PCB Tech - What is the difference between the 5G small base station of the mobile phone camera circuit board and 4G?

In the 4G era, the prosperity of the mobile Internet has prompted a continuous increase in the demand for network capacity, and 80% of network services occur in indoor scenarios. Entering the 5G era, with higher deployment frequency bands, the proportion of services carried by indoor base stations will increase accordingly. The editor of the mobile phone camera circuit board learned that, in addition to the public network, 5G will also carry indoor services for various vertical industries, changing the production methods of all walks of life. The small base station solution directly affects the quality and application mode of 5G indoor networks, and is an important technical means to solve indoor coverage. The maturity of the 5G small base station industry has also become a hot issue of urgent concern to operators.

5G network has clear requirements for small base stations

In recent years, data services in the public network and vertical industries have continued to develop. As of early 2020, the DOU for mobile Internet access by domestic operators has been close to 7GB, and the DOU for 5G users in a single month in December 2019 is even closer to 17GB. Most data services occur indoors, so coverage solutions for indoor scenes are getting more and more attention.

In the 4G era, the main solution for indoor coverage solutions is outdoor coverage and traditional DAS distribution systems. Entering the 5G era, operators’ main coverage frequency bands have increased from 1.8~2.3GHz to 2.6~4.9GHz, leading to many difficulties in the construction of traditional solutions:

1. The wear loss increased by about 6~10dB when playing outdoors, resulting in a significant reduction in the coverage ability of outdoors playing indoors;

2. The frequency response performance of passive components and feeders cannot meet the requirements of system construction above 2.7G, that is, 3.5G and 4.9GHz cannot use DAS indoor sub-system solutions;

3. For 2.6GHz, more than 90% of the traditional DAS deployed in 4G on the existing network are single-channel room divisions. In order to support the MIMO feature, it needs to be modified. The construction is difficult, and there are problems with the consistency of the new and old branches.

What are the changes in 5G small base stations compared to 4G?

The 5G small base station can overcome the above-mentioned traditional room division construction problems from the technical source, and has the advantages of low optical deployment and construction, flexible expansion, and support for visual operation and maintenance. At the same time, it greatly increases network capacity and improves network operation and maintenance efficiency.

In addition, industry network requirements are critical to the development of 5G. 5G technology has been applied in factories, ports, energy and other fields to support epidemic prevention and control and the resumption of production of enterprises. 5G technology has been used in emergency response and disaster preparedness., Prevention and control and other aspects have played an important role.

In the post-epidemic era, various business applications such as industrial Internet, telemedicine, intelligent quarantine robots, and online education have put forward higher requirements on key indicators such as industry network speed, delay, and reliability.

The 5G small base station supports flexible frame structure configuration to meet the needs of large uplink and low-latency services, can increase the overall network capacity through cell splitting capacity, support visual operation and maintenance to improve monitoring capabilities, and has DICT convergence capabilities to support multi-service and multi-scenarios Integration can meet the diverse, differentiated, and fragmented needs of various industries, and will be widely used in indoor scenarios in vertical industries.

5G small base stations have a big change compared to 4G

In the middle and late stages of 4G development, with the increase in indoor business demand, operators have introduced active room divisions, including distributed pico base stations, extended pico base stations and integrated leather stations, which are mainly used in transportation hubs, large venues, hospitals, etc. Mid-to-high-value scenarios such as hotels, business halls, coffee shops, etc. In general, the product types of small base stations are relatively comprehensive.

Entering the 5G era, the classification of small base stations is similar to that of 4G. The HDI board factory feels that considering the distributed deployment requirements of high-capacity public networks and large and medium-sized coverage industry networks, the current 5G active room sub-sites are mainly distributed and extended leather base stations. For extended leather base stations, compared with 4G products, 5G small stations have a wider range of application scenarios, higher technical requirements, richer functions, and a simpler network architecture.

(1) 5G small station application scenarios are more extensive

Because 4G small base stations are weak in the number of channels, cell capacity, user capacity, etc., they are mainly used in low- and medium-value and small-area areas such as hotels and office buildings to solve the problem of low signal coverage and improve the network's ability to support data services. .

Compared with 4G small stations, 5G expansion small stations face more scenarios and have planned diversified products such as 2T2R/4T4R, 5G single-mode/4G+5G dual-mode, etc., and have cell splitting capabilities, which can gradually change from medium to low-capacity scenarios. Expand to high-capacity scenarios such as hospitals and manufacturers. At the same time, 5G small stations support the characteristics of multi-service integration and cloud virtualization. With the gradual clarification of the needs of vertical industries, small base stations with simple deployment and flexible capacity expansion will become important solutions for industry networks.

