Appatatus and method for transmitting inter-working signal in wireless communication system

• US 20100056160A1
• Filed: 08/28/2009
• Published: 03/04/2010
• Est. Priority Date: 08/28/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kwun, Jong-Hyung, Cho, Young-Bo, Cho, Jae-Hee, Kim, Yung-Soo, Jeon, Young-Hyun, Lee, Ju-Mi, Jun, Byung-Wook
• Granted Patent: US 8,548,479 B2
• Time in Patent Office: Days
• US Class Current: 455/444
• CPC Class Codes: H04W 36/0055 Transmission or use of information for re-establishing the radio link
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A Base Station (BS) includes an apparatus and method for transmitting cell information. The BS is in the a communication system of a small cell size in a wireless communication environment in which a communication system of a large cell size and the communication system of the small cell size are hierarchically constructed in the same area. The method includes confirming reference signal transmission information for transmitting a reference signal including its own cell information, if a reference signal transmission interval arrives according to the reference signal transmission information, transmitting the reference signal through an operation frequency of a macro BS of the large cell size including the BS itself, and, if it is not the reference signal transmission interval, providing service through its own operation frequency or operating in a power saving mode.

Claims

1. A method for transmitting cell information in a Base Station (BS) of a small cell size in a wireless communication environment in which a communication system of a large cell size and the communication system of the small cell size are hierarchically constructed in the same area, the method comprising:

confirming reference signal transmission information for transmitting a reference signal comprising its own cell information;

if a reference signal transmission interval arrives according to the reference signal transmission information, transmitting the reference signal through an operation frequency of a macro BS of the large cell size; and

if the reference signal transmission interval does not arrive, providing service through its own operation frequency or operating in a power saving mode,

wherein, the BS is located within service area of the macro BS.

2. The method of claim 1, wherein the cell information comprises at least one of a cell identifier, a Closed Subscriber Group (CSG) identifier, a frequency of a cell or a frequency channel number, a preamble sequence index of the cell, a signal bandwidth of the cell, service level prediction information that can be provided by the cell, operation state information of the cell, active mode transition information of the cell, and reference signal transmission interval information.

3. The method of claim 1, wherein the transmitting of the reference signal comprises transmitting the reference signal through the whole or part of the operation frequency of the macro BS during the reference signal transmission interval.

4. The method of claim 1, wherein the own operation frequency is the same as or different from the operation frequency of the macro BS.

5. The method of claim 1, wherein the reference signal transmission interval is set using a partial resource of a frame comprising the reference signal transmission interval.

6. A method for handover of a Mobile Station (MS) in a wireless communication environment in which a communication system of a large cell size and a communication system of a small cell size are hierarchically constructed in the same area, the method comprising:

accessing a macro Base Station (BS) of the large cell size and communicating with the macro BS;

if a reference signal comprising cell information from a BS of the small cell size is received through an operation frequency of the macro BS, acquiring the cell information of the BS of the small cell size through the reference signal;

performing handover to the BS of the small cell size using the cell information; and

if the reference signal is not received through the operation frequency of the macro BS, maintaining an access with the macro BS.

7. The method of claim 6, wherein the cell information comprises at least one of a cell identifier, a Closed Subscriber Group (CSG) identifier, a frequency of a cell or a frequency channel number, a preamble sequence index of the cell, a signal bandwidth of the cell, service level prediction information that can be provided by the cell, operation state information of the cell, active mode transition information of the cell, and reference signal transmission interval information.

8. The method of claim 6, further comprising:

after confirming the cell information, confirming operation state information of the BS of the small cell size through the cell information;

if the BS of the small cell size operates in a power saving mode, making the BS of the small cell size transit to an active mode; and

if the BS of the small cell size operates in the active mode, proceeding to handover to the BS of the small cell size.

9. The method of claim 8, wherein making the BS transit to the active mode comprises requesting the macro BS for active mode transition of the BS of the small cell size.

10. The method of claim 8, wherein making the BS transit to the active mode comprises requesting the BS of the small cell size for active mode transition.

