Communications device, infrastructure equipment and methods
A communications device that, when in an inactive state, transmits a first signal comprising a random access preamble and a first portion of data to infrastructure equipment, receives a random access response message from the infrastructure equipment, and transmits a second signal comprising a second portion of the data to the infrastructure equipment.
1. A method of operating an infrastructure equipment providing a wireless access interface for transmitting data to or receiving data from a communications device in an inactive state, the method comprising:
receiving a first signal via the wireless access interface, the first signal including a random access preamble and a first portion of data from the communications device;
transmitting a random access response message to the communications device; and
receiving a second signal comprising a second portion of the data from the communications device; and
transmitting, based on whether the infrastructure equipment successfully receives the second portion, an acknowledgement or a negative acknowledgement (ACK/NACK) to the communications device.
2. The method according to claim 1 , wherein the first signal further comprises one or more of:
a first portion of user data,
an identifier of the communications device,
an indication that the second portion of data is available to be transmitted,
an indication of the size of the second portion of data, and
a Radio Resource Control, RRC, message comprising a request to resume an RRC connection or a request to set up a new RRC connection.
3. The method according to claim 1 , wherein the random access response message comprises one or more of:
an indication of an uplink grant, the uplink grant comprising second radio resources which can be used by the communications device for the transmission of the second signal,
a unique identifier which is assigned by the infrastructure equipment to identify the communications device for the transmission of the second signal,
an RRC response message in response to an RRC message comprised within the first signal,
an indication of a random access preamble and/or communications device identifier detected by the infrastructure equipment,
a second ACK/NACK based on whether the first portion of the data was successfully received by the infrastructure equipment, and
a timing advance command.
4. The method according to claim 3 , wherein the second signal further comprises a second RRC message in response to the RRC response message.
5. The method according to claim 1 , wherein the communications device selects the random access preamble from a set of random access preambles which are specifically used to indicate that a signal corresponding to the first signal is being transmitted.
6. The method according to claim 5 , wherein
the communications device determines first radio resources to be used for transmission of the first signal based on the random access preamble selected from the set of random access preambles, and
the first signal is transmitted by the communications device using the determined first radio resources.
7. Circuitry for an infrastructure equipment, the circuitry comprising:
transmitter circuitry;
receiver circuitry; and
control circuitry configured to control the transmitter circuitry and the receiver circuitry to:
provide a wireless access interface;
operate in an active state by controlling the transmitter circuitry and the receiver circuitry to transmit or receive signals representing data via the wireless access interface; and
operate in an inactive state by controlling the transmitter circuitry and the receiver circuitry to, via the wireless access interface:
receive a first signal comprising a random access preamble and a first portion of data from the communications device;
transmit a random access response message to the communications device;
receive a second signal comprising a second portion of the data from the communications device; and
transmit, based on whether the infrastructure equipment successfully receives the second portion, an acknowledgement or a negative acknowledgement (ACK/ACK) to the communications device.
8. The circuitry according to claim 7 , wherein the first signal further comprises one or more of:
a first portion of user data,
an identifier of the communications device,
an indication that the second portion of data is available to be transmitted,
an indication of the size of the second portion of data, and
a Radio Resource Control, RRC, message comprising a request to resume an RRC connection or a request to set up a new RRC connection.
9. The circuitry according to claim 7 , wherein the random access response message comprises one or more of:
an indication of an uplink grant, the uplink grant comprising second radio resources which can be used by the communications device for the transmission of the second signal,
a unique identifier which is assigned by the infrastructure equipment to identify the communications device for the transmission of the second signal,
an RRC response message in response to an RRC message comprised within the first signal,
an indication of a random access preamble and/or communications device identifier detected by the infrastructure equipment,
a second ACK/NACK based on whether the first portion of the data was successfully received by the infrastructure equipment, and
a timing advance command.
10. The circuitry according to claim 9 , wherein the second signal further comprises a second RRC message in response to the RRC response.
11. The circuitry according to claim 7 , wherein the communications device selects the random access preamble from a set of random access preambles which are specifically used to indicate that a signal corresponding to the first signal is being transmitted.
12. Circuitry for a communications device, the circuitry comprising:
transmitter circuitry;
receiver circuitry; and
control circuitry configured to control the transmitter circuitry and the receiver circuitry to:
operate in an active state by controlling the transmitter circuitry and the receiver circuitry to transmit or receive signals representing data via a wireless access interface provided by one or more infrastructure equipment; and
operate in an inactive state by controlling the transmitter circuitry and the receiver circuitry to, via the wireless access interface:
transmit a first signal comprising a random access preamble and a first portion of data to an infrastructure equipment of the one or more infrastructure equipment;
receive a random access response message from the infrastructure equipment;
transmit a second signal comprising a second portion of the data to the infrastructure equipment; and
receive, based on whether the infrastructure equipment successfully receives the second portion, an acknowledgement or a negative acknowledgement (ACK/NACK) from the infrastructure equipment.
13. The circuitry according to claim 12 , wherein the control circuitry is configured in combination with the transmitter circuitry to transmit the first signal using first radio resources indicated by the infrastructure equipment.
14. The circuitry according to claim 12 , wherein the first signal further comprises one or more of:
a first portion of user data,
an identifier of the communications device,
an indication that the second portion of data is available to be transmitted,
an indication of the size of the second portion of data, and
a Radio Resource Control, RRC, message comprising a request to resume an RRC connection or a request to set up a new RRC connection.
15. The circuitry according to claim 12 , wherein the random access response message comprises one or more of
an indication of an uplink grant, the uplink grant comprising second radio resources which can be used by the communications device for the transmission of the second signal,
a unique identifier which is assigned by the infrastructure equipment to identify the communications device for the transmission of the second signal,
an RRC response message in response to an RRC message comprised within the first signal,
an indication of a random access preamble and/or communications device identifier detected by the infrastructure equipment,
a second ACK/NACK based on whether the first portion of the data was successfully received by the infrastructure equipment, and
a timing advance command.
16. The circuitry according to claim 12 , wherein the second signal further comprises a second RRC message in response to the RRC response message.
17. The circuitry according to claim 12 , wherein the control circuitry is further configured to select the random access preamble from a set of random access preambles which are specifically used to indicate that a signal corresponding to the first signal is being transmitted.
18. The circuitry according to claim 17 , wherein the control circuitry is further configured to
determine first radio resources which should be used to transmit the first signal on the basis of the random access preamble selected from the set of random access preambles, and
control the transmitter circuitry to transmit the first signal using the determined first radio resources.