Prototype modems for satellite-based broadband connectivity matching the speed of terrestrial services relying on cables have been introduced by two European companies.
The modems, developed by an Italian company Space Engineering and Norwegian STM Norway, could enable anyone around the globe to have constant access to high-speed Wi-Fi without the need to build any infrastructure on the ground.
“Depending on satellite link budgets and other system design parameters, the modems can dynamically provide in excess of 20 Mbit/s download, and up to 5 Mbit/s or more upload,” said Stephane Combes, a communications engineer at the European Space Agency (ESA), who is overseeing the development.
“This is typically what a DSL or cable services offer, therefore the satellite service is able to match terrestrial competition, providing what end users would expect from their broadband service today,” he said, explaining the new technology offers a significant improvement on what satellite services have offered in the past.
To create the prototype devices, the companies have built on several technologies originally developed as a part of the European space research programme.
Higher-order modulations, for example, are mathematical methods, enabling squeezing greater amounts of digital data into the equivalent bandwidth. Advanced forward error correction schemes provide for redundancy of the systems while automatically identifying and correcting errors without the need for retransmission. Adaptive coding and modulation enables the system to respond in a dynamic way to the quality of the radio link and make up for temporary interferences such as rain fade. Internet protocol-friendly link layer encapsulation and efficient framing convert the signal data to Internet standards.
The prototypes have been tested in the framework of ESA’s Advanced Research in Telecommunications Systems( ARTES) programme before reaching the market readiness level.
“The technologies developed through these past ESA projects demonstrate far greater bandwidth efficiency, with particularly big gains on the return link – up to 250 per cent compared with previous generations,” Combes added.
The new technologies have now been incorporated into the newest Digital Video Broadcasting-Return Channel Satellite, DVB-RCS2, industrial standard published by the European Telecommunications Standard Institute.