Opportunities and challenges of the 5G golden frequency band: Is the 700MHz industry chain ready?

Spectrum resources are the core resources for the development of the mobile communications industry and will largely determine the future industrial development pattern. In the 5G era, high-quality spectrum resources, especially low-frequency band resources, are even more scarce. Among them, 700MHz is the world's first 5G low-frequency band (Sub-1GHz) large-bandwidth 5G international standard and is the only one.

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So, what role will 700MHz, which was the main low-frequency band in the 4G era, play in the 5G era? What new challenges will the seemingly mature 700MHz industry chain face in the 5G era? Are industry manufacturers ready for this?

Golden frequency band is once again up to the task

The 700MHz frequency band is known as the "golden frequency band" for its wide coverage, strong penetration and low networking cost. These excellent wireless propagation characteristics have made it widely used in terrestrial television broadcasting services in various countries and regions. With the vigorous development of mobile communication technology and market in recent years and the increasing demand for multimedia content, the integration of multimedia content and mobile communications has become a general trend, and the 700MHz frequency band has also shifted from traditional television broadcasting services to mobile communication services.

The commercial use of 700MHz-based 4G networks in 2014 kicked off the commercial use of 700MHz for mobile communications around the world, and it has gradually become the main low-frequency band. According to GSA statistics, as of May 2020, 57 700MHz 4G networks have been commercially used around the world, with 2,375 terminal models. 700MHz has also become the fifth most commercially used 4G frequency band in the world after FDD1800MHz, FDD800MHz, FDD850MHz, and FDD2.6GHz.

The 700MHz frequency band, which has been through many battles in the 4G era, has a new important role and task in the 5G era: at the 87th Access Network Plenary Meeting of 3GPP held in March this year, China Radio and Television's 700MHz frequency band 2×30/40MHz technical proposal was adopted and included in the 5G international standard, becoming the world's first 5G low-frequency band (Sub-1GHz) large-bandwidth 5G international standard. The successful formulation of this standard has set a new benchmark for the use of 5G spectrum resources in the global 700MHz frequency band.

There is no doubt that after the introduction of 700MHz, operators will obtain better 5G network coverage, and will be able to provide good coverage with much fewer base stations than in the medium and high frequency bands, effectively reducing the construction cost and energy consumption of 5G networks. A calculation shows that the coverage area of ​​700MHz is about 3-4 times that of 2.6GHz. It only takes 400,000 base stations to build a nationwide 5G network using the 700MHz frequency band, while the three major operators need to build 6 million macro base stations using their own frequency bands. Deploying 5G networks on the 700MHz frequency band will significantly reduce the construction costs of operators' base stations.

The global 700MHz industry chain in the 5G era is also developing very rapidly. In April and May 2020, 700MHz began to enter the commercial stage of 5G networks. Currently, there are 3 700MHz 5G networks in commercial use worldwide. All mainstream chip manufacturers already support 700MHz 5G NR, and there are more than 20 5G mobile phones in the world that support 700MHz.

In China, due to the lack of clear division of the 700MHz frequency band, there are relatively few types of terminals that support 700MHz on the terminal side. In April this year, the Ministry of Industry and Information Technology issued the "Notice on Adjusting the Frequency Use Plan of the 700MHz Band", requiring that some spectrum resources originally used for radio and television services be re-planned for mobile communication systems, and clearly adjusting the frequency use plan of the 702-798MHz band for mobile communication systems, and planning the 703-743/758-798MHz band for mobile communication systems with frequency division duplex (FDD) working mode. In the future, 700MHz 5G terminals will become more and more abundant.

700MHz faces three "new" challenges in the 5G era

It is not difficult to see that in terms of technical characteristics, 700MHz helps to achieve intensive and efficient coverage of 5G networks. In terms of industry chain maturity, 700MHz has accumulated a lot in the 4G era, but only a few operators have tried to deploy applications in the 5G era. Especially under the new industry trends and patterns in the 5G era, 700MHz, which has just arrived in the 5G era, will still face new challenges.

