Mobile communication system and mobile communication method used in a mobile communication system

• US 9,973,317 B2
• Filed: 10/27/2016
• Issued: 05/15/2018
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Fujishiro, Masato, Yamazaki, Chiharu, Morita, Kugo
• Primary Examiner(s): Chery, Dady
• Application Number:
  US15/336,507
• Publication Number:
  US 20170048050A1
• Time in Patent Office: 565 Days
• Field of Search: 370229, 370230, 370235, 370328, 370329, 370341
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

A mobile communication system performs communication of user data directly among a plurality of radio terminals without passing through a radio base station. The communication of user data directly performed among the plurality of radio terminals is performed by using apart of radio resources assigned to the mobile communication system. The plurality of radio terminals comprise: a transmission-side terminal that transmits the user data; and a reception-side terminal that receives the user data. The reception-side terminal transmits to a radio base station in a connected state where a radio connection is established with the reception-side terminal, a transmission acknowledgment signal indicating whether the user data transmitted from the transmission-side terminal has been received.

Claims

1. A radio terminal, comprising:

a receiver;

a controller; and

a transmitter, wherein

the receiver is configured to directly receive user data from another radio terminal by a direct communication between the radio terminals,

the receiver is configured to receive a control signal from a base station,

the controller is configured to determine to transmit a transmission acknowledgment signal to the base station on a basis of the control signal in order for the radio terminal to notify the another radio terminal of the transmission acknowledgment signal via the base station,

the transmitter is configured to transmit the transmission acknowledgment signal via the base station for the another radio terminal to determine whether to retransmit the user data to the radio terminal, and

the transmission acknowledgment signal indicates whether the radio terminal has directly received the user data from the another radio terminal.

2. The radio terminal according to claim 1, wherein

the control signal includes first information indicating that the transmission acknowledgment signal is notified via the base station, and

the transmitter is configured to transmit the transmission acknowledgment signal to the base station in response to the control signal including the first information.

3. The radio terminal according to claim 1, wherein

the control signal includes second information indicating that the transmission acknowledgment signal is notified without passing through the base station, and

the transmitter is configured to directly transmit the transmission acknowledgment signal to the another radio terminal in response to the control signal including the second information.

4. A control apparatus configured to control a radio terminal, configured to:

directly receive user data from another radio terminal by a direct communication between the radio terminals,

receive a control signal from a base station,

determine to transmit a transmission acknowledgment signal to the base station on a basis of the control signal in order for the radio terminal to notify the another radio terminal of the transmission acknowledgment signal via the base station, and

transmit the transmission acknowledgment signal via the base station for the another radio terminal to determine whether to retransmit the user data to the radio terminal, wherein

the transmission acknowledgment signal indicates whether the radio terminal has directly received the user data from the another radio terminal.

5. A radio terminal, comprising:

a transmitter;

a controller; and

a receiver, wherein

the transmitter is configured to directly transmit user data to another radio terminal by a direct communication between the radio terminals,

the receiver is configured to receive a control signal from a base station,

the controller is configured to determine to receive a transmission acknowledgment signal from the base station on a basis of the control signal in order for the another radio terminal to notify the radio terminal of the transmission acknowledgment signal via the base station,

the receiver is configured to receive the transmission acknowledgment signal via the base station for the radio terminal to determine whether to retransmit the user data to the another radio terminal, and

the transmission acknowledgment signal indicates whether the another radio terminal has directly received the user data from the radio terminal.

6. A control apparatus configured to control a radio terminal, configured to:

directly transmit user data to another radio terminal by a direct communication between the radio terminals; and

receive a control signal from a base station,

determine to receive a transmission acknowledgment signal from the base station on a basis of the control signal in order for the another radio terminal to notify the radio terminal of the transmission acknowledgment signal via the base station, and

receive the transmission acknowledgment signal via the base station for the radio terminal to determine whether to retransmit the user data to the another radio terminal, wherein

the transmission acknowledgment signal indicates whether the another radio terminal has directly received the user data from the radio terminal.

7. A base station, comprising:

a transmitter; and

a receiver, wherein

the transmitter is configured to transmit a control signal to a first radio terminal configured to directly receive user data from a second radio terminal by a direct communication between the first radio terminal and the second radio terminal, and to transmit the control signal to the second radio terminal configured to directly transmit the user data to the first radio terminal by the direct communication, wherein the control signal is used to determine that the first radio terminal notifies the second radio terminal of a transmission acknowledgement signal via the base station,

the receiver is configured to receive, from the first radio terminal, the transmission acknowledgment signal for the second radio terminal to determine whether to retransmit the user data to the first radio terminal,

the transmitter is configured to transmit the transmission acknowledgment signal to the second radio terminal, and

the transmission acknowledgment signal indicates whether the first radio terminal has directly received the user data from the second radio terminal.

8. The base station according to claim 7, further comprising a controller configured to calculate a data amount in the direct communication on a basis of the transmission acknowledgment signal.

9. A control apparatus configured to control a base station, configured to:

transmit a control signal to a first radio terminal configured to directly receive user data from a second radio terminal by a direct communication between the first radio terminal and the second radio terminal, and

transmit the control signal to the second radio terminal configured to directly transmit the user data to the first radio terminal by the direct communication, wherein the control signal is used to determine that the first radio terminal notifies the second radio terminal of a transmission acknowledgement signal via the base station, and

receive, from the first radio terminal, the transmission acknowledgment signal for the second radio terminal to determine whether to retransmit the user data to the first radio terminal, and

transmit the transmission acknowledgment signal to the second radio terminal, wherein

the transmission acknowledgment signal indicates whether the first radio terminal has directly received the user data from the second radio terminal.