Communication control method and user terminal for selecting synchronization reference of device-to-device (D2D)

• US 10,097,966 B2
• Filed: 11/09/2017
• Issued: 10/09/2018
• Est. Priority Date: 09/27/2013
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Morita, Kugo, Adachi, Hiroyuki, Fukuta, Noriyoshi
• Primary Examiner(s): Rivas, Salvador E
• Application Number:
  US15/808,730
• Publication Number:
  US 20180070217A1
• Time in Patent Office: 334 Days
• CPC Class Codes: H04L 12/1881 with schedule organisation, e.g. priority, sequence management
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04W 28/0215 based on user or device properties, e.g. MTC-capable devices services for machine-to-machine communication [M2M] or machine type communication [MTC] H04W4/70; wireless resource selection or allocation plan definition based on terminal or device properties H04W72/51
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 72/569 of the traffic information
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

D2D communication is appropriately controlled even in an environment in which a second user terminal inside the coverage and a first user terminal outside the coverage both exist. The first user terminal directly receives from the second user terminal device-to-device (D2D) synchronization information including coverage information that indicates that the second user terminal is in the coverage area, determines, based on the coverage information, whether the second user terminal is in the coverage area, selects the second user terminal as a synchronization reference of the first user terminal in response to determining that the second user terminal is in the coverage area, and receives usable resource information broadcasted from the second user terminal that becomes the synchronization reference, the usable resource information indicating D2D usable resources notified from a base station to the second user terminal by broadcast signaling.

Claims

1. A first user terminal comprising:

a controller containing at least one processor and at least one memory, wherein

in case that the first user terminal is out of coverage area of a communication network including a plurality of base stations, the controller is configured to execute processes of;

directly receiving device-to-device (D2D) synchronization information from a second user terminal being in the coverage area, the D2D synchronization information including coverage information that indicates that the second user terminal is in the coverage area;

determining, based on the coverage information, that the second user terminal is in the coverage area;

selecting the second user terminal as a synchronization reference of the first user terminal in response to determining that the second user terminal is in the coverage area; and

receiving usable resource information broadcasted from the second user terminal that becomes the synchronization reference, the usable resource information indicating D2D usable resources notified from a base station to the second user terminal by broadcast signaling.

2. The first user terminal according to claim 1, wherein

the controller is further configured to execute processes of:

transmitting another D2D synchronization information after selecting the second user terminal as the synchronization reference; and

selecting second time resources for transmitting the another D2D synchronization information, the second time resources being different from first time resources for transmitting the D2D synchronization information.

3. A method for performing by a first user terminal, comprising:

in case that the first user terminal is out of coverage area of a communication network including a plurality of base stations,

directly receiving device-to-device (D2D) synchronization information from a second user terminal being in the coverage area, the D2D synchronization information including coverage information that indicates that the second user terminal is in the coverage area;

determining, based on the coverage information, that the second user terminal is in the coverage area;

selecting the second user terminal as a synchronization reference of the first user terminal in response to determining that the second user terminal is in the coverage area; and

receiving usable resource information broadcasted from the second user terminal that becomes the synchronization reference, the usable resource information indicating D2D usable resources notified from a base station to the second user terminal by broadcast signaling.

4. The method according to claim 3, further comprising:

transmitting another D2D synchronization information after selecting the second user terminal as the synchronization reference; and

selecting second time resources for transmitting the another D2D synchronization information, the second time resources being different from first time resources for transmitting the D2D synchronization information.

5. A device for controlling a first user terminal, comprising:

at least one processor and at least one memory, wherein

in case that the first user terminal is out of coverage area of a communication network including a plurality of base stations, the at least one processor is configured to execute processes of;

directly receiving device-to-device (D2D) synchronization information from a second user terminal being in the coverage area, the D2D synchronization information including coverage information that indicates that the second user terminal is in the coverage area;

determining, based on the coverage information, that the second user terminal is in the coverage area;

selecting the second user terminal as a synchronization reference of the first user terminal in response to determining that the second user terminal is in the coverage area; and

receiving usable resource information broadcasted from the second user terminal that becomes the synchronization reference, the usable resource information indicating D2D usable resources notified from a base station to the second user terminal by broadcast signaling.

6. The device according to claim 5, wherein

the at least one processor is further configured to execute processes of:

transmitting another D2D synchronization information after selecting the second user terminal as the synchronization reference; and

selecting second time resources for transmitting the another D2D synchronization information, the second time resources being different from first time resources for transmitting the D2D synchronization information.