Sr Technologies, Inc.

Olivia Desiree Fernandez

Graham K Smith

Ryan Busser

Mark Passler

Steven M Romanow

A method in a monitoring station configured for communication with a wireless device is described. The method includes determining a round trip time, RTT, that corresponds to a first packet transmitted to the wireless device; receiving a second packet from the wireless device; determining the second packet from the wireless device has been received without error based at least in part on an error-detecting field; and receiving a subsequent packet from the wireless device. The method further includes determining that the subsequent packet received is a second packet retransmission; determining a preamble receipt time of the subsequent packet; determining a delay value based in part on the RTT of the first packet, the length field of the subsequent packet, and data rate field of the subsequent packet. The first acknowledgement packet is transmitted timed at the delay value after the preamble receipt time of the subsequent packet.

System and method for long range wireless local area network communications

Methods and devices are disclosed that derive an IQ magnitude parameter, and then determine the optimum IQ magnitude for wanted signals with negative signal to noise values. For each device installation, a calibration routine may be carried out that sets the baseband gain to produce this optimum IQ magnitude for each frequency channel.

Setting baseband gain for signals below noise

A method in a first wireless device (WD) is described. The method includes determining a plurality of expected response signals, each having a scrambling seed number and an expected sequence of time domain symbols; receiving a plurality of response signals; determining a plurality of frequency shifted time domain samples, cross-correlating each frequency shifted time domain sample with the expected sequence of time domain symbols, for each scrambling seed number of each expected response signal; determining a maximum correlation value for each frequency shift and each frequency shifted time domain sample; summing the maximum correlation value for each frequency shift, each frequency shifted time domain sample, and each response signal; determining a peak correlation value based on the summed maximum correlation value; and determining at least the round trip time associated with the plurality of ranging signals based at least in part on the peak correlation value.

Active geo-location for orthogonal frequency division multiplex wireless local area network devices

A method in a wireless device (WD) is described. The method is at least for determining a geo-location of a target station using round-trip times (RTTs) of a plurality of signals transmitted by the WD and a plurality of response signals received from the target station corresponding to the plurality of signals transmitted by the WD. The method includes determining an expected response signal, and, for each transmitted signal of the plurality of signals, determining that a response signal type matches an expected response signal type, cross-correlating a set of samples of the response signal, searching for a predetermined characteristic of the expected response signal, and correlating at least a subset of bits of the set of bits of the received response signal with the set of expected bits of the expected response signal. Further, a peak rolling sum correlation and the RTTs are determined.

Active geo-location for orthogonal frequency division multiplex wireless local area network devices using additive correlation

A method and measuring station to determine the geo-location of a wanted target station in the presence of rogue responder stations are disclosed. One method includes: transmitting a packet with a fictitious address not corresponding to the wanted target station address; transmitting a packet with the wanted target station address; determining at least one of: a first difference between a round trip time (RTT) associated with a response packet from a responder station and an RTT associated with a response packet from the wanted target station; and a second difference between a time of arrival (TOA) associated with the responder station's response packet and a TOA associated with the wanted target station's response packet; and distinguishing between the response from the responder station and the response from the wanted target station based on at least at least one of the first difference and the second difference.

Mitigating of rogue responders when geo-locating wireless devices

A method in a wireless device (WD) is described. The method is performed for determining a geo-location of a target station using round-trip times (RTTs) of a plurality of signals transmitted by the WD to the target station and a plurality of response signals received from the target station. The method includes determining expected time domain symbols of an expected response signal, and, for each transmitted signal of the plurality of signals, determining a first time, opening a reception window for receiving a response signal, receiving the response signal within the reception window, frequency shifting the expected time domain symbols, and cross-correlating the time domain symbols with the frequency shifted expected time domain symbols. In addition, the method includes determining a peak correlation value, a second time, and the RTT for each one of the transmitted plurality of signals based at least on the first time and the second time.

Active geo-location for orthogonal frequency division multiplex wireless local area network devices using additive correlation in the time domain

A method and wireless devices (WDs) for geo-location of wireless devices are disclosed. According to one aspect, a method in a first WD includes: transmitting a sequence of ranging signals and receiving a plurality of ranging response signals from a second WD, the ranging response signals being responsive to the ranging signals. For each of the plurality of ranging response signals, a received sequence of bits is determined. A correlation between the received sequence of bits and an expected sequence of bits is determined. The method also includes determining a subset of the plurality of received sequences of bits deemed not to arise from noise, and determining the subset being based at least in part on the correlations. The method also includes determining a distance between the first WD and the second WD based at least in part on a plurality of received sequences in the subset.

Peak to sigma ratio measurement with active geo-location for wireless local area network devices

A method for determining reception window timing using a measuring station receiving an antenna beam width, receiving an antenna tilt angle, receiving an altitude A, determining a far projection angle &#x394;f, determining a near projection angle &#x394;n, and determining a far projection range corresponding to the far projection angle &#x394;f and based at least upon the values of &#x394;f and A. The method further includes determining a near projection range corresponding to the near projection angle &#x394;n and based at least upon the values of &#x394;n and A, determining an end time of a reception window based at least upon the value of the far projection range the reception window being a window of time in which a response from the target station is expected to be received, and determining a start time of the reception window based at least upon the value of the near projection range.

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Boca Raton, FL, United States of America

Olivia Desiree Fernandez