Data transmission method and apparatus

1. A device, wherein the device is a serving base station or the device is an apparatus included in the serving base station, the device comprising:

at least one processor; and

one or more memories storing programming instructions executable by the at least one processor to perform operations comprising:

receiving, from a terminal, identification information of the terminal in an inactive state, wherein the identification information is allocated by an anchor base station of the terminal;

determining the anchor base station of the terminal according to the identification information; and

sending a cell radio network temporary identifier (C-RNTI) to the anchor base station, wherein the C-RNTI is allocated by the serving base station to the terminal.

2. The device according to claim 1 , wherein the operations further comprise:

receiving a logical channel identifier corresponding to to-be-sent data of the terminal; and

sending, to the anchor base station, an IP flow identifier, the logical channel identifier, or a channel type corresponding to the to-be-sent data.

3. The device according to claim 1 , wherein the identification information comprises:

a unique identifier indicating the terminal in an access-network notification area in which the terminal is located.

4. The device according to claim 1 , wherein the operations further comprise:

before receiving the identification information, broadcasting configuration information, wherein the configuration information comprises: feedback configuration information, retransmission configuration information, physical layer parameter configuration information, non-scheduled transmission configuration information, media access control (MAC) layer control information, or channel configuration information;

wherein the feedback configuration information or the retransmission configuration information comprises: a hybrid automatic repeat request (HARQ) process number, a retransmission redundancy version, an indication about whether to reset media access control (MAC), a physical downlink control channel (PDCCH) time-frequency resource used for feedback or downlink data sending, a timing relationship from uplink sending to downlink feedback, or a timing relationship from downlink sending to uplink feedback;

wherein the physical layer parameter configuration information comprises: transmission time interval (TTI) duration, a cyclic prefix (CP) length, a subcarrier spacing, or a physical channel type;

wherein the non-scheduled transmission configuration information comprises: a quantity of times of non-scheduled uplink blind retransmission, a non-scheduled automatic retransmission interval, non-scheduled transmission signal received power expected by a base station, a non-scheduled transmission power boost step, a demodulation reference signal (DRMS) list available for non-scheduled transmission, or a modulation and coding scheme (MCS) available for non-scheduled transmission;

wherein the MAC layer control information comprises: whether to report channel state information (CSI), periodic or aperiodic CSI reporting, a CSI reporting class, whether to report a power headroom report (PHR), periodic or aperiodic PHR reporting, whether to report a buffer status report (BSR), a BSR reporting format, or periodic or aperiodic BSR reporting; and

wherein the channel configuration information comprises: a radio link control (RLC) configuration corresponding to a service channel, a correspondence between a service channel and a flow identifier, or an RLC configuration corresponding to a control channel.

5. The device according to claim 1 , wherein the operations further comprise:

receiving key update indication information from the terminal.

6. The device according to claim 1 , wherein the operations further comprise:

establishing a media access control (MAC) entity or a radio link control (RLC) entity corresponding to the terminal; or

receiving configuration information or state information, from the anchor base station, of an RLC entity corresponding to the terminal.

7. The device according to claim 1 , wherein:

the C-RNTI is allocated by the serving base station to the terminal during random access channel (RACH) data transmission; or

the C-RNTI is allocated by the serving base station to the terminal during radio access network notification area location update notification.

8. The device according to claim 1 , wherein the operations further comprise:

sending an identifier of a cell that allocates the C-RNTI to the anchor base station, wherein the cell is of the serving base station.

9. The device according to claim 1 , wherein the operations further comprises:

receiving data from the terminal; and

sending the data to the anchor base station.

10. A device, wherein the device is an anchor base station of a terminal, or the device is an apparatus included in the anchor base station of the terminal, the device comprising:

at least one processor; and

one or more memories storing programming instructions executable by the at least one processor to perform operations comprising:

allocating, to the terminal, identification information of the terminal for the terminal to use in an inactive state;

receiving a cell radio network temporary identifier (C-RNTI) from a serving base station of the terminal, wherein the C-RNTI is allocated by the serving base station of the terminal to the terminal; and

updating a context of the terminal in the anchor base station according to the C-RNTI.

