Several years ago, the broadcast industry came to satellite operators with one request – to solve the problem of satellite interference, particularly to satellite news gathering (SNG). To that end, Carrier ID was born, and many of us believed that would be the best fix for SNG transmissions.
But, undoubtedly, CID has faced numerous hurdles throughout its adoption, not least because of a reluctance from broadcasters to get on board, either due to equipment upgrade costs or a change in the way broadcasters do business. On top of this, SNG, as we know it, has gone Mobile, VSAT and IP. As a result, Carrier ID hasn’t been the whole solution as many had hoped for.
Martin Coleman, Executive Director, IRG
Why should we care?
Satellite interference is a persistent problem across the globe and for broadcasters, interference can be more than just a nuisance if it comes to hamper the provision of content to customers. Some might say that incidences of interference occur so infrequently that they do not cause a big enough problem to warrant solving. The crux of this argument does not, however, align with the fact that almost everyone watching television in the world is dependent upon satellite services either directly or indirectly for the channels they watch. It’s mission critical for broadcasters that the playout of content is never hindered, as their revenue stream is wholly based upon consistent playout of content and advertisements, particularly for live transmissions. Any errors are likely to lead to an impact on the ‘User Experience’ and a loss in revenue.
Nigel Fry, Head of Distribution, BBC Global News
Having established that interference is a palpable threat to broadcasters, one might wonder why they haven’t taken up the gauntlet themselves. According to Nigel Fry, Head of Distribution at BBC Global News, “interference is affecting a greater number of broadcasters than in previous years [as well as more] companies from outside of the Middle East region”. Evidently, if broadcasters themselves have identified that interference is a growing threat, it seems reasonable to assume they would want to solve it. But Nigel goes on to explain that “broadcasters, in common with other businesses, seek to minimise their annual costs. A desire to maximise equipment life works to counter the introduction of Carrier ID”.
Michael Downey, Co-founder and CTO, Glowlink Communications Technology
All new equipment must now be equipped with Carrier ID, but what Nigel outlines here is the fact that many broadcasters will not see the value in replacing healthy and functioning equipment purely for the sake of adopting CID. Let’s not forget that for some causes of interference, Carrier ID is not helpful. In the case of an uncooperative user where the ID is unavailable, as is often the case with a jammer, it is all but useless.
Interference does not, as a rule, occur frequently. But as Michael Downey, Co-Founder and CTO at Glowlink, said, “when it does happen, it is very disruptive and generally difficult to track down and even harder to resolve”. As mentioned above, intentional jamming for political reasons is one of the causes of interference most difficult to identify and prevent, mainly due to its unpredictability. One of the worst effects of intentional interference, and why it’s usually so disruptive, is that all of the services transmitted via a multiplex are affected, even if only one channel in the multiplex is being targeted. This often means 10 or 11 individual services can become un-viewable.
In fact, Bob Potter, VP Signals and Ground Systems Technology at Kratos, went as far to say the following: “I’m not sure there is a preventative cure for deliberate interference of broadcast satellite communications, aside from solving the world’s geo-political issues, which is the main reason for attacks on broadcasters. But it has to be said these types of events are rare and the major issues are from failing hardware or human error”. The issue of human error is a hot topic of conversation at the moment. Unfortunately, many remote broadcast stations are unlikely to have a satellite engineer to hand, so are less likely to spot potential errors before they develop, leading to larger and more disruptive issues.
Bob Potter, VP Signals and Ground Systems Technology at Kratos
As gloomy as the current situation may seem, sectors across the satellite industry continue to work on new technologies and initiatives to counter interference, some of which are available now.
In the real world, completely reducing the likelihood of human error is challenging. Even with increased training for staff, broadcasters will no doubt experience some degree of interference as a result of hiring new, inexperienced staff. The key to tackling this type of interference perhaps lies within the automation of systems.
Roger Franklin, CEO of Crystal, believes that “most interference is caused by human error, so naturally the more we automate, the more we can reduce the chance of error, meaning the amount of interference will be instantly reduced. Automation is also important for reducing other types of errors, not just interference, making processes much more efficient, as well as requiring much less manpower to operate”.
Automated systems are capable of tracking most of the parameters for ensuring interference-free playout, namely accurate alignment of antennae, correct frequency and precise levels of power transmissions at the correct time of day. As a result, the nth degree of accuracy available from automation drastically reduces human error. A sophisticated system should also, according to Bob Potter, “be capable of identifying any interference that may be present, even at very low levels, and recover the CID or VSAT terminal ID, so that problems can be resolved before they become a major headache”.
