Anchor base station, slave cell and user equipment
A communications device acting as a relay device including a controller configured in combination with a transmitter and a receiver to receive from a remote communications device a first random access preamble message, the first random access preamble message comprising an identifier of the remote communications device, to transmit, in response to the first random access preamble message, a random access response message to the remote communications device, the random access response message comprising an indication of communications resources allocated to the remote communications device, to receive, from the remote communications device and using the communications resources indicated in the random access response message, a scheduled transmission comprising a connection request message and a first contention resolution identifier, and to transmit to the remote communications device a second contention resolution identifier.
1. A communications device acting as a relay device configured to communicate with an infrastructure equipment of a mobile communications network and a remote communications device operating with the mobile communications network, the communications device acting as the relay device comprising:
a receiver configured to receive signals representing data via a first wireless access interface from the infrastructure equipment for transmission to the remote communications device and to receive signals representing data via a second wireless access interface from the remote communications device for transmission to the infrastructure equipment,
a transmitter configured to transmit signals representing data via the first wireless access interface to the infrastructure equipment and to transmit signals representing data via the second wireless access interface to the remote communications device, and
a controller configured to control the transmitter to transmit the signals and to control the receiver to receive the signals, wherein the controller is configured in combination with the transmitter and the receiver
to receive from the remote communications device a first random access preamble message, the first random access preamble message comprising an identifier of the remote communications device,
to transmit, in response to the first random access preamble message, a random access response message to the remote communications device, the random access response message comprising an indication of communications resources allocated to the remote communications device,
to receive, from the remote communications device and using the communications resources indicated in the random access response message, a scheduled transmission comprising a connection request message and a first contention resolution identifier, and
to transmit to the remote communications device a second contention resolution identifier,
wherein in response to determining that the first contention resolution identifier is the same as the second contention resolution identifier, the controller is configured in combination with the receiver
to receive an indication from the remote communications device that a successful connection for data communications has been made between the remote communications device and the communications device acting as the relay device.
2. A communications device acting as a relay device as claimed in claim 1 , wherein the random access response message comprises a backoff indicator, the backoff indicator indicating a time delay between multiple random access preamble messages transmitted by the remote communications device.
3. A communications device acting as a relay device as claimed in claim 2 , wherein in response to determining that the first contention resolution identifier is different to the second contention resolution identifier, the controller is configured in combination with the receiver to receive from the remote communications device a second random access preamble message in accordance with the time delay indicated by the backoff indicator, the second random access preamble comprising an identifier of the remote communications device and being different to the first random access preamble message.
4. A communications device acting as a relay device as claimed in claim 3 , wherein at least one of the first random access preamble message and the second random access preamble message is provided from
system information broadcast by the infrastructure equipment to at least one of the remote communications device and the communications device acting as the relay device, or
signalled by the infrastructure equipment to at least one of the remote communications device and the communications device acting as the relay device, or
system information broadcast by the communications device acting as the relay device to the remote communications device.
5. A communications device acting as a relay device as claimed in claim 3 , wherein at least one of the first random access preamble message and the second random access preamble message is received from the remote communications device if the remote communications device has determined that a required transmit power to transmit the at least one of the first random access preamble message and the second random access preamble message to the communications device acting as the relay device is smaller than a predetermined threshold, the predetermined threshold being provided from by either
system information broadcast by the infrastructure equipment to the remote communications device, or
system information transmitted by the communications device acting as the relay device to the remote communications device, or
radio resource control signalling transmitted to the remote communications device.
6. A communications device acting as a relay device as claimed in claim 1 , wherein the random access response message comprises a timing advance command, the timing advance command comprising an indication that the remote communications device should adjust its timing such that-signals received from different remote communications devices can be aligned at the relay device.
7. A communications device acting as a relay device as claimed in claim 1 , wherein the communications resources allocated to the remote communications device are allocated from communications resources which have been pre-allocated to the communications device acting as the relay device by the infrastructure equipment.
8. A communications device acting as a relay device as claimed in claim 1 , wherein, in response to the first random access preamble message, the controller is configured in combination with the transmitter and the receiver
to transmit a scheduling request message to the infrastructure equipment,
to receive an indication of communications resources to be allocated to the remote communications device, and
to include the indication of the communications resources to be allocated to the remote communications device in the random access response message.
9. A communications device acting as a relay device as claimed in claim 1 , wherein the random access response message comprises a temporary remote communications device identifier, the temporary remote communications device identifier being used for further communications between the remote communications device and the communications device acting as the relay device, wherein the temporary remote communications device identifier is specific within a communication range of the relay device.
10. A communications device acting as a relay device as claimed in claim 1 , wherein the random access response message comprises a preamble identifier, the preamble identifier being used by the remote communications device to identify whether the random access response message is for the remote communications device or if the random access response message is for another communications device.
11. A communications device acting as a relay device as claimed in claim 1 , wherein the controller is configured in combination with the transmitter and the receiver
to transmit the received first random access preamble message to the infrastructure equipment,
to receive, from the infrastructure equipment, the random access response message, and
to transmit the received random access response message to the remote communications device.
