A mobile station comprising: a transmission buffer configured to store one or more data packets intended to be transmitted to a network station; a receiver configured to receive, from the network station, a contention-based scheduling grant, allocating contention-based resources for uplink transmission from the mobile station to the network station; and a transmitter configured to transmit, responsive to the contention based scheduling grant, one or more data packets, contained in the transmission buffer, on said contention-based resources, wherein if a buffer status report is pending, said transmitter is further configured to transmit the buffer status report with the transmitted one or more data packets on said contention-based resources; the mobile station being characterized by further comprising: a controller configured to maintain a pending status of the buffer status report and a corresponding scheduling request when one or more data packets remain in the transmission buffer after the buffer status report is transmitted on said contention-based resources, wherein the receiver is further configured to receive, from the network station, a dedicated scheduling grant, allocating dedicated resources for uplink transmission from the mobile station to the network station, and wherein the transmitter is further configured to execute a pro-active retransmission, when no data packets remain in the transmission buffer upon receipt of the dedicated scheduling grant, by transmitting, responsive to the dedicated scheduling grant, one or more data packets awaiting acknowledgement from a higher protocol layer on said dedicated resources. a transmission buffer configured to store one or more data packets intended to be transmitted to a network station; a receiver configured to receive, from the network station, a contention-based scheduling grant, allocating contention-based resources for uplink transmission from the mobile station to the network station; and a transmitter configured to transmit, responsive to the contention based scheduling grant, one or more data packets, contained in the transmission buffer, on said contention-based resources, wherein if a buffer status report is pending, said transmitter is further configured to transmit the buffer status report with the transmitted one or more data packets on said contention-based resources; the mobile station being characterized by further comprising: a controller configured to maintain a pending status of the buffer status report and a corresponding scheduling request when one or more data packets remain in the transmission buffer after the buffer status report is transmitted on said contention-based resources, wherein the receiver is further configured to receive, from the network station, a dedicated scheduling grant, allocating dedicated resources for uplink transmission from the mobile station to the network station, and wherein the transmitter is further configured to execute a pro-active retransmission, when no data packets remain in the transmission buffer upon receipt of the dedicated scheduling grant, by transmitting, responsive to the dedicated scheduling grant, one or more data packets awaiting acknowledgement from a higher protocol layer on said dedicated resources. a controller configured to maintain a pending status of the buffer status report and a corresponding scheduling request when one or more data packets remain in the transmission buffer after the buffer status report is transmitted on said contention-based resources, wherein the receiver is further configured to receive, from the network station, a dedicated scheduling grant, allocating dedicated resources for uplink transmission from the mobile station to the network station, and wherein the transmitter is further configured to execute a pro-active retransmission, when no data packets remain in the transmission buffer upon receipt of the dedicated scheduling grant, by transmitting, responsive to the dedicated scheduling grant, one or more data packets awaiting acknowledgement from a higher protocol layer on said dedicated resources.