[Editor's Note] The history of communications is the history of human constant efforts to connect. Since prehistoric times, the function of communications has served as a means of communication and promise for humans, who are social animals. In Korea, telecommunications was first introduced in 1888 during the Joseon Dynasty, and the information age began in the 1980s after liberation with the rapid development of communications businesses and technology. Now, as we enter the 5G and 6G eras, we are looking at satellite communications and quantum communications, which are considered the next-generation communications. With the development of cutting-edge technologies such as artificial intelligence (AI), robots, cloud computing, and UAM, communications are becoming increasingly important and are expected to continue to develop endlessly. Communications is the most basic and core technology that spans almost all fields. In this series, our magazine will cover various aspects of communications, from the history of communications to minor incidents, technologies, and trends.
■ The reason 5G is fast is in the bandwidth

The telecommunications industry entered a new phase with the first commercialization of 5G (5th generation) in Korea in 2019. Many issues related to 5G have been resolved, but some are still being resolved. 5G is based on New Radio (NR) technology and has spread with the characteristics of 'ultra-high speed, ultra-low latency, and hyper-connectivity' that are up to 100 times faster than the initial 4G (LTE). The initial maximum transmission speed of 5G was presented as 20Gbps.

In the 5G era, there is a belief that cutting-edge technologies such as AI, metaverse, robots, AR/VR, and self-driving cars will be possible based on high-speed networks. IoT (Internet of Things) technology connects people and objects, and objects and objects, and all kinds of AI services are increasing. Beyond the area of personalization, 5G is expected to be a communication that will enable many things in various industries such as media, video, medical, health, finance, security, manufacturing, automobiles, and UAM.

The reason why 5G can provide such a faster speed than LTE is bandwidth. The wider the bandwidth, the more data can be processed faster. To increase the bandwidth, the communication frequency must be increased. 5G has various frequency bands, and the bandwidth of the frequency band above 24 GHz, called mmWave, is up to 4 GHz. The 28 GHz frequency provides 8 times wider bandwidth than 3.5 GHz. It generally provides wider bandwidth than the Sub-6 GHz band. For example, if you make 10 coins with 1,000 won, they will be 100 won coins, but if you make 10 coins with 5,000 won, they will be 500 won coins.

However, the wider the bandwidth, the faster the speed, but the lower the diffraction to avoid obstacles. 5G provides high speeds, but the coverage is short, so it is easily disconnected and cannot go behind obstacles. It also absorbs moisture. Therefore, to compensate for this, base stations must be built densely or supplemented with technologies such as beamforming.

■ After 5G commercialization…

Domestic 5G (NR) is currently in progress. Consumers are still complaining about 5G speeds. From the commercialization stage, the 5G-specific services that consumers experience compared to 4G are limited to streaming high-definition videos.

The reason is that 5G is still half-baked. In our country, commercialization was achieved based on the 3.5GHz band among the 5G Sub-6GHz (3.5GHz below 6GHz) and mmWave (24GHz above) bands.

In the early days of 5G commercialization, the government and the three mobile carriers promoted 5G innovative services based on the 28GHz frequency band, but there has been ongoing controversy over the fact that the 28GHz band is currently incapable of B2C services.

The telecommunications company was allocated the 28GHz 5G frequency band through an auction in 2018, but ultimately failed to launch a nationwide network, citing difficulties in monetization. SKT's 28GHz band network deployment number is 1,650 devices, and although it was required to install 15,000 devices, it has effectively given up on deployment.

Accordingly, the Ministry of Science and ICT has issued a final notice of allocation cancellation due to non-compliance with frequency allocation conditions. The Fair Trade Commission imposed a fine of 33.6 billion won on SKT, KT, and LG Uplus, calling it a “deceptive advertising practice.”

The Ministry of Science and ICT has set out to discover new operators based on the 28GHz frequency. StageX was selected as the target company for the 28GHz band frequency allocation through an auction held in January. The final winning bid was 430.1 billion won, which is more than double the winning bid of the three mobile carriers in 2018, which was in the early 200 billion won range.

However, there has been constant noise since the process of applying for a new business. Telecommunications industry experts pointed out that StageX lacked capital and was not qualified. In June of this year, the Ministry of Science and ICT also raised issues with StageX’s capital and shareholder structure and initiated a hearing process to make a final decision on whether to cancel the selection of candidate qualifications. StageX, which is in crisis, is continuing its legal battle, but according to the industry, it is also believed that frequency reallocation will be difficult.

■ 5G Specialized Network, 28GHz Solution?

For rapid commercialization, mobile carriers have adopted the 3.5GHz frequency-based 5G non-standalone mode, or LTE-5G combined method (Non-Stand Alone, NSA). 5G NSA can utilize existing 4G LTE core infrastructure, reducing deployment costs. Some have also mentioned that it has the advantage of reducing smartphone battery usage compared to SA.

On the other hand, 5G standalone mode (SA) is a method of configuring a network based on a 5G core. The 28GHz frequency was considered essential for implementing the initial 5G SA. It is described as a ‘pure 5G’ that enables new services with features such as low latency and ultra-high speed.

Telecommunications equipment manufacturers such as Nokia and Ericsson claim that “5G SA requires a transition as it supports new functions such as network slicing, RedCap devices, and edge solutions.” Nokia CTO Han Hyo-chan said, “If 5G SA is satisfied, basic services such as network slicing technology will be possible.” India and the US are monetizing network slicing technology.

According to Nokia recently, SA implementation is possible if nationwide base station installation is completed in the 5G 3.5GHz frequency band. The three domestic mobile carriers have almost completed nationwide network construction for the 5G 3.5GHz frequency band. However, the three mobile carriers are maintaining NSA despite the Ministry of Science and ICT’s push for 5G SA implementation. This is because the theoretical speed is currently lower than that of NSA using LTE.

In the midst of this, the characteristics of the 5G 28GHz frequency band are expected to shine in the 5G specialized network (5G-linked network). The 5G-specific network refers to a customized 5G network that can be freely used by companies or organizations through frequency application to the government in specific areas such as buildings and land. It is aimed at high frequencies that are not possible for B2C as B2B services.

6G Forum Chairman Park Dong-joo said, “In the manufacturing industry, it is advantageous to secure uplink data transmission speeds, such as transmitting captured video and sharing sensor data, by using a wide bandwidth of 800 MHz or 600 MHz of 28 GHz to transmit data from terminals to servers.”

Last March, the Ministry of Science and ICT announced a new project for the '2024 5G Industrial Convergence Infrastructure Development Project' to promote digital transformation in the private sector through verification of convergence services based on 5G. Major service construction cases include: △Major accident prevention service based on real-time control in the manufacturing field, △Personal digital terminal (PDA) data processing in the logistics field, △AI-based autonomous driving robot delivery service, △Precision surgery service through 3D augmented reality (3D AR) and real-time non-face-to-face collaboration of patient computed tomography (CT)/magnetic resonance imaging (MRI) test results at hospitals, △Immersive virtual reality (VR) content, and △Military training service.

Samsung Electronics also built a 5G network for the Ieum 5G network in Suwon, Gyeonggi Province, in January of this year. It announced plans to utilize the 28GHz band in addition to the 4.7GHz band that is commonly used for Ieum 5G, in network equipment manufacturing sites, etc. Currently, the number of domestic corporations designated for Ieum 5G has increased to 12, expanding the scope of utilization to a total of 31 organizations and 56 locations.