access request comprises a random access preamble and uplink data;

a receiver, configured to receive a random access response sent by the network device;

a processor; and

a non-transitory computer readable medium having a program stored thereon for execution by the processor, the program including instructions to:

perform a state transition AND/OR operation determined to a message format to a message format of the random access response, wherein the message format of the random access response is a format of a plurality of formats comprising:

a first message format, wherein the random access response in the first message format comprises fields having the following information: a connection identifier, an uplink timing advance, and a cell radio network temporary identifier;

a second message format, wherein the random access response in the second message format comprises fields having the following information: a random access preamble sequence identifier, an uplink timing advance, uplink scheduling information, a cell radio network temporary identifier; and

a third message format, wherein the random access response in the third message format comprises a backoff indication;

wherein each format of the plurality of formats corresponds to a different AND/OR operation.

10. The communications apparatus according to claim 9 , wherein the program further includes instructions to determine the message format of the random access response according to a message format field in the random access response.

11. The communications apparatus according to claim 9 , wherein the program further includes instructions for performing at least one of:

switching a state of the communications apparatus to a connected state in response to the random access response being in a first message format;

maintaining a state of the communications apparatus to an inactive state and adjusting uplink timing in response to the random access response being in a second message format;

maintaining a state of the communications apparatus to the inactive state in response to the random access response being in a third message format, wherein data corresponding to the random access response in the third message format is successfully sent;

maintaining a state of the communications apparatus to the inactive state or switching a state of the communications apparatus to an idle state in response to the random access response being in a fourth message format, wherein data corresponding to the random access response in the fourth message format fails to be sent;

generating a radio resource control RRC connection request in response to the random access response being in a fifth message format; or

regenerating the random access request in response to the random access response being in a sixth message format.

12. The communications apparatus according to claim 9 , wherein the uplink data comprises a connection identifier.

13. A communications apparatus, comprising:

a receiver, configured to receive a random access request sent by a terminal device, wherein the random access request comprises a random access preamble and uplink data, and wherein the terminal device is in an inactive state; and

a transmitter, configured to send a random access response to the terminal device, wherein the random access response has a message format that is at least one of at least three message formats, wherein each message format of the at least three message formats indicates a different state transition AND/OR operation, and wherein the at least three message formats comprise:

a first message format, wherein the random access response in the first message format comprises fields having the following information: a connection identifier, an uplink timing advance, and a cell radio network temporary identifier;

a second message format, wherein the random access response in the second message format comprises fields having the following information: a random access preamble sequence identifier, an uplink timing advance, uplink scheduling information, and a cell radio network temporary identifier; or

a third message format, wherein the random access response in the third message format comprises a backoff indication.

14. The communication apparatus according to claim 13 , wherein the random access response comprises a message format field, and wherein the message format field indicates the message format of the random access response.

15. The communications apparatus according to claim 14 , wherein the uplink data comprises a connection identifier.

16. The communications apparatus according to claim 13 , wherein the connection identifier identifies at least one of a radio resource control connection before the terminal device switches from a connected state to the inactive state or access stratum context information that is of a radio resource control connection and that is saved when the terminal device switches from the connected state to the inactive state.

17. A non-transitory computer-readable storage medium, the computer-readable storage medium storing a program comprising instructions that, when executed by an apparatus, cause the apparatus to perform:

sending a random access request to a network device, wherein the random access request comprises a random access preamble and uplink data;

receiving a random access response sent by the network device, and

performing a state transition AND/OR operation determined according to a message format of the random access response, wherein the message format of the random access response is a format of a plurality of formats comprising:

a first message format, wherein the random access response in the first message format comprises a field that is at least one a connection identifier, an uplink timing advance, a cell radio network temporary identifier, or a radio resource control message;

a second message format, wherein the random access response in the second message format comprises a field that is at least one of a random access preamble sequence identifier, an uplink timing advance, uplink scheduling information, a cell radio network temporary identifier, or a backoff indication; or

a third message format, wherein the random access response in the third message format comprises a field that is at least one of a random access preamble sequence identifier or a backoff indication;

wherein each format of the plurality of formats corresponds to a different AND/OR operation.