Communications system, infrastructure equipment, communications devices and method

A communications device for transmitting data to a mobile communications network or receiving data from the mobile communications network, the communications device comprising:

• a transmitter configured to transmit signals representing data via a wireless access interface to an infrastructure equipment of the mobile communications network, the wireless access interface providing communications resources within a system bandwidth and in time divided units providing communications resources in the system bandwidth for allocation to communications devices of a first and a second type, the first type of the communications devices having a different capability to the second type of communications devices,
• a receiver configured to receive signals from the infrastructure equipment via the wireless access interface, and
• a controller configured in combination with the transmitter and the receiver to
• generate 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,
• transmit the random access message from the communications device to the mobile communications network, and
• in response to the random access message, to receive a random access response transmitted according to the capability of the communications device of the second type, the random access message being recognized as being from a reduced capability terminal from the selected one of the predetermined sequences allocated to reduced capability terminals, wherein
• the wireless access interface includes a narrowband carrier defining a set of communications resources of the system bandwidth for allocation to communications devices of the second type for transmitting or receiving signals within the communications resources of the narrowband carrier bandwidth, and
• the controller is configured in combination with the receiver to receive the random access response in accordance with the capability of the communications device of the second type by receiving the random access response at the communications device from communications resources allocated to the communications device within the narrowband carrier bandwidth, the communications device of the second type having a reduced capability compared to communications devices of the first type.

A method of transmitting data from a communications device to a mobile communications network or receiving data from the mobile communications network at the mobile communications device, the method comprising:

• providing, by the mobile communications network, a wireless access interface, for transmitting and receiving data to and from communications devices, the wireless access interface providing communications resources within a system bandwidth and in time divided units providing communications resources within the system bandwidth for allocation to communications devices of a first type and a second type, the first type of the communications devices having a different capability to the second type of communications devices;
• transmitting to the communications device from the mobile communications network an indication of a predetermined set of sequences, which are allocated to the second type of communications devices for generating the random access messages;
• selecting at least one predetermined sequence from the predetermined set of sequences comprising sequences for generating non-contention based random access messages and sequences for generating contention based random access messages, wherein the predetermined set of sequences which are allocated to the second type of communications devices for contention based random access are selected from the sequences for generating non-contention based random access messages;
• generating, at the communications device, a random access message based on the selected at least one predetermined sequence;
• transmitting the random access message from the communications device to the wireless communications network;
• and
• in response to the random access message, receiving a random access response at the communications device transmitted according to the capability of the communications device of the second type, the random access message being recognized as being from a communications device of the second type based on the selected at least one predetermined sequence.

A communications device for transmitting data to a mobile communications network or receiving data from the mobile communications network, the communications device comprising:

• a transmitter configured to transmit signals representing data via a wireless access interface to an infrastructure equipment of the mobile communications network, the wireless access interface providing communications resources within a system bandwidth and in time divided units providing communications resources in the system bandwidth for allocation to communications devices of a first and a second type, the first type of the communications devices having a different capability to the second type of communications devices,
• a receiver configured to receive signals from the infrastructure equipment via the wireless access interface, and
• a controller configured in combination with the transmitter and the receiver to
• receive from the mobile communications network an indication of a predetermined set of sequences, which are allocated to the second type of communications devices;
• select at least one of the predetermined set of sequences from the predetermined set of sequences comprising sequences for generating non-contention based random access messages and sequences for generating contention based random access messages, wherein the predetermined set of sequences which are allocated to the second type of communications devices for contention based random access are selected from the sequences for generating non-contention based random access messages;
• generate a random access message based on the selected at least one predetermined sequence;
• transmit the random access message from the communications device to the mobile communications network, and
• in response to the random access message, to receive a random access response transmitted according to the capability of the communications device of the second type, the random access message being recognized as being from a second type of communications device based on the selected at least one of the predetermined set of sequences.