Radio link failure detection method and apparatus for wireless communication system

• US 20100112956A1
• Filed: 11/05/2009
• Published: 05/06/2010
• Est. Priority Date: 11/05/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jeong, Kyeong In, Van Lieshout, Gert-Jan, Sun, Chengjun
• Granted Patent: US 9,629,029 B2
• Time in Patent Office: Days
• US Class Current: 455/67.110
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 17/26 using historical data, averaging values or statistics
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 76/18 Management of setup rejection or failure
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]

Abstract

A radio link failure detection method of a user equipment transitioning between a Discontinuous Reception (DRX) mode and non-DRX mode cyclically in a wireless communication system includes transitioning between a Discontinuous Reception (DRX) mode and a non-DRX mode in a wireless communication system. The method also includes adjusting, when a mode transition occurs, a size of a monitoring window for a transitioned operation mode; reporting a radio channel condition acquired by monitoring and averaging the channel condition within the monitoring window; and repeating adjustment of the monitoring window size and report of the radio channel condition while moving the monitoring window as time progress.

Claims

1. A radio link failure detection method for a user equipment transitioning between a Discontinuous Reception (DRX) mode and a non-DRX mode in a wireless communication system, comprising:

adjusting, when a mode transition occurs, a size of a monitoring window for a transitioned operation mode;

reporting a radio channel condition acquired by monitoring and averaging the channel condition within the monitoring window; and

repeating adjustment of the monitoring window size and report of the radio channel condition while moving the monitoring window as time progress.

2. The radio link failure detection method of claim 1, wherein the mode transition occurs from the non-DRX mode to the DRX mode.

3. The radio link failure detection method of claim 2, wherein the size of the monitoring window is determined by an equation:

monitoring window=(N1+n*DRX cycle length)

or

((n+k)*DRX cycle length)

where N1 is the duration for monitoring and averaging the radio channel condition to detect RLF in non-DRX mode, and n is n^th DRX cycle after the transition from the non-DRX mode to the DRX mode.

4. The radio link failure detection method of claim 2, wherein the size of the monitoring window is determined by an equation:

monitoring window=((n+k)*DRX cycle length),

where n is n^th DRX cycle after the transition from the non-DRX mode to the DRX mode, and k is 0 or positive integer.

5. The radio link failure detection method of claim 1, wherein adjusting a size of a monitoring window comprises setting the monitoring window size to a value obtain by multiplying an integer with a DRX cycle.

6. The radio link failure detection method of claim 1, wherein the mode transition occurs from the DRX mode to the non-DRX mode, and the monitoring window size is set to a value configured for the non-DRX mode.

7. The radio link failure detection method of claim 1, wherein adjusting a size of a monitoring window comprises:

setting, when an active time of a DRX cycle is less than the monitoring window in the non-DRX mode, the monitoring window to a value obtained by multiplying an integer with the DRX cycle.

8. The radio link failure detection method of claim 1, wherein adjusting a size of a monitoring window comprises:

setting, when the active time of a DRX cycle is greater than or equal to the monitoring window for the non-DRX mode, the monitoring window to a value equal to the monitoring window for the non-DRX mode.

9. A radio link failure detection apparatus configured to transition between a Discontinuous Reception (DRX) mode and a non-DRX mode in a wireless communication system, the apparatus comprising;

a channel measurer configured to measure radio channel to detect a radio link failure in a preset monitoring window;

a transceiver configured to report whether the radio link failure is detected; and

a controller configured to change, when a mode transition occurs, a size of the monitoring window for the transitioned operation mode and detect the radio link failure while moving the monitoring window as time progress.

10. The radio link failure detection apparatus of claim 9, wherein the mode transition occurs from the non-DRX mode to the DRX mode, and the controller determines the size of the monitoring window by an equation defined as:

monitoring window=(N1+n*DRX cycle length)

where N1 is the duration for monitoring and averaging the radio channel condition to detect RLF in non-DRX mode, and n is n^th DRX cycle after the transition from the non-DRX mode to the DRX mode.

11. The radio link failure detection apparatus of claim 9, wherein the mode transition occurs from the non-DRX mode to the DRX mode, and the controller determines the size of the monitoring window by an equation defined as:

monitoring window=((n+k)*DRX cycle length)

where n is n^th DRX cycle after the transition from the non-DRX mode to the DRX mode, and k is 0 or positive integer.

12. The radio link failure detection apparatus of claim 9, wherein the controller sets, when a predetermined time elapses after the transmission to the DRX mode, the monitoring window to a value obtained by multiplying an integer value with a DRX cycle length.

13. The radio link failure detection apparatus of claim 9, wherein the controller sets, when the mode transition occurs from the DRX mode to the non-DRX mode, the monitoring window to a value configured for the monitoring window for the non-DRX mode.

14. The radio link failure detection apparatus of claim 9, wherein the controllers sets, when an active time of a DRX cycle is less than the monitoring window in the non-DRX mode, the monitoring window to a value obtained by multiplying an integer with the DRX cycle, and sets, when the active time of a DRX cycle is equal to or greater than the monitoring window for the non-DRX mode, the monitoring window to a value equal to the monitoring window for the non-DRX mode.

15. A radio link failure detection method for a user equipment transitioning between a Discontinuous Reception (DRX) mode and a non-DRX mode and having a first fixed monitoring window, a second fixed monitoring window, and a variable monitoring window, in a wireless communication system, the method comprising:

reporting, when a mode transition occurs from the non-DRX mode to the DRX mode, a radio channel condition after averaging the channel conditions measured during the variable monitoring window;

reporting, when a predetermined time elapsed after the transition to the non-DRX mode, the radio channel condition after averaging the channel conditions measured during the second fixed monitoring window; and

reporting, when a time corresponding to the first fixed monitoring winder after the transition from the DRX mode to the non-DRX mode, the radio channel condition after averaging the channel conditions measured during the first fixed monitoring window, the variable monitoring window has a size between sizes of the first and second fixed monitoring windows.

16. The method of claim 15, wherein the size of the monitoring window is determined by an equation:

monitoring window=(N1+n*DRX cycle length)

or

((n+k)*DRX cycle length)

where N1 is the duration for monitoring and averaging the radio channel condition to detect RLF in non-DRX mode, and n is n^th DRX cycle after the transition from the non-DRX mode to the DRX mode.

17. The method of claim 15, wherein the size of the monitoring window is determined by an equation:

monitoring window=((n+k)*DRX cycle length),

where n is n^th DRX cycle after the transition from the non-DRX mode to the DRX mode, and k is 0 or positive integer.

18. The method of claim 15, further comprising adjusting a size of a monitoring window by setting the monitoring window size to a value obtain by multiplying an integer with a DRX cycle.

19. The method of claim 15, wherein the mode transition occurs from the DRX mode to the non-DRX mode and the monitoring window size is set to a value configured for the non-DRX mode.

20. The method of claim 15, further comprising adjusting a size of a monitoring window, wherein adjusting comprises:

setting, when an active time of a DRX cycle is less than the monitoring window in the non-DRX mode, the monitoring window to a value obtained by multiplying an integer with the DRX cycle; and

setting, when the active time of a DRX cycle is greater than or equal to the monitoring window for the non-DRX mode, the monitoring window to a value equal to the monitoring window for the non-DRX mode.