The success enjoyed by the commercial satellite sector over recent decades comes as no surprise to the engineers, technicians and managers who have been contributing to its remarkable growth by providing customers with accurate and reliable services around the globe. Yet, to the uninitiated, satellites can still be seen as daunting technology, perhaps because of the extreme environment in which they operate. Naturally, nothing could be further away from the truth. The continuous effort in the development of state-of-the-art technology in both the space and Earth segments, and the adoption of built-in redundancy at almost every level, make sure that satellite networks today support services that enjoy unmatched reliability.
In our experience, episodes of signals from unauthorized carriers and of cross-polarization make up 70 percent to 75 percent of radio frequency interference cases plaguing satellite operations. — Guillemin, Intelsat
But while satellite reliability and use have grown in parallel, there is a rise in the incidents of radio frequency interference reported each year. “Incidents of interference occur constantly all over the world. Large satellite fleets can experience up to 100 interference events a month,” says Thierry Guillemin, Intelsat’s CTO. “A majority of incidents are attributed to faulty ground terminals installation practices, uplink errors and poor equipment maintenance regimes,” he says. And Intelsat’s experience, of course, is far from being unique among satellite operators
While the severity of these events varies greatly, ranging from slight signal degradation to full outage, it is not difficult to understand why they can create problems to satellite operators and their customers. Radio interference disrupts data transmissions and degrades television signals being delivered via satellite, hindering both the smooth delivery of services and their quality. As a consequence, radio interference has a negative effect on business for satellite operators and their customers. While difficult to assess with precision given the erratic nature of the problem, the economic consequences of radio frequency interference are believed to be severe. According to analysis carried by the Satellite Users Interference Reduction Group (SUIRG), a global organization dedicated to combating this problem, satellite operators can suffer from hundreds of thousands to millions of dollars per year in lost revenue and additional manpower required to investigate episodes of radio frequency interference.
“Ultimately, radio frequency interference disrupts television signals, data transmissions and other customer services, hindering business growth,” says Guillemin. “This affects us as well, of course. As operators, we also have to troubleshoot and try to fix them as soon as possible.”
Radio frequency interference has many causes. Among the most important ones are the use of faulty equipment, often due to poor manufacturing quality or unmet performance specifications, and lack of industry standards and guidelines on equipment use. However, it is operational issues that make up the most widespread cause of radio interference. Typically, these include the reduction of orbital spacing between satellites and the unauthorized use of satellite space segment by carriers. The field experience of satellite operators such as Intelsat seems to confirm this.
“In our experience, episodes of signals from unauthorized carriers and of cross-polarization make up 70 percent to 75 percent of radio frequency interference cases plaguing satellite operations,” says Guillemin. “To this number, you should add a 15 percent to 20 percent of cases caused by adjacent satellite interference.”
Issues such as interference from unauthorized carriers and cross-polarization should be considered only as manifestations of the problem. The root cause of the majority of these episodes can be traced to the human factor, and the vast majority is unintentional — i.e., someone, somewhere making a mistake with the equipment, says Robert Ames, president and CEO of SUIRG. The human factor can take the form of lack of or insufficient training for staff, decrease in knowledgeable workforce due to staff turnover, as well as poor equipment installation and lack of routine maintenance.