With the rapid development of information technology, mobile communication technology continues to progress. From the first-generation analog communication technology to the fourth-generation digital communication technology, mobile communication networks have become essential infrastructure for people's daily lives and socio-economic development. Currently, the fifth-generation mobile communication technology (5G) has entered the commercial stage, providing people with faster, lower latency, more reliable, and smarter wireless connection services.

5G technology features high data rates, low latency, high energy efficiency, low cost, high system capacity, and massive device connections. It utilizes millimeter waves, large-scale MIMO, beamforming, network slicing, and other technological innovations to enhance the speed, flexibility, and intelligence of the network. The primary application areas of 5G technology include enhanced Mobile Broadband (eMBB), Ultra-Reliable Low Latency Communications (uRLLC), and Massive Machine Type Communications (mMTC).

Enhanced Mobile Broadband (eMBB) primarily addresses the explosive growth of mobile internet traffic, providing mobile internet users with an extreme application experience such as high-definition video, virtual reality, augmented reality, etc. Ultra-Reliable Low Latency Communications (uRLLC) primarily meet the needs of vertical industry applications with extremely high requirements for latency and reliability, such as industrial control, telemedicine, autonomous driving. Massive Machine Type Communications (mMTC) are primarily geared towards applications such as smart cities, smart homes, and environmental monitoring that aim at sensing and data collection.

The Current State of 5G Development in China

Currently, 5G is developing rapidly in China. Data from the Ministry of Industry and Information Technology shows that as of November 2022, the total number of 5G base stations in China reached 2.287 million, a net increase of 862,000 from the end of the previous year, accounting for 21.1% of the total mobile base stations, an increase of 6.8 percentage points from the end of the previous year. The number of 5G base stations in China accounts for more than 70% of the world's total. At the level of individual consumers, according to data statistics from operators, as of the end of April 2023, 5G network covered all prefecture-level cities and county towns across the country, with 634 million 5G mobile phone users. In terms of 5G package users, as of the end of April 2023, the total number of 5G package users accumulated by the three major telecommunications operators reached 1.213 billion.

However, in the number of 5G package users announced by operators, some 4G mobile phone users were also included in the statistics. Since 5G is not a rigid demand for mobile phone users, many 4G users do not have a strong desire to upgrade. Currently, the main group to upgrade and experience 5G is young users with certain consumption power. In the real scenario, the indoor WiFi and 4G experience will not be worse than 5G, and even better than 5G. It seems that the popularization process of 5G in the individual user market will be longer than that of 4G.

In terms of the enterprise side, in various industry fields such as industrial internet, connected car, smart city, smart medical, smart agriculture, etc., 5G is still in the process of actively promoting implementation. Operators, equipment vendors, and service providers have proposed many solutions combining 5G and the industry. There are many scenarios that can be commercialized and mature cases, but the specific effects and market feedback are not very ideal. The cost of 5G private network deployment is high, and the investment return period is long. The main body of 5G private network construction is still mostly operators, and the construction of the network is a heavy asset project, which small and medium-sized enterprises may find hard to bear. Therefore, it is necessary to give industry users more time to truly feel the enabling effect brought by 5G, and finally be willing to invest and pay for 5G.

Challenges in the Promotion and Application of 5G

Despite the numerous advantages and potential of 5G technology, it faces several challenges and difficulties in its promotion and application process, mainly in the following aspects:

(1) 5G coverage is narrower than 4G

Due to the frequency band, the signal coverage of a 5G base station is not as extensive as 4G. Data shows that the coverage radius of a 2G base station is about 5-10 kilometers; for 3G, it's about 2-5 kilometers; for 4G, it's about 1-2 kilometers. Because the 5G frequency point is too high, the base station's coverage radius is generally about 300-500 meters. Therefore, to achieve the same experience as 4G, the number of 5G base stations would have to be several times higher. Currently, our existing 5G base stations are primarily outdoor macro stations, and the scale of 5G users is not large, with ample resources. However, once we get indoors (where over 70% of traffic originates), carrier indoor base stations cannot be adequately deployed, which will inevitably affect the user experience and, consequently, their trust and acceptance of 5G. The expansion of 5G in the B-end (government and enterprise users) market is the same. Whether it can meet the requirements of industry application scenarios and provide the key indicators promised before (bandwidth, latency, reliability, etc.), whether it can achieve the usage effect and application cost of industrial WiFi, still needs continued observation.

(2) 5G energy consumption is higher than 4G

Because the 5G network requires a large number of base stations and spectrum resources, and these resources vary in distribution and utilization across different regions, there is an imbalance in 5G network construction. Some cities and regions have achieved a high level of 5G network coverage, while some remote and underdeveloped areas have not yet realized 5G network coverage or have poor coverage quality. Also, because the 5G network uses technologies like massive MIMO, each base station unit consumes 3-4 times the power of 4G, leading to an increase in energy costs and carbon emissions. It is estimated that without energy-saving measures, the energy consumption of China's telecom industry will increase 2.6 times by 2025.

