Apparatus and method for reducing interference and saving energy in femto/pico cell of hierarchical cell structure

• US 8,861,411 B2
• Filed: 03/08/2011
• Issued: 10/14/2014
• Est. Priority Date: 03/08/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ju, Hyeong-Jong, Kang, Hyon-Goo, Yi, Byoung-Ha, Han, Ki-Young
• Primary Examiner(s): Hamza, Faruk
• Assistant Examiner(s): LO, DIANE LEE
• Application Number:
  US13/043,328
• Publication Number:
  US 20110216683A1
• Time in Patent Office: 1,316 Days
• Field of Search: None
• US Class Current: 370/311
• CPC Class Codes: H04W 52/00 Power management, e.g. TPC [Transmission Power Control], power saving or power classes gain control in transmitters or power amplifiers H03G3/3042
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

An apparatus and a method manage power of a small base station. Whether a notify message indicating that a subscribed terminal enters a macro base station that includes an off-small base station is received from the macro base station under a closed access mode is determined. When the notify message is received, whether a service is providable to the subscribed terminal is determined. When the service is providable to the subscribed terminal, the small base station is turned on. During the closed access mode or when a load of a macro cell is large during an open access mode, when a terminal that should be serviced does not exist in the neighborhood of a small base station, an interference and power consumption unnecessarily generated may be reduced by turning off the small base station.

Claims

1. A method for managing power of a small base station, the method comprising:

receiving from a macro base station, by a power manager, a notify message indicating that a subscribed terminal enters the macro base station that includes a small base station in an off state and including information of the subscribed terminal;

receiving from the subscribed terminal, by the power manager, transmission power information of the subscribed terminal based on the information of the subscribed terminal;

determining an uplink path loss of the subscribed terminal based on the transmission power information and the information of the subscribed terminal;

determining, by the power manager, whether the uplink path loss of the subscribed terminal is supportable by the small base station; and

when a service is supportable to the subscribed terminal, turning on, by the power manager, the small base station in the off state.

2. The method of claim 1, wherein determining whether the uplink path loss of the subscribed terminal is supportable by the small base station comprises determining whether the uplink path loss of the subscribed terminal is smaller than a handoff average path loss of the subscribed terminal.

3. The method of claim 1, wherein the uplink path loss of the subscribed terminal comprises a value determined by subtracting a control message reception power of the subscribed terminal from the transmission power of the subscribed terminal, wherein the transmission power information of the subscribed terminal is received through the control message.

4. The method of claim 1, wherein the information of the subscribed terminal comprises a Basic Connection Identifier (BCID) of the subscribed terminal.

5. The method of claim 1, wherein the small base station is in a closed access mode.

6. An apparatus of a small base station for performing power management, the apparatus comprising:

a transceiver configured to communicate with a subscribed terminal and a macro base station; and

a power manager configured to receive from the macro base station a notify message indicating that the subscribed terminal enters the macro base station that includes a small base station in an off state and including information of the subscribed terminal, receive from the subscribed terminal transmission power information of the subscribed terminal based on the information of the subscribed terminal, determine an uplink path loss of the subscribed terminal of the subscribed terminal based on the transmission power information and the information of the subscribed terminal, determine whether the uplink path loss of the subscribed terminal is supportable by the small base station, and when a service is supportable to the subscribed terminal, turn on the small base station in the off state.

7. The apparatus of claim 6, wherein the power manager is further configured to determine that the uplink path loss of the subscribed terminal is supportable by the small base station when the uplink path loss of the subscribed terminal is smaller than the handoff average path loss of the subscribed terminal.

8. The apparatus of claim 6, wherein the uplink path loss of the subscribed terminal comprises a value determined by subtracting a control message reception power of the subscribed terminal from the transmission power of the subscribed terminal, wherein the transmission power information of the subscribed terminal is received through the control message.

9. The apparatus of claim 6, wherein the information of the subscribed terminal comprises a Basic Connection Identifier (BCID) of the subscribed terminal.

10. The apparatus of claim 6, wherein the small base station is in a closed access mode.

11. A method for managing power of a small base station, the method comprising:

receiving, by a power manager, information of at least one of a plurality of terminals from a macro base station that includes a small base station in an off state;

receiving from the terminal, by the power manager, transmission power information of the at least one terminal based on the information of the at least one terminal;

determining, by the power manager, an uplink path loss of the at least one terminal based on the transmission power information and the information of the terminal;

determining, by the power manager, whether the uplink path loss of the at least one terminal is supportable by the small base station;

determining, by the power manager, a number of the Plurality of terminals that is supportable by the small base station; and

when the number of the plurality of terminals is greater than a predetermined reference number, turning on, by the power manager, the small base station in the off state.

12. The method of claim 11, wherein determining whether the uplink path loss of the at least one terminal is supportable by the small base station comprises, determining whether the uplink path loss of the at least one terminal is smaller than a handoff average path loss of the at least one terminal.

13. The method of claim 11, wherein the uplink path loss of the terminal comprises a value determined by subtracting a control message reception power of the terminal from the transmission power of the at least one terminal, wherein the transmission power information of the at least one terminal is received through the control message.

14. The method of claim 11, wherein the small base station is in a open access mode.

15. An apparatus of a small base station for performing power management, the apparatus comprising:

a transceiver configured to communicate with a subscribed terminal and a macro base station; and

a power manager configured to;

receive information of at least one of a plurality of terminals from the macro base station that includes a small base station in an off state,

receive from the at least one terminal transmission power information of the at least one terminal based on the information of the terminal from the terminal,

determine an uplink path loss of the at least one terminal based on the transmission power information and the information of the at least one terminal,

determine whether the uplink path loss of the at least one terminal is supportable by the small base station,

determine a number of the terminals that is supportable by the small base station and when the number of the terminals is greater than a predetermined reference number, turn on the small base station in the off state.

16. The apparatus of claim 15, wherein the uplink path loss of the at least one of terminals is supportable by the small base station when the uplink path loss of the terminal is smaller than a handoff average path loss of the terminal.

17. The apparatus of claim 15, wherein the uplink path loss of the at least one terminal comprises a value determined by subtracting a control message reception power of the at least one terminal from a transmission power of the at least one terminal, wherein the transmission power information of the terminal is received through the control message.

18. The apparatus of claim 15, wherein the small base station is in a open access mode.