Method for performing timing measurement for location estimation of an electronic device with aid of one request sent to multiple peer devices, and associated apparatus

Abstract

A method and apparatus for performing timing measurement for location estimation of an electronic device are provided, where the method includes the steps of: sending a pre-association broadcast request frame to trigger multiple responders in a wireless network system to initiate timing measurement; and performing timing measurement according to a plurality of timestamps, for determining a location of the electronic device, wherein for a specific responder of the responders, a first timestamp and a second timestamp within the plurality of timestamps respectively correspond to a time of departure (ToD) and a time of arrival (ToA) of a pre-association uni-cast response frame received from the specific responder, and a third timestamp and a fourth timestamp within the plurality of timestamps respectively correspond to a ToD and a ToA of an acknowledgement frame corresponding to the pre-association uni-cast response frame, the acknowledgement frame sent from the electronic device to the specific responder.

What is claimed is: 
     
         1 . A method for performing timing measurement for location estimation of an electronic device, the method being applied to the electronic device, the method comprising the steps of:
 sending a pre-association broadcast request frame to trigger multiple responders in a wireless network system to initiate timing measurement; and   performing timing measurement according to a plurality of timestamps, for determining a location of the electronic device, wherein a portion of the plurality of timestamps is obtained from the responders,   wherein at least one timestamp is determined based on a pre-association uni-cast response frame received from one of the responders;   wherein no actual association is established between the electronic device and any of the responders.   
     
     
         2 . The method of  claim 1 , wherein a portion of the plurality of timestamps is determined within the electronic device. 
     
     
         3 . The method of  claim 1 , wherein for a specific responder of the responders, a first timestamp and a second timestamp within the plurality of timestamps respectively correspond to a time of departure (ToD) and a time of arrival (ToA) of a pre-association uni-cast response frame received from the specific responder, and a third timestamp and a fourth timestamp within the plurality of timestamps respectively correspond to a ToD and a ToA of an acknowledgement frame corresponding to the pre-association uni-cast response frame received from the specific responder, the acknowledgement frame sent from the electronic device to the specific responder. 
     
     
         4 . The method of  claim 3 , wherein the step of performing timing measurement according to the plurality of timestamps for determining the location of the electronic device further comprises:
 determining a time of flight (ToF) relative to the specific responder based on the equation of:
   ToF=(( t 4 −t 1)−( t 3 −t 2))/2;
 
   wherein the notations “t1”, “t2”, “t3”, and “t4” represent the first timestamp, the second timestamp, the third timestamp, and the fourth timestamp, respectively.   
     
     
         5 . The method of  claim 4 , wherein the step of performing timing measurement according to the plurality of timestamps for determining the location of the electronic device further comprises:
 determining a distance between the electronic device and the specific responder based on the equation of:
     D =( c *ToF); 
   wherein the notation “D” represents the distance between the electronic device and the specific responder, and the notation “c” represents the speed of light in vacuum; and   the distance between the electronic device and the specific responder is utilized for determining the location of the electronic device.   
     
     
         6 . The method of  claim 1 , wherein the pre-association broadcast request frame is a probe request frame, and the pre-association uni-cast response frame is a probe response frame. 
     
     
         7 . The method of  claim 1 , wherein the pre-association broadcast request frame is a Generic Advertisement Service (GAS) request frame, and the pre-association uni-cast response frame is a GAS response frame. 
     
     
         8 . An apparatus for performing timing measurement for location estimation of an electronic device, the apparatus comprises at least one portion of the electronic device, the apparatus comprising:
 a transceiver arranged to transmit or receive information for the electronic device; and   a processing circuit, coupled to the transceiver, arranged to control operations of the electronic device, wherein the processing circuit sends, by utilizing the transceiver, a pre-association broadcast request frame to trigger multiple responders in a wireless network system to initiate timing measurement, and performs timing measurement according to a plurality of timestamps, for determining a location of the electronic device, wherein a portion of the plurality of timestamps is obtained from the responders,   wherein at least one timestamp is determined based on a pre-association uni-cast response frame received from one of the responders;   wherein no actual association is established between the electronic device and any of the responders.   
     
     
         9 . The apparatus of  claim 8 , wherein a portion of the plurality of timestamps is determined within the electronic device. 
     
     
         10 . The apparatus of  claim 8 , wherein for a specific responder of the responders, a first timestamp and a second timestamp within the plurality of timestamps respectively correspond to a time of departure (ToD) and a time of arrival (ToA) of a pre-association uni-cast response frame received from the specific responder, and a third timestamp and a fourth timestamp within the plurality of timestamps respectively correspond to a ToD and a ToA of an acknowledgement frame corresponding to the pre-association uni-cast response frame received from the specific responder, the acknowledgement frame sent from the electronic device to the specific responder. 
     
     
         11 . The apparatus of  claim 10 , wherein the processing circuit determines a time of flight (ToF) relative to the specific responder based on the equation of:
   ToF=(( t 4 −t 1)−( t 3 −t 2))/2;
   wherein the notations “t1”, “t2”, “t3”, and “t4” represent the first timestamp, the second timestamp, the third timestamp, and the fourth timestamp, respectively.   
     
     
         12 . The apparatus of  claim 11 , wherein the processing circuit determines a distance between the electronic device and the specific responder based on the equation of:
     D =( c *ToF);   wherein the notation “D” represents the distance between the electronic device and the specific responder, and the notation “c” represents the speed of light in vacuum; and   the distance between the electronic device and the specific responder is utilized for determining the location of the electronic device.   
     
     
         13 . The apparatus of  claim 8 , wherein the pre-association broadcast request frame is a probe request frame, and the pre-association uni-cast response frame is a probe response frame. 
     
     
         14 . The apparatus of  claim 8 , wherein the pre-association broadcast request frame is a Generic Advertisement Service (GAS) request frame, and the pre-association uni-cast response frame is a GAS response frame.