The official account of Luoyang Unicom on its WeChat public address says that the AAU (active antenna processing unit) has been sleeping in depth at regular intervals recently to reduce the energy consumption of 5G base stations. As soon as the news came out, people had a lot of doubts about such a painstaking construction of 5g. Some people think this is the reason why immature technology is eager to start; Some people suspect that operators have invested heavily to promote 5g, but it has become a chicken rib. Is there a secret behind it; Some people worry that they can no longer play games all night. So what's the problem with our 5g base station?
Power consumption of base stationThe problem is serious,
The contradiction stems from the imbalance between supply and demand
According to the Ministry of industry and information technology, by the end of July, the cumulative number of 5g terminal connections in China had rapidly increased from 66 million at the end of June to 88 million at the end of July. At the same time, the accelerated popularization of 5g terminals is also promoting the rapid growth of 5g users.
In the half year performance of the three major operators, except that China Unicom did not announce the number of 5g users, the data of China Telecom and China Mobile show that the number of 5g users in China has exceeded 100 million. Of course, there are many users who are using 5g packages but have not replaced 5g devices (for example, the editor is one of them), but from the number of 5g terminal connections of more than 80 million, we can also see that the process of 5g popularization in China is accelerating.
5g development, base station first. Base station density is the basis of 5g signal coverage. Relying on national policies, operators have continuously increased investment in 5g base station construction since last year. According to the statistics of the Ministry of industry and information technology, by the end of 2019, China has built more than 130000 5g base stations; By the end of February 2020, 164000 5g base stations have been opened in China.
On June 6, 2020, at the "first anniversary of 5g licensing" online summit held by the news and publicity Center of the Ministry of industry and information technology, Lu chuncong, deputy director of the information and communication administration of the Ministry of industry and information technology, said that in terms of network construction, basic telecom enterprises have built more than 250000 5g base stations; Wu Hequan, academician of the Chinese Academy of engineering, predicts that by the end of 2020, the number of 5g base stations in China may reach 650000, and the number of 5g package users may reach 200 million, so as to realize 5g continuous outdoor coverage in all prefecture level cities, key coverage in counties and towns, and indoor coverage in key scenes.
Li Nan, deputy director of the Institute of wireless and terminal technology of China Mobile Communications Research Institute, also disclosed to the reporter of Huaqiang Electronics: "with the joint efforts of the industry, China Mobile's annual 5g base station construction goal is expected to be completed by the end of August. At present, we have built 300000 5g base stations and deployed more than 300 5g cities. This is also the first in the world, which shows our determination and confidence in 5g development of China Mobile. "
Li Nan, deputy director of wireless and terminal Technology Research Institute
China Mobile Communication Research Institute
"Power consumption is not only the biggest problem of 5g base station, but also the heaviest burden on the three operators. In addition to the capex (5g network construction investment) foundation of 5g, OPEX (network maintenance cost) based on energy consumption In fact, it is the top priority to determine whether 5g can develop smoothly. During 2017-2020, under the joint efforts of the industry, the power consumption of base stations has decreased significantly, but even so, its power consumption is about three times that of 4G base stations. "
Like a raging fire, China Unicom Luoyang branch has announced that its official account is 3 5G radio stations (AAU), which have already been connected to the network, and it will open the deep sleep function of the AAU in different periods at the same time.
Under the rendering of individual media, the panic atmosphere began to spread on the network, and various negative statements poured in. Many people worried that the network would not be available after the base station went dormant, or thought that 5g had "existed in name only". To crack these rumors, we must first understand what the "sleep" of the base station means.
According to Li Fuchang, deputy director of the wireless Research Department of China Unicom Network Technology Research Institute, the deep sleep function of the no-load state of the base station AAU equipment refers to that when the base station is idle for a long time, because there is no 5g user access, the base station AAU equipment can be allowed to turn off the power supply of most active equipment, so as to save the no-load power consumption of RF unit equipment. Because the 5g base station AAU equipment supports 64 channels or 32 channels, the 5g base station AAU adds a large number of active devices, baseband processing units and other devices than the traditional 4G equipment, so as to greatly improve the no-load power consumption of this type of equipment.
