The mobile station described herein comprises a transmission buffer, a receiver, a transmitter, and a controller. The controller triggers a scheduling request and buffer status report when data enters the transmission buffer. When the receiver receives a contention-based scheduling grant allocating contention-based uplink resources, the transmitter transmits one or more data packets retrieved from the transmission buffer along with the buffer status report on the contention-based resources to the network station. If one or more data packets remain in the transmission buffer after transmission of the buffer status report on the contention-based resources, the controller maintains the pending status of the buffer status report and the corresponding scheduling request.