System and method for specifying measurement request start time

• US 20070002757A1
• Filed: 05/03/2004
• Published: 01/04/2007
• Est. Priority Date: 05/09/2003
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Mangold, Stefan, Zhong, Zhun, Soomro, Amjad
• Granted Patent: US 7,903,570 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

The present invention relates to specification of the start time for taking measurements in wireless local area networks (WLAN), in which the start time of measurements to be taken is included in a Measurement Start Time field of a Measurement Request Frame and the interpretation of the start time for a specific measured element is determined by a Mode field included in each Measurement Request Element field of the Measurement Request Frame. Optionally, the start time of a Measurement Request Frame is specified using a time synchronization function (TSF) timer value or part thereof in order to avoid ambiguities in interpretation of the start time reported.

Claims

1. A method for specifying measurement start times in a network Measurement Request Frame (300), comprising the steps of:

formatting the Measurement Request Frame (300) to have a Measurement Request Elements field (305) comprising at least one Measurement Request Element (400,440), said at least one Measurement Request Element (400,440) comprising at least one Measurement Request (406,410) for a given type (405) of network measurement

specifying at least one of a first (304), second (408) and third (432) prioritized absolute Start Time, respectively, in a corresponding at least one of the Measurement Request Frame, the Measurement Request Elements (440), and the at least one Measurement Request (406).

2. The method of claim 1 where in said first (304), second (408) and third (432) Start Time field indicate in increasing priority order an applicable absolute Start Time, respectively, at which measurement of the first included Measurement Request Element (305) is to be initiated, the corresponding Measurement Request Element (440) is to be initiated, and the corresponding Measurement Request (432) is to be initiated.

3. The method of claim 1, further comprising the step of setting said first (304), second (408) and third (4320 Start Time field to one of a time synchronization function (TSF) timer (106) value and part of a TSF timer (106) value.

4. The method of claim 1, further comprising the step of setting at least one of the first 304), second (408), and third (432) Start Time field to zero to indicate that the corresponding measurement is to be initiated after reception of the Measurement Request Frame (300).

5. The method of claim 1, further comprising the step of setting at least one of the first (304), second (408), and third (432) Start Time field to zero to indicate that the corresponding measurement is to be initiated after reception of the Measurement Request Frame (300).

6. The method of claim 1, wherein:

said formatting step further comprises the step of including in said measurement request frame the following fields

MeasurementMeasurementDialogFrame orRequestCategoryActionTokenfirst Start TimeElementsOctets;

1118variable

a Category field (301) set equal to the value indicating a Radio Measurement or Spectrum Management category,

an Action field (302) set equal to the value indicating a Measurement Request,

a Dialog Token field (303) set equal to a non-zero value chosen by the transmitter of the Measurement Request Frame (300) in order to identify the request/report transaction,

an optional Measurement Frame/first Start Time (304) field set to a TSF timer (106) value, at which the measurement specified by the first of the Measurement Request Elements (305) is to be initiated and if the Measurement Frame/first Start Time (304) is set equal to zero, the measurement specified by the first Measurement Request Element (305) is to begin after reception of the Measurement Request Frame (303),

a Measurement Request Elements field (305)having at least one Measurement Request Element (400,440) comprising the following subfields

MeasurementElementMeasurementMeasurementMeasurementElement/secondMeasurementIDLengthTokenModeTypeStart TimeRequestOctets;

111111variable

an Element ID subfield (401)set equal to a unique identifier,

a Length subfield (402) is variable and depends on the length of the Measurement Request field (406), and the minimum value of the length field is 3,

a Measurement Token subfield (403) set to a non-zero number that is unique among the Measurement Request Elements (305) in a particular Measurement Request Frame (300).

an optional Measurement Mode subfield (404) set to include a Start (407) mode value that specifies the interpretation of the Measurement Frame Start Time (304,408,432) to be applied to the measured element,

a Measurement Type subfield (405) is set to the type of measurement being requested,

an optional Measurement Frame/second Start Time field (408) set to a TSF timer (106) value, at which the measurement specified by the first of the Measurement Request Elements (3050 is to be initiated and if the Measurement Frame/second Start Time (408) is set equal to zero, the measurement specified by the first Measurement Request Element (305) is to begin after reception of the Measurement Request Frame (300),

a Measurement Request subfield (406) is set to at least one parameter for accomplishing the type of Measurement Type, comprising the following subfields

ChannelMeasurementMeasurementNumberStart TimeDurationOctets;

182

a Channel Number subfield (431) set to the channel number to which the measurement request (406) applies,

a Measurement Frame/third Start Time field (432) set to a TSF timer (106) value, at which the measurement specified by the Measurement Request (406) is to be initiated and if the Measurement Frame/third Start Time (432) is set equal to zero, the measurement specified by the Measurement Request (406) is to begin after reception of the Measurement Request Frame (300),

a Measurement Duration subfield (433) set to the time over which the measurement is to be done.

7. The method of claim 6, further comprising the step for setting said Measurement Mode field (404) to a value that specifies how to interpret the applicable one of the first (304), second (408), and third (432) Start Time for starting measurement of the element.

