Communication is the most important downstream application area of PCB. According to Prismark data, communication accounted for 27.30% of total PCB output in 2017, which is the first PCB downstream application field. PCB has a wide range of applications in wireless networks, transmission networks, data communications, and fixed-line broadband, and is often a high value-added product such as backplanes, high-frequency high-speed boards, and multi-layer boards. 5G is the next-generation mobile communication network, and there will be a large number of infrastructure construction needs, which is expected to drastically drive the demand for communication boards.
国产自拍在线观看PCB is required in all aspects of the communication field
国产自拍在线观看The number of 5G base stations is expected to increase significantly. The peak rate of 4G is 100Mbps to 1Gbps, while 5G will provide peak bandwidth above 10Gbps, 1ms delay and ultra-high density connection, mobility up to 500km/h, and traffic density up to 10Mbps/m2. At present, China's three major operators have entered the 5G construction speed-up phase. The 5G scale test and application test have been piloted. The local governments have set a 5G coverage schedule and accelerated infrastructure construction to achieve the goal of large-scale commercial use in 2020.
Since 5G requires a large number of connections, the number of base stations in the 5G era will increase significantly compared to the 4G era. By the end of 2017, the number of 4G macro base stations in China has reached about 3.6 million, while the 5G macro base station plans of the three major operators are 1.5 times that of 4G, and the total number reaches about 5.4 million. The peak of 5G base station construction will be 2019~2023. period.
国产自拍在线观看5G will also drive the construction of tens of millions of micro base stations. Since the frequency spectrum used by the 5G communication is high, a large degree of attenuation occurs in the propagation process. Therefore, the micro base station is required to be used as a supplement to the macro base station to implement an ultra-dense networking. According to CCID Consulting's forecast, the number of 5G micro base stations is expected to be 4 to 5 times that of macro base stations, corresponding to approximately 25 million micro base stations.
5G will bring about major changes to the structure of the base station, and the usage and unit price of the communication PCB are expected to increase substantially. In the 4G era, a standard macro base station is mainly composed of a baseband unit (BBU), a radio processing unit (RRU) and an antenna. Since the 10 Gbps transmission capacity of the conventional CPRI (the public radio interface connecting the RRU and the BBU) is not enough in the 5G era, in order to reduce the transmission bandwidth, the 5G base station structure needs to be reconstructed.
In a 5G base station, since a Massive MIMO antenna is required, a part of the BBU functions with the RRU and the antenna to form a new active antenna unit AAU (ActiveAntenna Unit), and the remaining BBUs are split into CU-DUs. Two-level architecture, in which DU (Distributed Unit) is a distributed unit, is responsible for meeting real-time requirements, and has partial underlying baseband protocol processing functions; CU (Centralized Unit) is a central unit with non-real-time wireless high-level protocol processing functions.
4G base station basic architecture
5G base station reconstruction
The antenna frame of the 5G base station needs to use the PCB as a connection. Compared with the PCB of the 4G era, the PCB used by 5G will be upgraded in many aspects, resulting in a significant increase in usage and value.