Co-existence of terrestrial and satellite comms

Can terrestrial and satellite services live in the same band, avoiding interference while maximising the value of the spectrum?

Life would be a lot simpler in a world where electromagnetic spectrum was an infinite resource. Most of the clutter and inconvenience associated with building and maintaining fixed networks would melt into the past as we surged forward on a harmonious, wireless wave of technological progress.

One of the drawbacks of being able to rewrite the laws of physics in this way, however, would be that it would rob us of the wonders of the ‘black art’ otherwise known as spectrum management.

One has to feel more than a little sympathy for the ACMA, which is charged with orchestrating the best and most efficient use of the spectrum available to Australians, in the national interest.

It is a fiendishly complex, constantly morphing and mostly thankless task. The landscape is littered with powerful interest groups all vying for a piece of the action and all utterly convinced about what they perceive as the primacy of their individual requirements.

Imagine having to navigate on a daily basis across the competing demands of television broadcasters, big telcos, the defence forces, the scientific and meteorological sector, national broadband operators such as nbn, cabinet ministers, satellite operators, state governments and emergency services agencies, the commercial radio industry, national surveillance and security agencies… to name but a few.

What’s more, having to do this in an environment where countries such as Australia need to attempt to harmonise with spectrum decisions being made on a global basis… all while also trying to anticipate how rapidly the relentless evolution of technology and services will render yesterday’s and today’s decisions obsolete.

It’s a nightmare, really.

In a bid to bring some sense of order to the chaos, the ACMA publishes each year its Five-Year Spectrum Outlook (FYSO) document. This is a weighty tome that seeks to lay out the terrain and the multitude of issues and considerations that will inform the debate and decisions on how spectrum is divided, regulated, priced and used in the Australian arena during coming years.

The ACMA is now deeply immersed in consultation with industry around the draft version of the next FYSO, to be published later in 2018.

Looming also is the long-awaited introduction of a rewritten Radiocommunications Act, the legislation that oversees the whole process. This promises a simplified and more agile spectrum licensing regime to address many of the long-held criticisms of the difficulty of doing business with government in this area.

The ACMA faces a daunting array of new and powerful dynamics that are shaping the industry. The demand for spectrum for mobile broadband is exploding, driven by year-on-year increases of 30% or more in the volume of data being uploaded and downloaded. The distinction between fixed and mobile broadband is increasingly difficult to discern. The impending introduction of 5G mobile technology will exacerbate these trends and complicate spectrum management further as mobile networks densify to accommodate higher data loads.

And now the Internet of Things (IoT) is arriving, with the potential to tip the whole circus on its head. Increasingly we will see IoT-based networks and applications using thousands, even millions of sensors in a single network — all with a requirement for wireless connectivity that is affordable and narrowband in nature. So, it’s a challenge pretty much the opposite of the ‘broadband is good’ mantra that the nation has embraced during the past decade.

Meanwhile, massive new investments are being made around the world in new satellite technologies, many of them designed to operate at low and medium orbits with the objective of providing global or regional broadband services at low latencies that can better compete with terrestrial broadband. The O3B satellite network is already in place, providing broadband services to customers that are among the ‘other 3 billion’ people in tropical regions either side of the equator. The OneWeb network is close to launch and Elon Musk has incredibly ambitious plans for his Starlink project — a constellation that could one day use almost 12,000 small satellites to provide global broadband services.

More traditional geostationary satellite operators are also experiencing strong growth in their businesses, but have the misfortune of being squarely in the sights of terrestrial mobile broadband providers, who want to capture growth territory in frequency bands that are being used for satellite services.

This has focused debate on to what extent co-existence is possible — in other words, which frequency bands can be used in ways so that terrestrial and satellite services can live alongside one another in the same band, tailored and managed to avoid interference while simultaneously maximising the value of the chunk of spectrum and the number of end users it can service?

Current interest is focused in the so-called ‘millimetre-wave’ bands above 24 GHz, where ka-band satellite services and other applications exist, and where spectrum is being sought (both in Australia and overseas) for 5G applications.

Earlier decisions have seen the reallocation of spectrum for 5G in the 3.6 GHz band — a move that will displace some satellite players and wireless service providers.

The argument goes that 5G services and IoT-based services — the next two great global disruptors — will not succeed fully unless there is some complementarity between what operates in space and what operates on the ground. Hence the perceived urgency of the task.

Early industry feedback on the ACMA’s latest work in the spectrum space — as reflected in the draft 2018 FYSO — has been positive. It will take a strong collective effort by a host of stakeholders to solve the riddles in full.

Please follow us and share on Twitter and Facebook. You can also subscribe for FREE to our weekly newsletter and bimonthly magazine.