8. The method of claim 7, wherein said step for setting said Measurement Mode subfield (9404) is the step of setting the Start subfield (407) of the Measurement Mode subfield (404) to an indicator selected from the group consisting of

9. The method of claim 8, wherein said setting step further comprises the step of using a three bit encoding (407) to represent a selected indicator.

10. The method of claim 9, wherein said using step further comprises the step of using the following three bit encoding (407) to represent the selected indicator

11. The method of claim 1, further comprising the steps of:

including in the at least one Measurement Request Element (400,440) a Measurement Mode field (404); and

step for setting said Measurement Mode subfield (404) to a value that specifies how to interpret the applicable one of the first, second, and third Start Time for starting measurement of the element.

12. The method of claim 11, wherein said step for setting said Measurement Mode subfield (404) is the step of setting the Start subfield (407) of the Measurement Mode (404) subfield to an indicator (407) selected from the group consisting of

13. The method of claim 12, wherein said setting step further comprises the step of using a three bit encoding (407) to represent a selected indicator.

14. The method of claim 13, wherein said using step further comprises the step of using the following three bit encoding (407) to represent the selected indicator

15. An apparatus that formats a Measurement Request Frame having an unambiguous measurement Start Time, comprising:

a measurement acquisition circuit (103) that formats the Measurement Request Frame (300) to have a Measurement Request Elements field (305) that comprises at least one Measurement Request Element (400,440) that comprises at least one Measurement Request (406) for a given type (405) of network measurement;

a TSF timer (106); and

a control processor (105), coupled to said measurement acquisition circuit (103) and said TSF timer (106) and configured to set at least one of a first (304), second (408) and third (432) Start Time respectively in the corresponding Measurement Request Frame (300), the Measurement Request Elements (305), and at least one Measurement Request (406), said first (304), second (408) and third (432) Start Time set to a value of the TSF timer (106) to indicate in increasing priority order.

16. The apparatus of claim 15, wherein said value of the TSF timer (106) is a part of the value of the TSF timer (106).

17. An apparatus that specifies flexible measurement start times in a network Measurement Request Frame (300), comprising:

a measurement acquisition circuit (103) that formats the Measurement Request Frame (300) having a Start Time field (304) that specifies the time at which measurement of a first included Measurement Request Element (305) is to be initiated;

a timer (106); and

a control processor (105), coupled to said measurement acquisition circuit (103) and said timer (106) and configured to (1) set the Start Time field (304) to a value of the timer (106), and (2) include at least a first Measurement Request Element (400,440) having a Measurement Mode subfield (404); and

means for the control processor (105) to set said Measurement Mode subfield (404) to a Start value (4070 that specifies how to interpret the Start Time (304) for starting measurement of the element.

18. The apparatus of claim 17, wherein said timer (106) value is one of a TSF timer (106) and a part of the value of the TSF timer (106).

19. The apparatus of claim 18, wherein:

said Measurement Request Frame (300) is formatted to comprise the following fields

MeasurementMeasurementDialogStartRequestCategoryActionTokenTimeElementsOctets;

1118variable

a Category field (301) set to the value indicating a Radio Measurement or Spectrum Management category,

an Action field (302) set to the value indicating a Measurement Request,

a Dialog Token field (303) set to a non-zero value chosen by the transmitter of the Measurement Request Frame in order to identify the request/report transaction,

a Measurement Start Time field (304) set to a TSF timer value, at which the measurement specified by the first Measurement Request element is to start and the Measurement Start Time is set equal to zero, the measurement specified by the first Measurement Request element is to begin after reception of the Measurement Request Frame 300,

a Measurement Request Elements field (305) having at least one Measurement Request Element,

and the Measurement Request Elements field is formatted to comprise the following subfields

ElementMeasurementMeasurementMeasurementMeasurementIDLengthTokenModeTypeRequestOctets;

11111variable

an Element ID subfield (401) set to a unique identifier,

a Length subfield (402) is variable and depends on the length of the Measurement Request subfield, and the minimum value of the Length subfield is 3,

a Measurement Token subfield (403) set to a non-zero number that is unique among the Measurement Request Elements (305) in a particular Measurement Request Frame (300).

a Measurement Mode subfield (404) set to include a Start (407) mode subfield that specifies the interpretation of the Measurement Frame Start Time to be applied to the measured element,

a Measurement Request subfield (406) set to at least one parameter for accomplishing the type of Measurement Type, and is formatted to comprise the following subfields

ChannelMeasurementMeasurementNumberStart TimeDurationOctets;

182

a Channel Number subfield (431) set to the channel number to which the measurement request applies,

a Measurement Start Time subfield (432) set to the time at which the Measurement Request is to start,

a Measurement Duration subfield (433) set to the time over which the measurement is to be done.

20. The apparatus of claim 19, wherein the control processor (105) is further configured to set the Start subfield (407) of the Measurement Mode subfield (404) to a value selected from the group consisting of

21. The apparatus of claim 20, wherein said indicator is encoded with a three bit encoding (407).

22. The apparatus of claim 21, wherein said three bit encoding (407) is