A method for use in a mobile communications network that includes a plurality of infrastructure equipment each providing wireless connectivity within at least one cell, and a communications device configured to communicate wirelessly with at least a first infrastructure equipment including use of a radio bearer. The first infrastructure equipment performs the method including determining that there is a requirement to alter data handling resources allocated for handling the radio bearer in one or both of the first infrastructure equipment and the communications device, re-establishing, in response to the determination, its radio link control protocol layer, transmitting a reconfiguration message to the communications device to effect re-establishment of its radio link control protocol layer, and adding a new bit in the header of data packets transmitted to the communications device for a predetermined time after re-establishment of the radio link control protocol layer of the first infrastructure equipment.