Beyond Ka: Supporting Future Telecommunications

The satellite industry is developing at a rapid rate. New applications are emerging all the time. Due to the fact that satellite can be used for so many applications, such as broadcasting, mapping, meteorology, Earth observation and much more, the rapid increase in use over recent years has resulted in a serious shortage of bandwidth availability in the lower frequency bands.

The industry has been talking about this congestion for quite some time now. We have seen the industry move into new bands, from C to Ku and from Ku to Ka. The move to Ka band is expected to relieve the pressure on available bandwidth as there will be much more available. However, with demand growing for higher throughput, and the advent of Non-Geostationary Orbit (NGSO) constellations, the industry is considering the future. Now, the time has come to assess the potential that lies in other bands that can help support the growing demand for applications that require high throughput today and in the future.

So, we move up the satellite spectrum to Q/V band. This is the next frontier in terms of satellite frequency bands and can open up new possibilities for the fast deployment of telecommunications infrastructure.

The Q/V bands lie between 33-75 GHz, within the Extremely High Frequency (EHF) area of the radio spectrum. These frequencies are used mainly for satellite communications, remote sensing, terrestrial microwave communications and for radio astronomy studies.

It is hoped that EHFs will enhance the performance of the next generation of High Throughput Satellite (HTS) programs by enabling the offload of satellite links between a satellite and its hubs from the Ka band to the Q/V bands. This would make more bandwidth available for users in Ka-band and would also reduce the number of hubs required. This, in turn, will help drive down cost per bit.

Written here, it sounds simple, but the EHF bands are prone to signal propagation, which is the effect that the different regions of the atmosphere have on a satellite signal. At millimeter waves, which travel solely by line-of-sight, the effects of this propagation can be significant. Therefore, mitigation techniques, such as ACM, will be necessary to reduce this degradation. This, however, would need to be achieved in a cost-effective way.

“Due to the higher atmospheric and rain attenuation in these bands, they will initially be applied for high-bandwidth gateway feeder links using larger Earth stations to [Geostationary Earth Orbit] GEO systems” explains Mark Spiwak, president at Boeing Satellite Systems International. “But the high bandwidth available in Q/V-band systems also makes them attractive for user and gateway links for Middle-Earth Orbit (MEO) or Low-Earth Orbit (LEO) systems, since these orbits have lower path losses.”

If the Q/V bands are exploited, they could open up the potential for a wide range of new products and services for both military and commercial applications. However, what kind of appetite is there for a move into these new bands and how ready is the satellite industry to make the move? As with Ka-band, there will be both technical and regulatory challenges, so is this a realistic possibility for the industry?

Initiatives are already underway to test transmissions in the Q/V bands. In March this year, Eutelsat became one of the first commercial operators to test Q/V-band communications on its Eutelsat 65 West A satellite. “Our objective is to gain advanced insight into enhancing the efficiency and cost-effectiveness of future high throughput satellites,” says Yohann Leroy, Eutelsat CTO.

In partnership with, Space Systems Loral (SSL), Eutelsat confirmed that it had successfully carried out transmissions in EHF using an experimental payload. This payload was included to analyze the potential of the Q/V band at 40-50 GHz and to monitor whether this could be an enabler for Terabit satellite broadband programs.

“We believe that Q and V bands will shape the blueprint of future broadband communications systems as these bands will significantly enhance the performance of the next generation of high throughput satellite programs,” continues Leroy.

The launch of Alphasat in July 2013 was a significant step forward in the development of the use of the Q/V bands by the satellite industry. The largest telecommunications satellite ever built, Alphasat hosted a payload built by Thales Alenia Space, for the Italian Space Agency (ASI). Called Aldo Paraboni, after the late Italian scientist that inspired it, the technology demonstration payload is the first to explore the Q/V bands at 38 and 48 GHz.

The payload is testing the performance of the broadband data traffic between stations in Q/V bands to assess the performance under the atmospheric conditions that can affect signals so negatively.

The job has now begun for scientists at ASI, to analyze the two sets of data from the two signals transmitted from the payload across Europe. The scientists are comparing their performances to determine exactly how they are affected by weather. The data will be used to model future broadband communications from geostationary satellites. It is hoped that the project will result in more available bandwidth and the possibility of smaller user terminals as further research is expected to eradicate the need for oversized links to compensate for signal degradation.

“Building a solid network of back-up terrestrial gateways is a condition to overcome Q and V band’s sensitivity to weather conditions,” says Leroy. “Solutions will need to be developed to switch from one gateway to another in less than 30 seconds and integrate weather forecast intelligence into the network.”

The research taking place is very encouraging for future telecommunications deployments. However, where does the wider satellite industry stand on this? As we are waiting to see how the Ka-band will shake out, is this really a priority at this point in time and something that the industry at large should be considering?