(2) 5G small stations have higher technical requirements

With the increase in product types and performance improvements, and the full coverage of applicable scenarios, compared with 4G, 5G small stations have more station types, and technical requirements have also increased. First, in terms of baseband resources and radio frequency indicators, the bandwidth requirement is increased to 100MHz, the number of cells is expanded from only supporting a single cell to a maximum of 8 cells, and the number of users in a single cell is upgraded to supporting 200 users; The requirements of the device are higher, and the power requirement of a single channel reaches 400mW.

(3) 5G small station network architecture is simpler

The entire 5G small station system is based on a three-tier architecture, including BBU, RHub, and pRRU. It can be directly connected to the core network through the operator’s private transmission network, and the cell ID is configured by the BBU’s cell without access to security and convergence gateways. At the same time, the 5G small base station architecture design supports standardized southbound interfaces for network management in the early stage, and the small base station intelligent network management can be deployed uniformly, which is relatively simple in terms of the architecture and network management deployment of the 4G small base station.

(4) 5G small base stations have more functions

The 5G small base station adopts an open and flexible system architecture with richer functions. First, it supports cloud deployment and virtualization deployment, and can be integrated with lightweight MEC to provide low-latency and high-reliability solutions; secondly, 5G small base stations support network capability opening, and extend connections with existing IoT networks through Ethernet. The MEC realizes the integration and calculation of 5G NR transmission data and extended IoT data; in addition, the 5G small station realizes the local data forwarding between the wireless access network and the core network through the local core network, realizing the local offloading of data traffic, and ensuring data Safety.

5G small cell commercial deployment still faces challenges

After technology accumulation and application exploration in the 4G era, the development of 5G small stations is at a higher starting point, and the industry has invested more. However, the speed, delay, and reliability requirements of 5G networks have been greatly improved compared with 4G, and the demands of public network and industry users are also rising. For commercial deployment, the current 5G station is still in terms of technical capabilities, cost, and maturity. There are many problems and challenges.

(1) The maturity of some products needs to be improved

At present, small station manufacturers in the industry have generally completed the development of 2TR 100MHz products, but the number of cells, power consumption, user capacity and other functional performance still need to be improved, and the support capability in multi-mode high bandwidth is slightly insufficient. At the same time, in order to provide more competitive solutions, the small station still needs to be further optimized in terms of overall cost and power consumption.

(2) Unbalanced development of upstream and downstream industries

In contrast to the public network and the industry’s demand for digitalized room products, the current small base station industry chain as a whole presents a rugby-like characteristic of "thickness in the middle and thinness on both sides". The industrial resources are mostly concentrated in the system and equipment integration links in the middle reaches. The chip industry investment in the upstream of the chain is slightly insufficient, and the solution is relatively simple. Currently, the server matching accelerator card solution is mainly used. The ARM and SOC solutions are gradually being improved, and the maturity needs to be improved; software and downstream landing services are an important part of operation The link involves customer delivery, innovative applications and exploration of business models. It is particularly important for indoor coverage. At present, it is necessary to increase investment and make up for shortcomings in order to achieve balanced development and strengthen the industrial chain.

(3) Need to pay attention to deployment issues

Compared with the traditional DAS that has been deployed on a large scale, the introduction of 4G expanded small base stations is later, the network construction cost is higher, and the activation process is complicated. Coupled with the uneven delivery and operation and maintenance capabilities of some small station manufacturers, the scale application of the extended leather station in the 4G period is limited.

In view of the problems in deployment, it is recommended that 5G small stations pay attention to deployment issues: first, strengthen the integration capabilities of the existing network and fully connect with other network elements to enhance the deployment and delivery capabilities; second, pay attention to the improvement of product mass production and after-sales capabilities. Establish a complete service system to improve operation and maintenance service capabilities; third, for the prominent problems of indoor and outdoor co-frequency interference that exist during large-scale deployment, research and optimization schemes to improve overall network performance.

5G is an important infrastructure in the era of digital economy and the first of my country's new infrastructure. The diverse needs of public networks and industry applications have prompted the continuous enrichment of 5G solutions. 5G small base stations are flexible in deployment, high in capacity, efficient in maintenance, and can support the construction needs of a variety of industries and different scenarios. The PCB editor feels that in the subsequent development process, it is necessary to further improve product maturity, pioneer and innovate, improve network performance, reduce construction costs, pay attention to deployment and operation and maintenance issues, provide the best solution while reflecting the best cost performance, and fully Balance the upstream and downstream industrial chains, build a more solid foundation for commercial landing, and achieve value win-win with operators and the industrial ecological chain.