Academician Wu Hequan: "Spectrum Blockchain" can be used to solve the 5G spectrum shortage problem

At the 2020 China Radio Conference which opened yesterday, Wu Hequan, an academician of the Chinese Academy of Engineering, delivered a speech saying that 5G has activated the application of high-bandwidth services. Currently, 5G is being explored in the vertical industry market. On the one hand, enterprises can rent operator networks and provide virtual private networks in the form of network slicing. Operators need to have protection isolation to deal with mutual interference.

On the other hand, enterprises can apply for dedicated frequencies to build their own 5G private networks, and flexibly configure TDD uplink and downlink time slots on demand without having to consider compatibility with the public network TDD uplink and downlink time slot configurations.

As 5G commercialization deepens, the problems of insufficient 5G spectrum and low utilization have become prominent. To meet the challenge of radio spectrum shortage, Wu Hequan proposed three solutions: developing new spectrum resources, tapping the potential of existing spectrum resources, and improving spectrum utilization efficiency.

How to develop new frequency bands? More frequency bands have been identified for 5G at the WRC-19 conference held in November 2019, including 24.25~27.5GHz, 37~43.5GHz, 45.5~47GHz, 47.2~48.2GHz, and 66~71GHz. 3GPPR17 further expands the 5G NR spectrum range. Domestically, China Unicom and China Telecom have taken the lead in the project of adding 50MHz bandwidth on the 2.1GHz band, which was successfully established in R17.

Exploit the potential of existing spectrum resources, such as dynamic spectrum sharing technology (DSS). By dynamically and flexibly allocating spectrum resources to different technologies in the same frequency band, it can not only improve spectrum efficiency, but also help 5G utilize high-quality low-frequency 4G spectrum resources. Wu Hequan pointed out that the 5G NR physical layer design is similar to 4G, which is the basis of dynamic spectrum sharing. Under the same subcarrier spacing and similar time slot structure, dynamic spectrum sharing between 4G and 5G is feasible.

To improve the efficiency of spectrum utilization, the currently popular blockchain technology can be used. Wu Hequan mentioned that based on the consensus mechanism, the confirmation information and spectrum resources are effectively bound and registered and stored before spectrum transactions, and all network nodes can confirm the right owner of spectrum assets. At the same time, rules are established in spectrum transactions, and smart contract code expressions are used instead of contracts to realize on-chain payments, which improves the intelligence level of transactions.

Of course, Wu Hequan also emphasized that the spectrum blockchain must take into account the administrative approval and supervision of the national radio management department, as well as the multi-party participation of private networks, public networks, radio and television networks and other relevant departments. In order to achieve rapid supervision and efficient sharing, a hierarchical heterogeneous hybrid blockchain architecture solution combining alliance chains and private chains is required.

"To meet the challenge of limited spectrum resources, we need the support of management innovation, evaluate the spectrum occupancy effect through supervision, introduce dynamic adjustment mechanisms and business models, and improve the scientific rationality of spectrum resource allocation and utilization." Wu Hequan said.