Spiwak believes that there is interest and that things could move into the Q/V-band area sooner rather than later. “There is certainly increasing interest among HTS operators,” he explains. “Moving gateway antennas to these bands frees up Ku-band and Ka-band spectrum for increased user capacity, allowing greater access to connectivity for these users.”

Satellite operator interest in new bands must be expected, as they must look so far ahead. The satellite business, for operators especially, is a long term one, and so future requirements need to be addressed far in advance.

However, for broadband communications provider Advantech Wireless, the move to Q/V band is only marginally on the radar. “We see them being used potentially as ‘feeder’ links to high throughput satellites,” says Steve Richeson, senior vice president of global sales and business development at Advantech Wireless. “The wide bandwidth available can provide efficiency in network architectures requiring a single hub station for an uplink to multiple independent spot beams. We are working with customers to keep an eye on the requirements for these bands. It is early days in the commercial deployment of these systems and there is no practical demand or solution today.”

The United States Federal Communications Commission (FCC) has recently passed its Spectrum Frontiers proposal, which will expedite the fast track of 5G services, the first of which could be seen as early as next year. The proposal stresses that the FCC will promote sharing schemes to ensure that different users are able to share spectrum. The FCC’s factsheet states: “It would also create a path for continued and expanded satellite operations in the 28 GHz, 37 GHz, and 39 GHz bands. It would adopt several mechanisms to provide flexibility to satellite operators and predictability to terrestrial operators.”

However, there is unease within the satellite industry, and great concern that satellite may not be given the best deal in the Q/V bands. After the fight for C-band at the World Radiocommunication Conference in 2015 (WRC-15), there is concern that the industry may have to fight yet again.

There is unease within the satellite industry, and great concern that satellite may not be given the best deal in the Q/V bands.

The FCC’s new rules provide access to 5G carriers in the satellite downlink band and that this will affect the placement of V-band gateways. “There are also proposed rules that may provide 5G carriers with access to the satellite uplink bands,” explains Spiwak. “Internationally, studies are underway at the International Telecommunication Union (ITU) to develop the process and rules to enable the successful coordination of the Q/V band between satellites and other allocated services.”

There is much potential for a clash of horns. The level of interest in the Q/V bands from some HTS operators is significant. Along with Boeing and Eutelsat, other operators such as Viasat, Inmarsat, OneWeb, O3b and Iridium are also taking great interest in and working on initiatives in EHF, and there is fear that access to the spectrum could be under threat if 5G deployment is favored over the needs of the satellite industry.

“In particular, the satellite industry is looking for an endorsement of the governments in 2019 during WRC-19 confirming the attractiveness for the satellite industry, to integrate these bands, through clear regulatory provisions, in the deployment of future satellite broadband solutions,” says Wladimir Boquet, director of spectrum management policy at Eutelsat.

It is important that dialogue is encouraged across all industries and agencies concerned.

“Boeing has been working closely with the FCC, the ITU, the Satellite Industry Association (SIA) and terrestrial operators to advocate the needs of satellite systems,” says Spiwak. “We are also working directly with terrestrial operators to understand the upcoming 5G deployments and to find ways to optimize satellite spectrum usage under these new regulations.”

The other main hurdle that must be cleared in terms of accessibility to Q/V band is the issue of cost and the new technology that must be developed to enable it. At present, the space and ground hardware required is not currently built at high volumes, so affordability is going to be key, but this will require considerable investment. “Cost will be a big challenge in terms of making these bands accessible. The cost of components needs to be reduced and volume needs to increase before yields can become predictable,” says Richeson.

This is a similar path to the development of commercial Ka-band that began a couple of decades ago. With the deployment of Ka-band systems still relatively new, it may seem a little premature to be discussing options on what happens next, but satellite operators in particular are keen to see the results of testing in the Q/V band. Their long-term businesses rely upon careful market predictions — trying to figure out what the level of demand will be in the future. If they don’t act now, and the HTS market does grow exponentially as predicted, the bandwidth will be required. Nobody wants to be left behind.

In terms of timeframe, there are different opinions out there as to how long this might take. For Boeing, construction of Q/V-band satellites could begin in the short term. “In addition to the experimental payloads already being flown, we expect to see commercial satellite orders using these bands operationally in the next six to 12 months,” says Spiwak.

Leroy, however, believes that “the conditions and timetable for adopting enabling technologies take us into the early part of the next decade.” And Richeson believes that access will take longer — between 10 and 12 years. “At the moment, there’s not much of an appetite — there’s a coming glut of capacity, but there are always niche applications that need more bandwidth,” he says.

So, with testing underway, there are varying levels of inclination to pursue these bands. However, there are clear benefits to be had from using them. Before this happens though, there are some serious hurdles to clear. VS