TU-TESL

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Behind etc is a technical standard war between DSRC and c-v2x. One of the things that has become more popular recently is the installation of etc. According to the Circular of the Ministry of transport on the progress of the key work of canceling the toll stations at the provincial boundary of expressways, as of December 18, the total number of users of etc installed in China has reached 192.234.4 billion, and the development and promotion of etc has finally come to an end. It used to be a good thing, but China's business has always been to engage in "raids", only from. Reflecting the grass-roots level, many high-speed toll stations are not very friendly to vehicles without etc. As reported by the media, there are even toll station staff who say, "let him stop if you don't do etc now, that's all. We have opened more channels. We have to take responsibility. Who will take the responsibility? " This article does not discuss the social topics during the installation and execution of these etc. We are concerned about the technical and standard issues reflected behind etc. Because, just on December 12, something happened in America on the other side of the ocean, which made us have a clearer understanding of this future technology dispute, and also let us smell the smell of 5g war. In fact, when we look back on the development of etc (Electronic Toll Collection), we can see that it took more than ten years for etc to accelerate from the start of demonstration project by the Ministry of transport in 2007, to the national networking of etc in 2015, to the presentation of this year's government work report. Globally, no country has been able to achieve this. It should be noted that although China's etc technology standard was originally based on DSRC (dedicated short range communication), China has gradually stepped out of its own standard road and is in the forefront of application when the 5g era is coming. Of course, this involves the very popular v2x (vehicle to everything) in recent years, which is often referred to as the "interconnection of all things". Early v2x was mainly based on DSRC. DSRC is the leading communication technology in Europe and America at first, and it has been developed and tested in the United States for many years. It is only with the development of cellular mobile communication technology that c-v2x (cellular v2x) appears. On December 12, when Chinese reveled in shopping, the Federal Communications Commission, the top management agency in the field of communications in the United States, decided to tilt the balance of application to c-v2x. In other words, the radio spectrum resources with a bandwidth of 75MHz originally allocated to DSRC 20 years ago are divided into three parts. The bottom 45mhz is open to the whole society, and the top 20MHz gives c-v2x. The DSRC can only allocate 10MHz. In fact, DSRC supporters, who have long heard of the FCC's vacillation, have been watching. In April of this year, it announced to suspend the plan of carrying DSRC for American market models from 2021. But in China, Ford, who started the counterattack with "more, more China", has been firmly in the c-v2x camp. GM, which has always been very conservative, kept silent after learning the FCC resolution (GM is the only vehicle company in the United States to realize the mass production application of DSRC technology, but CTS models equipped with this function failed to achieve large-scale sales, so it must be very difficult to hear this news at this time). We can see that although Europe is still swinging, at least DSRC in the United States has gone. The communication technology and standard pattern of the whole American automobile industry and even the global automobile industry are also being rewritten. In a word, DSRC was supported by the United States and the European Union before, but 3GPP behind the c-v2x finally gained the leading position in the 5g era of mobile communication. 3GPP, including Huawei, Ericsson, Intel, Nokia and other members, is becoming more and more powerful, including Toyota and other car companies in this camp. In 2017, 3GPP announced the first set of c-v2x physical layer standards for V2I and V2V communication, which are different from IEEE 802.11p technology. Subsequently, the gap between c-v2x and DSRC in the industrialization process was rapidly narrowed. On June 14, 2018, 3GPP plenary session (TSG × 80) approved the freezing of independent networking function of the fifth generation mobile communication technology standard (5gnr). This also marks the introduction of the first version of 5g standard. In 2020, 5g will become commercial. Moreover, with the development of cellular communication technology, China has been in LTE layout for many years, and the network covers most parts of the country. At present, it has become the largest LTE market in the world. If 5g communication starts to be commercially used in 2020, c-v2x has greater advantages in terms of continuous iteration, reliability and signal transmission delay, and should have a broader market in China. The choice of FCC in the United States is helpless and wise. How does DSRC gradually decline? It has its natural short board. Take WiFi, which we are very familiar with now, for example, DSRC is a homologous technology, which is based on the standards defined by WLAN. The WiFi we use usually follows a series of protocols such as 802.1a and 802.11ac. DSRC follows 802.11p. Although their advantages lie in low communication delay and stable quality, their signal range is limited because they are essentially local area networks. In addition, the weakness of DSRC based on IEEE 802.11p lies in