Determining clock models

Abstract

Examples disclosed herein relate to methods and apparatuses for observing signals transmitted by one or more transmitters in an asynchronous communication network and applying a time reference to generate a clock model. In one embodiment, parameters representing the clock model may then be forwarded to other mobile devices to assist in positioning operations.

1 . A method for modeling timing of signals, comprising:
 receiving from each mobile device of one or more mobile devices fine time measurements determined based, at least in part, on a first time reference in one or more first signals received at the each mobile device from an asynchronous network and a second time reference;   computing a clock model descriptive of timing of at least one signal transmitted from a transmitter in the asynchronous network based, at least in part, on the fine time measurements,
 wherein the computed clock model includes at least one of a clock drift parameter, a clock time uncertainty parameter or a clock frequency uncertainty parameter; and 
   transmitting parameters representative of the computed clock model to one or more receiving mobile devices.   
     
     
         2 . The method of  claim 1 , wherein the second time reference comprises a time reference obtained from acquisition of a satellite positioning system (SPS) signal. 
     
     
         3 . The method of  claim 1 , wherein the second time reference comprises a time reference based, at least in part, on an internal clock of the mobile device. 
     
     
         4 . The method of  claim 1 , wherein the fine time measurements comprise at least a time-stamped frame number observed in the one or more first signals, and wherein the clock model further comprises a time offset applied to the time-stamped frame number. 
     
     
         5 . The method of  claim 1 , further comprising weighting the fine time measurements based, at least in part, on at least one of a position uncertainty or a time uncertainty. 
     
     
         6 . The method of  claim 1 , wherein the computed clock model is adapted to predict a timing of a signal in the future. 
     
     
         7 . The method of  claim 1 , wherein the computing the clock model comprises computing the clock model based, at least in part, on timed batches including fine time measurements. 
     
     
         8 . The method of  claim 1 , wherein the transmitter is a serving base station having a clock, and wherein the computed clock model is representative of the clock. 
     
     
         9 . An apparatus comprising:
 a receiver to receive messages from a communication network;   a transmitter to transmit messages to the communication network; and   one or more processors configured to:   compute a clock model descriptive of timing of at least one signal transmitted in an asynchronous network based, at least in part, on fine time measurements received in messages from each mobile device of one or more mobile devices, the clock model being computed based, at least in part, on a first time reference in on or more first signals received at the each mobile device from the asynchronous network and a second time reference,
 wherein the computed clock model includes at least one of a clock drift parameter, a clock time uncertainty parameter or a clock frequency uncertainty parameter; and 
   initiate transmission of messages containing parameters representative of the computed clock model through the transmitter to one or more receiving mobile devices.   
     
     
         10 . The apparatus of  claim 9 , wherein the second time reference comprises a time reference obtained from acquisition of a satellite positioning system (SPS) signal. 
     
     
         11 . The apparatus of  claim 9 , wherein the fine time measurements comprise at least a time-stamped frame number observed in the one or more first signals. 
     
     
         12 . The apparatus of  claim 9 , wherein the apparatus is a serving base station having a clock, and wherein the computed clock model is representative of the clock. 
     
     
         13 . A non-transitory storage medium comprising machine-readable code stored thereon which is executable by a special purpose computing apparatus, comprising:
 code to compute a clock model descriptive of timing of at least one signal transmitted in an asynchronous network based, at least in part, on fine time measurements received in messages from each mobile device of one or more mobile devices, the fine time measurements being determined based, at least in part, on a first time reference in one or more first signals received at the each mobile device from the asynchronous network and a second time reference,
 wherein the computed clock model includes at least one of a clock drift parameter, a clock time uncertainty parameter or a clock frequency uncertainty parameter; and 
   code to initiate transmission of messages containing parameters representative of the computed clock model to one or more receiving mobile devices.   
     
     
         14 . An apparatus comprising:
 means for receiving from each mobile device of one or more mobile devices fine time measurements determined based, at least in part, on a first time reference in one or more first signals received at the each mobile device from an asynchronous network and a second time reference;   means for computing a clock model descriptive of timing of at least one signal transmitted from a transmitter in the asynchronous network based, at least in part, on the fine time measurements,
 wherein the computed clock model includes at least one of a clock drift parameter, a clock time uncertainty parameter or a clock frequency uncertainty parameter; and 
   means for transmitting parameters representative of the computed clock model to one or more receiving mobile devices.