AsianScientist (Jan. 30, 2020) – By Rebecca Tan and Li Lidao – At 11pm local time on April 3, 2019, South Korea became the first country in the world to launch a 5G network, beating the US by a hair’s breadth of just one hour. Although the service was initially available to only six people, South Korea subsequently saw over two million people sign up for 5G in the next four months.
While these numbers point to the burgeoning consumer demand for greater internet speeds, what is really at stake with 5G is the future of communication, not just between people on their mobile phones, but between people and machines, and—more importantly for Industry 4.0—machine-to-machine communication.
Want to know more about how 5G works and how it will impact the world? Read on to find out!
Why do we need 5G?
To answer this question, we need to go back to the start: 1G, the first generation of wireless phones. What now look to us like comically bulky bricks were in fact revolutionary for their time because they were designed for people on the move. These early wireless phones—and as you’ll see later, even 5G ones—were essentially glorified radios, sending and receiving voice signals through radio towers. In contrast, the original telephones invented a century earlier by Alexander Graham Bell relied on a network of physical wires.
The next generational leap in the 1990s was when those wireless networks switched from transmitting analog to digital signals with 2G.The following decade saw 3G phones—like the revolutionary iPhone first released in 2007—that had internet connectivity, enabling web browsing on top of basic voice calls. By 4G, data rates had improved so much that video streaming calls became routine. Tomorrow’s 5G networks promise speeds of up to 20 Gbps, which roughly work out to downloading a high definition movie in seconds.
But 5G is about much more than watching Netflix on your phone. The main reason 5G was developed was to address 4G’s limitations of latency and bandwidth. If you think about data as water flowing through a pipe, latency is analogous to the length of the pipe while bandwidth is similar to the diameter. If the pipe is short, the latency is low and data flows from point to point very quickly. Similarly, if the diameter of the pipe is large, the bandwidth is high and more data can flow at the same time.
Just as 4G enabled unexpected services like Uber to emerge, 5G networks could spawn entirely new industries. For starters, 5G’s low latency would enable self-driving cars to respond at near real-time speed and avoid accidents, while its high bandwidth would allow the rapidly growing number of Internet of Things (IoT) devices to access the internet without clogging up the network.
The fundamental principles behind wireless communication remain unchanged in 5G: essentially, phone antennas send and receive packets of radiowave data. However, to achieve the desired combination of low latency and high bandwidth communication, 5G networks had to move into a part of the spectrum that hadn’t been used for communication before: a higher range of frequencies including what is known in the industry as the millimetre wave band (mmWave).
While higher frequencies allow the network to pack in more bandwidth and reduce latency, there are considerable trade-offs involved. The laws of physics dictate that frequency is inversely proportional to wavelength, and that higher frequency waves travel much shorter distances before fading away. Shorter wavelength radiowaves are also more easily blocked by buildings and are even affected by factors like rain. All this means that many more base stations will need to be installed to ensure decent coverage—400 times more than a 4G network, by some estimates.