Near wireless-control technology between smart devices using inaudible high-frequencies
For wireless control between smart devices, recent studies have mainly used Wi-Fi or Bluetooth technology. However, for Wi-Fi, the user requires extra infrastructure such as an access point. For Bluetooth, both users must have the same mobile operating system (OS), and several seconds elapse when pairing the smart devices. This paper proposes a near wireless control technology between smart devices using a microphone and the speaker of a smart device at near distances, to solve these problems. The control signals of the proposed method use the inaudible high frequencies of an audible domain that cannot be recognized by humans. The other smart device receives the control signals and then executes the specific function. Currently, if only a high frequency is used for the control signal, errors owing to unexpected sounds in the environment can occur. Therefore, our method uses two types of frequency signals. One signal is based on an audio file of the signals, and the other signal is a low-latency audio frequency. To evaluate the efficacy of the proposed method, we experimented with a near wireless-controlled camera in various situations and at various distances. The success rate was about 96%. Then, we conducted an experiment to determine whether or not the people located around the device recognized the control signals when we used it. The percentage of people who were not conscious of the control signals was 97%. Therefore, the proposed method is a useful technique for many types of near wireless-control between smart devices.
near wireless-control smart device high frequency inaudible frequency mobile communication