Device to-device communications apparatus and methods

• US 10,257,871 B2
• Filed: 03/17/2015
• Issued: 04/09/2019
• Est. Priority Date: 03/18/2014
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Yamada, Shohei, Sheng, Jia
• Primary Examiner(s): Nowlin, Eric
• Application Number:
  US14/660,491
• Publication Number:
  US 20150271720A1
• Time in Patent Office: 1,484 Days
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 76/14 Direct-mode setup

Abstract

As a result of the selection/reselection operation, a wireless terminal (26) selects the high priority candidate frequency for use in the device-to-device (D2D) communications. During the cell selection/reselection operation, the wireless terminal (26) is required to consider selection/reselection candidate frequencies at which the wireless terminal (26) cannot receive or transmit device-to-device (D2D) signals to be of low priority candidate frequencies when the wireless terminal (26) is capable of device-to-device (D2D) communications and is receiving or transmitting, or anticipating receiving or transmitting, device-to-device (D2D) signals on device-to-device (D2D) supported frequencies. In another basic mode predefined RRC Idle Mode state transition(s) are used to determine when a wireless terminal (26) encounters an out-of-coverage situation for device-to-device (D2D) communications purposes; and when the out-of-coverage situation is determined, the wireless terminal (26) uses pre-configured device-to-device (D2D) radio resources for the device-to-device (D2D) communications.

Claims

1. A method carried out by a wireless terminal which is in wireless communications with a radio access node over a radio interface, the method comprising:

performing a cell selection/reselection operation; and

setting one frequency to a highest priority frequency with respect to the cell selection/reselection operation while the wireless terminal is simultaneously performing;

(i) device-to-device (D2D) communications in a state where the wireless terminal camps on the one frequency; and

(ii) the cell selection/reselection operation.

2. The method of claim 1, further comprising as a result of the selection/reselection operation the wireless terminal selecting a candidate frequency for use in the device-to-device (D2D) communications.

3. The method of claim 1, further comprising during the cell selection/reselection operation, requiring the wireless terminal to set selection/reselection candidate frequencies at which the wireless terminal cannot receive or transmit device-to-device (D2D) signals to be of low priority candidate frequencies when the wireless terminal is capable of device-to-device (D2D) communications and is receiving or transmitting, or anticipating receiving or transmitting, device-to-device (D2D) signals on device-to-device (D2D) supported frequencies.

4. The method of claim 1, further comprising during the cell selection/reselection operation, requiring the wireless terminal to set only cell selection/reselection candidate frequencies which are device-to-device (D2D)-supported frequencies when the wireless terminal is capable of device-to-device (D2D) communications and is receiving or transmitting, or anticipating receiving or transmitting, the device-to-device (D2D) signals on the device-to-device (D2D) supported frequencies.

5. The method of claim 1, further comprising:

determining whether the wireless terminal when engaged in device-to-device (D2D) communications encounters a wireless terminal selected resource mode; and

the wireless terminal determining whether to transmit the device-to-device (D2D) signals using resources selected by the wireless terminal from pre-configured device-to-device (D2D) radio resources or using network-allocated radio resources scheduled by the radio access node based on determining whether the wireless terminal encounters the wireless terminal selected resource mode.

6. The method of claim 1, further comprising the wireless terminal transmitting device-to-device (D2D) signals using device-to-device (D2D) radio resources selected in accordance with the cell selection/reselection operation.

7. A wireless terminal of a communications network which communicates over a radio interface with a radio access node, the wireless terminal comprising:

a processor;

a memory in electronic communication with the processor;

instructions stored in the memory, the instructions being executable to;

perform a cell selection/reselection operation; and

set one frequency to a highest priority frequency with respect to the cell selection/reselection operation while the wireless terminal is simulataneously performing;

(i) the device-to-device (D2D) communications in a state where the wireless terminal camps on the one frequency; and

(ii) the cell selection/reselection operation.

8. The wireless terminal of claim 7, wherein, as a result of the selection/reselection operation, the instructions are executable to further select a candidate frequency for use in the device-to-device (D2D) communications.

9. The wireless terminal of claim 7, wherein the instructions are executable to further require, during the cell selection/reselection operation, the wireless terminal to set selection/reselection candidate frequencies at which the wireless terminal cannot receive or transmit device-to-device (D2D) signals to be of low priority candidate frequencies when the wireless terminal is capable of device-to-device (D2D) communications and is receiving or transmitting, or anticipating receiving or transmitting, device-to-device (D2D) signals on device-to-device (D2D) supported frequencies.

10. The wireless terminal of claim 7, wherein the instructions are executable to further require, during the cell selection/reselection operation, the wireless terminal to set only cell selection/reselection candidate frequencies which are device-to-device (D2D)-supported frequencies when the wireless terminal is capable of device-to-device (D2D) communications and is receiving or transmitting, or anticipating receiving or transmitting, device-to-device (D2D) signals on device-to-device (D2D) supported frequencies.

11. The wireless terminal of claim 7, wherein the wireless terminal further comprises a transceiver which transmits device-to-device (D2D) signals using device-to-device (D2D) radio resources selected in accordance with the cell selection/reselection operation.