Abstract: System and method for generating a dynamic route map for a person trapped in an enclosed space and for enabling quick evacuation of the person is disclosed. When a request for evacuation is made by the person, the evacuation system locates the person based on the RFID person identifier tag and localizes the location of the person with respect to plurality of RFID floor tags and plurality of self-identifying RFID reader antenna tags. Further, condition of the floor is assessed by comparing the RSSI readings of the plurality of RFID floor tags and the RSSI readings of the plurality of self-identifying RFID reader antenna tags and the environmental information with pre-defined baseline RSSI readings of the plurality of RFID floor tags, RSSI readings of the plurality of self-identifying RFID reader antenna tags and an environmental threshold. A dynamic floor map is generated by collecting the RSSI readings from the plurality of RFID floor tags, self-identifying RFID reader antenna tags.

Abstract: Provided are methods and devices for determining a stop period of a mobile device in a location, according to geolocation data available on the mobile device. A predicted position of the mobile device and an associated level of uncertainty related to the predicted position is determined according to either the current position of the mobile device if it is available, or, if not, according to an artificial position obtained from a previously known position of the mobile device. The mobile device is considered to be in a stop period if the normalized prediction error between the predicted position and either the current position or the artificial position, depending on the situation, is smaller than a prediction error threshold. Upon detection of a stop period, an action on the mobile device is triggered.

Abstract: In one aspect, a device includes a processor, an infrared (IR) detector accessible to the processor and that receives signals from a primary IR emitter on a hand-held device and a secondary IR emitter on the hand-held device, a projector accessible to the processor, a transceiver accessible to the processor, and storage accessible to the processor. The storage bears instructions executable by the processor to use a location of the secondary IR emitter as sensed by the IR detector and orientation data of the hand-held device received from the transceiver to extrapolate a handwriting projection reference. The instructions are also executable to use the handwriting projection reference to project handwriting onto a projected whiteboard.

Abstract: The present disclosure provides methods, systems, and devices for tracking a mobile device in an indoor area or bounded area. A method for tracking a mobile device includes receiving sensor data from a mobile device and generating a heuristic map based on the sensor data describing a set of possible current locations of the mobile device in the bounded area. The method further includes receiving additional sensor data from the mobile device, and determining a change in position of the mobile device based on the additional sensor data. The method further yet includes updating the heuristic map to disqualify a first possible current location from the set of possible current locations, and outputting the updated set of possible current locations for display on a user interface.

Abstract: Apparatus for management of communications resources of a moving platform comprising an on-board communications system configured to effect wireless data communication between said moving platform and another node, said communications resources comprising a plurality of wireless communications links and a plurality of antennas associated therewith, the apparatus comprising an antenna analysis and selection module residing with said communications system and configured to: —receive, during a mission from one or more systems/subsystems and/or functions of said moving platform, attribute data representative of said emissions control criteria, said attribute data comprising (i) location data representative of a specified emissions control region, and/or (ii) position and/or attitude and/or velocity data representative of an adversary node defining an emissions control region; —determine, using said attribute data and based on said emissions control criteria, suitability of one or more on-board antennas and/or por

Abstract: Embodiments are directed to representing radio frequency (RF) signals in a visualization using particle bursts. In one scenario, a computer system instantiates RF signal sources in a virtualization, where each RF signal source is configured to emit RF signals. The computer system then generates a stream of particle bursts to represent at least one of the emitted RF signals, and provides a visualization that shows the instantiated RF signal sources along with the generated particle bursts representing the emitted RF signals. In some cases, the visualization may be used to illustrate an anti-access, aerial denial (A2AD) environment. In other cases, the visualization may be used to illustrate network communications using particles, where each particle represents network data packets.

Abstract: Systems and methods for providing alerts to end users of networked enabled portable devices are provided so that the end users are made aware when broadcast emergency alerts are issued. The systems and methods provide a way for a portable device to receive information about an emergency alert broadcast of which the user should be aware, e.g., from the EAS, and to notify the user of the emergency alert. A flag provides an indication the EAS should be on and the systems and method override the settings made by a user to a portable device to enable EAS reception. The user may then be automatically taken to the emergency alert information by having the portable device automatically tune to the emergency broadcast information, or the user may optionally retrieve the emergency information by tuning to the emergency broadcast channel, or the user may otherwise be presented with a reference to the emergency data (e.g., a link to the information).

