Space is becoming more dynamic than ever with mega-constellations, multi-orbit satellites, and software-defined payloads. The world’s demand for broadband connectivity has created a new generation of high-throughput satellites in geosynchronous Earth orbit (GEO), medium Earth orbit (MEO), and now low Earth orbit (LEO).
In the future, 5G networks will represent the global telecommunication infrastructure of the digital economy, which should cover the whole world including inaccessible areas not covered by earlier terrestrial networks. However, there are several use cases where standard terrestrial coverage is either not present or possible, making satellite systems uniquely positioned to provide a solution to bridge this gap.
The pace of technological change has led some to question whether the ground segment can keep up and avoid becoming the bottleneck between innovations in space and terrestrial networks including 5G. This is particularly important given the technological shift from the world of Geostationary Orbit (GEO) satellites to a Low-Earth Orbit (LEO) and Medium-Earth Orbit (MEO) world, where satellite’s relative motion throw up additional challenges.
A proliferation of low-cost, high-revisit smallsats capable of capturing high-resolution images of the planet has democratized space. Recent use of Ka band platforms for high data-rate missions, and developments in advanced data-processing analytics have brought the need to scale operations. This in turn requires space platforms to interact dynamically with the ground network in more collaborative, usage-based and cloud-empowered ways.
New Ground segment innovations to support “New Space” revolution
In the new multi-orbit world, says Carl Novello, CTO of NXT Communications Corp. (NXTCOMM), an Atlanta, Georgia area-based startup, the biggest challenge on the ground will be flexibility. Traditionally satellite operators have been tightly vertically integrated, with terminals designed to work with a single constellation across a relatively narrow portion of spectrum. With operators adopting a multi-orbit approach, that increasingly won’t cut it.
“The challenge is how do you move from being a product that is relatively fit for a single purpose to becoming the Swiss Army knife of antennas?” Novello asks. “One that will work in GEO use cases and LEO use cases and MEO use cases, with different requirements for frequency bands, uplink power, different regulatory requirements to meet, and so on.” In other words, concludes Novello, “How do we build a better antenna fit for this brave new world of satellite connectivity?”
But advancements in technology are shifting the ground system from purpose-built, proprietary hardware architectures to software-defined, cloud-centric, and extensible virtual platforms that support multiple satellites, payloads and orbits on demand. This is being enabled by a series of innovations in antenna technology, waveform processing and system design, quietly starting a “New Ground” revolution down on Earth, as well.
NSR, a market research and consulting firm, estimates that cumulative revenues for the entire ground segment through 2028 will total $145 billion. The market will generate $14.4 billion annually by 2028, the firm states in its recent report, Commercial Satellite Ground Segment, 4th Edition (CSGS4). The user terminal will command a substantial portion of this spend.
Virtualized Ground network
However, in light of the mentioned extensive set of innovations in space, performance-focused developments on the ground are necessary, but not sufficient to deal with the challenges and opportunities foreseen in the coming intersection of space assets with 5G telecom, enterprise, EO and government networks. The complexity of the satellite network being built today will require accelerated efforts towards the, “fully virtualized ground network.” It will require multiple abstraction layers managed and orchestrated by common service definitions that meet new needs in terms of capacity, flexibility, cost, service creation, and resiliency.
NSR identified the following technological developments as key building blocks for ground network virtualization:
• Virtual Network Functions (VNF) : Functions that have been carried in the analog domain and/or performed on proprietary hardware will need to be virtualized to reduce hardware costs and augment flexibility. Certain functions could be exposed to provide access to services via containerization technology.
• Infrastructure-as-a-Service (IaaS): IaaS is key to the future of managed services and integration with telecoms. Leading satellite and teleport operators have introduced an array of managed services solutions but need to drive further efficiencies in teleport facilities and core compute centers.
• Cloud Platforms: The adoption of cloud computing has quickly become a key driving force for businesses today, as applications are moved out of on-premise data centers in a bid to innovate, cut costs and increase agility.
• Electronically Steered Antennas (ESA): While use of parabolic antennas will remain vital in the teleport / gateway infrastructure, development in new ESAs with the right performance and price points will be key to unlock the full potential of Non-GEO constellations and accelerate adoption in mobility markets.
