A method for determining whether an acknowledgement received by a user equipment from an external device is a forced acknowledgement. The method including transmitting a set of data stored in an uplink buffer to an external device, receiving an acknowledgement from the external device, determining if the acknowledgement received from the external device was a forced acknowledgement and flushing out an uplink buffer if determined that the acknowledgement was not a forced acknowledgement. The determining the acknowledgement is a forced acknowledgment being based on whether an uplink retransmission collides with one or more scheduled transmission times, a Physical Hybrid-ARQ Indicator Channel (PHICH) falls between gap measurements and an uplink retransmission collides with one of the gap measurements or a TTI bundling retransmission collides with a gap measurement. If the acknowledgement is not a forced acknowledgment, a set of data stored in the uplink buffer is retransmitted to the external device.