A method for a user equipment, UE, operating in a wireless communication system, the method comprising: configuring a first logical channel for first uplink data, that is allowed to transmit a contention based resource and a second logical channel for second uplink data, that is not allowed to transmit the contention based resource; checking whether at least one of the first uplink data and the second uplink data become available for transmission; based on the second uplink data becoming available for transmission without the first uplink data, transmitting a first protocol data unit, PDU, on the contention based resource, wherein the first PDU includes a buffer status reporting, BSR, for an amount of the second uplink data, and the first PDU does not include the second uplink data; based on the first uplink data becoming available for transmission without the second uplink data, transmitting a second PDU on the contention based resource, wherein the second PDU includes all of the first uplink data when the second PDU can accommodate all of the first uplink data; based on the first uplink data becoming available for transmission without the second uplink data, transmitting a third PDU on the contention based resource, wherein the third PDU includes a part of the first uplink data and no BSR when the third PDU cannot accommodate all of the first uplink data; and based on both of the first uplink data and the second uplink data becoming available for transmission, transmitting a fourth PDU on the contention based resource, wherein the fourth PDU includes the BSR, and the fourth PDU does not include the first uplink data and the second uplink data, wherein a padding bit is included in the fourth PDU based on remaining space in the fourth PDU after including the BSR. configuring a first logical channel for first uplink data, that is allowed to transmit a contention based resource and a second logical channel for second uplink data, that is not allowed to transmit the contention based resource; checking whether at least one of the first uplink data and the second uplink data become available for transmission; based on the second uplink data becoming available for transmission without the first uplink data, transmitting a first protocol data unit, PDU, on the contention based resource, wherein the first PDU includes a buffer status reporting, BSR, for an amount of the second uplink data, and the first PDU does not include the second uplink data; based on the first uplink data becoming available for transmission without the second uplink data, transmitting a second PDU on the contention based resource, wherein the second PDU includes all of the first uplink data when the second PDU can accommodate all of the first uplink data; based on the first uplink data becoming available for transmission without the second uplink data, transmitting a third PDU on the contention based resource, wherein the third PDU includes a part of the first uplink data and no BSR when the third PDU cannot accommodate all of the first uplink data; and based on both of the first uplink data and the second uplink data becoming available for transmission, transmitting a fourth PDU on the contention based resource, wherein the fourth PDU includes the BSR, and the fourth PDU does not include the first uplink data and the second uplink data, wherein a padding bit is included in the fourth PDU based on remaining space in the fourth PDU after including the BSR. <EOS>