Method and apparatus for buffer status report in mobile communication system

1. A method for radio communication with a base station, by a user equipment (UE), the method comprising:

identifying whether the UE has an uplink resource allocated for transmission to the base station if a buffer status report for transmission to the base station has been triggered;

transmitting an uplink packet for the buffer status report using the uplink resource, if the UE has the uplink resource; and

transmitting a scheduling request to the base station, if the UE does not have an uplink resource and a first timer has been expired, wherein the first timer starts when the buffer status report is triggered.

2. The method of claim 1 , further comprising starting, after transmitting the uplink packet for the buffer status report, a second timer for a periodic buffer status report.

3. The method of claim 2 , wherein the buffer status report is triggered whenever the second timer expires.

4. The method of claim 1 , wherein the buffer status report is triggered when there is no data to be transmitted by the UE to the base station.

5. An apparatus in a user equipment (UE) for radio communication with a base station, the apparatus comprising:

a controller configured to identify whether the UE has an uplink resource allocated for transmission to the base station, if a buffer status report for transmission to the base station has been triggered; and

a transceiver configured to transmit an uplink packet for the buffer status report using the uplink resource if the UE has the uplink resource, and, otherwise, transmitting a scheduling request to the base station if the UE does not have an uplink resource and a first timer has been expired, wherein the first timer starts when the buffer status report is triggered.

6. The apparatus of claim 5 , wherein the controller is further configured to start, after transmitting the uplink packet for the buffer status report, a second timer for a periodic buffer status report.

7. The apparatus of claim 6 , wherein the controller is further configured to trigger the buffer status report whenever the second timer expires.

8. The apparatus of claim 6 , wherein the buffer status report is triggered when there is no data to be transmitted by the UE to the base station.

9. A method for radio communication with a user equipment (UE) by a base station, the method comprising:

if there is an uplink resource allocated for reception from the UE, receiving an uplink packet for a buffer status report from the UE using the uplink resource; and

if, after a predetermined time after the buffer status report is triggered by the UE, an uplink resource has not been allocated to the UE, receiving a scheduling request from the UE, wherein the scheduling request is received if the UE does not have an uplink resource and a first timer has been expired, and wherein the first timer starts when the buffer status report is triggered.

10. The method of claim 9 , wherein the buffer status report is triggered whenever a second timer for a periodic buffer status report expires, and the second timer starts after transmitting the buffer status report.

11. The method of claim 9 , wherein the buffer status report is triggered when there is no data to be transmitted by the UE to the base station.

12. An apparatus in a base station for radio communication with a user equipment (UE), the apparatus comprising:

a receiver configured to receive an uplink packet for a buffer status report and a scheduling request from the UE; and

a controller configured to allocate an uplink resource to the UE in response to the scheduling request,

wherein, if there is an uplink resource allocated for reception from the UE, the receiver is further configured to receive the uplink packet for the buffer status report from the UE using the uplink resource, and,

otherwise, if, after a predetermined time after the buffer status report is triggered by the UE, an uplink resource has not been allocated to the UE, the receiver is further configured to receive the scheduling request from the UE, wherein the scheduling request is received if the UE does not have an uplink resource and a first timer has been expired, and wherein the first timer starts when the buffer status report is triggered.

13. The apparatus of claim 12 , wherein the buffer status report is triggered whenever a second timer for a periodic buffer status report expires, and the second timer starts after transmitting the buffer status report.

14. The apparatus of claim 12 , wherein the buffer status report is triggered when there is no data to be transmitted by the UE to the base station.