Interference Efforts Improve but Asia Situation Causes Concern
The mood between both the panel and the audience at the “Engineering Forum CTO Roundtable Breakfast for Radio Frequency Interference” was one of progress. The advances with Carrier ID have begun to yield tangible results in reducing the amount of interference between different satellite operators and their users. But while the feeling of progress was warm, the panelists assured that this was still the beginning, albeit successful so far, of the plan to fully eliminate interference.
Raphael Mussalian, CTO, Eutelsat began the panel with statistics about the propagators of satellite interference. He pointed out that approximately 94 percent of satellite interference is non-intentional. This makes the majority of interference easier to approach and solve. The remaining 6 percent are deliberate efforts to cause harm, which, in many cases, arise from political factors. Because of this spread, to truly end interference all satellite users need to be involved.
“We need the help of everybody: the government, international institutions and others,” said Mussalian.
It was clear that an environment of collaboration was encouraged, even between competitors. With the majority of interference coming from unintentional sources, the real focus needs to be on finding and correcting mistakes. Mussalian added that the majority of the attention given to interference falls on that 6 percent; a misrepresentation of the big picture, he said.
“About 76 percent of the events are caught in the first 15 minutes … and we are able to kill it very quickly after that,” Thierry Guillemin, SVP and CTO of Intelsat explained. “As soon as the customer knows they are causing interference, they stop. If we have the signature in the signal of where the uplink comes from and what operator it comes from … we can have it removed.”
The strength of Carrier ID is how it allows for sources of interference to be quickly identified. Carrier ID provides a standard for recognizing and identifying the sources of interference independently from where the source is located. Guillemin hopes that most of Intelsat’s firmware updates will be completed by the end of the year, and all of the company’s uplinks will be equipped with Carrier ID between 2015 and 2018.
One of the top challenges for Carrier ID implementation is the need to address every single ground system that poses a risk of interference. David Jupin, VP of Hughes’ international division, mentioned that his company currently has more than 800,000 user terminals installed, and they are adding more than 15,000 VSATs every week.
Hughes uses a variety of tools from the start to prevent interference from happening with new systems. One of the primary methods is onsite verification. In real time, Hughes is able to maintain contact with the installers and has set thresholds that must be met for the VSAT to operate. If improperly serviced, the device will not function, rather than functioning poorly. Furthermore, Hughes is able to run tests during off hours at night so they can take corrective action when needed.
Roger Tong, VP of engineering and operations at AsiaSat, discussed how the situation differs in Asia compared to Europe and North America. While Ka-band promises to offer a new wave of Carrier ID opportunities in these regions, Asia is not yet moving toward that part of the spectrum.
“When it comes to Ka spot beams, we are only experimenting right now,” he said.
Tong mentioned that people are largely unwilling to give up their privacy for carrier ID and that weather frequently causes issues for VSATs that are not sturdy enough to handle frequent precipitation. Furthermore, lots of old and outdated equipment, which cannot be remotely controlled, remains in use.
“We had a TDMA interference in our network,” he said. “It’s a very large network, only 2000 terminals, but it took us three months to find it. Building a satellite is much easier than dealing with ground interference. We need a lot of help on the ground systems side.”
According to Tong, a major focus of Asia needs to be on producing equipment that is “better, not just cheaper.” Asian operators have been focused primarily on RF performance at the expense of mechanical stability. When major storms come through, they can cause significant damage to existing infrastructure.
A challenge for Carrier ID globally is the high turnover rate of installers. Customers often see installation as a simple task rather than a complicated task. Ruy Pinto, CTO, Inmarsat mentioned that in as little as six months, a trained installer may leave the company, creating a gap that must be filled with a skillset that must be relearned.
A method that Inmarsat and others use in fighting interference is setting aside a certain amount of capacity for intermittent issues.
“We are very efficient in using that surplus capacity for moving around users,” said Pinto. “It costs money, but its something we do and it is worth it for our customers. It is an important mitigation measure.”
Guillemin commented on this solution, adding that while Intelsat does keep reserve capacity for this purpose, customers often do not want to move.
“Its one of the tools in the toolbox,” he said, “but reducing interference is better.”
Guillemin also discussed the advances in mobile terminals for vehicles like aircraft, calling the situation “better than you would think, given the circumstances,” but warned that the technology needs to be strengthened as it moves into regular use in these new settings. Tong also described mobile uses in Asia as “fairly positive,” though most mobile terminals on the continent are new.
A final major improvement discussed for mitigating interference was the use on geolocation equipment. Intelsat is refreshing its entire base of geolocation equipment over the next 12 months. This technology is very helpful in identifying sources of interference, but comes with concerns over privacy. This overlaps with the increasing use of mobile services, as when it comes to military applications they often do not want to be tracked. Respect of privacy and security are paramount for reducing interference, which sometimes comes from soldiers. Tong encouraged operators to work together, saying the need for collaboration is great in Asia. Additionally, several operators use small fleets, which limits the use of geo-location.
“It is like pulling teeth trying to get information from our neighbors,” said Tong. “How can we get the operators to work closer on a technological basis?”
Many of the panelists praised the work done by the Global VSAT Forum as well as the Radio Interference Reduction Group End Users Initiative for spearheading much of the work around Carrier ID. It was agreed that there is a noticeable deficit of Asian satellite companies included in these discussions. While encouraging work with these groups, many of the panelists encouraged AsiaSat and other Asian operators to join the Space Data Association, stating that it provides a “safe legal framework,” and that since it is not attached to a government, it has “no politics or bureaucracy.”