that a large number of new roadside units are needed for networking. The new cost of this kind of base station equipment is large, and the cost of its hardware products is relatively high. C-v2x can directly use the existing cellular network (that is, the network for mobile phones), and use the existing base station and frequency band, so the networking cost is significantly reduced. This also determines the fate that DSRC will be eliminated in etc application. As we know from the initials of c-v2x cellular, c-v2x and the communication technology used by our mobile phones belong to the same system. This is also the reason why c-v2x began to rise after 4G network was deployed. Therefore, with the coming of mobile communication era, c-v2x has shown great potential. Moreover, DSRC has a fatal weakness, that is, it cannot make a smooth transition to 5g. This is because the underlying communication protocol is different. If DSRC wants to coexist with 5g, in addition to building two sets of infrastructure, it must carry two sets of vehicle end communication units in one vehicle, and cut out two non-interference spectrum In the era of 5g, it must be a fool to deploy DSRC on a large scale and then switch to c-v2x under 5g. The U.S. Department of transportation has estimated that the large-scale deployment of DSRC requires at least billions of dollars in infrastructure spending. NHTSA calculated that the cost of DSRC deployment at the vehicle end was about $300 per vehicle. That's why the US FCC is moving to the other side. Of course, the FCC still leaves DSRC with such a small chance. C-v2x can be more smoothly transferred to 5g and absorbed as a subset of 5g technology. In fact, the roadmap of c-v2x from 4G to 5g era - from LTE v2x to LTE ev2x to NR v2x, that's what it does. In a sense, if a country accelerates the promotion of c-v2x, it means that the automobile industry in this country will gain the first mover advantage in 5g era. Therefore, China could have walked on the DSRC road for a longer time. But when 4G networks were rolled out on a large scale in China, China quickly entered the c-v2x camp. At the 2017 World Internet of things Expo, commercial applications based on c-v2x began to demonstrate. "We are pushing lte-v (4G based c-v2x)," Li Jun, academician of the Chinese Academy of engineering, said in an interview In 2018, the Ministry of industry and information technology issued the management regulations on the use of 5905 ~ 5925mhz for the direct communication of the Internet of vehicles, which clearly planned 5.9G frequency band as the working frequency band of the direct communication of the Internet of vehicles based on LTE c-v2x technology. Since then, c-v2x has gained an overwhelming position in China. However, we also need to be aware that in its (intelligent traffic system) field represented by etc, for car companies and industries keen to do multi topic selection, it is rare to stand in line with a clear technical choice before. This is because c-v2x has a strong promotion organization, namely 5gaa, which was established in September 2016. At the 5gaa meeting in April 2018, Ford released joint test results with Datang and Qualcomm to compare the actual road test performance of DSRC and c-v2x (lte-v2x). The test results show that under the same test environment, when the communication distance is between 400m and 1200m, the bit error rate of lte-v2x system is significantly lower than that of DSRC system, and the communication performance of c-v2x is significantly better than that of DSRC in terms of reliability and stability. With such a test result, Ford finally gave up DSRC and chose c-v2x. In fact, Qualcomm has supported DSRC before, and until 2017, Qualcomm also sought compatibility between DSRC and c-v2x in its technical solutions. But in the end, it turned to the c-v2x camp. Today, the members of the 5gaa alliance cover major global vehicle enterprises, operators, chip manufacturers, automotive electronic enterprises and information service enterprises, including Huawei, Datang and other major system manufacturers and operators in China, who are also members of the alliance, with more than 100 members. From the distribution of spectrum in 1999 to the establishment of the standard for the first time in 2004, to the abandonment of DSRC to choose c-v2x, the United States has obviously fallen behind in this standard competition. Even if the U.S. Department of transportation has spent more than $700 million on DSRC promotion, it can not stop the trend. Moreover, although Europe has yet to show its attitude and remain neutral. But when the trend comes, it will probably not go against the trend. According to the white paper research on the development of China's Internet of vehicles industry issued by China International Economic Exchange Center Guojing Consulting Co., Ltd. in August last year, it is predicted that by 2020, the global market size of the Internet of vehicles v2x will exceed 614 billion yuan, and the Chinese market will reach 200 billion yuan. This is a market full of opportunities. From the confrontation between DSRC and c-v2x, we can see that Datang, Huawei and other Chinese enterprises are making rapid efforts in this competition in the future, and they are already in the forefront of the standard team. This is our pride, but as a whole, there are still many shortcomings in the automobile industry. We have not mastered the real technology leadership. We need to give up the opportunistic thinking of "overtaking on the curve", and "forge hard villages, fight hard battles" and forge ahead like Zeng Guofan. Therefore, in the light of 5g, there is no reason for independent brands in the automobile industry not to strive.