USER TERMINAL, RADIO BASE STATION AND RADIO COMMUNICATION METHOD

• US 20170099635A1
• Filed: 05/08/2015
• Published: 04/06/2017
• Est. Priority Date: 05/15/2014
• Status: Abandoned Application

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Uchino, Tooru, Kiyoshima, Kohei
• Application Number:
  US15/311,092
• Publication Number:
  US 20170099635A1
• Time in Patent Office: Days
• CPC Class Codes: H04W 52/02 Power saving arrangements in wired systems H04L12/12; signaling of mobile application services, e.g. low battery notifications H04W4/20
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The present invention is designed to reduce the power consumption of user terminals more in comparison to conventional DRX control. The present invention provides a receiving section, which receives a DL signal including at least a UL grant, and a DRX control section, which controls the discontinuous reception operations, and the DRX control section, when receiving the DL signal including a UL grant, controls the discontinuous reception operations based on the DRX transition command information that is included in the DL signal. Also, a command for a transition to the discontinuous reception state is transmitted by using downlink control information that includes a UL grant, or a MAC control element.

Claims

1. A user terminal comprising:

a receiving section that receives a DL signal, which at least includes a UL grant; and

a DRX control section that controls a discontinuous reception operation, wherein the DRX control section, when receiving the DL signal including the UL grant, controls the discontinuous reception operation based on DRX transition command information included in the DL signal.

2. The user terminal according to claim 1, wherein, when a transition to a discontinuous reception state is commanded by the DL signal including the UL grant, the DRX control section transitions to the discontinuous reception state after a predetermined period.

3. The user terminal according to claim 1, wherein, when, after the transition to the discontinuous reception state is commanded by the DL signal including the UL grant, the DRX control section receives a command to start or re-start a DRX-inactivity timer before making the transition to the discontinuous reception state, the DRX control section cancels the transition to the discontinuous reception state.

4. The user terminal according to claim 1, wherein, even when the transition to the discontinuous reception state is commanded by the DL signal including the UL grant, if the DRX control section does not receive a positive delivery acknowledgement signal in response to a UL signal that has been transmitted based on the UL grant, the DRX control section cancels the transition to the discontinuous reception state.

5. The user terminal according to claim 1, wherein the DRX control section does not start or re-start a DRX-inactivity timer when the transition to the discontinuous reception state is commanded by the DL signal including the UL grant.

6. The user terminal according to claim 1, wherein the DRX transition command information is included in downlink control information that indicates a UL grant and transmitted in a downlink control channel.

7. The user terminal according to claim 1, wherein the DRX transition command information and the UL grant are included in a MAC control element and transmitted.

8. The user terminal according to claim 7, wherein the MAC control element to include the DRX transition command information and the UL grant uses a MAC random access response that indicates the UL grant in a MAC payload.

11. The user terminal according to claim 2, wherein the DRX transition command information is included in downlink control information that indicates a UL grant and transmitted in a downlink control channel.

12. The user terminal according to claim 3, wherein the DRX transition command information is included in downlink control information that indicates a UL grant and transmitted in a downlink control channel.

13. The user terminal according to claim 4, wherein the DRX transition command information is included in downlink control information that indicates a UL grant and transmitted in a downlink control channel.

14. The user terminal according to claim 5, wherein the DRX transition command information is included in downlink control information that indicates a UL grant and transmitted in a downlink control channel.

15. The user teiiiiinal according to claim 2, wherein the DRX transition command information and the UL grant are included in a MAC control element and transmitted.

16. The user terminal according to claim 3, wherein the DRX transition command information and the UL grant are included in a MAC control element and transmitted.

17. The user terminal according to claim 4, wherein the DRX transition command information and the UL grant are included in a MAC control element and transmitted.

18. The user terminal according to claim 5, wherein the DRX transition command information and the UL grant are included in a MAC control element and transmitted.

9. A radio base station comprising:

a transmission section that transmits a UL grant to indicate UL allocation to a user terminal; and

a generating section that generates DRX transition command information for controlling a discontinuous reception operation of the user terminal, wherein the transmission section transmits DRX transition command information with the UL grant at the same timing.

10. A radio communication method for a user terminal that performs discontinuous reception and a radio base station, the radio communication method comprising the steps of:

in the radio base station;

transmitting, to the user terminal, a DL signal that includes a UL grant, which commands UL allocation, and DRX transition command information, which is for controlling a discontinuous reception operation in the user terminal; and

in the user terminal;

receiving the DL signal including the UL grant and the DRX transition command information; and

controlling discontinuous reception based on the DRX transition command information received.