11. The method of claim 6, wherein the handover comprises:

performing scanning using the cell information;

deciding whether to perform handover considering the scanning result; and

if deciding to perform handover, performing handover to a target BS selected through the scanning.

12. An apparatus for transmitting cell information in a Base Station (BS) of a small cell size in a wireless communication environment in which a communication system of a large cell size and the communication system of the small cell size are hierarchically constructed in the same area, the apparatus comprising:

a reference signal generator configured to generate a reference signal comprising cell information for the BS;

a scheduler configured to schedule, when not in a reference signal transmission interval, to provide service through its own operation frequency or operate in a power saving mode and, during the reference signal transmission interval, scheduling to transmit the reference signal through an operation frequency of a macro BS of the large cell size; and

a transmitter configured to transmit the reference signal through the operation frequency of the macro BS during the reference signal transmission interval according to the scheduling information,

wherein, the BS is located within service area of the macro BS.

13. The apparatus of claim 12, wherein the reference signal generator generates a reference signal that comprises at least one piece of cell information among a cell identifier, a Closed Subscriber Group (CSG) identifier, a frequency of a cell or a frequency channel number, a preamble sequence index of the cell, a signal bandwidth of the cell, service level prediction information that can be provided by the cell, operation state information of the cell, active mode transition information of the cell, and reference signal transmission interval information.

14. The apparatus of claim 12, wherein the transmitter transmits the reference signal through the whole or part of the operation frequency of the macro BS during the reference signal transmission interval.

15. The apparatus of claim 12, wherein the transmitter transmits the reference signal during the reference signal transmission interval that is set using a partial resource of a frame comprising the reference signal transmission interval.

16. The apparatus of claim 12, wherein the scheduler schedules to operate the BS itself in an active mode and, if it is not the reference signal transmission interval, provide service through its own operation frequency that is the same as or different from the operation frequency of the macro BS.

17. An apparatus for handover of a Mobile Station (MS) in a wireless communication environment in which a communication system of a large cell size and a communication system of a small cell size are hierarchically constructed in the same area, the apparatus comprising:

a receiver configured to receive a first signal;

a transmitter configured to transmit a second signal;

a reference signal analyzer configured acquire cell information of a Base Station (BS) of the small cell size through the reference signal, the reference signal analyzer acquiring the cell information when accessing a macro BS of the large cell size and communicating with the macro BS, and when receiving a reference signal comprising cell information from the BS of the small cell size through an operation frequency of the macro BS; and

a controller configured to, wherein when the cell information is acquired from the reference signal analyzer, control the handover is controlled to the BS of the small cell size using the cell information and, when the reference signal is not received, maintain an access with the macro BS.

18. The apparatus of claim 17, wherein the reference signal analyzer acquires, from the reference signal, the cell information that comprises at least one of a cell identifier, a Closed Subscriber Group (CSG) identifier, a frequency of a cell or a frequency channel number, a preamble sequence index of the cell, a signal bandwidth of the cell, service level prediction information that can be provided by the cell, operation state information of the cell, active mode transition information of the cell, and reference signal transmission interval information.

19. The apparatus of claim 17, wherein, if the BS of the small cell size operates in a power saving mode according to the acquired cell information, the controller controls so that the BS of the small cell size transits to an active mode, and

if the BS of the small cell size operates in the active mode, the controller controls to handover to the BS of the small cell size.

20. The apparatus of claim 19, wherein, if controlling so that the BS transits to the active mode, the controller controls to request the macro BS for active mode transition of the BS of the small cell size.

21. The apparatus of claim 19, wherein, if controlling so that the BS transits to the active mode, the controller controls to request the BS of the small cell size for active mode transition.

22. The apparatus of claim 17, wherein, if acquiring the cell information from the reference signal analyzer, the controller controls to scan a neighbor cell using the cell information, decides whether to perform handover depending on the scanning result, and, if deciding to perform handover, controls to handover to a target BS selected through the scanning.