Li Fuchang, deputy director of Wireless Research DepartmentChina Unicom Network Technology Research Institute
"The deep sleep function of the no-load state of the base station AAU device means that when the base station is idle for a long time, because there is no 5g user access, the base station AAU device can be allowed to turn off the power supply of most active devices, so as to save the no-load power consumption of the RF unit device. Because the 5g base station AAU device supports 64 channels or 32 channels, the 5g base station AAU is much more than the traditional 4G device Active devices, baseband processing units and other devices, so as to greatly improve the no-load power consumption of this type of equipment. "
In addition, the reporter also learned that the sleep mechanism of base station AAU is actually very flexible. For example, when the traffic volume of 5g network decreases sharply late at night, the operator can judge the time period of business idle according to the statistical data and turn on the sleep mode. When the sleep function is enabled, the operator will also keep the 4G network online to meet the normal use needs of users.
When sleep is turned on, when special circumstances occur, 5g access users suddenly increase, and the operator can timely wake up the base station AAU equipment within a few minutes to provide 5g service again. This has a relatively small impact on users.
However, it should be acknowledged that the power consumption of 5g base stations is indeed a serious problem at present. In order to verify the specific power consumption of 5g base stations, the operator has tested the power consumption of ZTE and Huawei's 5g base stations. The results show that the power consumption of BBU is related to the inserted boards, which is not affected by the service load, and the overall power consumption is also at the level of 293-330w. The power consumption of AAU is closely related to the service load. Under 100% load, the power consumption of AAU can reach 1127-1175w; At 50% load, the average power consumption of AAU is 892-956w.
"Power consumption is not only the biggest problem of 5g base stations, but also the heaviest burden on the three operators." Li Nan said frankly: "in addition to the capex (5g network construction investment) foundation of 5g, OPEX (network maintenance cost) based on energy consumption is actually the top priority to determine whether 5g can develop smoothly. During 2017-2020, under the joint attack of the industry, the power consumption of base stations has decreased significantly, but even so, its power consumption is about three times that of 4G base stations.
At present, the full load power of a single 5g base station even reaches nearly 3800w, and the general power of a 4G base station is about 1000W. Li Nan said that under normal load, RF accounts for most of the power consumption of 5g base stations. The other part is used for base station processing, because after the bandwidth increases and the rate increases, the processing capacity of the base station needs to be higher.
However, from the perspective of energy efficiency ratio, although the power consumption of 5g base stations has increased a lot, with the same power consumption, the network capacity of 5g is dozens of times that of 4G. Objectively speaking, it is very normal that the power consumption is larger than 4G. However, at present, 5g has not been popularized by the whole people. The premise of 5g popularization requires that the base station density coverage reach a certain level. At present, it is in the period of 4G transition to 5g. Therefore, the high operating cost of 5g base stations with low utilization makes it difficult for major operators to sleep and eat.
A staff member of an operator once told reporters: "the number of 5g base stations is three times that of 4G; the power consumption of a single 5g base station is three times that of 4G; and the price of a single 5g base station is three times that of 4G." In addition, due to the small number of users in some areas, it is not uncommon that the base station has been completed and has not been powered on. It is not a secret that the base station is dormant or even not powered on, and the exponential cost increase is also a forced choice for operators. Therefore, operators need to find more ways to solve the problem of "power consumption anxiety" both operationally and technically.
There are various energy-saving solutions for base stations,
But the challenge goes far beyond that
Compared with the previous 3G / 4G, the launch of 5g in recent years is indeed in a hurry. It took only one year from the freezing of standards to the completion of commercial deployment, and there is still much room for improvement in related technologies. According to the current technical conditions, similar to the timed sleep adopted by the current operators, the use of AI technology to control the dynamic power consumption of 5g base stations is regarded by major manufacturers as an important breakthrough in reducing energy consumption, and significant results can be achieved in the short term.
According to Li Junfeng, communication engineering engineer of China Unicom: "At present, the AI algorithm is mainly used to automatically generate energy-saving strategies, including cell shutdown, carrier shutdown, RF channel shutdown, symbol shutdown, etc. each strategy corresponds to different energy-saving effects, has its specific adaptive scenarios, and has different impact on network quality 。 Therefore, the current research content is how to adapt the automatically generated energy-saving strategy to the actual scene, which needs to be developed in cooperation with equipment manufacturers, and optimized and trained according to the actual situation. "
Li Nan believes that the power consumption problem can also be improved from the structure and internal components of the base station itself. He said: "How to further improve the efficiency of our PA and reduce the energy consumption of our digital chips is actually the key to reducing the power consumption of our base stations. It is also hoped that the industry will invest energy in this and help our operators solve this problem together. I believe that only when this problem is solved, operators can let go to deploy more base stations and open more 5g base stations."