• Digitization of the RF Chain: As a guiding principle, NSR believes in the value of digitizing the RF signal as early as possible in the IF-to-RF chain. “Digital IF” can be valuable for the virtual processing of individual satellite carriers (independently from antenna location), both for the transport of data across the core terrestrial network and for quality monitoring or management purposes and extraction of insight from such data. Digitization of the connection between the antenna and teleport hardware (IF signal flow) will bring physical-layer flexibility and cost reduction by decoupling traditional RF-chain conversion and amplification functions from the actual location where signals are digitally processed.
• Solutions for the “Integrated Enterprise”: 77% of enterprises have at least one application or a portion of their enterprise computing infrastructure in the cloud. Thus, seamless, cloud-enabled interworking with satellite technology is key.
• Industry Standards: Ultimately, for the industry to transition from niche to mainstream, the adoption of open standards is a must as all major industries have been built around standards.
• Big Data Analytics: The ability to extract actionable insights from large quantities of a variety of digitized information carried across the network will provide platforms with an informational advantage for natural evolution.
Satellite Ground Segment: Moving to the Cloud
Multiple stakeholders in the satellite communications market, ranging from teleport/gateway operators and satellite operators to service providers and ground system vendors are expected to employ best practices to adapt to Cloud-based architectures. This is recognized as a key step necessary along the roadmap of satellite’s eventual integration into a 5G future, with the understanding that Cloud Computing is more than just an expenditure to be handled.
EO players currently make up the largest share of the data downlink market, with a vast majority of data downlinked onto the Cloud from satellites in the >1,000 kg mass range. NSR’s Cloud Computing via Satellite research report forecasts 486 PB of raw EO data to be downlinked over the next ten years onto Cloud servers, driven by innovations in EO sensor capabilities that will lead to newer optical, hyperspectral, and Synthetic Aperture Radar (SAR) constellations coming online.
As such, commercial EO satellite operators with a focus on investing capital in the space segment for launch and manufacture, have an additional path to a partially/fully outsourced ground service model that leverages the technological capabilities and financial strategies of the Cloud era. A satellite operator subject to demand uncertainties will find the scheduled contact via the pay-per-minute pricing means spending less capital compared to procuring ground station antennas priced in the millions.
With on-demand measurability and flexibility in spinning up of services, Cloud-based solutions provide a shift from the traditionally CAPEX-heavy investments of satellite ground infrastructure to a reduced OPEX consideration that is flexible and open. In the case of AWS Ground Station, the service is aimed at offering flexible per-minute access to antennas across eight locations for self-service scheduling. This in turn alleviates the customer’s need to buy, lease, build or manage a fully owned ground segment.
By reducing need for ownership of hardware/software, such solutions also allow satellite players to cooperate with Cloud service providers(CSPs) and deploy their applications/serve their customers with great efficiency. The traditional CAPEX play of a satellite operator leasing/buying an antenna is giving way to a Cloudnative OPEX play, which is a “pay-per-use” model similar to most Cloud service price offerings.
Cloud-enabled ground systems will be a key enabler in opening up the revenue opportunity here across verticals and regions, as technology rises to meet and innovate on the supply of satellite data. With expanded and flexible Cloud Computing capacity close to the processing node, insight extraction is also local to end users, thereby also alleviating unnecessary Cloud costs.
Digital ground networks can establish private cloud environments to extend capabilities and connect with functions and services available in major public cloud environments. The leading cloud players, namely Amazon (AWS), Microsoft (Azure) and Google (Cloud) have been gravitating towards enabling platforms hooks into A.I, machine learning, automation, and block chain technologies, allowing ecosystem participants to benefit from these technologies.
Examples include the announced “Azure Express-Route” Microsoft partnerships with Intelsat and SES, as well as Amazon’s extension of its AWS platform to ground stations.
Electronically steerable antennas (ESAs), often referred to as flat panels, are the critical link for next-generation constellations. Compared with their bulkier mechanical cousins, flat-panel antennas offer greater efficiency and performance while being modular and dynamically steerable—all of which are needed for the future ground segment.
