What Is a VSAT Satellite Communication System?

VSAT satellite communication systems, as an important communication system, are no longer unfamiliar and are widely used in land communications. However, their application on ocean-going vessels is limited due to high communication costs, international conventions favoring GMDSS systems, and a general lack of sufficient understanding of VSAT by the crew onboard. As a result, VSAT has yet to be fully recognized and accepted in this context. Even on vessels that use it, there are issues such as incomplete ship intranet setups and underutilized system functions in maritime mobile communication applications. The VSAT satellite communication system has enormous potential for applications in ship-to-shore information exchange, internet services, remote technical guidance, video transmission, ship-to-shore medical collaboration, remote maintenance of marine facilities, and real-time updates of electronic nautical charts. Therefore, its application to ocean-going vessels has significant research value.

What is VSAT Satellite?

Very Small Aperture Terminal (VSAT) is a type of satellite communication equipment, usually referring to satellite communication earth stations with terminal antenna diameters of about 1.2 ~2.8 m. It is an IP satellite communication terminal device developed in the early 1980s. Due to its strong flexibility, high reliability, ease of use, and the ability for small stations to be directly installed at the user end, VSAT systems have seen widespread development in recent years.

VSAT System is a great choice for dedicated long-distance communication systems. Using a VSAT user data terminal, it can directly connect to a computer network, performing communication tasks such as file transfer, image transmission, and more just like a ground communication network, without the need for intermediate ground relay stations.

Main Features of VSAT System

  • Equipment is simple, small in size, and lightweight. Depending on the usage conditions, the diameter of the small station antenna can range from 0.6 ~4.5 m. The terminal part is also very small. In the relatively cramped space on a vessel, the equipment layout can be completed well. Additionally, installation, maintenance, and operation are simple and convenient.

  • Flexible networking and convenient connections. The network components are modular, making it easy to expand and adjust the network structure. It can adapt to the growth of user business volume and changes in user requirements.

  • High communication efficiency, good performance quality, and high reliability. The communication capacity can be adaptive, suitable for various data rates and business types, and can form an ISDN network.

  • Can establish direct circuits facing users, especially suitable for remote areas with dispersed users and low business volume, as well as private and public communication networks with widely distributed user terminals.

With the rapid development of VSAT technology, it has now extended the communication range of ground networks to the vast ocean, providing satellite-based broadband communication services to shipping companies and vessels, becoming a new communication solution between ship and shore. As a new member providing maritime communications, VSAT system is increasingly gaining attention and popularity due to its higher speeds and lower costs.

Currently, maritime communication methods include long wave, very long wave, short wave communications, the Inmarsat system, Yaogan Satellite system, Suya satellite system, and VSAT system using fixed satellite service frequency bands. Traditional communication methods have become a bottleneck in modern communications due to limited bandwidth and single communication modes. In the vast ocean, voice communications, data transmissions, and wide-area network access between ships and shore, and between ships, are effective measures to ensure maritime safety, improve crew operations, and enhance crew work efficiency. The VSAT  antenna and ship station utilize the Ku band transponder to establish a dedicated ship communication network with the central station, applying the more mature VSAT technology used onshore to vessels, potentially solving the above issues.

Onboard VSAT System facilitates the establishment of ship-to-shore communication networks. Ships can communicate one-on-one, and shipping companies can communicate duplex and broadcast with multiple vessels they manage. VSAT System operates from C-band, evolving to Ku band, and further to Ka band, offering significantly broader bandwidth compared to L  band. Looking at future trends, VSAT will be used for broadband regular communications, while the Inmarsat system will mainly be used for narrowband emergency communications and backup communication devices.