A system and method for determining a presence of a mobile device located in a predetermined detection zone within a vehicle may include a plurality of transmitters located within the vehicle, in which each of the plurality of transmitters is configured to transmit an acoustic signal into an acoustic environment within the vehicle, and in which each of the acoustic signals comprises at least one ultrasonic pulse, a mobile device configured to periodically record sounds in the acoustic environment, and a processor configured to determine that a periodically recorded sound by the mobile device comprises each of the acoustic signals transmitted by the plurality of transmitters, determine a location of the mobile device within the vehicle based on the acoustic signals recorded by the mobile device, and determine that the location of the mobile device matches the predetermined detection zone.

A system and methods are disclosed for synchronizing two or more groups of base stations in a wireless location system. In one embodiment, a first wireless base station belonging to a first group of wireless base stations transmits a first RF beacon for synchronizing the first group of wireless base stations and a second RF beacon that is used to synchronize a second group of wireless base stations. Wireless base stations in the first and second groups transmit respective non-RF (e.g., infrared, ultrasound, etc.) beacons that can be used to locate a portable tag.

Ultrasonic transmitters periodically transmit ultrasonic ranging signals, and an ultrasonic receiver receives the ultrasonic ranging signals on a mobile device in order to locate the mobile device in a venue. A controller determines a noise level in the venue, and varies a sound level of the periodically ranging signals based on the determined noise level, thereby optimizing the position of the mobile device.

A transmitter device transmits an ultrasonic signal encoding a binary identifier. Each bit position in the identifier is associated with a pair of frequencies and with first and second time positions in the signal. The bit value determines which of the pair of frequencies is transmitted at the first time position, with the other being transmitted at the second time position. A receiver device receives the signal. Each bit position of the identifier is decoded based on the strength of the received signal at (a) the first frequency and first time position associated with the particular bit position, (b) the associated first frequency and second time position, (c) the associated second frequency and first time position, and (d) the associated second frequency and second time position. The decoded identifier is used to determine information relating to the position of a mobile one of the devices.

According to one embodiment, a mobile body position estimation system includes an energy source, a mobile body, a plurality of physical quantity, and a processor. The energy source generates energy whose physical quantity changes. The mobile body is a position estimation target. The plurality of physical quantity detectors are provided in the mobile body. The plurality of physical quantity detectors detect the physical quantity of the energy generated from the energy source. The processor estimates a position of the mobile body based on a position of the energy source, an attitude angle of the energy source, and a plurality of physical quantity values respectively detected by the plurality of physical quantity detectors.

A locational information transmission apparatus that transmits information for identifying a location is provided. The locational information transmission apparatus includes a radio communication unit that performs radio communication; a sound wave transmitting unit that transmits a sound wave including first identification information; a radio wave transmitting unit that transmits a radio wave including second identification information; and a transmission control unit that changes, depending on control information reported via the radio communication, a method of transmitting the sound wave or a method of transmitting the radio wave.

A system and methods for estimating the location of a mobile device are disclosed. In accordance with one embodiment, a mobile device receives a wireless electromagnetic signal and an ultrasound signal from a first beacon during a first occurrence of a time slot. The mobile device further receives a wireless electromagnetic signal and an ultrasound signal from a second beacon during a second occurrence of the time slot, where the ultrasound signals from the first and second beacons have non-overlapping areas of coverage. The electromagnetic and ultrasound signals from the first beacon are used to estimate a first location of the mobile device, and the electromagnetic and ultrasound signals from the second beacon are used to estimate a second location of the mobile device.

The invention relates to hydroacoustics and more specifically to hydroacoustic devices comprising, disposed in a single housing, a converter of liquid-medium oscillations and electrical signals, capable of receiving and/or transmitting hydroacoustic signals, the converter being disposed on a board which is connected to a switch cable for providing power and transmitting electrical signals, and may be used as a receiver and/or transmitter of hydroacoustic signals in water. According to the invention, the housing of the to hydroacoustic device is formed by the outer surfaces of the converter and board, and by a protective material which coats all of said surfaces, said material allowing for a transmission of hydroacoustic oscillations and being capable of transitioning from a highly-elastic or viscous-flow state to a solid state. The achieved technical result consists in simplifying the design of the device.

A transmitter is provided that is capable of communicating with a management apparatus via a network and is configured to output a plurality of sound waves in a plurality of different directions. The transmitter includes a memory storing a program, and a processor configured to execute the program to implement processes of outputting a first sound wave including first unique information in a first output direction of the plurality of different directions, outputting a second sound wave including second unique information that differs from the first unique information in a second output direction that differs from the first output direction, and individually controlling the first sound wave output by the first sound wave output unit and the second sound wave output by the second sound wave output unit based on a request from the management apparatus.

Provided is an ultrasonic-wave communication system where the influence of ambient noise and the Doppler effect are suppressed and where a user of a portable terminal is prevented from hearing unwanted sound. After performing encryption processing of predetermined information such as store information, a beacon 5 sends out predetermined-information-containing beacon information of one channel as ultrasonic waves into the salesroom 3 by combining a control carrier, a first carrier, and a second carrier in such a way that a first carrier signal and a second carrier signal are output between control carrier signals a number of times according to the predetermined information and that a state where the first carrier signal and/or the second carrier signal is output is maintained.