4.5G is just a step toward 5G era

SK Telecom announced on Monday that it expanded a so-called 4.5G network to 75 cities and 31 districts in Korea. On the launch of the service in June, it was available in about 23 cities.

What is the difference between our current LTE network, the fourth generation (4G) network, and the 4.5G and 5G network of the future?

SK says the 4.5G network is nine times faster than the existing LTE network, which means people can download a conventional high-definition movie, about 2 gigabytes, in only 23 seconds.

The 4.5G network, thus far, only works with devices that have Exynos 9 chipsets, used in Samsung Electronics’ Galaxy S8 smartphone and Galaxy Note8 phablet.

KT, the second largest mobile carrier in the country and the official sponsor of the PyeongChang Olympic Games that open next February, also offers 4.5G network speed. But it is more focused on promoting its progress with 5G technology. KT hopes to show off 5G technology with a 5G-enabled pilot device to be unveiled by Samsung Electronics.

According to KT, 5G will be at least 20 times faster than the current 4G LTE network. People will be able to download a 2.5 gigabyte ultra-high-definition movie in one second. This faster network will be a game changer for the IT and electronics industry as 5G-powered Internet of Things technology will accelerate industry disruptions started by the previous generation networks.

The major difference between 4.5G and 5G is that the latter requires a major hardware change both from network providers and device manufacturers.

To make 4.5G possible, SK Telecom aggregated five existing LTE frequency bands to enhance the speed and data transmission. Frequency bands can be thought of as roads on which data travels.

“Just as cars move faster on wider roads, the aggregation means data can move faster on the wider band,” said Choi Seung-won, head of network infrastructure at SK Telecom.

5G, however, needs to be set up on new frequency bands, and international discussion is ongoing over what frequency bands are most fit for the next generation network.

Based on the frequency bands, network equipment makers like Nokia and Ericsson as well as device makers like Samsung Electronics and chipset producers Qualcomm all need to come up with new industry standards.

This is why some refer to 4.5G as a marketing term for the most advanced version of 4G LTE.

Though a complete disruption in the telecoms industry will be brought on by 5G, customers for the time being can benefit from faster networks provided by 4.5G.

While both KT and SK Telecom have set 2019 as a target to commercialize 5G, it is unclear if that will ultimately happen.

BY KIM JEE-HEE [kim.jeehee@joongang.co.kr]