Have you ever played a game of “hide and seek” with your Wi-Fi signal at home? Like a moody courier, it is sometimes enthusiastic, full of signal parcels accurately delivered to your living room so that you enjoy smooth Internet surfing; but in the blink of an eye, when you step into another room, it is like suddenly lost, the signal has become hidden as if deeply attracted to a corner of the room, and can no longer find the way out. At this point, you will not lament the elusiveness of the signal. The future “network signal guardian” - Reconfigurable Intelligent Surface (RIS), is ready to solve this problem for you.

RIS is like a seasoned courier manager with exceptional insight and control. Rather than being helpless in the face of Wi-Fi signal “capriciousness”, it will quickly mobilise its intelligent network to precisely guide and optimise the signal. Whether the living room is bright and spacious or the room is small and hidden, it can ensure that the signal package is accurately delivered to your hands so that you can enjoy stable and efficient network services at any time and anywhere. This “network signal guardian” is not only smart and clever but also very flexible. It can dynamically adjust its own “express route” according to changes in the environment and the needs of users to ensure that the signal transmission is always maintained in the best state. Like a real courier manager, it always finds the optimal solution to make the signal transmission fast and reliable.

Let's say that all the walls and ceilings in your home have been turned into intelligent “mirrors”. They can change the angle of reflection as needed and send the signal to wherever you want. The signal is no longer arbitrary run, but by these intelligent surface obedient “guide”, as if a live command “signal express”. These intelligent surfaces are covered with small, invisible “antenna units”. Each unit can precisely control the direction of signal reflection, like adjusting the volume. In traditional wireless communication, the signal is loss through the wall, around the obstacles, like a lost deliveryman. The smart surface is like a “see-through” signpost, turning complex signal paths into straight lines efficiently and accurately. 

Simply put, RIS allows wireless signals to work together as a “collective action” instead of on their own. By adjusting the reflected waves in real-time, they ensure that the signal takes the shortest path to the destination, even if your house has more walls. If the 5G network is compared to a highway, RIS is installed on both sides of the highway with “intelligent road signs”. They can dynamically adjust the path to reduce “traffic jams” (signal interference) so that data transmission is faster. Especially in complex scenarios, such as subway stations and stadiums, RIS is like a signal “navigator” to help them avoid congestion all the way through. Moreover, this thing can also save energy and protect the environment. Traditional base stations want to cover every corner, so you need to constantly increase the power, RIS is like a “signal relay station” with the minimum energy consumption so that the signal runs farther and more accurately.

Right now, this technology is still in the laboratory stage, but the future is promising. As if the walls of your home may become “invisible routers”, and windows, desktops, and even mirrors become signal conditioners. You brush the drama in the kitchen, not afraid of lag, into the bathroom to listen to music, music is still smooth. 

What's even cooler is that RIS may also be used in intelligent transportation and unmanned driving. In High-rise cities, the signal messes into a pot of porridge, RIS spread all over the building facade, helps signal “navigation” so that self-driving vehicles can maintain the real-time network connection. Reconfigurable Intelligent Surfaces (RIS) simply turn ordinary surfaces into “smart guides” for signals. It transforms the signal from a random scattering of signals into an organised “precision delivery”. In the future, these smart surfaces could be the heroes behind the scenes, making sure you're seamlessly connected to the world, whether it's your home network or your city's communications. Signal “everywhere”.

（Writer：Cily）