A method of transmitting/receiving data between a communications device and a mobile communications network including a wireless access interface providing communications resources within a system bandwidth and in time divided units allocated to communications devices of first and second types having different capabilities. The method generates, at the communications device, a random access message, by selecting a sequence from a predetermined set of sequences, which have been allocated to the communications devices of the second type and transmitting the random access message from the communications device to the wireless communications network, and in response to the random access message, receives a random access response at the communications device transmitted according to the capability of the communications device of second type, the random access message being recognized as from a communications device of second type from the selected one of the predetermined sequences allocated to the communications devices of second type.