11. The device according to claim 10 , wherein the operations further comprise:

receiving an IP flow identifier, a logical channel identifier, or a channel type corresponding to to-be-sent data of the terminal that is sent by the serving base station.

12. The device according to claim 10 , wherein the operations further comprise:

receiving a terminal identity deletion instruction from the serving base station; and

deleting the identification information of the terminal according to the terminal identity deletion instruction.

13. The device according to claim 10 , wherein the operations further comprise:

sending configuration information to the terminal, wherein the configuration information comprises: feedback configuration information, retransmission configuration information, physical layer parameter configuration information, non-scheduled transmission configuration information, media access control (MAC) layer control information, or channel configuration information;

wherein the feedback configuration information or the retransmission configuration information comprises: a hybrid automatic repeat request (HARQ) process number, a retransmission redundancy version, an indication about whether to reset media access control (MAC), a physical downlink control channel (PDCCH) time-frequency resource used for feedback or downlink data sending, a timing relationship from uplink sending to downlink feedback, or a timing relationship from downlink sending to uplink feedback;

wherein the physical layer parameter configuration information comprises: transmission time interval (TTI) duration, a cyclic prefix (CP) length, a subcarrier spacing, or a physical channel type;

wherein the non-scheduled transmission configuration information comprises: a quantity of times of non-scheduled uplink blind retransmission, a non-scheduled automatic retransmission interval, non-scheduled transmission signal received power expected by a base station, a non-scheduled transmission power boost step, a demodulation reference signal (DRMS) list available for non-scheduled transmission, or a modulation and coding scheme (MCS) available for non-scheduled transmission;

wherein the MAC layer control information comprises: whether to report channel state information (CSI), periodic or aperiodic CSI reporting, a CSI reporting class, whether to report a power headroom report (PHR), periodic or aperiodic PHR reporting, whether to report a buffer status report (BSR), a BSR reporting format, or periodic or aperiodic BSR reporting; and

wherein the channel configuration information comprises: a radio link control (RLC) configuration corresponding to a service channel, a correspondence between a service channel and a flow identifier, or an RLC configuration corresponding to a control channel.

14. The device according to claim 10 , wherein the operations further comprise:

receiving, from the serving base station, an identifier of a cell that allocates the C-RNTI, wherein the cell is of the serving base station.

15. The device according to claim 10 , wherein the operations further comprise:

receiving data of the terminal from the serving base station.

16. A communication system, comprising:

a serving base station; and

an anchor base station;

wherein the serving base station is configured to:

receive, from a terminal in an inactive state, identification information of the terminal in the inactive state;

determine the anchor base station according to the identification information; and

send a cell radio network temporary identifier (C-RNTI) to the anchor base station, wherein the C-RNTI is allocated by the serving base station to the terminal; and

wherein the anchor base station is configured to:

allocate the identification information to the terminal;

receive the C-RNTI from the serving base station; and

update a context of the terminal in the anchor base station according to the C-RNTI.

17. The system according to claim 16 , wherein the identification information comprises:

a unique identifier indicating the terminal in an access-network notification area in which the terminal is located.

18. The system according to claim 16 , wherein:

the C-RNTI is allocated by the serving base station to the terminal during random access channel (RACH) data transmission; or

the C-RNTI is allocated by the serving base station to the terminal during radio access network notification area location update notification.

19. The system according to claim 16 , wherein the serving base station is further configured to:

send an identifier of a cell that allocates the C-RNTI to the anchor base station, wherein the cell is of the serving base station; and

wherein the anchor base station is further configured to:

receive the identifier of the cell from the serving base station.

20. The system according to claim 16 , wherein the serving base station is further configured to:

receive data from the terminal; and

send the data to the anchor base station.