USER APPARATUS AND TRANSMISSION CONTROL METHOD

• US 20170188393A1
• Filed: 04/30/2015
• Published: 06/29/2017
• Est. Priority Date: 05/09/2014
• 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, Teshima, Kunihiko, Takeda, Kazuki, Nagata, Satoshi
• Application Number:
  US15/308,793
• Publication Number:
  US 20170188393A1
• Time in Patent Office: Days
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0058 Allocation criteria
• CPC Class Codes: H04L 5/0092 Indication of how the channel is divided
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/281 taking into account user or data type priority
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/365 Power headroom reporting
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/38 TPC being performed in particular situations
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections
• CPC Class Codes: H04W 76/34 Selective release of ongoing connections
• CPC Class Codes: H04W 76/38 triggered by timers

Abstract

A user apparatus in a communication system including a first base station and a second base station that perform communication with the user apparatus by inter-base station carrier aggregation, including: a maximum transmission power holding unit configured to hold a maximum transmission power that is configured beforehand for the first base station; a transmission power determination unit configured to determine whether a transmission power that is used by the user apparatus for performing signal transmission to the first base station reaches the maximum transmission power held by the maximum transmission power holding unit; and a transmission control unit configured, when it is determined that the transmission power reaches the maximum transmission power by the transmission power determination unit, to stop signal transmission to the second base station.

Claims

1. A user apparatus in a communication system including a first base station and a second base station that perform communication with the user apparatus by inter-base station carrier aggregation, comprising:

a maximum transmission power holding unit configured to hold a maximum transmission power that is configured beforehand;

a transmission power determination unit configured to determine whether a transmission power that is used by the user apparatus for performing signal transmission reaches the maximum transmission power held by the maximum transmission power holding unit; and

a transmission control unit configured, when it is determined that the transmission power reaches the maximum transmission power by the transmission power determination unit, to stop signal transmission to the second base station.

2. The user apparatus as claimed in claim 1, wherein the transmission power determination unit determines whether the transmission power reaches the maximum transmission power when the user apparatus performs signal transmission using a specific channel, and

wherein the transmission control unit stops signal transmission to the second base station if it is determined, by the transmission power determination unit, that the transmission power reaches the maximum transmission power when the user apparatus performs signal transmission using the specific channel.

3. The user apparatus as claimed in claim 1, wherein, the user apparatus performs signal transmission to the first base station using a plurality of component carriers, and

wherein, when signal transmission to the second base station is stopped by the transmission control unit, the user apparatus performs signal transmission to the first base station using a component carrier for performing signal transmission of a specific channel in the plurality of component carriers.

4. The user apparatus as claimed in claim 2, wherein the specific channel is a PRACH.

5. The user apparatus as claimed in claim 1, wherein the user apparatus performs signal transmission to the second base station using one or a plurality of component carriers forming a cell group, and

wherein the transmission control unit stops signal transmission to the second base station by releasing the cell group.

6. The user apparatus as claimed in claim 1, wherein the transmission power determination unit determines that the transmission power reaches the maximum transmission power when detecting that the transmission power becomes the maximum transmission power continuously for a predetermined period or detecting that the transmission power becomes the maximum transmission power equal to or greater than a predetermined number of times within a predetermine period.

7. The user apparatus as claimed in claim 1, wherein, when the transmission control unit stops signal transmission to the second base station, the transmission control unit reports a power headroom to the first base station or the second base station.

8. The user apparatus as claimed in claim 1, wherein, when the transmission control unit stops signal transmission to the second base station, the transmission control unit notifies the first base station or the second base station of performing the stop.

9. The user apparatus as claimed in claim 1, wherein the second base station includes a plurality of base stations, and the transmission control unit stops signal transmission to the plurality of base stations in a stepwise manner for each base station when it is determined, by the transmission power determination unit, that the transmission power reaches the maximum transmission power.

10. A transmission control method executed by a user apparatus in a communication system including a first base station and a second base station that perform communication with the user apparatus by inter-base station carrier aggregation,

the user apparatus including a maximum transmission power holding unit configured to hold a maximum transmission power that is configured beforehand;

the transmission control method comprising;

a transmission power determination step of determining whether a transmission power that is used by the user apparatus for performing signal transmission reaches the maximum transmission power held by the maximum transmission power holding unit; and

a transmission control step of, when it is determined that the transmission power reaches the maximum transmission power by the transmission power determination step, stopping signal transmission to the second base station.

11. The user apparatus as claimed in claim 2, wherein, the user apparatus performs signal transmission to the first base station using a plurality of component carriers, and

wherein, when signal transmission to the second base station is stopped by the transmission control unit, the user apparatus performs signal transmission to the first base station using a component carrier for performing signal transmission of a specific channel in the plurality of component carriers.

12. The user apparatus as claimed in claim 3, wherein the specific channel is a PRACH.

13. The user apparatus as claimed in claim 2, wherein the user apparatus performs signal transmission to the second base station using one or a plurality of component carriers forming a cell group, and

wherein the transmission control unit stops signal transmission to the second base station by releasing the cell group.

14. The user apparatus as claimed in claim 3, wherein the user apparatus performs signal transmission to the second base station using one or a plurality of component carriers forming a cell group, and

wherein the transmission control unit stops signal transmission to the second base station by releasing the cell group.

15. The user apparatus as claimed in claim 2, wherein the transmission power determination unit determines that the transmission power reaches the maximum transmission power when detecting that the transmission power becomes the maximum transmission power continuously for a predetermined period or detecting that the transmission power becomes the maximum transmission power equal to or greater than a predetermined number of times within a predetermine period.

16. The user apparatus as claimed in claim 3, wherein the transmission power determination unit determines that the transmission power reaches the maximum transmission power when detecting that the transmission power becomes the maximum transmission power continuously for a predetermined period or detecting that the transmission power becomes the maximum transmission power equal to or greater than a predetermined number of times within a predetermine period.

17. The user apparatus as claimed in claim 2, wherein, when the transmission control unit stops signal transmission to the second base station, the transmission control unit reports a power headroom to the first base station or the second base station.

18. The user apparatus as claimed in claim 3, wherein, when the transmission control unit stops signal transmission to the second base station, the transmission control unit reports a power headroom to the first base station or the second base station.

19. The user apparatus as claimed in claim 2, wherein, when the transmission control unit stops signal transmission to the second base station, the transmission control unit notifies the first base station or the second base station of performing the stop.

20. The user apparatus as claimed in claim 2, wherein the second base station includes a plurality of base stations, and the transmission control unit stops signal transmission to the plurality of base stations in a stepwise manner for each base station when it is determined, by the transmission power determination unit, that the transmission power reaches the maximum transmission power.