Roger Franklin, CEO, Crystal
Alongside automation, 24/7 monitoring of said systems can go a long way to reducing interference. Consistent monitoring can enable broadcasters to spot when a piece of equipment is unable to function or when, for example, a terminal is out of alignment. Ultimately, if interference issues can be resolved before the effects trickle down to consumers, then we’re half way to prevention already.
Roger Franklin also added: “although tools to rectify interference once it has occurred will remain important for unexpected interference, such as jamming, prevention is much more feasible than a cure. Automation and continual monitoring can drastically reduce errors occurring in the first place, making transmissions much more efficient, which ultimately saves time and money, but more importantly keeps users connected wherever they may be operating from”.
Although intentional interference, or jamming as it is sometimes known, is not a frequent cause for concern, it happens to be one of the most difficult to solve. Clearly, intentional jammers do not wish to be detected and so will not display their ID, therefore dismissing the usefulness of CID. Secondly, intentional interference is unpredictable and difficult to prevent before it occurs, meaning most occurrences are usually very disruptive.
Geolocation manufacturers have been working towards increasing the accuracy of systems so that jammers’ locations can be detected to a very small margin. Aside from this, as Nigel Fry told us, “at present, most solutions we at the BBC employ for the mitigation of intentional interference are tactical with respect to the choice of uplink frequency and location”.
The tactical solutions mentioned by Nigel can be extremely affective in terms of jamming. If broadcasters choose to do so, HTS alongside Ka and Ku band now allow uplink transmissions from a separate beam in a wholly different location. As we have already established, most intentional jamming tends to be associated with political turmoil, which is often the case in the Middle East region. For a broadcaster who is aware of the potential for jamming and looking to deliver content into this region, they can instead choose to send that content via a terrestrial connection to a location where interference is unlikely. This can then be uplinked from a safe location, and downlinked into the desired region.
Another option available is the possibility of grouping together many services on one uplink frequency. If a jammer recognises that an uplink contains a multiplex of services including one they do not want to lose, they will be less likely to interfere with its transmission for fear of losing the entire bouquet of channels.
Evidently, technological developments are lacking in the jamming department. But many in the industry see advancements in modem technology as a potential solution to jamming as well as accidental interference. If the main disruptive property of intentional interference is the impossibility of preventing or predicting an attack, then mitigation solutions should logically lie within automatic resistance instead.
“In the future, broadcasters will be able to purchase new satellite modems with built-in interference resistance, which will allow them to survive even high power co-channel interferences. Up to this point, nobody believed this was possible”, added Michael Downey. “This will enable broadcasters to survive the majority of interference events without breaking a sweat, while the satellite operator works to find the source of the interference using either geolocation or Carrier ID. The key is that the broadcaster can continue broadcasting completely oblivious to these interference events, while the satellite operator works to remove the interference as it is still robbing power from the satellite transponder.”
Nigel Fry also added that the BBC is “supporting industry developments regarding modem technologies that could help counter intentional interference to uplinks”.
It seems that prevention is the pot of gold at the end of the rainbow, but for some forms of interference, it simply isn’t possible. The most likely solution will probably be, as Bob Potter believes, embedded techniques or after-market products whereby broadcasters can still receive signals even in the event of interference rather than a system which completely prevents interference from happening.
Where do we go from here?
Evidently there are initiatives and technologies available to assist broadcasters as they continue to deal with the issue of interference, but they seem to lack viability. More worryingly, many industry professionals recognise that interference is a growing problem, and one which is likely to get worse as advancements in technology create new standards of complex waveforms that are more susceptible to interference. Competition for spectrum, as well as an increased growth of VSAT terminals is highly likely to increased incidents of interference unless suitable control measures are put in place.
Technology is advancing, so it is feasible to imagine a world where interference is highly infrequent and out-of-the-ordinary. Although there may never be one silver bullet to fix all, the satellite industry and in turn, the broadcasters, are now given more choice as a result of these technological advancements. It may be the case that a combination of these will be key to forming a workable solution for all.
Martin Coleman will be moderating a panel at NAB Las Vegas titled “Is Technology Actually Solving Interference for the Broadcaster?” Joining him on the panel will be Nigel Fry, Head of Distribution; BBC World Service Group, Michael Downey, Co-founder and CTO; Glowlink, Roger Franklin, President & CEO; Crystal Solutions, and Bob Potter, VP Signals and Ground Systems Technology; Kratos Defense.
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