Abstract: The present invention relates to technology for monitoring a gas in a closed space, and more particularly, to a system for monitoring a gas in a closed space and an operating method of the system, which monitor a gas in a closed space and diagnose and correct an abnormality of a closed-space gas measurement apparatus.

Abstract: Disclosed herein are a marine data collection apparatus, a maritime IoT device, and a marine data transmission method. The maritime IoT device includes a marine data collection unit for collecting marine data including at least one of ocean state information and service application data using one or more sensors, a phase information calculation unit for analyzing the collected marine data and then generating phase information and period information of waves, a communication schedule management unit for generating communication-scheduling information including communication-available time information, which indicates a time during which communication with a marine data collection apparatus is available, based on the phase information and the period information, and a communication unit for transmitting the marine data including at least one of the ocean state information and the service application data to the marine data collection apparatus during the communication-available time.

Abstract: A portable device for measuring gas in a closed space includes an air intake and exhaust unit configured to suction external air and discharge the suctioned air, a sensor unit configured to measure characteristics of the air suctioned by the air intake and exhaust unit, a communication unit configured to communicate with a host system, a power supply unit configured to supply power to the air intake and exhaust unit, the sensor unit, and the communication unit, and a control unit configured to control the air intake and exhaust unit, the sensor unit, the communication unit, and the power supply unit so that the sensor unit measures the characteristics of the air suctioned by the air intake and exhaust unit and configured to transmit measurement information to the host system through the communication unit.

Abstract: A portable device for measuring gas in a closed space includes an air intake and exhaust unit configured to suction external air and discharge the suctioned air, a sensor unit configured to measure characteristics of the air suctioned by the air intake and exhaust unit, a communication unit configured to communicate with a host system, a power supply unit configured to supply power to the air intake and exhaust unit, the sensor unit, and the communication unit, and a control unit configured to control the air intake and exhaust unit, the sensor unit, the communication unit, and the power supply unit so that the sensor unit measures the characteristics of the air suctioned by the air intake and exhaust unit and configured to transmit measurement information to the host system through the communication unit.

Abstract: A multi-hop relay maritime communication apparatus installed in a ship is disclosed. The maritime communication apparatus includes a first access module configured to comprise a plurality of directional antennas integrally formed; a second access module configured to comprise an omni-directional antenna; and a bridge configured to be connected to the first access module and the second access module via an Ethernet interface.

Abstract: A multi-hop relay maritime communication apparatus installed in a ship is disclosed. The maritime communication apparatus includes a first access module configured to comprise a plurality of directional antennas integrally formed; a second access module configured to comprise an omni-directional antenna; and a bridge configured to be connected to the first access module and the second access module via an Ethernet interface.

Abstract: The present invention relates to an apparatus and method of performing wireless communication using multiple directional antennas. The transportation means according to the present invention includes at least two communication devices, wherein one of the at least two communication devices, communication device A, includes a directional antenna group 1, and the other communication device, communication device B, includes a directional antenna group 2, and wherein the communication device A performs directional antenna selection control of the directional antenna group 1 included in the communication device A depending on whether the communication device B is connected with a network. According to the present invention, one of the communication devices gains access to a satellite station, a base station, or other ships, at least one antenna of another communication device may be used to relay wireless communication and may play a role as a base station or an AP.

Abstract: Disclosed herein are a maritime communication apparatus and method. The maritime communication apparatus includes a land-based network communication unit, a maritime network communication unit, and a communication control unit. The land-based network communication unit communicates with a land-based communication network. The maritime network communication unit communicates with a maritime communication network. The communication control unit links the communication of the land-based network communication unit with the communication of the maritime network communication unit in accordance with a destination address of data provided by any one of the land-based network communication unit and the maritime network communication unit.

Abstract: An antenna switching system according to an exemplary embodiment of the present invention includes a plurality of directional antenna which is mounted in a ship to receive a wireless signal; an antenna switch which selects one of the plurality of directional antennas; a modem which is connected to the directional antennas through the antenna switch to extract a strength of a received signal; and a switching determining unit which outputs an antenna selection signal to the antenna switch based on the strength of the received signal and GPS/DR information of a transmission side ship and its own ship.

Abstract: Disclosed herein are a method and apparatus for generating multiband Radio Frequency (RF) signals in maritime wireless communication. The apparatus includes a baseband conversion unit, a phase compensation unit, a Direct Current (DC) offset compensation unit, and an RF transmission unit. The baseband conversion unit converts RF signals corresponding to a baseband modulation signal having a negative frequency and a baseband modulation signal having a positive frequency into baseband signals, respectively. The phase compensation unit eliminates the images of multiband signals so as to correspond to the baseband signals. The DC offset compensation unit compensates the baseband modulation signals for DC offsets using the multiband signals from which the images have been eliminated. The RF transmission unit generates the RF signals using the signals which have been compensated for the DC offsets, and sends the RF signals via an antenna.

Abstract: The present invention relates to an apparatus and method of performing wireless communication using multiple directional antennas. The transportation means according to the present invention includes at least two communication devices, wherein one of the at least two communication devices, communication device A, includes a directional antenna group 1, and the other communication device, communication device B, includes a directional antenna group 2, and wherein the communication device A performs directional antenna selection control of the directional antenna group 1 included in the communication device A depending on whether the communication device B is connected with a network. According to the present invention, one of the communication devices gains access to a satellite station, a base station, or other ships, at least one antenna of another communication device may be used to relay wireless communication and may play a role as a base station or an AP.

Abstract: Disclosed herein are a maritime communication apparatus and method. The maritime communication apparatus includes a land-based network communication unit, a maritime network communication unit, and a communication control unit. The land-based network communication unit communicates with a land-based communication network. The maritime network communication unit communicates with a maritime communication network. The communication control unit links the communication of the land-based network communication unit with the communication of the maritime network communication unit in accordance with a destination address of data provided by any one of the land-based network communication unit and the maritime network communication unit.