Martin Coleman of the Satellite Interference Reduction Group (IRG) adds: “Interference wastes valuable resources and ultimately costs any user both time and money”.
However, the causes of interference are both preventable and rectifiable, agree Mr Hartshorn and Mr Coleman. Taking the human factor first, Mr Hartshorn says: “Interference due to human error happens for the most part due to lack of training. It stands to reason that an untrained operator will be likely to make mistakes.” But other factors, like the way the terminals are designed, can either help or hinder the issue.
Mr Coleman is in favour of getting as much automation in place as possible, because it tends to be less prone to inaccuracy: “Many of the services are unmanned auto-deploy systems which automatically send and receive signals. For the most part this works well, and some of these systems are built in such a way that they will switch off the transmission if there is any error,” says Mr Coleman, adding that other systems “will simply continue as normal and the error will go unnoticed until interference affects the service”.
Mr Hartshorn explains that there are good systems out there: “A few key manufacturers of auto-deploy systems have taken great care and pride in ensuring that their systems will only operate within specified parameters,” he says. This is an “absolute” in any auto-deploy system. Mr Coleman explains that Inmarsat and some of the newer VSAT systems have a closed-loop transmission control scheme that avoids this pitfall, but he adds that most other satellite systems have to be designed to be ‘open’ in capability. “However, most satellite networks are built to allow for a host of different technologies and thus have to cope with all types of signals and equipment topologies, video and data links included, generated by a wide range of services and uses.”
So, the satellite industry is working hard to combat the issue of interference and both GVF and IRG have a number of practical initiatives, including training, which are beginning to have a positive effect. In particular, GVF established the GVF Maritime Satcom Forum (MSF) in 2010 to facilitate more productive satellite sector engagement with shipping companies.
However, Mr Hartshorn points out that a further consideration is selecting the best systems from an increasingly diverse portfolio of satellite products. Although most are extremely good quality, some are not and are prone to failure. In short, there’s more room for initiatives like Inmarsat’s, which is extending its insistence on type approvals to terminal equipment (in coordination with the GVF Quality Products Framework), reducing the risk of interference caused by equipment failure.