(3) 5G operation and maintenance costs are higher than 4G

5G is an ultra-complex network. With 2G/3G networks not yet completely phased out, the superimposition of old and new technologies exacerbates the overall network architecture's complexity. In recent years, equipment vendors have been striving to simplify product operation and maintenance, and carriers are actively exploring intelligent operation and maintenance. However, due to various reasons, the transition of operation and maintenance work and the shift in operation and maintenance personnel's thinking is slower than expected. The slower the change, the shorter the time window. If operators do not accelerate the promotion of operation and maintenance reform, it may affect their own transformation.

(4) The construction of 5G application scenarios requires multi-party collaboration

Due to the characteristics and advantages of 5G technology, it can support more application scenarios and business models, such as industrial IoT, smart healthcare, vehicle networking, etc. However, the commercial value and feasibility of these application scenarios are not clear enough and mature enough, requiring more exploration and verification. At the same time, because these application scenarios involve multiple fields and levels, they need to coordinate multiple departments and units, such as industry regulatory departments, technical standards departments, data security departments, etc., which presents significant complexity and coordination difficulties. For instance, remote equipment control and machine vision inspection, the construction cost of their 5G private network is several times that of industrial WiFi, but the actual use effect has not met expectations. Industry experts acknowledge the lack of scalable applications and call for global participants to explore the "integrated synergistic effect" between 5G modules and industries or factories to fully release the potential of 5G bandwidth and make solutions replicable in various environments.

Promotion of 5G Needs to Solve Pain Points

(1) Develop D2D and other potential 5G technologies to reduce operation and maintenance costs

Device-to-Device (D2D) technology in 5G is a technology that allows direct communication between 5G terminal devices without the need to go through a base station or core network. When a 5G user is not within the coverage of a 5G base station, they can connect to the 5G base station through nearby user mobile phones. This can improve communication efficiency, reduce latency, increase connection density, and enable more 5G application scenarios, such as vehicle networking, industrial IoT, smart cities, etc. Additionally, it can reduce the demand for 5G base stations in total. D2D technology can also enhance the security and privacy of communications, as data cannot be intercepted or tampered with by intermediate nodes.

In the future, by developing potential 5G key technologies such as 5G D2D, new multi-carriers, flexible duplexing, new modulation coding, and full duplex (also known as "simultaneous same-frequency full duplex"), we can build a technology system centered on new multi-addressing, large-scale antennas, ultra-dense networking, and full-spectrum access to fully meet the future needs of 5G technology.

(2) Solve the problem of high energy consumption of base stations

By optimizing the hardware design and software strategy of base station equipment, improving the efficiency and performance of baseband boards, RF units, power amplifiers, and other devices, we can realize the modularization, simplification, and high integration of base station equipment. Using AI technology to control base station power automatically and dynamically, adjust the working state and energy-saving mode of the base station according to the change in business load, we can balance service quality and energy saving. Employing liquid cooling, air cooling, and other technologies to reduce the cooling load of base station equipment, reduce the use of air conditioning equipment, and lower the energy consumption of supporting facilities. Using wireless microwave, relay, and other technologies, we can reduce the dependence and cost of fiber optic transmission and improve transmission capacity and flexibility.

(3) Match technology advancement with business needs

In promoting the construction of 5G, we need to ensure that technology investments match business needs. Overinvestment in technology without corresponding business returns may lead to a bubble. We should conduct thorough research and analysis of the needs of various industries to ensure that the application of 5G technology meets actual business needs. In the construction of 5G infrastructure, investment planning should be rational to avoid overinvestment. Excessive base station construction and spectrum purchases can lead to resource waste and increased operational costs. Scientific planning and evaluation are needed, with investment scale and rhythm determined according to actual demand.

In addition, we need to emphasize the sustainability of business models in the construction of 5G. They should be able to support the healthy development of operators and related industrial chains, rather than relying on short-term subsidies and incentives. We should encourage innovation and collaboration to find sustainable business models to ensure the long-term sustainability of 5G construction. At the same time, costs should be reduced through standardization. For example, in the consumer sector, due to the sufficiently large production scale of 5G phones, costs have decreased significantly. Therefore, before the issue of standardization is resolved, it is difficult for 5G applications in the industrial sector to scale up, which restricts the cost reduction of 5G. In the future, we could allocate dedicated frequencies for industrial applications, separating industrial use channels from consumer use channels, thereby reducing interference, and lowering the cost of 5G in industrial scenarios.