Giving SatCom users more BANG for the buck

Broadband in Aviation – Next Generation assesses new technologies for onboard communication

Today, we can hardly live or effectively work without internet connection. The global data network has already conquered many areas of our everyday lives. This now also applies to the aircraft cabin. Hardly any airline can afford not to provide its passengers with access to the Internet. With a few exceptions that allow terrestrial mobile communications in flight, this onboard Internet data traffic is mainly handled via satellite communications (SatCom for short).

The range of corresponding SatCom systems, technologies, frequencies and providers has considerably grown in recent years in line with the increased demand, and is now very broadly diversified and thus complex. However, while mobile communications users on the ground are used to being able to switch regularly between rates, networks and providers in order to always use the best package for them in terms of price and performance, airlines have much less flexibility in this respect.

By choosing the hardware installed in and on the aircraft, an airline commits itself to its possible SatCom providers for the Internet service, since the existing providers usually use different technologies, for example for the modem or the antenna. Airline customers who decide for a particular SatCom provider and have the corresponding components installed in and on their aircraft therefore often have little opportunity to switch to another provider quickly and cost-effectively. In most cases, the hardware already installed would simply not support this change. The reality is that existing SatCom solutions have almost no flexibility or modularity in this respect. Large, and therefore expensive, modification and de-modification programs are therefore the order of the day.

An open, modular and flexible satcom platform - the goal of the BANG project

The aim of the research project "Broadband in Aviation - Next Generation" (BANG for short) is to change the situation described above and to give airlines significantly more options for using their SatCom installations in the future. Together with IMST GmbH, Hamburg Harburg University of Technology (TUHH) and the Fraunhofer Institute for Integrated Circuits (IIS), and funded by the German Federal Ministry of Economics and Climate Protection, my team and I at Lufthansa Technik are looking for ways to make future SatCom systems much more flexible and thus open up numerous new freedoms for their users. In doing so, we are looking at a wide variety of approaches to solutions for future aircraft hardware, which should overcome previous system-related, constructional, certification-specific and aerodynamics-related hurdles through new knowledge.

Our ultimate goal is to create an open, independent, modularly deployable, flexibly combinable and, in particular, future-oriented SatCom communications platform for commercial aircraft. It should enable airlines and other aircraft operators to react quickly and conveniently to changes in technology, user behavior, costs, or regulations in the future and to adapt their SatCom systems comparatively quickly and with significantly less effort.

Installation of a SatCom antenna in an Airbus A321neo at Lufthansa Technik in Budapest. Today's technology for such installations usually forces airlines to make a long-term and inflexible commitment to a particular provider for satellite communications. (Image source: Lufthansa Technik AG - Photographer: Juergen Mai)

Analysis of the status quo - Of lame pings and other pain points

Along the way, the first priority was a comprehensive analysis of the entire technical and commercial ecosystem, which we conducted from 2019 to 2021. To do this, we held working groups with different stakeholders along the entire value chain, from the airline as our customer, to the connectivity and satellite providers in the middle, to the system OEMs and hardware suppliers at the other end of the chain. The resulting vulnerability analysis, based on in-depth feedback from a wide variety of airlines from around the world, clearly showed us in various examples where the complexities of today's SatCom market are located. Below are a few selected findings:

• Airlines today must deal with very high costs in the initial modification and equipping of their aircraft, but also with high operating costs - in addition, this effort is often countered by barely satisfactory performance (Internet speed). Today, business models based on strong connectivity are very sensitive, unstable and only partially successful on the part of the airlines. The end customer in the form of the passenger, on the other hand, often must contend with high prices and grueling registration processes - which are then countered by connectivity that is reminiscent of the speeds of old ISDN modems in private households from over 15 years ago. Today′s technical supplier landscape, on the other hand, has to serve largely closed system landscapes and is stuck in a dilemma with often very high development costs.
• In addition, we were able to document how fast-moving and sometimes risky changes in the market for SatCom systems currently are: Existing providers have to constantly reinvent themselves due to technological advancements (see next chapter) and invest in cost-intensive research and development in order to keep up with the times. As a result, they are merging and new players are entering the market without having any precise idea of what the future world of Aircraft Connectivity will even look like. Confronted with such uncertainties and imponderables, many airlines as a result install sometimes outdated system architectures or extend existing SatCom contracts with providers, although the service may obviously not be satisfactory and the technology not up-to-date.
• In some cases, there are also political complexities, as not every government is unconditional regarding the Internet. In some countries, a SatCom system is only allowed to establish connections and exchange data with satellites of the official government provider. The technical requirements necessary for this are not always easy to meet, especially for airlines flying in from abroad. Moreover, they are not compatible with the SatCom conditions in other regions of the world. As a result, airlines may be forced to maintain special aircraft for special routes or world regions if they want to keep their promise of onboard Internet access to all their customers. But this operational constraint is not an option for many airlines. As a result, a truly global on-board Internet service simply does not seem feasible at this time.

