Unpacking Antenna Developments for the Multi-Orbit Era

In this new, multi-orbit era, some satcom customers are demanding unprecedented network resiliency. Users want fully integrated terminals to enable true multi-orbit mobile connectivity. For users demanding the ultimate redundancy, a single terminal able to seamlessly switch between Low-Earth Orbit (LEO), Medium-Earth Orbit (MEO), Geostationary Orbit (GEO), and Highly Elliptical Orbit (HEO) and terrestrial networks is the answer. These multi-orbit terminals coming to market boast sleek, flat panels and lower-profile designs. They have a small footprint but their capabilities are enormous.

Multi-orbit use cases are cropping up within the premium segments, encompassing military/defense, high-stakes enterprise, government aviation, and business aviation. In short, it’s any user from the premium markets where there is no margin for reliance on one network, and where there is no physical space for multiple systems. These users want true redundancy and are comfortable with terminals that are sleek but larger than LEO-only antennas.

Via Satellite spoke with experts in the terminal and mobility space about the evolution of antennas for the multi-orbit era.

Military Sleek

In the first quarter of this year, Kymeta released to market the Osprey u8 HGL, a hybrid GEO/LEO electronically steered terminal for military communications on the move (COTM). Building on its Kymeta u8 portfolio, the u8 HGL integrates multiple modems – a GEO modem, a OneWeb LEO modem and a cellular modem – into its low-profile terminal.

“The dimension is set by GEO operation. We took the capabilities of the Osprey HG and Hawk GEO products and layered this with LEO capabilities. It’s larger in size than a Starlink antenna but is still small enough to be integrated on cars,” says Lilac Muller, vice president of Product Management at Kymeta Corporation. “The laws of physics can’t be changed, but technology and capabilities do evolve.”

Part of this evolution is in network requirements, explains Muller. Operators want network efficiency, maximizing the value of the bandwidth they have in orbit. End users want a resilient broadband connection based on various use cases. At the same time, GEO networks are also starting to understand that flat panel antennas behave differently. This is happening while LEO is disrupting GEO, leading to operators looking at their capacity in fresh ways. GEO operators who have tremendous capacity in orbit and a great value proposition want to offer their customers the best of both GEO and LEO worlds. This type of multi-orbit service requires rules-based switching between networks that can be improved by AI and machine-learning algorithms over time. These will help switching to evolve, giving the customer the resilient connection that they need.

Starlink made waves this summer with the announcement of Starlink Mini, a small Starlink terminal with an integrated router that runs on battery power. While Starlink terminals take a LEO-only approach, Muller stresses the benefits of blending the orbits for certain use cases.

“This is not only from GEO and LEO, but cellular, too,” Muller says. “GEO, LEO, and cellular are all blended and managed in a transparent manner for the customer. Some customers really need a higher level of resiliency, and these terminals are more sophisticated. While these will get smaller, we really can’t think of them in the same way as a Starlink or Kuiper [terminal]. They simply have a different value proposition. This is what we do – we take the benefits of cellular, LEO and GEO and we put them in a single package. We don’t want customers to even think about it. Connections shouldn’t be an issue for them; they should just know it works.”

The other part of the evolution is taking place in-house at Kymeta. The u8 HGL is second-generation technology. Tracking its GEO products and then its LEO products, Kymeta’s combining these capabilities to meet ultra-resilient network demands seems like a natural progression. Is it safe to assume that the next-gen multi-orbit terminals will be even more compact with heightened capabilities? While not yet ready to reveal anything, Muller hints that noteworthy developments are underway.

Low Profile for Aviation

With a seemingly avant-garde “every orbit to every seat” motto, ThinKom is a multi-orbit player and has been so for a number of years — its ThinAir Ka2517 terminal has been available in the market since 2018. The terminal developer has been waiting for Ka-band LEO operators to catch up with Starlink and OneWeb, the only two LEO systems currently available, both of which operate in Ku-band. When these new Ka-band LEO systems come online, namely Amazon’s Project Kuiper and Telesat’s Lightspeed, they’ll be compatible with the Ka2517 terminal, along with the likes of O3b mPower’s MEO constellation and Inmarsat’s GX10A and GX10B satellites that are designed to operate in HEO.

The mechanically steered single-beam ThinAir Ka2517 is a “Type 4” antenna, a classification for the satellite-based aero antenna market made by the Seamless Air Alliance Architecture/Interoperability group. Chaired by Airbus and Boeing, the group’s Type 1 means GEO-only, Type 2 means LEO-only, and Type 3 is hybrid with limited GEO coverage while Type 4 is hybrid with full GEO coverage.

For flights in need of both LEO and GEO, a Type 3 antenna just doesn’t cut it, explains Bill Milroy, chairman and CTO at ThinKom Solutions, Inc.

“They’re not going to work with GEO when you get north of 50-degree latitude — that’s north of Boston, Chicago, or London. They just can’t perform – the performance starts off so low, that by the time they’re looking down to 37-degree elevation, they’re unreliable,” Milroy says.

Milroy believes a multi-orbit solution will win out as the best option for in-flight connectivity (IFC) service.

“While some applications can be supported adequately by LEO, GEO will remain the backbone of IFC,” he says. “When customers understand the limitations of LEO regarding density, there will be a strong true multi-orbit trend play out in the next 12 to 18 months.”

