COMMUNICATIONS DEVICE AND METHOD FOR IMPROVING THE TRANSMISSION OF RANDOM ACCESS MESSAGES

• US 20180042053A1
• Filed: 10/18/2017
• Published: 02/08/2018
• Est. Priority Date: 09/20/2013
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: MARTIN, Brian Alexander
• Granted Patent: US 10,111,256 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 28/0205 at the air interface dynamic wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/0221 power availability or consumption
• CPC Class Codes: H04W 56/0005 synchronizing of arrival of multiple uplinks
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 74/085 collision avoidance
• CPC Class Codes: Y04S 20/30 Smart metering, e.g. specially adapted for remote reading

Abstract

A communications device to transmit data to a mobile communications network includes one or more network elements providing a wireless access interface for communication. The communications device includes a controller controlling a transmitter to transmit a random access message to a first network element via a random access channel of the wireless access interface common to one or more other communications devices, to receive in response an acknowledgement indicating an allocation of communications resources of a shared up-link channel for the communications device to transmit signals to the mobile communications network, or a negative acknowledgment indicating the communications device has not been allocated communications resources of the shared up-link channel. After detecting random access failure conditions by the controller, the controller in combination with the transmitter re-transmits the random access message one or more times, with a variable delay greater than or equal to a delay of a previous re-transmission.

Claims

1. A communications device for communicating via a mobile communications network, the mobile communications network including one or more network elements providing a wireless access interface for transmitting signals to or receiving signals from the communications device, the communications device comprising:

a transmitter configured to transmit the signals to the mobile communications network via the wireless access interface provided by the one or more network elements of the mobile communications network, and

a receiver configured to receive the signals from the mobile communications network via the wireless access interface provided by the one or more network elements of the mobile communications network, and

a controller configured to control the transmitter

to transmit a random access message to a first network element via a random access channel of the wireless access interface which is common to one or more other communications devices,

to receive from the first network element an acknowledgement in response to the random access message providing an indication of an allocation of communications resources of a shared up-link channel for the communications device to transmit signals to the first network element or a negative acknowledgement providing an indication that the communications device has not been allocated communications resources of the shared up-link channel, wherein

in response to detection of one or more random access failure conditions by the controller, the controller is configured in combination with the transmitter

to retransmit the random access message one or more times, each retransmission of the random access message being after a variable delay which is greater than or equal to the delay of a previous retransmission.

2. A communications device as claimed in claim 1, wherein each delay before the retransmission of the random access message is comprised of a delay randomly selected from between a minimum delay period and a maximum delay period, wherein the maximum delay period associated with each retransmission is greater than that of a previous retransmission.

3. A communications device as claimed in claim 1, wherein in response to the detection of one or more random access failure conditions by the controller, the controller is configured in combination with the receiver to select a second network element to which to transmit a subsequent random access message to, the second network element having been selected in accordance with a network element selection or reselection criterion.

4. A communications device as claimed in claim 3, wherein the network element selection or reselection criterion includes a negative offset configured to be applied to a signal strength of signals received from the first network element, and the controller is configured in combination with the receiver and the transmitter

to receive signals transmitted by the one or more network elements,

to determine a signal strength of each of the received signals from each of the one or more network elements and establish corresponding parameters associated with the selection or reselection criterion,

to apply the negative offset to the parameter associated with the selection or reselection criterion associated with the first network element, and

to select the second network element in accordance with the selection or reselection criterion associated with the respective network elements.

5. A communications device as claimed in claim 4, wherein the offset has a size which has an effect of preventing reselection of the first network element.

6. A communications device as claimed in claim 1, wherein the controller in combination with the transmitter is configured

to increase a power with which the random access message is retransmitted for each of the times which the random access message is retransmitted.

7. A communications device as claimed in claim 1, wherein the random access failure conditions include transmitting the random access message a predetermined number of times.

8. A communications device as claimed in claim 1, wherein the random access failure conditions include failing to receive within a predetermined time an acknowledgement providing an indication of an allocation of the shared up-link channel.

9. A communications device as claimed in claim 1, wherein the controller is configured in combination with the receiver to receive a broadcast message from the first network element, the broadcast message indicating one or more of the random access failure conditions.

10. A communications device as claimed in claim 1, wherein the random access message is retransmitted at a power less than or equal to a maximum transmit power.

11. A communications device as claimed in claim 1, wherein the controller is configured in combination with the receiver to receive a broadcast message from the first network element, the delay being calculated in accordance with a parameter indicated in the broadcast message.

12. A communications device as claimed in claim 1, wherein the controller is configured in combination with the receiver to receive a broadcast message from the first network element, a network element reselection criterion parameter being indicated in the broadcast message.

13. A method of communicating via a mobile communications network, the mobile communications network including one or more network elements providing a wireless access interface for transmitting signals to or receiving signals from the communications device, the method comprising:

transmitting the signals to the mobile communications network via the wireless access interface provided by the one or more network elements of the mobile communications network,

receiving the signals from the mobile communications network via the wireless access interface provided by the one or more network elements of the mobile communications network, the transmitting including

transmitting a random access message to a first network element via a random access channel of the wireless access interface which is common to one or more other communications devices,

receiving from the first network element an acknowledgement in response to the random access message providing an indication of an allocation of communications resources of a shared up-link channel for the communications device to transmit signals to the first network element or a negative acknowledgement providing an indication that the communications device has not been allocated communications resources of the shared up-link channel, wherein

in response to detection of one or more random access failure conditions, re-transmitting the random access message one or more times, each re-transmission of the random access message being after a variable delay which is greater than or equal to the delay of a previous re-transmission.