Method and apparatus for configuring transmission time interval, data transmission method and apparatus and system

1. An apparatus for configuring transmission time interval (TTI), applicable to an eNB, the apparatus comprising:

a memory that stores a plurality of instructions;

a processor that couples to the memory and is configured to execute the instructions to:

transmit to a user equipment (UE) configuration information about data radio bearers (DRBs), the configuration information about DRBs indicating TTI length to which each DRB configured by the eNB for the UE is applicable, wherein the DRBs are configured by radio resource control (RRC),

notify a target eNB of the TTI length to which each DRB of the UE is applicable when the UE needs to be handed over, and

schedule two or more uplink grants of the UE, an uplink grant of the two or more uplink grants corresponding to a TTI length different from another TTI length of another uplink grant.

2. The apparatus according to claim 1 , wherein,

the TTI lengths to which the uplink grants correspond are indicated by fields in downlink control information scheduling the uplink grants.

3. The apparatus according to claim 1 , wherein,

there is a corresponding relationship between the TTI length to which the uplink grant corresponds and a downlink control channel scheduling the uplink grant.

4. The apparatus according to claim 3 , wherein,

the corresponding relationship between the TTI length to which the uplink grant corresponds and the downlink control channel scheduling the uplink grant is a predefined relationship or is determined by the eNB.

5. The apparatus according to claim 1 , wherein,

there is a corresponding relationship between the TTI length to which the uplink grant corresponds and a serving cell of the UE to which the uplink grant corresponds.

6. The apparatus according to claim 5 , wherein,

the corresponding relationship between the TTI length to which the uplink grant corresponds and the serving cell of the UE to which the uplink grant corresponds is determined by the eNB.

7. The apparatus according to claim 1 , wherein multiple uplink grants are scheduled by one or more downlink control information.

8. The apparatus according to claim 1 , wherein transmission of uplink data to which each uplink grant corresponds occurs at an m-th TTI starting from the TTI scheduling the uplink grant, the length of the TTI being the TTI length to which the uplink grant corresponds, and m being a predetermined value.

9. The apparatus according to claim 8 , wherein transmission of uplink data to which uplink grants scheduled at different TTIs correspond temporally overlaps or not.

10. The apparatus according to claim 1 , wherein the DRBs to which the TTI length corresponds provide data for the UE to generate a media access control protocol data unit (MAC PDU).

11. The apparatus according to claim 1 , wherein the DRBs to which the TTI length of the uplink grant corresponds provide data for media access control (MAC) layer of the UE to generate a media access control protocol data unit (MAC PDU) for the uplink grant.

12. A communications system, comprising an eNB and a UE,

the eNB comprising:

a memory that stores a plurality of first instructions; and

a processor that couples to the memory and is configured to execute the first instructions to:

transmit to the UE configuration information about data radio bearers (DRBs), the configuration information about DRBs indicating TTI length to which each DRB configured by the eNB for the UE is applicable, the DRBs being configured by radio resource control (RRC);

notify a target eNB of the TTI length to which each DRB of the UE is applicable when the UE needs to be handed over, and

schedule two or more uplink grants of the UE, an uplink grant of the two or more uplink grants corresponding to a TTI length different from another TTI length of another uplink grant,

the UE comprising:

a memory that stores a plurality of second instructions; and

a processor that couples to the memory and is configured to execute the second instructions to:

receive the configuration information about DRBs transmitted by the eNB;

establish a data processing entity of MAC layer and an uplink shared channel corresponding to each TTI length; and

transmit data using the established data processing entity of MAC layer and the uplink shared channel corresponding to each TTI length according to received uplink grant.