What is 5G? A Guide to the Transformative Wireless Tech That's Being Hyped to Change Everything

Imagine you’re sitting at a red traffic light. The light turns green, allowing you to proceed. As you take your foot off the brake, however, your car senses that a vehicle approaching the intersection is moving too fast and will likely run the red light. In response, your car applies the brakes to keep you safe as the scofflaw blasts through the intersection.

Your car didn’t see the other vehicle using motion sensors or cameras, which is how today’s crash-avoidance systems work. Instead, your car was talking to the other car wirelessly via 5G. It knew the direction of travel, the speed, and whether or not the driver was braking. Your car saved your life thanks to the power of 5G.

This is just one scenario of many thousands that will be made possible by the next-generation of wireless networks—if we choose to believe the marketing departments of carriers and equipment vendors. Real-world deployments will play out differently and won’t initially live up to this level of hype. Here’s why.

What is 5G?

5G is the fifth generation of wireless networking technology. The high speeds you enjoy on your phone today are powered by 4G, which has been the prevailing technology the last five to eight years. Globally, most people see maximum 4G speeds of about 16.9 megabits per second (Mbps), according to Open Signal. 5G promises to deliver Gigabit speeds (>1Gbps). Where 4G allows you to stream your favorite YouTube videos in full HD, 5G will make it possible to stream 4K HDR content—and more.

But 5G isn’t all about speed. The 5G standard (called 5G New Radio, or 5G NR), also includes shifts in how many cell sites are required and how many devices can connect to a signal cell site. For instance, Today’s networks rely on 200-foot towers to blanket large areas with signal. About 25,000 are sprinkled around the U.S. There will be far more 5G cell sites, each covering a smaller area. Moreover, those 5G sites will be able to connect many times more devices to the network at once. And that’s important because there will be many more devices demanding data. Think sensors and cars, not just phones.

The third goal of 5G is to lower latency, or how long it takes the network to respond to a request. Today, latency is about 9 milliseconds (ms). With 5G, that will drop to 1ms. Latency is particularly critical in automotive applications. Think about the distance a car travels at 60mph in 9 ms compared to in 1 ms. That distance can be the difference between life and death. Latency is also key to providing good experiences when exploring new worlds in virtual reality, or stomping through the latest online multiplayer video game.