The ThinAir Ka2517 has already been adopted by mainline airlines, but installations have been done in two separate radomes. According to Milroy, some players, such as Hughes Network Systems, are, in the nearest term, envisioning pairing the Ka2517 (or ThinKom’s Ka1717) together with a separate tandem-mounted Type 2 electronically steered array (ESA) in its own separate radome. An example of this multi-radome approach is in Hawaiian Airlines which made history this February as the world’s first major carrier to deploy Starlink’s high-speed, low-latency broadband internet.

“Hawaiian installed two radomes with talks about having up to four. We just don’t think that’s practical. We believe a fully integrated system is the easiest way to go,” says Milroy. “ThinAir also allows you to fuse low-latency LEO and high-density/high-bandwidth GEO together. This means you can operate simultaneously on two different networks, allowing passengers to enjoy seamless connectivity as latency-sensitive traffic, which typically represents 10 percent, is routed over LEO, and the remaining 90 percent of high-capacity traffic, such as streaming and video, is routed over the much higher bandwidth GEO service.”

ThinKom is also launching ThinAir Plus, a fully integrated, multi-orbit, multi-constellation and multi-beam hybrid solution. It includes the Ka2517 antenna – giving customers the Ka-band connectivity in LEO, MEO, GEO and HEO – as well as the Ku-band LEO-only ESA, adding compatibility with the current LEO networks.

Linefit Offerability & the Case for LEO Only

Other satcom players bringing multi-orbit, multi-beam ESAs to market include Stellar Blu, Gilat Satellite Networks, and Get SAT. Stellar Blu is developing a multi-beam version of its first-generation Type 3 multi-orbit Sidewinder ESA for commercial aviation. The next-gen Sidewinder will retain the current fitment as its secured linefit offerability with Boeing, and to keep Stellar Blu’s radome-free ESA positioning as an easily retrofittable solution for carriers. This package is being used by Intelsat and Panasonic Avionics to support their nascent multi-orbit IFC services, leveraging their GEO networks together with OneWeb LEO service.

Get SAT will be supplying in-flight entertainment company Safran Passenger Innovations with its Type 4 Ku-band Aero LESA terminal (an ESA) that will be delivered linefit on Airbus aircraft from 2026.

“Linefit has a huge role to play in the success of a system, impacting whether it’s deemed ‘right’ for the market or not. In short, in commercial aviation, if an antenna gets linefit, it’s huge.” says Daniel Welch, co-founder and senior researcher at mobility-focused firm Valour Consultancy.

“At this point in time, I see these multi-orbit terminals gaining traction because they are being linefit. But I have also seen the need for the LEO-only antenna,” adds Welch, referencing Hughes and Starlink. “There are airlines that consider the coverage from LEO-only capacity as good enough and see the value of having a very discreet, low-weight antenna that fits into the ARINC 792 standard provisions. This makes them comfortable with the LEO-only play, and I believe we will see this desire for really small, easy-to-install antennas dominating in the next five years.”

With the likes of Amazon’s Project Kuiper and Telesat’s Lightspeed on the way, the market is going to be inundated with LEO-only capacity. This, notes Welch, will be convenient for narrowbodies and regional jets that are looking for a small-form factor antenna.

Maritime’s Expansive Real Estate

In maritime, particularly in the cruise market, taking a dual-system approach is commonplace, notes Welch, adding that similarly to widebody fleets in aviation, maritime has the space available to do it. Here, the focal point has been to blend capacity from multiple networks together seamlessly.

“The smart edge network architecture allows the platform to receive and direct traffic based upon priority, type, varying tiers of premium customers, and higher profile crew. These smart networks allow the platform to do this more effectively than we’ve seen before. These capabilities have been something of a game changer. We anticipate seeing this become increasingly prevalent in the aviation world soon,” says Welch.

While two systems seem to meet demand in the cruise sector, more broadly in the general maritime market, single-orbit solutions are still optimal, adds Welch. “We expect to see a significant volume of land mobility and maritime move into LEO-only. There are a multitude of use cases – notably in land mobility, with buses, surface mining and autonomous mining as examples – where LEO only, or a LEO hybrid network with cellular, works perfectly well.”

The Journey to Multi-Orbit

For critical missions and high-stakes operations, industry players say a multi-orbit solution is the only way to go. To make this possible, tech providers have to navigate the complexities of software-defined modems (SDM) and the lack of interoperability between networks. A challenge is that each network has its own waveform and modems – there is not a universal solution that works across them all.

At the same time, while SDMs offer flexibility and adaptability, they also add complexity around seamless integration across multiple orbits; dynamic configuration that requires sophisticated algorithms and real-time processing capabilities; increased hardware requirements to support a wide range of signals and frequencies; regulatory compliance; and network management.

While the Digital Intermediate Frequency Interoperability (DIFI) Consortium, comprising multiple satellite industry stakeholders, is committed to solving interoperability challenges, the satellite industry still has a way to go before it reaches connectivity nirvana.

“While the satellite industry is making progress, it’s still a far way off from where the cellular industry is with interoperability. Today, I can land just about anywhere in the world, turn on my phone, and it just works, as if miraculously. It took decades, but they achieved standards-based interoperability. The satellite industry isn't there yet,” says Kymeta’s Muller.

Realizing a standards-based modem could see the costs of multi-orbit terminals come down and the number of use cases go up. Until then, however, the ground segment will continue to evolve in line with technological advancements and shifting market needs. VS