Science

5G? LTE? Your guide to how wireless networks work

Every day you hear commercials about how one mobile carrier is faster or has better coverage than the others. They throw around terms like 4G, LTE, and 5G and expect people to know what they are. As far as the average person is concerned, five is higher than four, so it must be better — right? Maybe. Let this be your guide to how wireless networks operate.

Wireless networks

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At their most basic, wireless networks work in the same way as any telephone or radio that’s been around for a hundred years. Information is processed, encoded into a radio signal, and sent to another receiver. The receiver decodes the signal and does the whole process over again. Some of these transmissions are one-way, like the radio in your car, but most networks transmit information back and forth.

Instead of calling and receiving like a phone, wireless networks use downloading and uploading. When you click on the Facebook app on your phone, your phone receives (or downloads) the encoded information from the Facebook server using radio waves, and decodes it so that you can see what your friend ate for dinner last night. When you want to send her the filtered picture you took of that dinner, your phone encodes the photo into radio waves and sends (or uploads) it to the Facebook server for decoding and posting. 3G, 4G, LTE and 5G are all just ways to make that process move faster.

Radio frequencies

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This is how information doesn’t get mixed up. It wouldn’t be good if you sent a text and it made your neighbor’s TV fuzzy.

An easy-to-understand example of this is a basic walkie-talkie. Changing the channel on a walkie-talkie changes the radio frequency at which it operates. You and your friend need to be talking on the same frequency to hear each other. People at other frequencies aren’t going to hear you. The busier the frequency, the harder it’s going to be for you and your friend to communicate. It’s the same for mobile networks.

What does “G” stand for?

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When looking at 3G, 4G, and 5G, the “G” stands for the generation of technology. For example, 5G will be the fifth generation of wireless network technology. Each generation has set standards.

Currently, to be considered a true 4G network, connection speeds need to be at least 100 megabits per second (Mbps) at their peak. For reference, 25Mbps is needed for peak video streaming. When these standards were announced, 100Mbps speeds were unheard of, which made some wireless companies nervous. They were making strides in technology but couldn’t advertise them truthfully. That’s where LTE comes in.

LTE is in line with the phrase “sort of.” It stands for “long-term evolution” and is used to describe technology that’s attempting to reach the 4G standard. If your phone displayed a 4G LTE symbol, you didn't have true 4G speeds, but you were close. You “sort of” had 4G.

5G revolution

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Although the basic principles of the technology have largely remained the same, the radio frequencies that each generation operates on have fluctuated. 4G doesn’t work on the same frequencies as 3G, and 5G won’t work on the same frequencies as 4G. That means that with each rollout, new hardware needs to be developed to handle the new generation. If you have a 4G phone, it will never be able to truly manage a 5G connection.

Each form of wireless technology uses different radio frequencies. With the amount of wireless technology that exists, the frequencies are pretty busy, as you can imagine. To reach the speeds necessary for 5G, mobile carriers are looking at using higher frequencies that aren’t used as much and would offer more bandwidth. The problem is that higher radio frequencies don’t have as much range as lower frequencies, which means less coverage. But, if carriers can solve the coverage issue, high-frequency 5G will offer multi-gigabyte-per-second speeds (up to 10 times faster than 4G), latency (responsiveness) as low as one millisecond, and allow much more traffic than 4G.

Looking ahead

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Carriers are already starting to unveil their 5G networks, although none of them is true 5G yet. Much like 4G LTE, 5G Evolution is the precursor to true 5G. People wanting the high speeds and low latency of 5G will likely still have to wait a few years. It’s estimated that by 2021 or 2022, most carriers will offer 5G networks and 5G-specific devices.