While ESAs’ flat and conformal characteristics can have aesthetic benefits, the real benefit comes from their performance. LEO and MEO satellites require the ability to track and communicate with two or more satellites in view at the same time, and this can only be done with multiple mechanical antennas. With no moving parts, ESAs are more reliable and efficient as they can connect to multiple satellites at the same time. This gives a single ESA the ability to interoperate with multiple orbits—not just GEOs.
Many different approaches can be taken to develop next-generation flat-panel antennas. All consist of small antennas, known as radiating elements, and both receive- and transmit-side amplification. A passive antenna takes one signal from the power amplifier (PA) on the transmit side and divides this signal out to the transmit radiating elements, then combines the receive signals from the radiating elements before feeding the receive-side low-noise amplifier (LNA). An active antenna, in contrast, has a single amplifier per radiating element, for both transmit (TX) and receive (RX). In general, passive antennas are less complex, while active antennas provide greater gain performance.
Automation and Integration
Working with cutting edge technology is at the center of the business model for Comtech Xicom Technology, says Vice President of Sales Eric Schmidt. The company, which has been making signal amplifiers and block upconverters for 30 years in Santa Clara, California, is focused on improving its products to meet the more rigorous demands of the new multi-orbit world, like the extremely high frequency Q- and V-bands.
“Our R&D philosophy is to focus on the underlying technology, the fundamentals, for instance of circuit design, to deliver the best performance,” he says. “We spend a lot of R&D money on the technology and the infrastructure, as opposed to the way some companies do it, where they’re essentially providing a company subsidy to underwrite the development of new products. In our case, we start with trying to build a new foundation — the technology — and then build the products on that.”
Over the next decade or so, Schmidt says automation and integration will be key differentiators in the ground segment, as new constellations require growing numbers of ground stations, some in remote locations. “Reducing the footprint, reducing the power consumption, reducing the maintenance burden … That’s going to count for more and more,” he says. “I think the trend is more and more towards complex and increasingly autonomous systems that are fully integrated, so the system itself can automatically increase power, change waveform, change modulation, change coding or whatever is needed for the link condition that the system itself senses.”
MRC Mx-DMA Multi-Resolution coding (MRC)
Singapore-based ST Engineering iDirect has already made strides towards that vision of a self-managing signal. Seven years ago, the company pioneered its Mx-DMA, a milestone waveform technology which upended the return link market — the way the terminal talks back to the satellite. This year, the company unveiled the second generation of that waveform technology: Mx-DMA MRC (for multi-resolution coding).
In a Satellite Return Link (RTN), a single up to thousands of terminals (e.g. cruise ships, fishing boats, broadband users, towers or airplanes) access a single gateway through a single satellite transponder, thereby sharing a common bandwidth. The specifications per terminal may vary greatly, from low (fishing boat) to high throughput (cruise ship), from low (IoT or downloading) to high (audio call) jitter sensitivity, from low-cost (broadband users) to high-end (cruise ships) terminals.
Thousands of terminals should potentially be able to log on in a few seconds, e.g. due to mobility or when the network recovers from an outage. For a profitable business, the required number of Multi-Carrier Demodulators (MCDs) needed at the gateway to demodulate up to thousands of terminals should be limited and as low as possible, without compromising the efficiency of transmission (number of bits per Hz that can be transmitted). In order to address this, we have designed and productized a single return technology that captures all the above requirements and which represents a significant improvement on our previous 3 return (RTN) link technologies SCPC, Mx-DMA and CPM.
This new RTN link technology is referred to as MRC Mx-DMA. Multi-Resolution coding (MRC) can demodulate, on a single MCD, any combination of terminal transmissions (from high demanding (high throughput, no jitter) to low cost (low throughput, no jitter sensitive transmissions) terminals). Keep-alive traffic does not cost any noticeable bandwidth. Guard bands are minimized. Jitter is as low as a single FEC word duration, even though a burst from a terminal spans up to 100 FEC words. Automatic in-band regrowth detection without any calibration prevents terminals from saturating BUCs while maximizing power transmission. This results in a single RTN link transmission that is as efficient as SCPC for high throughput terminals while achieving CPM like scalabilities, overbooking ratios and efficiencies for services with high overbooking. There is no need for mode switching between CPM and SCPC, as it is all done within a single time-frequency frame using a single technology on a single MCD.
