Window Glass on Public Transportation Hinders Cell Service

Window Glass on Public Transportation Hinders Cell Service — Until Now

A Swiss startup — known for its process that makes glass permeable to telecommunication frequencies — requires the right components to create their revolutionary technology.

Edited by EE Staff

Cool Stuff

Apr 27, 2026

As the world becomes increasingly more reliant on wireless technology in both professional and personal applications, wireless users continue to face certain unique challenges. Making calls or using data indoors can still be a hassle in many locations. This is especially true for those using public transportation like trains, where window glass greatly impacts wireless signals.

While wireless signals have become stronger and more efficient in recent years, they still struggle to penetrate building materials, including insulated glass. This makes it difficult, and in some cases impossible, to get service. Everyday clear glass can reduce wireless signals by up to 4 decibels (dB), while coated glass can reduce signals by as many as 30 dB (x1000). This is especially a problem in public transportation vehicles like trains, where passengers may struggle to receive wireless signals at all. It is an issue faced by commuters worldwide, for which Swiss startup nu glass has developed a cutting-edge solution.

*nu glass’s revolutionary glass cutting pattern allows wireless signals to better penetrate windows. The engraving can be completed on-site without having to remove windows.*

Unique Glass Cutting Pattern

Most glass is insulated with a thin metal layer invisible to the naked eye. nu glass uses a patented laser technology to engrave a pattern on this layer, allowing for wireless frequencies to penetrate the glass. This treatment can increase indoor signal by up to 1000 times. The etching is nearly invisible, and it has no detrimental impact on the glass, which keeps its original protective properties.

nu glass uses a portable system to complete the engraving process, allowing them to visit customers on site. The system can engrave glass while it’s in place, preventing the costly and time-consuming process of removing and reinstalling individual panes of glass. The process is fast and efficient and can be applied parallel to standard maintenance, allowing for trains to keep on their schedule and return to service on time with enhanced connectivity. nu glass’s system is currently used exclusively on trains but could potentially be used on glass installed in buildings or other structures.

KNF diaphragm pumps play an integral role in nu glass’s cutting process. Multiple N 838 pumps are used in suction plates, which help adhere the system to the window during the engraving process. The pumps allow for the precision process to take place with minimal vibration.

The N 838 is an outstanding gas transfer pump option. It offers a maximum flow rate of 34 l/min with an ultimate vacuum down to 100 mbar (abs.). Also available are a variety of motor options, including brushless DC motors for energy efficiency. The N 838 has excellent reliability and operates oil free, preventing media contamination.

*KNF’s N 838 diaphragm gas pump plays a vital role in nu glass’ engraving system, holding it in place during the precision etching process.*

While finding the ideal pump for their system was important, nu glass wanted to make sure they were working with a partner that shared their values. A focus on quality and sustainability were key components of those values. It was also important for nu glass, which began its life at the EPFL Lausanne, to work with a local company. This made working with KNF, with multiple facilities in nearby cities and a strong presence in the community, a natural choice. KNF has locations in 24 countries and a commitment to collaborative pump design, which allows each location to serve their communities directly.

*Images courtesy of KNF.

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