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

1. A UE (User Equipment), the UE comprising:

a receiver configured to:

receive configuration information about data radio bearers (DRBs) from a base station, the configuration information indicating Transmission Time Interval (TTI) length to which each DRBs for the UE corresponds, the DRBs being configured by radio resource control (RRC), and

receive one or more uplink grants from the base station, each of the uplink grants of the one or more uplink grants corresponding to a TTI length different from another TTI length of other uplink grants; and

a transmitter configured to transmit data to the base station using an uplink shared channel corresponding to each TTI length according to an uplink grant in the one or more uplink grants.

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

processor circuitry configured to establish a data processing entity of media access control (MAC) layer and an uplink shared channel corresponding to each TTI length.

3. The UE according to claim 2 , wherein

the processor circuitry is further configured to:

determine TTI length to which the uplink grant corresponds;

generate a media access control protocol data unit (MAC PDU) by acquiring data from a DRB to which the TTI length corresponds; and

transmit the MAC PDU to the base station at an m-th TTI starting from the TTI receiving the uplink grant, length of the TTI being the TTI length to which the uplink grant corresponds, and m being a predetermined value.

4. The UE according to claim 2 , wherein

the processor circuitry is further configured to release data processing entities of MAC layers and uplink shared channels to which other TTI lengths than a default TTI length correspond when the UE initiates radio resource control (RRC) connection reestablishment.

5. The UE according to claim 2 , wherein the data processing entity of MAC layer comprises:

a logic channel prioritization entity, a multiplexing/demultiplexing entity, and a hybrid automatic repeat request (HARQ) entity.

6. The UE according to claim 1 , wherein the received uplink grant corresponds to a TTI length different from another TTI length of another uplink grant.

7. The UE according to claim 1 , wherein the DRBs are configured by the radio resource control (RRC) when a handover occurs.

8. A base station comprising:

a transmitter configured to:

transmit, via radio resource control (RRC) signal, configuration information about data radio bearers (DRBs) to a terminal, the configuration information indicating Transmission Time Interval (TTI) length to which each DRBs for the UE corresponds, and

processor circuitry configured to schedule one or more uplink grants of the terminal, each uplink grant of the one or more uplink grants corresponding to a TTI length different from another TTI length of another uplink grant, wherein

the transmitter transmits the one or more uplink grants to the terminal.

9. A wireless communication system comprising:

a terminal; and

a base station configured to communicate with the terminal, wherein

the base station is further configured to:

transmit, via radio resource control (RRC) signal, configuration information about data radio bearers (DRBs) to the terminal, the configuration information indicating Transmission Time Interval (TTI) length to which each DRBs for the UE corresponds,

schedule one or more uplink grants of the terminal, each uplink grant of the one or more uplink grants corresponding to a TTI length different from another TTI length of other uplink grants, and

transmit the one or more uplink grants to the terminal, and the terminal is further configured to:

receive the configuration information from the base station,

receive the one or more uplink grants from the base station, and

transmit data to the base station using an uplink shared channel corresponding to each TTI length according to an uplink grant in the one or more uplink grants.