In considering the theme for this month’s column my prompt came from threads of discussion featuring in GVF’s continuing online events program (https://gvf.org/webinars/) which resumed in January, following our successful 2020 online content response to the limiting circumstances of a pandemic world. Mid-February’s Zoom into the subject of ground segment attracted 400 registrations, 300 actual attendances from 60 countries, and over 30 live questions, in addition to the moderator-led Roundtable dialogue.
The initial 60-minute focus on transportable terminals will be developed and extended during March with additional explorations into (a) the frontiers of satellite systems size, weight, and power; and (b) the development and evolution of capability and performance of satellite networks solutions. A combination of these three threads serves to frame the below.
Providing solutions for today’s cellular backhaul, consumer broadband, enterprise networks, IoT, managed services, rural connectivity, satcoms-on-the-move and other connectivity application requirements is the very stuff of the development path of the modern Very Small Aperture Terminal. However, the term VSAT is less common today; we hear fewer references to the assembly of the antenna, BUC/power amplifier, LNB, IDU, etc., in favor of transition to a more “holistic” view of the terminal, or user equipment, i.e., a migration away from looking at the separate parts to looking at wholly integrated systems, from thinking of individual technical elements to focusing on overall functionality, and indeed of services too. This both reflects demand for, and is an enabler of, an improved user experience built on, and exemplified by, terminal deployment/installation simplification, use of graphical user interfaces, the placing of greater sophistication in the terminal with complexity taken away from the user, with the latter being based, in part, in software defined virtualization of networks.
It is also a reflection of changes in the way that customers express their requirements, less so in terms of such specifications as EIRP, or G/T, more so in terms of data rate throughput performance, or the requirements of a particular application, parameters which may need to be dynamically flexible over time.
The accelerating advances in the performance capabilities of terminal equipment brings elevated link optimization, and greater connection security, all whilst manufacture is achieved at progressively lower cost. Of course, ground segment technology development is richly paralleled by, and inter-related with, developments in the space segment, with both increasingly powerful individual satellites in GEO, and the assembly of constellations of NGSOs the design and build parameters of which include reduced mass and volume.
As NGSO networks come into service, complementing existing and additional GEO systems, wider considerations relating to the “holistic” terminal come into play, pertaining to multi-network, multi-band, multi-orbit networking operations, supporting expanded and multiple user scenarios facilitated by the combination of greater capabilities and reduced cost.
Just as new design options for satellites have resulted from electronics manufacturing innovation, including Very High-Density Integrated Circuits (VHDICs), and from new methods for embedding COTS components; just as new frontiers in Size, Weight and Power (SWaP) have been established, suggesting the question, “Where is future of manufacturing of ever-smaller high-performance electronics taking satellite systems?”, the direction of terminal design is towards smaller form-factors whilst meeting increased power targets to support RF signal performance.
Of course, application, capability, flexibility, performance, form factor, and various other characteristics, additionally inter-relate with the emerging new antenna environment, featuring the respective advantages of the parabolic reflector and various flat panel antenna (FPA) technologies.
FPAs have for long been a niche alternative to parabolic antennas, with the fixed phased array type in use since the 1950s. Due to high costs and variable performance market potential has been limited, until today’s “Goldilocks Zone” with just the right coincidence of factors – new demand from evolving and expanding markets and associated opportunities for scale, radical technologies, advanced engineering techniques and manufacturing processes – combining to address the issue of unit cost. Additionally, the FPA market is benefiting from partnerships – arising from the widespread recognition that the satellite industry is in a state of fundamental transformation necessitating a deeper integration of the industry’s value chain – with operators, service providers, ground equipment manufacturers, forming relationships to drive advances in antenna ecosystem development to achieve the right mix between performance and price.
The paradigm-shift in the nature, pace, and scale of the drivers of increased market demand for better performing satellite solutions, leveraging the inter-related advances in space and ground segments, has led us to great expectations for FPAs. Most specifically active electronically scanned arrays (AESAs) – characterized by such defining attributes as low aperture, high reliability and pointing accuracy, small form factor, and low weight – wherein each antenna element has an individual transmitter/receiver unit, controlled by a computer, and hence AESAs can radiate multiple beams of radio waves in different directions, at multiple frequencies, at the same time. Also coming to market is optical beam forming FPA technology which, beginning from the simplicity and high efficiency of the parabolic antenna with its geometric structure focusing energy into a single feed source, features a structure of multiple beam-forming sources, each of which can support an individual beam.
The technology provides an integrated solution that includes modem, BUC and LNB components in a single package. The solution can handle GHz of instantaneous bandwidth, ensuring that the terminal is never the bottleneck, supporting any commercial carrier size currently available. These various FPA technologies have become one of the evolving pieces of the industry’s complex re-engineering of the terminal, and of the users’ experience.
Ground segment engineers, like their space segment counterparts, are joining the mass production line-like industrialization of space with COTS components augmented by speed of innovation in miniaturization. Ground segment design is shifting from extremely high quality and low quantity to high quality and high quantity, maintaining reliability, resilience, and dependability, but at lower cost. Increased terminal modularity suggests the increasing significance of a satcoms-as-a-service paradigm which goes beyond managed platforms-as-a-service models which combine hub, teleport/data center uplinks, and terrestrial networking elements to enable easy global deployment of high-throughput connectivity to user customer locations. This paradigm would be reflected in a virtuous circle, something akin to the familiar decreasing launch costs > more satellites launched more often > reduced redundancies > reduced mass and volume > further reducing launch cost, but looking something like the formula pictured below (somewhat less elegant) summary of the thoughts conveyed here:
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Martin Jarrold is Vice-President of International Program Development of GVF. He can be reached at: martin.jarold@gvf.org