What will we need in the future? - From general requirements to concrete fields of application

In our future SatCom solutions, weaknesses such as those mentioned above should be a thing of the past. For this reason, we then derived, defined, categorized and prioritized very specific future use cases and requirements for future SatCom systems from the analysis mentioned at the beginning. The following graphic provides an overview and shows some high-level example requirements:

Based on the initial analysis, the BANG project team formulated overarching requirements that future SatCom systems should fulfill. (Image source: BANG project)

In the next step, BANG broke down the general minimum requirements for future SatCom solutions listed in the graphic into individual sub-aspects and project partners. For me and my colleagues at Lufthansa Technik, the main focus was on the requirements regarding the design of SatCom components and the corresponding regulations for their integration into the hardware and software architecture of an aircraft. In addition, we were able to define numerous technical, infrastructural, integrative, operational and maintenance-specific requirements.

The requirements matrix resulting from all these considerations ultimately covers various aspects such as communication stability, data rate and latency as well as design aspects, for example the resilience and transmissivity of materials. A welcome side effect for us as an MRO provider is that our requirements matrix also allows the evaluation of potential new business models for future communication platforms, from flight route management to maintenance and repair.

An important example here is so-called "digital twins" of aircraft, as known from our AVIATAR digital offering, among others. They can help, for example, to manage complex fleets in real time or to predict component failures in good time so that expensive technical diversions can be avoided by proactive replacement. Such applications are nothing less than the future of maintenance, but they can only realize their full potential with resilient and fast Internet connectivity. In view of this continuing and even intensifying trend toward ever more connectivity in MRO as well, it therefore makes sense for us at Lufthansa Technik to equip ourselves today for future requirements and customer requests beyond our current portfolio. Here, too, BANG makes a valuable contribution.

Finally, a fast Internet connection on board also opens up many new fields of application for the airlines and the passengers themselves: Whether it's in-flight shopping, smart-home control, gaming, social media, etc. - the in-flight potential is huge and ties in directly with our now thoroughly digitally determined lives on the ground.

How can (future) SatCom technology keep pace with these requirements?

To realize the above-mentioned applications in the future, we believe that targeted and consistent further development of all technical components involved in a SatCom system is required. These include antennas and modems, for example, as well as radomes and mounting systems. Their complex interaction and, above all, the resulting overall system as well as its integration into the aircraft structure are integral parts of the required qualification and certification process. For this reason, these aspects are also being intensively investigated as part of BANG.

On the part of Lufthansa Technik, we are taking a closer look at the following three key areas that we call "technical streams":

1. Hardware and software technologies in the entire "Connectivity" ecosystem: Here the focus is on (airborne) antennas and antenna terminals, satellite constellations, service providers and cabin equipment.
2. Composite materials: Here we deal with radome material compositions, multi-material systems and new, functional and more integral concepts, as well as production technologies for radome systems.
3. Aircraft integration and installation, as well as operation: Here the focus is, for example, on the mechanical connection to, as well as the positioning of the installation on the aircraft fuselage. Aerodynamic considerations as well as calculations and simulations are also part of these tasks.

Lufthansa Technik is also contributing its extensive expertise in the development, testing and production of radomes and attachment structures to the BANG project. (Image source: Project BANG and Lufthansa Technik) ?

