VSAT systems for sea and river transport
With an increase in the volume of information flows and an increase in the number of communication interactions in which people participate daily, the means of communication have developed rapidly over the past two to three decades: now we use mobile phones and the Internet on a regular basis.
Having the opportunity to contact anyone and whenever on land, a person can no longer afford to remain without communication for a long time while traveling on water. The same applies to receiving news: we are already used to learning about important events in a matter of minutes after they are completed, therefore it is not surprising that when sailing across the sea, we want to watch news programs, sports matches and new releases of our favorite TV shows in real time.
All this led to the development of technologies that can provide people traveling on seas and rivers with the same communication capabilities as those on land. One of the revolutionary solutions giving such opportunities was the marine VSAT (Very Small Aperture Terminal) – satellite communication systems using a stabilized antenna with a dish size of up to 3 meters.
84036483.jpg Technical features of marine VSAT
Despite the fact that the diameter of the dish can be up to 3 meters, most of the VSAT systems on the market have antennas ranging in size from 75 centimeters to 1.2 meters. These antennas work both on reception and transmission, while the reception speed is, as a rule, up to 2 Mbit / s, and transmission – from 56 Kbit / s to 4 Mbit / s, which, of course, is not the limit: for the presence of additional modules, the speed can be significantly increased.
The marine VSAT system provides the ability to use satellite communications through the VSAT terminal, which is located on a ship at sea. Given the characteristics of the vessel’s movement in water, heading changes, and pitching, the antenna must be stabilized relative to the horizon and the true north, so that it will constantly move relative to the earth’s surface and thereby maintain its focus on the satellite that it uses to receive and transmit the signal .
Initially, marine VSAT systems used SCPC technology, which was mainly suitable for large consumers like drilling rigs and oil platforms, since the allocated frequencies were reserved for specific subscribers and could not be used by someone else when the subscriber did not need them. Later they began to use TDMA, a technology that allows several subscribers to access the carrier frequency through the use of different time slots. This led to a reduction in the cost of implementing VSAT systems for ships and tariffs.
Elements of the marine VSAT system
All elements included in marine VSAT systems can be divided into external (Outdoor unit, ODU) and internal (Indoor unit, IDU) units, which, in turn, also consist of several elements.
ODU includes antenna, BUC (frequency converter), LNB converter, polarization sector of the antenna and interconnect cable;
The IDU consists of an antenna control unit, a satellite modem and other additional equipment that may be needed on the ship – routers, servers.
All elements together ensure the operation of the system and the implementation of all the functions necessary for subscribers. It should be borne in mind that the installation of a marine VSAT is quite time-consuming and it is better to trust it to qualified specialists in order to avoid incorrect settings, which can interfere with the correct operation of the system.
Marine VSATs have been actively used on ships of Western countries for more than ten years, and for some time now Russian users have been paying more attention to these systems and are actively introducing them in their sea and river transport.
This popularity is due to the wide range of capabilities that the marine VSAT provides, as well as its advantages over other satellite communication systems used on ships. Providing high speed of reception and transmission, VSAT systems are also more cost-effective than their competitors, since VSAT tariffs for data exchange and telephony are very close to those used on land. All this provides the crew of ships and other people traveling on seas and rivers, the opportunity not only to exchange text messages, but also to send and receive heavier files (scans of documents, video and audio) – quickly and at an affordable price.
Marine VSAT can be used for communication at work, and for entertainment. The crew, managers, managers and representatives of other professions on board the vessel can use the usual features and services that are familiar to office workers while sailing:
Email and other business applications that require Internet access;
Conference call (both audio and video);
Traditional and VoIP telephony;
Distance learning using modern technology.