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StealthCase signals a change for phone reception

StealthCase’s technology makes walls, windows and construction materials double as passive antennas. No more bad mobile reception indoors. Adobe

If you have ever balanced next to an open window just to get mobile signal, Finnish startup StealthCase has some good news for you: time to wave goodbye to poor reception indoors.

It all started from a moment of frustration. Juha Lilja, StealthCase’s founder, had just moved to a new stone house and once again was forced to sit out on the balcony to use his mobile phone as the signal didn’t quite reach indoors. As an antenna specialist at Nokia he started to think something must be done about this.

“Later I read an article in [Finnish technology magazine] Tekniikka ja Talous on how much energy efficient houses weaken mobile signal and realised this isn’t just me, it’s a widespread problem,” Lilja recalls.

A self-declared ‘propeller-head’, Lilja started to test an idea for turning insulation materials, windows and other construction elements into mobile signal boosters. Based on passive antenna technology, his innovation helps mobile signals travel through minuscule gaps in the wall elements which otherwise wouldn’t let the signal through. Consequently, mobile networks can work reliably inside a building without any extra equipment needed.

The technology quickly convinced Lilja’s two university friends, Janne Mansikkamäki and Antti Kallonen, to jump on board and StealthCase was born in late 2014. Today the company has one patent in its pocket, another in the process and the first construction materials featuring its technology are expected to launch later this year.

Energy efficient problems

StealthCase targets a growing problem. As building regulations demand more energy efficient construction, mobile signal strength struggles to reach inside walls that have been designed to block thermal radiation.

“A modern energy efficient building can weaken a mobile signal 100 times more [20dB] than one built before the 2000s,” Mansikkamäki says. “The same problems arise in older buildings after window renovations.”

While other companies have tried to solve the issue with internal networks or mobile phone optimised windows, StealthCase argues its approach is cheaper and simpler. The technology is integrated directly into construction materials, doesn’t require any additional setup from the inhabitants, works with any mobile network and window type and doesn’t affect the energy efficiency of a building.

StealthCase has already successfully piloted its technology with a few companies, including Finnish rental housing giant VVO. Now the company is in talks with construction material manufacturers interested in licensing its technology and it hopes to announce news regarding this soon. It is also working on a solution to retrofit its technology into existing buildings.

“In an optimal situation we would have 10 big manufacturing customers. They gain a competitive advantage from our technology as they can sell mobile device friendly construction materials,” Mansikkamäki explains. “They can ask potential customers if they want to ensure mobile devices work inside their building for the next 20 years or if they want to buy a competitor’s product which doesn’t offer this.”

Aim high

StealthCase is in a good position for a small startup as it has paying customers plus outside backing from Finnish investor Butterfly Ventures. The company has also secured funding from Tekes*, the Finnish Funding Agency for Innovation, which helps the startup expand its patent portfolio and market reach.

StealthCase is already in touch with a few potential European partners and hopes to expand to new markets next year, starting with the wider Nordic region. But this is only the start of the company’s ambitions.

“In five years’ time, we aim to be part of 10 to 30 per cent of all buildings constructed or renovated in the Western world,” Mansikkamäki says. “We believe this is possible by partnering up with big manufacturing companies.”


*Part of Business Finland since 2018

By: Eeva Haaramo