Abstract: Provided are a method, device and system for estimating the location of a user device by using radio signals emitted from access point (AP) devices. In the location estimating method implemented by the user device may include steps of measuring received signal strength of a signal received from two or more AP devices deployed within a specific range, establishing a binding box for each of the two or more AP devices by using the measured received signal strength, and estimating a current location of the user device by using points of contact between the established binding boxes.

Abstract: A method for creating dynamic safe zones comprises determining, by a tracking device, the tracking device is outside a domicile, monitoring, by the tracking device, a location of the tracking device, in response to the location satisfying a condition, creating a safe zone for the tracking device, and while the tracking device is within the safe zone, reducing power consumption of the tracking device, wherein the method is performed using one or more computing devices.

Abstract: An apparatus for estimating carrier frequency offset includes an Mth-power circuit, a spectrum generating circuit, a spectrum adjusting circuit, a peak frequency determining circuit and a frequency offset determining circuit. The Mth-power circuit performs an Mth-power calculation on an input signal to generate an Mth-power calculation result. The spectrum generating circuit generates a spectrum according to the Mth-power calculation result. The spectrum adjusting circuit identifies a partial energy peak value in a partial frequency range from the spectrum, and increases the partial energy peak value to be higher than any other energy in the spectrum to generate an adjusted spectrum. The peak frequency determining circuit identifies a peak frequency having a maximum energy peak value from the adjusted spectrum. The frequency offset determining circuit determines an estimated carrier frequency offset result according to the peak frequency.

Abstract: The movement guidance device includes a first unit which calculates at least one of an error range of a first arrival time and an error range of a first movement time in a first route to the destination, a second unit which calculates at least one of an error range of a second arrival time and an error range of a second movement time in a second route, which is a route to the destination and is different from the first route, at a point where the second route is branched from the first route, and an output unit which outputs at least one of the error range of the second arrival time and the error range of the second movement time calculated by the second unit based on whether the error range calculated by the second unit is smaller than the error range calculated by the first unit.

Abstract: A space-time calibration system and method implement space-time solutions, in which, in one preferred embodiment, a single node determines its own space-time solutions based on other network nodes with which the single node communicates. In other preferred embodiments, space-time solutions for the node can be generated using other resources in the network. The disclosed system and method enable reliable, precise object positioning particularly for environments where the Global Positioning System (GPS) is blocked or subject to interference such as within the urban core.

Abstract: Defined herein is a system for communicating data includes a first data source that transmits data through the air, and a second data source that is remote from the first data source. The second data source at least one of receives and transmits data through the air. The system further includes at least one aircraft that receives data through the air from the first and second data sources, and transmits data through the air to at least one of the first and second data sources.

Abstract: Examples are disclosed for techniques for a new method of calculating multiple locations of a wireless communication device based on the same or a subset of the same raw data measurements (such as WiFi Time-Of-Flight/Fine-Time-Measurements or RSSI) and client specific fixed location device locations sources and/or database. Additionally, new APIs and implementation methods to support the new method are disclosed.

Abstract: Described herein are technologies related to an implementation of Wi-Fi CCA detection and transmission decision making using a histogram data block. For example, the histogram data block facilitates threshold values that are used for the transmission decision making to avoid Wi-Fi signal retransmission and/or collision.

Abstract: A system for implementing a positioning functionality. An apparatus (e.g. a directional transceiver) (706) may receive a signal (704) for positioning and measure characteristics associated with the received signal (704). If the directional transceiver (706) then determines that the received signal (704) comprises calculator identifier information, the apparatus may forward the measured characteristics based on the calculator identifier information. Otherwise, the directional transceiver (706) may forward the measured characteristics to a buffer (712). From the perspective of the apparatus (700) transmitting the signal (704) for positioning, a determination may be made as to whether calculator identifier information is known. If determined to be known, the transmitting apparatus (700) may include the calculator identifier information in the signal (704) for positioning. Otherwise, the other apparatus may transmit the signal (704) for positioning without any calculator identifier information.

Abstract: The present invention, pertaining to the field of wireless communications, discloses a mobile broadcast-based method and apparatus that includes: receiving a mobile broadcast signal; demodulating a location spreading signal inserted in the header of a time slot or a transmission frame of the mobile broadcast signal to acquire navigation message information, and measuring and acquiring location characteristic parameters, wherein the navigation message information includes the identifier of a mobile broadcast station, and the location characteristic parameters correspond to the identifier; and acquiring location data according to the location characteristic parameters and the navigation message information.

