https://www.cnet.com/news/the-biggest-5g-breakthrough-may-be-this-harmless-little-plastic-strip/

Enter a seemingly innocuous strip of plastic found in the Mobile World Congress booth of Ericsson, the Swedish supplier of telecom equipment. The strip contains printed circuit boards and tiny antennas able to pick up and send 5G data. Along the walls at one of Ericsson's demos, the strip was embedded behind a thin piece of wallpaper or hidden by a thin plastic housing. Another strip was laid under a long train of carpet that was rolled up. 

"This is how easy your network rollout will be," Pal Frenger, a researcher at Ericsson, said as he placed the roll on the floor and kicked it open. He liked the joke so much, I heard him say it again a few minutes later.