Challenge 1: How to support innovative functions on the system side and promote the maturity of the industry chain? For example, at the 87th RAN plenary meeting of 3GPP that ended in March this year, China Radio and Television's 2*30/40MHz technical proposal on the 700MHz frequency band was included in the 5G international standard by 3GPP, becoming the world's first 5G low-frequency band (Sub-1GHz) large-bandwidth 5G international standard. This is a great innovation, but it also requires the promotion of a mature industry chain system to support it in order to ensure commercial success. In terms of base station hardware products, it is critical to develop high-quality hardware products that meet both operator requirements and global standards in a very short period of time.

Challenge 2: How to solve the new problems brought about by "co-construction and sharing"? Not long ago, China Mobile and China Broadcasting Corporation signed a 5G co-construction and sharing cooperation framework agreement. The two parties jointly determined the network construction plan, jointly invested in the construction of 700MHz 5G wireless network in a 1:1 ratio, and jointly owned and had the right to use 700MHz 5G wireless network assets. This kind of co-construction and sharing network deployment with large bandwidth in the 1GHz low frequency band is the first in the world. It is bound to require corresponding development and a large amount of interconnection and interoperability testing. The entire industry needs to work together to promote the successful commercialization of 700MHz 5G network with an open and cooperative attitude and in the most effective, reliable and compatible way.

Challenge 3: How to coordinate with medium and high frequency bands? With the deployment of 5G networks, although medium and high frequency bands have the advantage of large bandwidth, their shortcomings of high coverage cost and weak deep coverage have also begun to emerge. It has been a global consensus to achieve 5G deep and wide coverage based on traditional FDD frequency bands and to conduct carrier aggregation and collaborative networking with medium and high frequency 5G. For operators with "golden frequency bands", how to formulate a strategy for the coordinated development of the 700MHz frequency band and medium and high frequency bands is crucial.

Experienced "masters" are urgently needed

In view of the many new challenges facing 700MHz in the 5G era, the industry urgently needs manufacturers with rich 700MHz deployment experience to help operators better utilize the "golden frequency band."

Among them, Ericsson, a century-old company, was the first equipment manufacturer to participate in and drive the construction of global 4G networks in the 700MHz frequency band. According to GSMA statistics, Ericsson is also the manufacturer with the most 700MHz 4G commercial network deployments to date.

It is reported that these networks using Ericsson equipment can smoothly evolve to 5G through software upgrades. Ericsson expects that its system equipment will be able to support the commercial deployment of carrier aggregation in 700MHz and medium and high frequency bands by the fourth quarter of this year.

Wu Riping, Director of Ericsson Radio Network System Product Department in China, said: Ericsson is the leading equipment manufacturer for the three earliest 700MHz 5G commercial networks deployed in the world. These networks have given Ericsson more experience in network deployment, interconnection, subsequent evolution, and collaborative networking than the industry, which can better support the successful commercial deployment of 700MHz by domestic operators. We not only hope to bring Ericsson's global 700MHz experience and technology to China, but also bring China's good experience and innovation to the world.

"Supporting the development of China's communications market has been Ericsson's firm commitment for many years." Wu Riping recalled that Ericsson has fully participated in the entire process of China Mobile's construction from 1G to 5G. Ericsson promises that China is not only a very important market for Ericsson, but also its most important R&D base outside of Sweden and one of the most important production bases in the world. In the past five years, Ericsson's R&D investment in China has reached 15 billion yuan, and there are more than 5,500 R&D engineers in China; in 2019, Ericsson invested 500 million Swedish kronor in the intelligent upgrade of its Nanjing production base.

"700MHz is a very good spectrum resource and should be fully utilized for all services, including traditional eMBB services, 5G voice services, and the potential to provide wide-area IoT services in the future." Wu Riping said: "We are very much looking forward to and firmly believe that with the construction of China Mobile and China Broadcasting Corporation's 700MHz network in the future, the development and maturity of the entire 700MHz industry chain will be greatly accelerated. Ericsson is willing to have in-depth discussions and cooperation with China Mobile and China Broadcasting Corporation on 700MHz 5G networking strategies, product features and application exploration. We believe that with Ericsson's mature commercial experience in the global 700MHz system, it can better help operators build a high-quality, efficient, green and open 700MHz 5G network.