Abstract: The present invention relates to a method by which a terminal takes measures on a neighboring cell in a wireless communication system, which includes the steps of: receiving a channel state information-reference signal (CSI-RS) transmitted from the neighboring cell by using first time information received from a serving cell; and taking measurements using the CSI-RS, wherein the first time information is generated on the basis of the second time information of a serving cell, which receives an uplink signal from the terminal, and the third time information from a neighboring cell, which receives the uplink signal.

Abstract: A locating device locates a source emitting a short-duration high power microwave pulse. The locating device contains at least three separately disposed receiving antennas that are not disposed on a line, each with an associated detection device for detecting the point in time of the reception at the antenna of the high power microwave pulse. At least one short time measurement device is provided for determining at least two time differences between the points in time of reception of each two of the detection devices. A computing device is provided for calculating a location of the origin of the high power microwave pulse based on at least two of the measured time differences.

Abstract: A hearing aid includes: a signal processor; a wireless communications unit connected to the signal processor; and an antenna system with a data terminal and at least one control terminal, wherein the data terminal is connected to the wireless communications unit, the antenna system comprising a first antenna and one or more antenna feeds including a first antenna feed, the antenna system further comprising an antenna configurator for configuring the antenna system to operate in a selected antenna mode selected from a plurality of antenna modes including a first antenna mode and a second antenna mode according to a control signal transmitted on the at least one control terminal, wherein the antenna configurator is configured to apply a first antenna configuration to the data terminal when operating in the first antenna mode, and to apply a second antenna configuration to the data terminal when operating in the second antenna mode.

Abstract: A mechanism is described for facilitating dynamic client-side triangulation to determine global position of computing devices according to one embodiment of the invention. A method of embodiments of the invention includes detecting, at a computing device, first location information associated with static wireless access points. The method may further include detecting, at the computing device, second location information associated with roaming computing devices broadcasting the second location information relating to their current locations, and dynamically determining a current location of the computing device based on the first and second location information.

Abstract: Estimation of mobile device presence inside a defined region is facilitated. In one example, a device receives location information representing locations of a mobile device and corresponding time information for the locations of the mobile device. The device determines an estimated path of travel for the mobile device based on the location information and, based on the corresponding time information for the locations of the mobile device, determines whether the estimated path of travel traverses, at a defined time period of interest, a defined region that includes a defined portion.

Abstract: The invention provides a method and system for determining path traversed by a mobile communication device in an unobtrusive manner. The method involves providing a tower transition data involving identifying a set of GPS coordinates associated with a cellular network tower ID, and identifying the tail GPS coordinate and head GPS coordinate of consecutive cellular network tower IDs. Then the distance between the tail and head is estimated, based on which the sequence of cellular network tower IDs are determined, which provides the path traversed by the mobile communication device.

Abstract: Disclosed is a mobile broadcast signal demodulation chip for location. The demodulation chip includes a reception demodulation and module and a measurement module, where the reception and demodulation module is configured to demodulate a spread spectrum signal for positioning inserted in the header of a time slot or in the header of a transmission frame of a received mobile broadcast signal to acquire navigation message information; and the measurement module is configured to measure and acquire location characteristic parameters. The demodulation chip is not only capable of demodulating broadcast data in a mobile broadcast signal, but also capable of demodulating a spread spectrum signal for positioning-inserted in the header of a time slot or in the header of a transmission frame of a received mobile broadcast signal to acquire navigation message information and location characteristic parameters, thereby effectively improving location accuracy.

Abstract: Provided is a method of processing information on a tuple comprising latitude, longitude, and a timestamp collected from a position information collection device. The method includes changing a significant level value for calculating the statistical value of the speeds of past tuples in order to determine whether the current tuple has an error.

Abstract: Systems, devices, features, and/or methods for determining a location of a mobile device are disclosed. A method may include (a) receiving, into a mobile device, a common RF signal on a common carrier frequency, wherein the common RF signal includes a respective RF signal output by each of three or more transmitters on a common time basis in a round-robin manner, and wherein each of the three or more transmitters is positioned at a known location, (b) capturing data representing the common RF signal, (c) based on the captured data, discriminating between each respective RF signal that forms the received common RF signal, (d) determining a relative phase shift of each respective RF signal, and (e) determining the location of the mobile device based on the determined relative phase shifts and the known locations of the three or more transmitters.

