Software Defined Car


During the past 100 years, there has been only one major technical revolution in cars: combustion engine in 1890s. In the following 10 years, we will see not just one but four major disruptions in the industry: connectivity, electrical vehicles, self-driving and car sharing. In all of these the enabling technology is software. Where cars of today are defined by engines, cars of tomorrow will be defined by software. In this post we present two aspects of software defined car and benefits software can bring to cars.


Car of today consists of over 200 different electrical control units (ECUs) controlling the separate in-car systems. During the last decade the amount of ECUs has been increasing due to new car functions and features developed for comfort and convenience of driver. OEMs are facing a challenge of managing complexity and costs of modern vehicles.

With software and more powerful computers, multiple ECUs can be integrated into one single ECU, reducing HW complexity and increasing cost-efficiency and security. Combining many ECUs into one can simplify ECU communication, helping R&D processes to focus on essentials and adopt new features faster.

Even though multiple ECUs can be combined, reasons remain to keep certain functions separated: we will always need more than one ECU. First, some functions require different types of processors, so it makes sense to group systems based on similarity. Second, integrating similar systems together allows bringing them closer to the functions they control. For instance, Smart Antenna / Connectivity Gateway ECU can be placed close to antennas to reduce high antenna cable costs.

More important than the number of ECUs is the development trend towards a truly efficient and functional system. There has been many different architecture proposals so far and the future will show which will be the dominant one.

Software Defined Car
PICTURE 1. Combining multiple ECUs into one can reduce HW complexity of a modern car.

With fewer ECUs, carmakers can streamline maintenance and repair process, allowing smoother maintenance for car owners. More systems can be updated or repaired at once, and that improves customer satisfaction and cost-efficiency. However, this will also move development focus towards software and require even higher quality standards.


More intelligent ECUs and new, more developed network technologies like Automotive Ethernet enable major security improvements in ECUs (=in the whole car). The car can be remotely diagnosed with the intelligent ECUs, and development of new features becomes faster due to improved development tools.

Many new features can be brought into cars with software (and in some cases with additional hardware). This allows carmakers to differentiate their vehicles, which has been really difficult traditionally. New features may include automatic driving assistance systems (ADAS), cloud services and improving the whole user experience of a car.

At the end we would like to summarize the benefits software can bring to cars:

  1. reduced HW complexity
  2. security
  3. cost-efficiency
  4. new features
  5. better user experience
ECU Integration
PICTURE 2. Multiple ECUs integrated into one in Motion T connected carputer.

Link Motion has 10 years of experience on automotive software and integration work, and the company is about reducing complexity in car computing. Company’s first own product Motion T, a connected carputer, brings together five different ECUs: instrument cluster, infotainment display, head-up display, plus connectivity and telematics units. The goal is to implement also ADAS features to the system with BroadR-Reach Ethernet, and eventually create a self-driving platform.


Our Technologist Mikko Hurskainen will give more in-depth talk on software defined car at AGL All Member Meeting in Tokyo 8-10 February. Welcome to listen!

Mikko Hurskainen is currently Technologist at Link Motion, focusing on technology development and forward looking projects. Mikko has extensive experience of embedded software development, he has been working on research, smart phone development and telecommunications. Prior joining to Link Motion he has been working at Nokia, Symbio, ST-Ericsson and start-ups. He holds M. Sc. from Tampere University of Technology.