ADAPTIVE POWER EFFICIENT RADIO ENVIRONMENT MEASUREMENTS

• US 20070225051A1
• Filed: 03/21/2006
• Published: 09/27/2007
• Est. Priority Date: 03/21/2006
• Status: Active Grant

• Current Assignee: SAGO Strategic Solutions LLC
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Palenius, Torgny, Nader, Ali
• Granted Patent: US 7,555,319 B2
• Time in Patent Office: Days
• US Class Current: 455/574
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 17/327 Received signal code power [RSCP]
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 52/0238 where the received signal is an unwanted signal, e.g. interference or idle signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

User equipment (UE) in a cellular telecommunications system is operated such that the UE is caused to begin operating in a power saving state by determining that a first set of predefined criteria have been satisfied and is caused to leave the power saving state by determining that a second set of predefined criteria have been satisfied. Determining that the second set of predefined criteria have been satisfied includes making a plurality of signal quality measurements of a signal received from a serving cell during power saving state; determining which of the plurality of signal quality measurements represents a best one of the signal quality measurements; determining a threshold value as a function of the best one of the signal quality measurements; and determining that the second set of predefined criteria have been satisfied if a current signal quality measurement satisfies a predefined relationship with respect to the threshold value.

Claims

1. A method of operating user equipment (UE) in a cellular telecommunications system, the method comprising:

causing the UE to begin operating in a power saving state by determining that a first set of predefined criteria have been satisfied; and

causing the UE to leave the power saving state by determining that a second set of predefined criteria have been satisfied,

wherein determining that the second set of predefined criteria have been satisfied includes;

making a plurality of signal quality measurements of a signal received from a serving cell during power saving state;

determining which of the plurality of signal quality measurements represents a best one of the signal quality measurements;

determining a threshold value as a function of the best one of the signal quality measurements; and

determining that the second set of predefined criteria have been satisfied if a current signal quality measurement satisfies a predefined relationship with respect to the threshold value.

2. The method of claim 1, wherein determining the threshold value as a function of the best one of the signal quality measurements comprises:

subtracting a signal quality measurement of a neighboring cell'"'"'s signal from the best one of the signal quality measurements.

3. The method of claim 1, comprising:

receiving a serving cell offset value from a serving cell of the UE; and

wherein determining the threshold value as a function of the best one of the signal quality measurements comprises;

adjusting the best one of the signal quality measurements by subtracting a signal quality measurement of a neighboring cell'"'"'s signal from the best one of the signal quality measurements and by adding the serving cell offset value.

4. The method of claim 3, wherein determining the threshold value as a function of the best one of the signal quality measurements comprises:

selecting the adjusted best one of the signal quality measurements if the adjusted best one of the signal quality measurement does not indicate a lower quality than a predetermined low limit value.

5. The method of claim 1, comprising:

determining that the second set of predefined criteria have been satisfied if the current signal quality measurement satisfies a predetermined relationship with respect to a term derived from one or more telecommunication network-supplied parameters.

6. The method of claim 5, wherein the telecommunications system is a Wideband Code Division Multiple Access (WCDMA) telecommunications system, and the term derived from the one or more telecommunication network-supplied parameters is S_intrasearch+QqualMin,

wherein S_intrasearch is a parameter that specifies a threshold for intra-frequency measurements, and QqualMin defines a minimum required quality level within the serving cell.

7. The method of claim 1, wherein the plurality of signal quality measurements are a plurality of signal-to-noise ratio measurements.

8. The method of claim 1, wherein the plurality of signal quality measurements are a plurality of received signal code power measurements.

9. The method of claim 1, comprising:

upon entering a full measurement state from the power saving state, remaining in the full measurement state for a predefined period of time regardless of a determination that the first set of predefined criteria have been satisfied during the predefined period of time.

10. The method of claim 1, wherein:

the power saving state comprises a first power saving state and a second power saving state, wherein fewer measurements are made during the second power saving state than in the first power saving state; and

the method comprises;

entering the first power saving state from a full measurement state; and

detecting that the first set of predefined criteria have been satisfied for a predefined period of time, and in response to said detection, causing the UE to begin operating in the second power saving state.