12. A communications device acting as a relay device as claimed in claim 11 , wherein the controller is configured in combination with the transmitter and the receiver
to transmit the received random access response message to the remote communications device and one or more other communications devices.
13. A communications device acting as a relay device configured to communicate with an infrastructure equipment of a mobile communications network and a remote communications device operating with the mobile communications network, the communications device acting as the relay device comprising:
a receiver configured to receive signals representing data via a first wireless access interface from the infrastructure equipment and to receive signals representing data via a second wireless access interface from the remote communications device for transmission to the infrastructure equipment,
a transmitter configured to transmit signals representing data via the first wireless access interface to the infrastructure equipment, and
a controller configured to control the transmitter to transmit the signals and to control the receiver to receive the signals, wherein the controller is configured in combination with the transmitter and the receiver
to receive from the remote communications device a first random access preamble message, the first random access preamble message comprising an identifier of the remote communications device,
to transmit the first random access preamble message to the infrastructure equipment, the first random access preamble message indicating to the infrastructure equipment that it should transmit a random access response message to the remote communications device, the random access response message comprising an indication of communications resources allocated to the remote communications device,
to receive from the infrastructure equipment the indication of the communications resources allocated to the remote communications device,
to receive, from the remote communications device and using the communications resources indicated in the random access response message, a scheduled transmission comprising a connection request message and a first contention resolution identifier, and
to transmit the scheduled transmission to the infrastructure equipment,
wherein in response to determining that the first contention resolution identifier is the same as a second contention resolution identifier transmitted to the remote communications device by the infrastructure equipment, the controller is configured in combination with the receiver
to receive an indication from the remote communications device that a successful connection for data communications has been made between the remote communications device and the communications device acting as the relay device.
14. A communications device acting as a relay device as claimed in claim 13 , wherein the random access response message comprises a backoff indicator, the backoff indicator indicating a time delay between multiple random access preamble messages transmitted by the remote communications device.
15. A communications device acting as a relay device as claimed in claim 14 , wherein in response to determining that the first contention resolution identifier is different to the second contention resolution identifier, the controller is configured in combination with the receiver to receive from the remote communications device a second random access preamble message in accordance with the time delay indicated by the backoff indicator, the second random access preamble comprising an identifier of the remote communications device and being different to the first random access preamble message.
16. A communications device acting as a relay device as claimed in claim 15 , wherein at least one of the first random access preamble message and the second random access preamble message is provided by either
system information broadcast by the infrastructure equipment to at least one of the remote communications device and the communications device acting as the relay device, or
signalled by the infrastructure equipment to at least one of the remote communications device and the communications device acting as the relay device, or
system information broadcast by the communications device acting as the relay device to the remote communications device.
17. A communications device acting as a relay device as claimed in claim 15 , wherein at least one of the first random access preamble message and the second random access preamble message is received from the remote communications device if the remote communications device has determined that a required transmit power to transmit the at least one of the first random access preamble message and the second random access preamble message to the communications device acting as the relay device is smaller than a predetermined threshold, wherein the predetermined threshold is provided from either
system information broadcast by the infrastructure equipment to the remote communications device, or
system information broadcast by the communications device acting as the relay device to the remote communications device, or
radio resource control signalling transmitted to the remote communications device.
18. A communications device acting as a relay device as claimed in claim 13 , wherein the random access response message comprises a timing advance command, the timing advance command comprising an indication that the remote communications device should adjust its timing such that signals received from different remote communications devices can be aligned at the relay device.
19. A communications device acting as a relay device as claimed in claim 13 , wherein the random access response message comprises a temporary remote communications device identifier, the temporary remote communications device identifier being used for further communications between the remote communications device and the communications device acting as the relay device,
wherein the controller is configured in combination with the receiver to receive an indication of the temporary remote communications device identifier from the infrastructure equipment, and
wherein the temporary remote communications device identifier is specific within a communication range of the relay device.
20. A communications device acting as a relay device as claimed in claim 13 , wherein the random access response message comprises a preamble identifier, the preamble identifier being used by the remote communications device to identify whether the random access response message is for the remote communications device or if the random access response message is for another communications device.
21. A method of operating a communications device acting as a relay device configured to communicate with an infrastructure equipment of a mobile communications network and a remote communications device operating with the mobile communications network, the method comprising:
receiving from the remote communications device via a wireless access interface a first random access preamble message, the first random access preamble message comprising an identifier of the remote communications device,
transmitting, in response to the first random access preamble message, a random access response message to the remote communications device, the random access response message comprising an indication of communications resources allocated to the remote communications device,
receiving, from the remote communications device and using the communications resources indicated in the random access response message, a scheduled transmission comprising a connection request message and a first contention resolution identifier, and
transmitting to the remote communications device a second contention resolution identifier,
wherein in response to determining that the first contention resolution identifier is the same as the second contention resolution identifier, the method comprises
receiving an indication from the remote communications device that a successful connection for data communications has been made between the remote communications device and the communications device acting as the relay device.