At the same time, improving the heat dissipation efficiency can also achieve the effect of reducing power consumption. Due to the introduction of large-scale antenna technology, the 5g base station AAU integrates the active antenna part into the AAU chassis. Therefore, its volume is 4 times that of 4G and its weight is 2 times that of 4G, which brings great challenges to the deployment of 5g base station.
The challenge of deployment comes from the space problem of antenna mast. When the heating capacity of AAU is huge, dense equipment will make it difficult to deal with heat dissipation. At present, 5g base station suppliers also have many new solutions to solve the heat dissipation problem, such as liquid cooling, new heat dissipation structures and new materials. Li Nan said: "through our preliminary analysis, nearly 20% of the existing sky can not deploy and build 5g sky resources, which brings great challenges to our 5g deployment in the next stage. I hope our industry can collectively tackle the problem of lightweight and miniaturization of 5g equipment, reduce the size and importance of our sky and improve the heat dissipation efficiency as soon as possible."
However, some manufacturers have found another way to use high-speed point-to-point wireless transmission technology to provide flexible networking for 5g and help operators reduce operating costs. In short, it is an ultra-high upgraded version of the traditional microwave transmission system. In the past 2G, 3G and 4G era, the microwave technology used in wireless transmission can only support 1Gbps, and even 2gbps and 3gbps in multi port, but the support rate of single port can only reach 1Gbps at most.
Yao Kui, deputy general manager of sales of shengweilun Communication Technology Co., Ltd., said: "In the current 5g era and the future 6G era, the return rate is higher and higher, and the bandwidth requirements are greater and greater. In some places in China, optical fiber transmission can be realized to solve the problem of wired transmission, but with the intensive networking of 5g and 6G, only wired transmission can not solve the problem of networking flexibility, so the wireless high broadband transmission requirements come with it.
However, in the past, the single port rate can only support 1Gbps at most, which is difficult to meet 5g requirements. Therefore, Sheng Weilun took the lead in launching a 10Gbps point-to-point high-speed wireless transmission system in the industry, which supports the transmission rate of single port 12g at the highest, and can meet the transmission demand of 200 meters to 1 mile, while the power consumption is less than 30W.
"5g itself uses high frequency, and the signal space loss is relatively large. The coverage of 5g is about 300 meters, so the distance between two base stations of 5g is 500 or 600 meters. Our transmission distance can reach 1 mile, that is, 1.7 km, so we have enough use in 5g data return."
When it comes to base station power consumption, Yao Kui said: "At present, although the construction of 5g communication base stations is in full swing, the annual electricity bill of operators is very large and the burden of operation cost is very heavy. Therefore, on the premise of meeting the transmission distance, we try to reduce the power as much as possible. Reducing the power means low power consumption and can reduce the operation cost of operators. At the same time, we will not rule out high-speed rail or military industry from this mountain in the future The temporary construction of real-time data from the head to another mountain requires such a point-to-point transmission and flexible network layout. "
Although there are various methods to solve the power consumption problem of base stations, overall, the power consumption of 5g base stations is still the biggest challenge for major operators in recent years. If the cost problem caused by power consumption cannot be completely solved, the propulsion and landing of 5g will be affected to a great extent.
Therefore, operators are also looking for management means to reduce electricity charges. For example, China iron tower Shanxi company, in consultation with the government and the three major operators, has formulated the "one station, one policy" transformation plan. In 2020, it plans to complete the transformation of 4273 direct station sites. At the same time, we actively participated in power market transactions, and the unit price of direct power supply electricity charges decreased by an average of 9.5%, saving costs and making full profits. It is expected to save nearly 140 million yuan in electricity charges for the three operators in 2020.
However, the editor believes that while promoting 5g construction, operators need to develop more 5g application scenarios in addition to solving the problem of base station power consumption. Operators should also think about how to create 5g application ecology, attract users and crack the "5g useless theory". Otherwise, the embarrassing situation of "countless empty base stations and difficult to find users" will only be placed in front of operators.
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