Uplink transmission based on UL-grant associated with specific logical channel priority

1. A method for a user equipment (UE) transmitting uplink signals in a wireless communication system, the method comprising:

receiving a physical downlink control channel (PDCCH) including uplink grant;

based on the PDCCH including a logical channel priority indication, constructing a protocol data unit (PDU) including data from a radio bearer (RB) with first a logical channel priority corresponding to the logical channel priority indication; and

based on the PDCCH not including a logical channel priority indication, constructing the PDU including data from a RB with a lowest value which can be allocated as the logical channel priority indication; and

transmitting the PDU to a network based on the uplink grant.

2. The method of claim 1 , wherein the PDU further includes data from RB with next higher logical channel priority than the logical channel priority corresponding to the logical channel priority indication, if there is remaining space in the PDU after including the data from the RB with the logical channel priority corresponding to the logical channel priority indication.

3. The method of claim 1 , wherein PDU further comprises padding, if there is remaining space in the PDU after including the data from the RB with the logical channel priority corresponding to the logical channel priority indication.

4. The method of claim 1 , wherein the lowest value to which can be allocated as the logical channel priority indication means a highest quality of service (QoS).

5. The method of claim 1 , wherein the PDCCH is used for

the only one logical channel priority indication associated with multiple uplink grants.

6. The method of claim 1 , wherein the PDCCH is used for the only one logical channel priority indication

associated with the uplink grant.

7. A user equipment (UE) for transmitting uplink signals in a wireless communication system, the UE comprising:

a transceiver; and

a processor configured to:

control the transceiver to receive a physical downlink control channel (PDCCH) including uplink grant;

based on the PDCCH including a logical channel priority indication, construct a protocol data unit (PDU) including data from a radio bearers (RB) with a logical channel priority corresponding to the logical channel priority indication;

based on the PDCCH not including a logical channel priority indication, construct the PDU including data from a RB with a lowest value which can be allocated as the logical channel priority indication; and

control the transceiver to transmit the PDU to a network based on the uplink grant.

8. The UE of claim 7 , wherein the PDU further includes data from a RB with next higher logical channel priority than the logical channel priority corresponding to the logical channel priority indication, if there is remaining space in the PDU after including the data from the RB with the logical channel priority corresponding to the logical channel priority indication.

9. The UE of claim 7 , wherein the PDU further includes padding, if there is remaining space in the PDU after including the data from the RB with the logical channel priority corresponding to the logical channel priority indication.

10. The UE of claim 7 , wherein the lowest value to which can be allocated as the logical channel priority indication means a highest quality of service (QoS).

11. The UE of claim 7 , wherein the PDCCH is used for the only one logical channel priority indication associated with multiple uplink grants.

12. The UE of claim 7 , wherein the PDCCH is used for the only one logical channel priority indication associated with the first uplink grant.