window of opportunity for 5G connectivity

Small cells have seen phenomenal growth since the advent of the latest wireless network across the globe spawned hundreds of millions of 5G users who prize speed.

The term small cell refers to a mobile base station used to boost 5G signals in indoor areas such as malls and offices.

It is used because 5G millimeter wave signals don't travel very far and can't penetrate walls, and small cells have multiple-input, multiple-output antennas to boost network capacity.

According to the Small Cell Forum, a technology standards development organization, the total installed base of 5G small cells next year will reach 13.1 million.

Now, glass curtain walls have become popular high-rise fixtures due to their aesthetics, energy efficiency and versatility.

They have emerged as a symbol of modernity, blending aesthetics with engineering prowess.

Cellular radio engineers are focusing antenna design aspects with performance parameters like compactness, efficiency and isolation, while architects and urban designers are looking into visual appearance and aesthetic impacts of small cells.

Both cellular and construction industries are collaborating and taking further steps toward achieving advanced building materials that can adopt the 5G technology and designing small cell antennas that can avoid installing more unsightly equipment.

This week, I want to look at an innovative technology of glass antennae that converts windows into base stations by using transparent conductive materials that transmit and receive 5G signals.

The concept of glass window antennae emerged around 2020.

Branded as Waveantenna, it was developed in Japan by AGC, a glass manufacturer, NTT Docomo, a mobile carrier, and JTower, an infrastructure firm that deployed these antennae in urban environments.

AGC has been instrumental in developing the transparent conductive materials used in these antennas.

The main motivation was to enhance the carrier's 5G coverage without cluttering urban landscapes with traditional antennae.

The technology involves sandwiching transparent conductive materials between glass panes, similar to those used in laminated windshields.

Embedding the materials within the glass allows the window to function as an antenna without altering its appearance.

This design allows the antennae to be almost invisible, maintaining buildings' aesthetics and providing 5G coverage.

This is particularly effective for the Sub6 band (frequencies below 6 GHz), which are crucial for 5G deployment due to their ability to penetrate buildings better than higher frequency signals.

Glass antennae can further be tailored to reduce dropped connections on the go by enhancing reception in automobiles.

By integrating the antennae into car windows, vehicles can maintain better connectivity, especially in urban environments where signal strength can fluctuate.

There remain two key challenges to overcome, despite the pilot being installed on a window in Shinjuku, Tokyo.

First, it's essential to ensure that the antennae effectively transmit and receive signals without significant loss or reflection in varying weather conditions.

More advanced transparent conductive materials to improve the signal strength and durability of antennae are being developed.

Next up is the challenge of seamlessly integrating the antennae into existing infrastructure without disrupting the aesthetics of buildings and vehicles.

Glass antennae are expected to see wider deployment to more applications, including residential buildings and public transportation, and that will lead to economies of scale and lower installation costs, making them even more accessible.

It is an innovative technology that not merely represents a significant step forward in telecommunications infrastructure but also offers a solution to the challenges of 5G deployment in dense urban areas.

Dr Jolly Wong is a policy fellow at the Centre for Science and Policy,

University of Cambridge