Abstract: A system and method for effectively performing enhanced device location procedures to determine the current physical location of a mobile device includes a plurality of satellites that wirelessly transmit satellite beacon signals, a plurality of base stations that wirelessly transmit pilot signals, and a plurality of access points that wirelessly transmit access-point beacon signals. A location detector of the mobile device coordinates a device location procedure by measuring the satellite beacon signals, the pilot signals, and the access-point beacon signals to generate corresponding satellite information, base station information, and access point information. The location detector analyzes the satellite information, the base station information, and the access point information to select an optimal system configuration from the most effective satellites, base stations, and access points.

Abstract: Methods and apparatus enabling a wireless network to generate data that can be used by a receiver (e.g., UE) to resolve the contributions of individual transmitters, such as to determine its location without resort to external devices such as GPS satellites. In one embodiment, the wireless network comprises a single frequency network (SFN), and a unique base station identifier is embedded within the data, and encoded in a manner which allows the UE to calculate path characteristics (such as path latency, and Direction of Arrival) to triangulate its position. In one variant, the data encoding comprises weighting frames of data from different base stations using an orthogonal matrix. Advantageously, the encoding and embedded identifier are also transparent to legacy UE, thereby allowing for implementation with no infrastructure or UE modifications other than software. Network and user apparatus implementing these methodologies, and methods of doing business, are also disclosed.

Abstract: Determining the physical location of a mobile wireless device. A computer receives 1-hop and 2-hop neighbor information from a mobile wireless device for neighbor devices of the mobile wireless device responding to a discovery request transmitted by the mobile wireless device in an ad hoc wireless communications protocol. The computer determines a physical location of the mobile wireless device based in part on stored fixed physical locations of responding devices; an area in which the mobile wireless device is in range of responding 1-hop neighbors associated with a fixed physical location; and an area in which the mobile wireless device is in range of responding 1-hop neighbors not associated with a fixed physical location, which are in the range of 2-hop neighbors associated with fixed physical locations.

Abstract: A wireless communication terminal includes a communication status measurement element for measuring communication status data representing a communication status of the self terminal at the time of wireless communications; a reference data storage element for storing respective pieces of preset reference data representing communication statuses of a terminal which can be measured at respective locations at the time of wireless communications, in association with respective pieces of location data identifying the respective locations, and a location specifying element for comparing the communication status data measured by the communication status measurement element with the respective pieces of reference data stored in the reference data storage element, and based on the comparison result, specifying a location corresponding to the location data associated with a particular piece of reference data as a location of the self terminal.

Abstract: A method for identifying transmitters by a terminal in a single-frequency network comprising a plurality of transmitters. The transmitters are synchronized and transmit with an artificial delay ?i, specific to each transmitter. The method comprises at least one step of acquiring the approximate position of the terminal {circumflex over (p)}, the position pi of a list of transmitters {Tx} in the vicinity of the terminal and the delays ?i associated with them, a step of measuring pseudo-distances ?i between the transmitters and the terminal and a step of associating the measurements ?i with the transmitters of known positions pi by minimizing a cost function, said cost function ?(?i,{circumflex over (p)},?) corresponding to the norm of the error between the measurements ?i and a model of measurements of the pseudo-distances applied to a permutation of the position of the transmitters ?.

Abstract: A system for supporting and tracking at least one item includes a plurality of support structures adapted to support at least one item, at least one signal receiving arrangement associated with the plurality of support structures, at least one indicator arrangement associated with the plurality of support structures, and at least one controller in communication with the at least one signal receiving arrangement and the at least one indicator arrangement. The at least one signal receiving arrangement is configured to receive data from a transponder associated with the at least one item. The controller is programmed and/or configured to control the plurality of indicator arrangements based at least partially on at least a portion of the data received from the at least one signal receiving arrangement.

Abstract: Systems and methods are provided for determining position location information in a wireless network. In one embodiment, timing offset information is communicated between multiple transmitters and one or more receivers. Such information enables accurate position or location determinations to be made that account for timing differences throughout the network. In another embodiment, transmitter phase adjustments are made that advance or delay transmissions from the transmitters to account for potential timing differences at receivers. In yet another embodiment, combinations of timing offset communications and/or transmitter phase adjustments can be employed in the wireless network to facilitate position location determinations.

Abstract: An auxiliary positioning method, applied to a portable electronic device operative in a wireless communication network system and a satellite positioning system, for determining current position information of the potable electronic device, includes steps of receiving a plurality of current signals from at least one base station in the wireless communication network system to generate current signal information; accessing at least one track record related to the current signal information from a track record database, wherein the track record database includes a plurality of track records which record respective position information and signal information of base stations corresponding to the position information; and calculating the current position information according to the at least one track record.

