The smart aircraft cabin of the future takes the travel experience to a new level. Fast Wi-Fi for streaming favorite series on personal devices, smart lighting for increased well-being and less jetlag, and individual temperature control at the seat provide personalized comfort in the aircraft cabin. Additional cabin services can be booked via smartphone, allowing drinks and custom meals to be delivered to the seat on time. However, for this vision to become a reality, the technical solutions must pass a bottleneck: integration into the cabin network. The problem is that today’s cabin networks consist of several isolated individual networks that are incompatible with each other and already pushing the allowed weight in the aircraft. How can passengers still enjoy smart aircraft cabins in a timely manner? In the DELIA research project, ZAL GmbH developed a promising solution in collaboration with partners.

Smart cabin can only be realized as part of a cooperative effort

A smart aircraft cabin offers advantages for both users and operators. While passengers can enjoy customizable comfort, airlines and cabin crews can benefit from support in routine tasks such as automated information transmission about full and free overhead bins or occupied seats in combination with correctly fastened seat belts.However, the challenges to implementing smart cabins are significant. Today’s onboard electronics in aircraft often come from various suppliers and use different interfaces or programming languages. These are often proprietary, meaning that developers from other companies have no way to connect to existing systems and expand their functions. This means that each new device must be connected with its own data cables, power supply, and end devices. In turn, this means more weight, more fuel consumption, and higher emissions for flight operations. Furthermore, with each device, the complexity of maintenance and any repairs increases.The reasons for this situation are diverse and result from different interests and working methods of manufacturers, suppliers, and airlines. To change this, it quickly becomes clear that the vision of a smart cabin can only be realized together. Against this background, ZAL GmbH initiated a project team based on actors from science and industry. The resulting dialogue makes it possible to define industrial requirements and develop scientifically-technical solutions that are powerful and adaptable at the same time to integrate further applications. The research project started in 2019 under the name DELIA and was successfully completed in 2022.

One core question of the research team was whether and how to equip a cabin network with fewer components but achieve more performance. The project partners Solectrix and AED developed a solution for this. Under the name “DELIA module,” they realized a versatile hardware platform on which any programs, such as light control, in-flight entertainment, or cabin climate control, can be executed. The solution envisages the use of multiple modules placed in different locations in the cabin. This structure corresponds to a so-called “distributed system.” Distributed systems have the advantage that tasks can be performed by multiple devices, and computational loads can be dynamically distributed. The trick: if more computing power is needed, additional modules can be retrofitted without difficulty. Especially in combination, the DELIA modules unfold their potential. For this purpose, they are connected by powerful optical fibers that allow data rates of up to 10 Gbit/s. As a comparison: the use of a single cable could enable up to a thousand households to access streaming services simultaneously. An ideal prerequisite for use in the aircraft cabin.

All-rounder in the cabin network

However, processing large volumes of data alone is not enough for use above the clouds. Another essential performance criterion for future cabin solutions is their security. Transmission failures must be avoided and the execution of important functions must be ensured. To safeguard transmission paths against interference, all DELIA modules are arranged in a ring-shaped network, also known as a ring topology. This ensures that each module is in contact with two other modules. If one path is interrupted, data can continue to be sent reliably via the second path. If the DELIA module itself fails, other modules take over its tasks. The DELIA modules thus combine processor and network properties.

Traffic rules for the network

Another development for safeguarding cabin networks is TSN, Time Sensitive Networking – a collective term for various technologies that regulate the flow of data in real time. This ensures that certain data reaches its destination at all times, completely and without delay, regardless of whether all passengers are watching a movie at the same time or a cable is damaged. TSN works like a traffic policeman. For example, TSN holds back unimportant data to free up a data lane or sets up a detour if the path is blocked (TSN switch). This not only guarantees that the data arrives in full, but also at what time interval. With TSN, this is in the microsecond range.

The engineers at ZAL GmbH successfully tested that TSN technology works on their own cabin demonstrator. To test the real-time capability of TSN switches using the example of lighting control, the terminal device of the lighting control system was removed during operation. In response, the TSN switches switched the data traffic to a functioning lighting control. To simulate a heavy workload in parallel, the network was flooded with control commands. The network architecture withstood the demands and there were no glitches or failures. The LED running strips and cabin lighting were not affected.

ZAL Endpoint connects devices to the network

While DELIA modules process and forward information, another system must execute the commands. ZAL GmbH has developed the ZAL Endpoint for this purpose – a versatile electronic component that is compatible with the most common interfaces in aircraft. A ZAL Endpoint then controls, for example, the seat lights, the passenger service unit or feeds data from a sensor back into the network. Multiple endpoints then send their data to a DELIA module.

What’s next?

The DELIA research project demonstrates the potential of distributed systems to realize the vision of connected and smart cabins. TSN technologies mean that there is no need to compromise on speed for reliability and security.

Open-source software and open standards were consistently used throughout the project. Future research and industrial projects can thus seamlessly follow up on these results.

Are you interested in smart networked cabins? Then let us know what you think and give us a call:

Data & Power Networks
Dr. Leonid Lichtenstein
Head of Data & Power Networks
+49 40 248 595 143

DELIA project partner:

ZAL GmbH
AED Engineering GmbH
Solectrix GmbH
University of Stuttgart
University of Hamburg
Airbus Operations GmbH
Tyco Electronics Raychem GmbH