Maritime VSAT

Maritime VSAT is the technology of satellite communication used for the organization of a broadband channel between the water transport and the coast via satellites on geostationary earth orbits.

VSAT (Very Small Aperture Terminal) is the station of satellite communication with a small aperture (the size determining really accepted signal power) of the antenna (less than 3 m in the diameter) working for acceptance and transfer^[1].

Systems working in the Ku-range have the size from 75 cm to 1.5 m, as a rule. The systems of S-range have the size to 2.8 m. Data transfer rate ranging from 56 KB / with up to 4 Mbps. For work of VSAT use satellites on geostationary earth orbits which transfer data from small satellite stations (terminals) to the Central Terrestrial Station (HUB), in case of a "star" configuration or to other terminals, in case of the mesh configuration^[2].

Main consumers of technology of sea VSAT:

• Modern Commercial Fleet;
• Military fleet / Fleet state. organizations;
• Commercial fleet;
• Fishing fleet;
• Undersized fleet;
• Fleet of internal waterways.

For January, 2017 the maximum capacity of 4 Mbps in direct and 2 Mbps in the return channels, but this limit can be expanded, and is limited to equipment opportunities.

The main possibility of the systems of sea VSAT — providing broadband access to the Internet on the vessel, data transmission and telephony. The possibility of the organization of a broadband satellite channel on the vessel allows to implement a number of the services and services earlier unavailable owing to lack of cheap data transmission channel. The video conferencing, remote connection and management, monitoring of ship parameters from the coast and another can be such services.

Antennas for sea satellite stations, (2015)

• Standard means of communication on the fixed unlimited rates (data transmission, telephony, the Internet, a video conferencing);
• additional resources of communication for crew and passengers (The Internet, telephony, VoIP, GSM, satellite TV);
• integration into onboard navigation systems (INB, ECDIS, VDR, Hydrometeorological System, etc.);
• electronic declaring (electronic digital signature, electronic trade journal);
• telemetry and video surveillance behind ship processes (a navigation complex, the engine room, a cargo system);
• online consultation and remote control (technical and information support, telemedicine);
• unified information environment between shipping company, coast guards and vessels of the fleet;
• the protected corporate network;
• distance learning of crew;
• possibility of the organization of alternative channels of communication on the vessel.

Antennas for sea satellite stations, (2015)

Structure of VSAT

VSAT consists of two main parts:

• ODU (OutDoorUnit) — the external block - the antenna and the transceiver, usually 1-2 W
• IDU (InDoorUnit) is the internal block or the satellite modem.

The block of an outdoor installation (ODU) — the external block installed in antenna focus which transfers to the hub and receives from it via the satellite the modulated radio signals. The semiconductor amplifier (SSPB, BUC), the down-converter of the low-noise block (LNB) and the polarization selector (OMT) are a part of ODU. BUC and LNB are connected to separate ports OMT. Such configuration provides acceptance of a signal with polarization of a certain type and signal transmission with polarization of other type, usually orthogonal. The interconnect cable has F-type connectors. Factory VSAT antennas are completed with the irradiator and OMT.

The internal block (IDU) - the desktop device (the satellite modem) transforming information between analog communications on the satellite and local devices, such as phones, computer networks, PC, TV, etc. In addition to the main conversion programs IDU may contain additional functions as security, acceleration of network and other properties.

Notes