“The difference is scalability,” explains ST Engineering iDirect CTO Frederik Simoens, “You have a lot of users, they’re all transmitting to the satellite, but you have to orchestrate all those transmissions to make sure they’re not overlapping. To dynamically allocate resources to make sure everyone has the bandwidth they need, you have to do it automatically. It’s about the ability to scale that, to achieve the highest throughput per user, but also to achieve the fact that you can have many thousands of users with very different use patterns and bandwidth demand transmitting at the same time, all using the same platform. Coping with all of that is what this new generation Mx-DMA MRC technology does.”
In addition to the efficiency benefits the new return waveform offers, says Simoens, there are operational benefits, too. “As an operative, you don’t have to configure carriers, you don’t have to configure modulation schemes, it’s just handing out a bunch of spectrum slots through the system, and the system will take care of assigning them automatically.”
The development of commercial operators led to new approaches to improve the productivity of infrastructures in space and on the ground to increase profitability. The introduction of software-defined technologies is considered a major technological trend to reduce costs and improve the efficiency of operations. “Software-defined” means any traditionally implemented hardware components replaced by software to configure a function dynamically and programmatically. On one hand, the shift from hardware functions to software enables mass and cost reduction. On another hand, software solutions support the automatization of operations and make systems more flexible and scalable as configurable with a simple file upload.
Software-defined satellites are raising interest from Satcom operators who are interested in more flexible communication to better address demand for connectivity. Traditionally, a GEO satellite was launched for a specific mission with an essentially fixed design during its whole life (i.e. 10-20 years). Once in orbit, it could not repurpose its mission even if the demand changed. A flexible satellite uses a Software-defined(SD) payload to reconfigure the antenna beam on-demand that is programmable by sending a new program in uplink communication. Essentially a software-defined satellite should offer the ability to dynamically modify the coverage beams and the capacity and power distribution
In order to consider an end-to-end software defined and optimized network, the ground segment also needs to adapt to the new requirement in fleet and capacity management. A software-defined solution on the ground can be seen as a way forward to align gateways with the changing communication requirements of a GEO flexible satellite and the management of the increasing traffic. Indeed, the satcom industry being increasingly data centric with more than 9 Tbps of traffic to manage by the end of the decade with a 5-fold increase compared to 2020.
One big enabler of automation, Simoens says, is virtualization. “With software-defined networking, it becomes possible to automate and orchestrate a lot of the things that used to be manual, like configuring a network for a new beam. That used to be a manual action, but now it can be fully automated, because of that network function virtualization. This is the future.”
The Kratos Space’s Open Space platform offers a set of virtual tools for ground segment management, based on an extensible, open and totally software defined architecture. “It’s enabling that move from legacy analog infrastructure to a digital and software-defined infrastructure,” says Stuart Daughtridge, vice president of Advanced Technology in Kratos Space, Training, and Cybersecurity division.
Nonetheless, virtualization isn’t entirely complete, and frequencies higher than 6 gigahertz have to be converted by a piece of analog hardware called a frequency converter. “Eventually though, as digitizers get better, the technology gets faster, you’ll continue to be able to digitize at higher and higher frequencies, so that you’ll get rid of the frequency converters,” Daughtridge explains. “The bottom line is, your amplifiers will stay hardware, your antennas will stay hardware and your satellites will stay hardware, at least on the outside. Pretty much everything else in between gets virtualized.” And that’s a good thing, too, argues Chris Boyd, senior director for product management in Kratos Space, Training, and Cybersecurity division.
“When things were all hardware, if you wanted to roll out a new capability, you’d have to lay cable, you’d have to provision new hardware. It would take weeks or months. With virtualized network functions that demand cycle can be closed a lot quicker. With Open Space we can satisfy that demand very much like how big IT networks are managed today, getting it down in some cases to minutes,” he says. And that flexibility gives Open Space users the ability to support more dynamic services for their customers, Boyd points out, which means more opportunities to monetize the capabilities of new satellite constellations. “The capabilities are amazing but at the end of the day, you need a dynamic and flexible ground system to be able to monetize that. And that means software defined,” Boyd says.