What our orientation to the technical streams means in concrete terms can be seen by taking a look at what is probably the most visually striking component of a SatCom system: a radome, i.e. the "protective cap" or cladding of the antenna. This component is necessary to meet aerodynamic and structural requirements. A radome made of fiber composite material must also be permeable to high-frequency signals so that the antenna underneath can communicate with the respective satellite network in its respective frequency band.

The transmission properties of radomes are significantly influenced by the materials used. As part of the BANG project, we were able to identify novel (fiber composite) materials and material systems for radomes at Lufthansa Technik's Composite Competence Center in Hamburg, investigate their aerospace suitability and verify them in a next step in prototypes and test campaigns. The internally already existing methods for the prediction of new radomes are supplemented in the project by sensitivity analyses and an optimization tool as well as further parameters. As a result, BANG will enable us to identify promising approaches and technologies for future radomes, such as various new prepreg (pre-impregnation) and resin systems as well as dry fiber textiles, binders, foam core systems and coatings.

When investigating technologies for antenna terminals, we draw on both the expertise of the individual project partners and current data from the global "in-flight connectivity" industry as part of BANG. On this basis, we systematically evaluated the antenna systems under development. This gave us a comprehensive picture of manufacturers, frequency bands, orbits, the number of apertures and simultaneous beams, dimensions and mass, as well as information on the type of electronic control and heat dissipation solutions. Furthermore, this also provided us with information on transmit and receive performance data and the maturity of each technology for use as an aircraft component.

Our primary goal in the third stream is to create a maximally flexible mechanical interfacing concept that allows for a variety of antenna-radome combinations. The concept should also be as independent as possible regarding aircraft type, which is not the case, or only to a limited extent, with the systems available on the market today. In a first concrete approach to achieve the desired maximum flexibility, we have now already been able to define requirements for a modular adapter plate within the framework of BANG, which provides a fixed connection between the antennas and the aircraft fuselage.

Overview of the research topics within BANG: The project deliberately looks at the overall "onboard satellite communication" eco-system from two different angles. Business models, value chains and use cases on the requirements side are contrasted with concrete innovations on the technological side. (Image source: Project BANG)

From theory to practice - next stop: technology demonstrators!

The first two phases of the project described up to this point have already laid good theoretical foundations for the further progress of the BANG project. In the coming phases until the end of the project in mid-2023, however, the concepts of one or more modular connectivity platforms should now no longer be evaluated exclusively in theory, but ultimately demonstrated in practice. To this end, we also want to completely redesign new system elements - such as radomes.

To demonstrate the practical suitability of the technologies envisaged for this purpose, the next step will be to create scaled technology demonstrators that will be tested on the ground with simulated interfaces to existing systems. For this purpose, BANG will use the innovative and collaborative laboratory infrastructure of the ZAL Center for Applied Aeronautical Research in Hamburg. In addition, the project can rely on specific in-house test environments at Lufthansa Technik`s Hamburg base as well as at the project partners.

Through close coordination of all hardware and software interfaces of the developed subsystems, the resulting technology demonstrators will be able to show numerous interdependencies between the subcomponents and provide early indications of possible constructional or aeronautical hurdles of various new setups. This will provide a solid foundation for the final work package within BANG: the individual technology demonstrators will ultimately become a functional demonstrator.

This will be created as an integrated laboratory environment in which all the conceived subcomponents of the communication system can be specifically examined and evaluated with regard to their interaction and integration into the entire aircraft system. The theoretical knowledge generated in the laboratory tests of the individual components will again be specifically evaluated in practice. This is the only way to reliably determine whether the technologies actually interact successfully in the overall system of a real connectivity platform.

We intend to explore all of this together with our partners in the BANG project by the middle of next year. With the findings and deductions, we have made so far, we have already come a long way and created a solid basis for the next steps and all the following progress of which we will be happy to report on. Knowing the great importance of satellite communications for future aviation, we hope that our research will ultimately deliver exactly the impact that our project acronym promises. ;-)

Of course, the BANG team and I are looking forward to any input from outside: Suggestions, questions and constructive criticism are always welcome. So: Feel free to comment!

Thank you for your attention,

Dennis