11. The method of claim 1, wherein determining that the first set of predefined criteria have been satisfied includes:

making a current signal quality measurement of a signal received from the serving cell during a non-power saving state;

determining a threshold value as a function of a constant stored in the UE; and

determining that the first set of predefined criteria have been satisfied if the current signal quality measurement satisfies a predefined relationship with respect to the threshold value.

12. The method of claim 11, wherein determining the threshold value as a function of the constant stored in the UE comprises combining the constant stored in the UE with a value supplied by the telecommunications network.

13. An apparatus for operating user equipment (UE) in a cellular telecommunications system, the apparatus comprising:

logic configured to cause the UE to begin operating in a power saving state by determining that a first set of predefined criteria have been satisfied; and

logic configured to cause the UE to leave the power saving state by determining that a second set of predefined criteria have been satisfied,

wherein determining that the second set of predefined criteria have been satisfied includes;

making a plurality of signal quality measurements of a signal received from a serving cell during power saving state;

determining which of the plurality of signal quality measurements represents a best one of the signal quality measurements;

determining a threshold value as a function of the best one of the signal quality measurements; and

determining that the second set of predefined criteria have been satisfied if a current signal quality measurement satisfies a predefined relationship with respect to the threshold value.

14. The apparatus of claim 13, wherein determining the threshold value as a function of the best one of the signal quality measurements comprises:

subtracting a signal quality measurement of a neighboring cell'"'"'s signal from the best one of the signal quality measurements.

15. The apparatus of claim 13, comprising:

receiving a serving cell offset value from a serving cell of the UE; and

wherein determining the threshold value as a function of the best one of the signal quality measurements comprises;

adjusting the best one of the signal quality measurements by subtracting a signal quality measurement of a neighboring cell'"'"'s signal from the best one of the signal quality measurements and by adding the serving cell offset value.

16. The apparatus of claim 15, wherein determining the threshold value as a function of the best one of the signal quality measurements comprises:

selecting the adjusted best one of the signal quality measurements if the adjusted best one of the signal quality measurement does not indicate a lower quality than a predetermined low limit value.

17. The apparatus of claim 13, wherein determining that the second set of predefined criteria have been satisfied includes:

determining that the second set of predefined criteria have been satisfied if the current signal quality measurement satisfies a predetermined relationship with respect to a term derived from one or more telecommunication network-supplied parameters.

18. The apparatus of claim 17, wherein the telecommunications system is a Wideband Code Division Multiple Access (WCDMA) telecommunications system, and the term derived from the one or more telecommunication network-supplied parameters is S_intrasearch+QqualMin,

wherein S_intrasearch is a parameter that specifies a threshold for intra-frequency measurements, and QqualMin defines a minimum required quality level within the serving cell.

19. The apparatus of claim 13, wherein the plurality of signal quality measurements are a plurality of signal-to-noise ratio measurements.

20. The apparatus of claim 13, wherein the plurality of signal quality measurements are a plurality of received signal code power measurements.

21. The apparatus of claim 13, comprising:

logic that, upon entering a full measurement state from the power saving state, causes the UE to remain in the full measurement state for a predefined period of time regardless of a determination that the first set of predefined criteria have been satisfied during the predefined period of time.

22. The apparatus of claim 13, wherein:

the power saving state comprises a first power saving state and a second power saving state, wherein fewer measurements are made during the second power saving state than in the first power saving state; and

the apparatus comprises;

logic that, after entering the first power saving state from a full measurement state, detects that the first set of predefined criteria have been satisfied for a predefined period of time, and in response to said detection, causes the UE to begin operating in the second power saving state.

23. The apparatus of claim 13, wherein determining that the first set of predefined criteria have been satisfied includes:

making a current signal quality measurement of a signal received from the serving cell during a non-power saving state;

determining a threshold value as a function of a constant stored in the UE; and

determining that the first set of predefined criteria have been satisfied if the current signal quality measurement satisfies a predefined relationship with respect to the threshold value.

24. The apparatus of claim 23, wherein determining the threshold value as a function of the constant stored in the UE comprises combining the constant stored in the UE with a value supplied by the telecommunications network.