System and method for specifying measurement request start time

• US 7,903,570 B2
• Filed: 05/03/2004
• Issued: 03/08/2011
• 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
• Primary Examiner(s): Yao; Kwang B
• Assistant Examiner(s): Kao; Jutai
• Application Number:
  US10/556,010
• Publication Number:
  US 20070002757A1
• Time in Patent Office: 2,500 Days
• Field of Search: None
• 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 processor-based method for specifying measurement start times in a network Measurement Request Frame in a wireless network comprising one of a station and an access point, wherein at least one of the station and the access point is adapted to perform the steps comprising:

formatting the Measurement Request Frame to have a Measurement Request Elements field comprising at least one Measurement Request Element, said at least one Measurement Request Element comprising at least one Measurement Request for a given type of network measurement; and

specifying an absolute Start Time in at least one of the Measurement Request Frame, the Measurement Request Element, and the Measurement Request, wherein the absolute Start Time is set to zero to indicate that the corresponding measurement is to be initiated after reception of the Measurement Request Frame.

2. The method of claim 1, further comprising the step of setting a Measurement Mode field to a value that specifies how to interpret the absolute Start Time for starting measurement of the element.

3. The method of claim 2, wherein said setting step further comprises the step of using a three bit encoding to represent a selected indicator.

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

including in the at least one Measurement Request Element a Measurement Mode field; and

setting said Measurement Mode field to a value that specifies how to interpret the absolute Start Time for starting measurement of the element.

5. The method of claim 4, wherein said setting step further comprises using a three bit encoding to represent a selected indicator.

6. The method according to claim 1, wherein said absolute Start Time is based on a time synchronization function (TSF) timer value.

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

a measurement acquisition circuit that formats the Measurement Request Frame to have a Measurement Request Elements field that comprises at least one Measurement Request Element that comprises at least one Measurement Request for a given type of network measurement;

a TSF timer; and

a control processor coupled to said measurement acquisition circuit and said TSF timer and configured to set an absolute Start Time in at least one of the Measurement Request Frame, the Measurement Request Element, and the Measurement Request, wherein the absolute Start Time is set to zero to indicate that the corresponding measurement is to be initiated after reception of the Measurement Request Frame.

8. The apparatus according to claim 7, wherein said absolute Start Time is based on a time synchronization function (TSF) timer value.