Abstract: A method for localizing a node in a wireless network, the method including: receiving location signals transmitted by beacons, the location signals including information about the locations of the respective beacons; detecting the respective received signal strengths of the received location signals; obtaining information about the different signal levels at which the beacons can transmit; studying the received location signals; determining the signal levels used by each of the beacons for the transmission of the location signals, based on the studying of the received signals; calculating a distance to each of the beacons based on the detected signal strengths and the determined signal levels; and localizing the node by means of the received location information and the calculated distances. The invention also relates to a node ant to a wireless network.

Abstract: A mobile terminal capable of recognizing at least one of the presence or absence of a user and a location of the user are provided. The mobile terminal includes: a terminal main body; a user tracking unit configured to recognize at least one of the presence or absence of a user and a location of the user within a certain range based on the terminal main body; and a controller configured to generate a control signal for controlling a function of the terminal based on at least one of the presence or absence of the user or the user location.

Abstract: This disclosure relates to a positioning system and a method based on a radio communication apparatus including multiple antennas, and more particularly, to a positioning system and a method of positioning a terminal using a communication apparatus including multiple antennas. The positioning system and the method based on a radio communication apparatus including multiple antennas calculate a position of a terminal using a single communication apparatus in which the multiple antennas are mounted and can calculate the position of the terminal more accurately by using two or more communication apparatuses. In addition, the positioning system and the method communicate with a transception apparatus, a relay station, or a wireless access point of an existing communication system, thereby accurately obtaining the position of the terminal.

Abstract: The invention relate to a collision avoidance apparatus (100, 200, 300, 22), system (10) and method (500). The apparatus (100, 200, 300, 22) includes a UHF (Ultra High Frequency) transceiver (102) operable to send and receive UHF signals in electric field (E-field) mode, a VLF (Very Low frequency) transceiver (104) operable to send and receive VLF signals in magnetic field (H-field) mode, and a SHF (Super High Frequency) transceiver (106) operable to send and receive SHF signals in electric field (E-field) mode. The apparatus (100, 200, 300, 22) further includes a control module (110) operable to direct the operation of the respective transceivers (102, 104, 106), thereby to detect receipt of a signal via at least one of the transceivers (102, 104, 106), and determine whether or not an alert is to be issued, based on the nature of the received signal.

Abstract: For indoor location of a wireless device, use of Digital Television (DTV) signals for receiver location allows for high yield, precise location estimates. The device location is determined based on pseudo-ranges between the device and a plurality of DTV transmitters. The pseudo-ranges are determined based on the known and a priori unknown portions of the DTV signals received by the device and monitor stations. A new Payload Correlation Procedure (payload=unknown DTV data segments) to locate a client device is employed, and a Field Correlation Procedure, which uses only known data segments of the DTV signal, may be used in conjunction with the Payload Correlation Procedure. This approach addresses the problem presented by the limited size of the radio communications link between the Location Server and Client versus the very large bandwidth of multiple DTV channels.

Abstract: A system for instantaneous and continuous nanosecond-level accuracy determination of a relative time offset between at least two non-collocated timing units, the system including at least two non-collocated timing units located at known positions, each timing unit comprising a frequency source and a collocated receiver, each frequency source being disciplined at a frequency domain using a time source to generate corrections of the relative frequency drift between the frequency source and the time source.

Abstract: A system for indoor localization using GPS signals in a Distributed Antenna System includes a plurality of Off-Air Access Units (OAAUs). Each of the plurality of OAAUs is operable to receive a GPS signal from at least one of a plurality of GPS satellites and operable to route signals optically to one or more HUBs. The system also includes a plurality of remote units (RUs) located at a Remote location. The plurality of RUs are operable to receive signals from a plurality of local HUBs. The system further includes an algorithm to delay each individual GPS satellite signal to provide indoor localization at each of the plurality of RUs.

Abstract: Herein is presented, a low power on-die 60 GHz distribution network for a beamforming system that can be scaled as the number of transmitters increases. The transmission line based power splitters and quadrature hybrids whose size would be proportional to a quarter wavelength (˜600 ?m) if formed using transmission lines are instead constructed by inductors/capacitors and reduce the area by more than 80%. An input in-phase I clock and an input quadrature Q clock are combined into a single composite clock waveform locking the phase relation between the in-phase I clock and quadrature Q clock. The composite clock is transferred over a single transmission line formed using a Co-planar Waveguide (CPW) coupling the source and destination locations over the surface of a die. Once the individuals the in-phase I and quadrature Q clocks are required, they can be generated at the destination from the composite clock waveform.

