The satellite and 5G communities have an ambivalent relationship. On the one hand, there are interesting developments which could integrate the two technologies far more effectively to boost overall capacity and coverage. On the other, the two groups remain at loggerheads over certain spectrum bands, traditionally occupied by satellite but now coveted for cellular.
On the former side, a good example is the SaT5G project, launched in 2017 with funding from the European Union’s Horizon 2020 program, with the goal of developing plug-and-play satcom systems for 5G in which the two technologies cooperate, and are orchestrated in the same virtual networks, to facilitate applications from backhaul to inflight connectivity to hyperdense video.
On the latter front, the GSMA has fired the latest salvo in the spectrum wars which usually escalate during the run-up to a World Radiocommunications Conference (WRC), the events at which global and regional allocations for wireless spectrum are established. The next WRC will take place in Egypt at the end of October, and the GSMA has issued a pre-emptive strike by warning the satellite industry not to erect barriers to 5G services in millimeter wave bands between 24 GHz and 86 GHz.
The mobile operators’ trade alliance said: “Some in the space industry are determined to limit mobile use of airwaves that 5G requires to reach its full potential. This protectionist attitude is ringing alarm bells throughout the mobile communications world.”
There are already tensions about the most important band for early 5G deployments, the C-band around 3.5 GHz (3.4-4.2 GHz), but the next battleground will be higher up the spectrum. The GSMA argued that the full socio-economic potential of 5G could not be achieved without full access to the mmWave airwaves.
In its report, it argued that releasing 5G mmWave capacity would create $565bn of economic expansion, or an additional 2.9% of global GDP growth, by 2034, with a disproportionate impact on emerging economies. Its research calculated that the GDP boost for sub-Saharan Africa during the period would be worth $5.2bn, while in south east Asia the figure would be $45bn, and in Latin America, $20.8bn.
“We can’t let misinformation and the overly protectionist attitudes of the space industry derail the 5G revolution,” said Brett Tarnutzer, head of spectrum at the GSMA. “Over-stringent protection will limit the spectrum needed for 5G and have huge consequences for society. This could put the economic and innovation bonanza accompanying ultra-fast networks on hold for a generation. Billions of citizens are counting on more innovation and more investments in their future economic prosperity to improve their lives.”
The outburst seems to have been prompted by an attempt by two US space bodies – the US National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA) – to prevent the FCC auction of 24 GHz spectrum, on the basis that it could jeopardize the accuracy of weather forecasting.
The FCC’s chairman, Ajit Pai, said no concrete evidence had been presented and proceeded with the auction, saying: “The Commission’s decisions with respect to spectrum have been and will continue to be based on sound engineering rather than exaggerated and unverified last minute assertions.”
But the issue is not settled. From December 10, the FCC will move on to auction spectrum in other mmWave bands including Upper 37 GHz, 39 GHz and 47 GHz, which will be the largest auction in US history in terms of the quantity of airwaves on offer (3,400 MHz). But these sales, and similar ones elsewhere as other countries start to free up mmWave bands, are sure to provoke further protests from space and satellite players.
So far, these arguments have not reached the intensity of the C-band debates, but they may do so as the mmWave spectrum becomes more desirable to mobile operators round the world, and not just in the few countries which are currently using it, like the USA and South Korea. Presumably this is why the GSMA decided to go on the warpath proactively, making its case before any international, coordinated campaign might materialize from the space industry, especially ahead of WRC-19.
Certainly, the FCC has become less conciliatory towards the space industry as the mmWave bands have become more commercially attractive to its operators. When it set out its Spectrum Frontiers program in 2015, it was very reluctant to clash with the satellite industry and was careful – as was the WRC-15 conference when it set out its mmWave candidate bands for 5G – to avoid outlining plans which would create direct conflicts with satellite.
Indeed, in 2015, two of the commissioners complained that the FCC should have included more bands, including 24 GHz, 32 GHz, 42 GHz, 70 GHz and 80 GHz, and had instead left “thousands of MHz of spectrum on the cutting room floor”.
But now the high frequency spectrum is in such high demand that it will be impossible to please both industries. The US operators’ representative body, CTIA, has already called on the FCC to allocate almost all the spectrum 24 GHz to 50 GHz to mobile broadband, and support shared access in the 70 GHz band. It proposed squeezing the satellite players into part of the 50 GHz band, on the basis that (it claimed) their current frequencies were underused, and letting them keep the 81-86 GHz band for uplink capacity.
The Satellite Industry Association (SIA) responded by saying such a plan would represent “an unjustified and unsustainable abandonment of the Commission’s long-standing commitment to the principle of technology neutrality”.
If the C-Band example is anything to go by, satellite industry opposition could lead to a prolonged and acrimonious debate ahead of the December mega-auction, and could even delay the whole process by years; and similar disputes will emerge in other regions too.
Pai is keen to rely on a combination of spectrum sharing, and incentive auctions like the one that saw broadcasters making way for 5G in 600 MHz, to enable satellite/terrestrial coexistence. A big step in that direction, with global impact, came last October when the C-Band Alliance was formed to support a compromise solution in the midbands, backed by four satellite operators, SES, Intelsat, Eutelsat and Telesat. This quartet, whose members occupy the vast majority of satellite C-band services in the USA, effectively gave the green light for establishing a technical framework to give MNOs access to spectrum in the 3.7-4.2 GHz band.
This is working on the key technical and commercial steps necessary to enable implementation of the spectrum clearing process. Earlier in the year, SES and Intelsat had submitted plans to reallocate 100 MHz of C-band spectrum in which many fixed satellite services (FSS) downlink sites operate – a proposal which was criticized by Google and the Broadband Access Coalition for not being directly applicable to point-to-multipoint (P2MP) coexistence, and therefore missing an opportunity to bring gigabit-class broadband to millions of Americans.
The CBA claims it will enable spectrum clearing in such a way that protects incumbent users and their content distribution and data networks in the US from potential interference. This aims to cement the FCC’s Notice of Proposed Rulemaking published in the Federal Register at the end of August. Essentially the CBA has been formed to protect the quality and reliability of the extensive services currently provided by satellite operators in C-band, enabling terrestrial mobile operators to quickly access a portion of the band. This hopes, in turn, to bring faster deployment of 5G services without interfering with the operations of broadcasters, media companies and data firms in C-band.