To better understand 5G's potential, it's worth quickly reviewing how cell phones work. You can see the in-depth story at How Cell Phones Work. Cell phones, at their most basic, are essentially two-way radios. They convert your voice into digital data that can be sent video radio waves, and of course, smartphones can send and receive Internet data, too, which is how you're able to ride a city bus while playing "Flappy Bird" and texting your friends.
Because there are a limited number of radio frequencies and a whole lot of people with cell phones, cellular systems divide areas into cells that overlap with one another. A cell phone tower in that area transmits the radio signal that you need to talk or use online apps. As cell phones users travel around the area, their phones seamlessly jump from tower to tower. That way, the same frequency can be reused throughout the city without becoming completely overloaded, which results in delays or even service disruptions.
Many areas now have full 4G LTE (long-term evolution) service, the fastest 4G standard. In many cases, 4G LTE is so fast that video conferencing and movie streaming work often without any delays – in other words, much faster than 3G ever dreamed of.
The widespread use of mobile devices has encouraged people to consume much more data in the form of video and images on their devices. But these devices use the same bands of the radio-frequency spectrum that cell phone carriers have always been used, which means slowing connections for everyone. To get around the lack of bandwidth, phone providers have been looking into using millimeter waves rather than radio waves for 5G.