Abstract: Methods and apparatuses for determining locations of a plurality of access points (APs) are presented. In some embodiments, the method includes obtaining measurements from at least 3 measurement points using a mobile device, wherein the locations of the at least 3 measurement points are unknown and are at different locations. The method may also include computing distance measurements from the mobile device to each of the plurality of APs, at each of the at least 3 measurement points, using the measurements, computing a set of mutual distance values in a matrix of mutual distances between each of the plurality of APs, using the distance measurements, and determining the locations of the plurality of APs using the computed matrix of mutual distances, relative to the at least 3 measurement points.

Abstract: A client device includes an application to request a client device location, and a receiver to receive a signal from a transmitter. The receiver extracts a transmitter identifier (ID) and a wave propagation parameter (WPP) from the signal. A validator validates the extracted transmitter ID based on comparisons of the extracted ID against a list of pre-assigned transmitter IDs. A location calculator computes the client device location based at least in part on the extracted WPP and provides the computed client device location to the application, if the transmitter ID is validated by the validator.

Abstract: Disclosed herein is a method and system to help reduce latency in responding to a location based service request from a mobile station. According to the method, the mobile station will include base station delay measurements with the location based service request. That way, when a network entity (such as the location based service provider, or a proxy between the mobile station and the location based service provider) receives the mobile station's request for a location-based service, the entity may readily convey the provided base station delay measurements to the positioning system to enable the positioning system to triangulate the mobile station's location without the need to request the base station delay measurements from the mobile station.

Abstract: Techniques are provided for utilizing one or more mobile devices to estimate distances between wireless access points (APs). Embodiments can, for example, enable mobile devices, wireless APs, and/or other systems to estimate a distance between two wireless APs using Round-Trip Time (RTT) measurements obtained by one or more mobile devices. The RTT measurements can be utilized based on whether one or more related Received Signal Strength Indication (RSSI) measurements exceed a threshold value. Embodiments can also utilize crowdsourcing to obtain distance estimation data (e.g., distance estimates, RTT and/or RSSI measurements, etc.) from one or more mobile devices and/or propagate a determined distance, based on the distance estimation data, to multiple devices.

Abstract: The subject matter disclosed herein relates to providing assistance information to a mobile station for performing position estimation operations.

Abstract: Mobile devices are able to determine their location based radio transmitters that are visible at the device to provide geographic location services. A knowledge of the location of the transmitters is required for the mobile device to determine a location estimate, however this can be difficult in network environments where the transmitters are temporary and their locations are not identified in location databases. Locations of temporary transmitters can be provided to mobile devices in order to augment the available location data used in determining the mobile device location. 3rd parties can provide temporal location data on transmitters that are set up for short period of time, as well as better control the distribution of the location data.

Abstract: A technique for determining the position of a mobile device includes receiving messages from respective mobile reference devices. Each of the messages is broadcast beginning at one of several predetermined message start opportunity (MSO) times that have known timings relative to a reference time. Each of the messages contains a MSO value identifying the MSO time at which transmission of the message started. The MSO value is used to determine the time of transmission of each of the messages received at the mobile device, and the position of the mobile device is determined via multi-lateration. According to another approach, the mobile device receives a set of ADS-B messages from a respective set of mobile reference devices. The time of transmission of each of the ADS-B messages is supplied in the ADS-B message itself or in a subsequent message and used to determine the position of the mobile device.

Abstract: Communication between a remote locator and a transponder is used to determine the relative position of the transponder. The transponder and locator each include a transmitter and a receiver. The locator transmits an inquiry in the form of a relatively powerful cyclically encoded signal with repetitive elements, uniquely associated with a target transponder. Periodically, each transponder correlates its coded ID against a possible inquiry signal, determining frequency, phase and framing in the process. Upon a match, the transponder transmits a synthesized response coherent with the received signal. The locator integrates multiple cyclical response elements, allowing low-power transmissions from the transponder. The locator correlates the integrated response, determines round-trip Doppler shift, time-of-flight, and then computes the distance and angle to the transponder. The transponder can be wearable, bionically implanted, or attached to, or embedded in, some object.