Communications device and method for improving the transmission of random access messages

• US 10,575,337 B2
• Filed: 10/11/2018
• Issued: 02/25/2020
• 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
• Primary Examiner(s): O Connor, Brian T
• Application Number:
  US16/157,728
• Publication Number:
  US 20190045555A1
• Time in Patent Office: 502 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 retransmits 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 that includes one or more network elements providing a wireless access interface, the communications device comprising:

circuitry configured to

transmit signals to the mobile communications network via the wireless access interface;

receive signals from the mobile communications network via the wireless access interface;

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;

receive, from the first network element in response to the random access message in a case that communications resources of a shared uplink channel are allocated for the communications device to transmit signals to the first network element, an acknowledgement that provides an indication of the allocation of the communications resources of the shared uplink channel for the communications device;

receive, from the first network element in response to the random access message in a case that the communications resources of the shared uplink channel are not allocated for the communications device, a negative acknowledgement providing an indication that the communications device has not been allocated the communications resources of the shared uplink channel; and

retransmit, in response to detection of one or more random access failure conditions, the random access message one or more times such that each retransmission of the random access message is performed after a variable delay which is greater than or equal to a delay of a previous retransmission, wherein

the circuitry is further configured to receive a broadcast message from the first network element, the broadcast message indicating one or more of the random access failure conditions.

2. The communications device of 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, and

the maximum delay period associated with each retransmission is greater than that of a previous retransmission.

3. The communications device of claim 1, wherein in response to the detection of one or more random access failure conditions, the circuitry is configured 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. The communications device of 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 circuitry is configured to

receive signals transmitted by the one or more network elements;

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

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

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

6. The communications device of claim 1, wherein the circuitry is configured to increase a power with which the random access message is retransmitted for each time that the random access message is retransmitted.

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

8. The communications device of 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 uplink channel.

9. The communications device of claim 1, wherein the random access message is retransmitted at a power less than or equal to a maximum transmit power.

10. The communications device of claim 1, wherein the circuitry is configured to receive a broadcast message from the first network element, the delay being calculated in accordance with a parameter indicated in the broadcast message.

11. The communications device of claim 1, wherein the circuitry is configured to receive a broadcast message from the first network element, a network element reselection criterion parameter being indicated in the broadcast message.

12. A method of communicating via a mobile communications network that includes one or more network elements providing a wireless access interface, the method comprising:

transmitting, by a communications device, signals to the mobile communications network via the wireless access interface;

receiving signals from the mobile communications network via the wireless access interface;

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, by the communications device from the first network element in response to the random access message in a case that the communications resources of a shared uplink channel are allocated for the communications device to transmit signals to the first network element, an acknowledgement that provides an indication of the allocation of the communications resources of the shared uplink channel for the communications device;

receiving, by the communications device from the first network element in response to the random access message in a case that the communications resources of the shared uplink channel are not allocated for the communications device, a negative acknowledgement providing an indication that the communications device has not been allocated communications resources of the shared uplink channel;

receiving a broadcast message from the first network element, the broadcast message indicating one or more of the random access failure conditions; and

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

13. Circuitry for a communications device that communicates via a mobile communications network that includes one or more network elements providing a wireless access interface, the circuitry configured to:

transmit signals to the mobile communications network via the wireless access interface;

receive signals from the mobile communications network via the wireless access interface;

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;

receive, from the first network element in response to the random access message in a case that communications resources of a shared uplink channel are allocated for the communications device to transmit signals to the first network element, an acknowledgement that provides an indication of the allocation of the communications resources of the shared uplink channel for the communications device;

receive, from the first network element in response to the random access message in a case that the communications resources of the shared uplink channel are not allocated for the communications device, a negative acknowledgement providing an indication that the communications device has not been allocated the communications resources of the shared uplink channel;

receive a broadcast message from the first network element, the broadcast message indicating one or more of the random access failure conditions; and

retransmit, in response to detection of one or more random access failure conditions, the random access message one or more times such that each retransmission of the random access message is performed after a variable delay which is greater than or equal to a delay of a previous retransmission.