APPARATUS AND METHOD FOR REDUCING INTERFERENCE AND SAVING ENERGY IN FEMTO/PICO CELL OF HIERARCHICAL CELL STRUCTURE

• US 20110216683A1
• Filed: 03/08/2011
• Published: 09/08/2011
• Est. Priority Date: 03/08/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Han, Ki-Young, Kang, Hyon-Goo, Yi, Byoung-Ha, Ju, Hyeong-Jong
• Granted Patent: US 8,861,411 B2
• Time in Patent Office: Days
• 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:

determining, by a power manager, 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;

when the notify message is received, determining, by the power manager, whether a service is providable to the subscribed terminal; and

when the service is providable to the subscribed terminal, turning on, by the power manager, on the off-small base station.

2. The method of claim 1, wherein determining whether the service is providable to the subscribed terminal comprises:

measuring an uplink path loss of the subscribed terminal;

determining whether the uplink path loss is in a serviceable range; and

when the uplink path loss is in the serviceable range, determining that the service is providable to the subscribed terminal.

3. The method of claim 2, wherein determining whether the determined uplink path loss is in the serviceable range comprises, when the uplink path loss is smaller than a handoff average path loss of the subscribed terminal, determining that the determined uplink path loss is in the serviceable range.

4. The method of claim 2, wherein the uplink path loss comprises a value determined by subtracting a control message reception power of the subscribed terminal from a transmission power for a control message transmitted from the subscribed terminal.

5. The method of claim 1, further comprising:

determining, by the power manager, a terminal to be determined by the off-small base station using information periodically received from the macro base station under an open access mode;

periodically monitoring, by the power manager, a transmission signal of the determined terminal;

determining, by the power manager, a terminal to which the service is providable using a monitoring result;

determining, by the power manager, a number of terminals to which the service is providable; and

when the number of the terminals to which the service is providable is greater than a predetermined reference number, turning on, by the power manager, the off-small base station under the open access mode.

6. The method of claim 5, wherein determining the terminal to which the service is providable using the monitoring result comprises:

measuring an uplink path loss of the terminal;

determining whether the uplink path loss is in a serviceable range; and

when the uplink path loss is in the serviceable range, determining that the terminal is the terminal to which the service is providable.

7. The method of claim 6, wherein determining whether the uplink path loss is in the serviceable range comprises, when the uplink path loss is smaller than a handoff average path loss of the determined terminal, determining that the uplink path loss is in the serviceable range.

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

a power manager configured to determine 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, when the notify message is received, determine whether a service is providable to the subscribed terminal, and when the service is providable to the subscribed terminal, turn on the off-small base station; and

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

9. The apparatus of claim 8, wherein the power manager is further configured to determine an uplink path loss of the subscribed terminal, determine whether the uplink path loss is in a serviceable range, and when the uplink path loss is in the serviceable range, determine that the service is providable to the subscribed terminal.

10. The apparatus of claim 9, wherein when the uplink path loss is smaller than a handoff average path loss of the subscribed terminal, the power manager is further configured to determine that the uplink path loss is in the serviceable range.

11. The apparatus of claim 9, wherein the uplink path loss comprises a value determined by subtracting a control message reception power of the subscribed terminal from a transmission power for a control message transmitted from the subscribed terminal.

12. The apparatus of claim 8, wherein the power manager is further configured to determine a terminal to be determined by the off-small base station using information periodically received from the macro base station under an open access mode, periodically monitor a transmission signal of the determined terminal, determine a terminal to which the service is providable using a monitoring result, determine a number of terminals to which the service is providable, and when the number of the terminals to which the service is providable is greater than a predetermined reference number, turn on the off-small base station under the open access mode.

13. The apparatus of claim 12, wherein the power manager is further configured to determine an uplink path loss of the terminal, determine whether the uplink path loss is in a serviceable range, and when the uplink path loss is in the serviceable range, determine that the terminal is the terminal to which the service is providable using the monitoring result.

14. The apparatus of claim 13, wherein when the uplink path loss is smaller than a handoff average path loss of the terminal, the power manager is further configured to determine that the uplink path loss is in the serviceable range.

15. A small base station that performs power management, the small base station comprising:

a transceiver configured to communicate with terminals and a macro base station; and

a power manager configured to determine whether a subscribed terminal has entered a cell of the macro base station that includes the small base station that is currently in an off-state during a closed access mode, determine whether a service is providable to the subscribed terminal when the subscribed terminal has entered the cell of the macro base station when the small base station is currently in the off-state during the closed access mode, and turn on the small base station when the service is providable to the subscribed terminal.

16. The small base station of claim 15, wherein the power manager is further configured to determine an uplink path loss of the subscribed terminal, determine whether the uplink path loss is in a serviceable range, and determine that the service is providable to the subscribed terminal when the uplink path loss is in the serviceable range.

17. The small base station of claim 16, wherein when the uplink path loss is smaller than a handoff average path loss of the subscribed terminal, the power manager is further configured to determine that the uplink path loss is in the serviceable range

18. The small base station of claim 16, wherein the uplink path loss comprises a value determined by subtracting a control message reception power of the subscribed terminal from a transmission power for a control message transmitted from the subscribed terminal.

19. The small base station of claim 15, wherein the power manager is further configured to determine a terminal to be determined by the off-small base station using information periodically received from the macro base station during an open access mode, periodically monitor a transmission signal of the terminal, determine whether the service is providable to the terminal based on a result of monitoring the transmission signal, determine a number of terminals to which the service is providable, and turn on the small base station under the open access mode when the number of the terminals to which the service is providable is greater than a predetermined reference number.

20. The small base station of claim 18, wherein the power manager is further configured to determine an uplink path loss of the terminal, determine whether the uplink path loss is in a serviceable range, and when the uplink path loss is in the serviceable range, determine that the service is providable to the terminal using the result of monitoring the transmission signal, and

determine that the uplink path loss is in the serviceable range when the uplink path loss is smaller than a handoff average path loss of the terminal.