Design Of Blockchain System For 6G Network And Research On Some Key Technologies

In the future 6G network,the contradiction between service capacity limitation and user demand growth will undoubtedly make sharing one of the most important features of the 6G network.Network co-construction and sharing and distributed intelligent allocation of resources are inevitable trends.However,the high sharing of 6G networks will inevitably lead to the transformation of network construction and operation from the single-agent centralized mode with the participation of network operators to the decentralized cooperation mode of network operators,equipment providers,resource providers and other multi-agent.Such a transformation will bring many security and trust problems that cannot be solved by the traditional centralized security framework.The introduction of blockchain can provide an extended Trust-as-a-Service（TAAS）distributed sharing solution for sharing and cooperation in 6G networks,establish trust at low cost in an untrusted competitive environment,solve the problem of single point failure in a centralized environment,achieve trusted co-construction and sharing of network infrastructure and efficient scheduling,help the future network integrate an open Internet architecture,and finally realize the combination of openness and distributed control.However,as a special distributed technology system,blockchain naturally needs to face the"impossible triangle"problem:in the case of ensuring security and decentralization,scalability will inevitably become the Achilles heel of the blockchain system.For this reason,this paper tries to find a design method of blockchain,so as to improve the scalability as much as possible under the condition of ensuring security and decentralization,and further seek the dynamic balance between the three according to the actual needs of the application.The main research contents of this paper are as follows:（1）A high throughput blockchain system for 6G networks is designed.The blockchain network consists of some important nodes in the 6G network.It divides these nodes into a main chain and several shard chains.Each shard executes consensus and confirms transactions in parallel,so that the transaction throughput of the system increases approximately linearly with the increase of nodes participating in consensus throughout the network.At the same time,it combines digital twins and federated learning to achieve secure sharing and intelligent scheduling of network infrastructure on the basis of ensuring the security and credibility of data privacy,achieve deep integration of blockchain and wireless communication,break the trust barrier between"people-machine-thing-network",and improve the efficiency and security of wireless networks:introduce digital twins at the device layer,Establish and update a digital twin model based on relevant data files such as network load and device scheduling stored in a segmented blockchain to help the device layer make intelligent predictions and analysis decisions;Introduce federated learning in the core cloud layer,and train the global model based on data collected by the main chain,such as network service requirements,network infrastructure scheduling,and idle conditions,to facilitate future prediction and global scheduling.This design has excellent throughput performance and efficient scalability.（2）An optimization problem for system throughput is established.The efficiency of the blockchain network is evaluated by analyzing the consensus time and transaction throughput of the blockchain network,and it is proved that the optimization problem is a convex optimization problem.By optimizing the number of shards in the blockchain network,the calculation and communication time of consensus are reduced,and the transaction throughput of the system is improved.At the same time,the security performance analysis model of the high throughput blockchain system oriented to the 6G network is established.The measures taken by the high throughput blockchain system oriented to the 6G network against the Byzantine attack are described.The security performance of the system when attacked by malicious nodes is analyzed through the attack model and defense model.Analysis and simulation results show that the transaction throughput of the proposed method can reach more than 30 times larger than that of a non-sharding scheme.They also show that when one-third of the nodes in the system are attacked,the consensus of the system is hardly affected;even if the number of nodes being attacked at the same time reaches half of the total number of nodes,the probability of the occurrence of failed shards is still less than 10^-4,and the system still has good survivability.（3）Based on the high throughput blockchain system for 6G networks,a design method for autonomous evolution of high-performance sharded alliance chain is designed.This method introduces concepts such as reputation system,node evaluation,subjective logic,and stackelberg game to empower the segmented blockchain to achieve a triangular balance that meets application needs:use blockchains to provide a platform for cross organizational co construction and sharing of6G networks,and automatically design segmented blockchains based on the scalability and security requirements of actual applications;treat blockchain nodes as individuals with differences,score each node from the perspective of scalability and security,and use subjective logic methods to dynamically adjust the score based on the node’s historical behavior and neighbor evaluation;according to the scoring results,a stackelberg game is used to complete the leadership selection and fragmentation of the fragmented alliance chain,achieving high-performance autonomous evolution of the fragmented alliance chain.The simulation and analysis results show that the scalability score uniformity between the segments of the segmented blockchain generated using this design method is much higher than that of Elastico and Omni Ledger;At the same time,in the performance comparison of"short board"fragmentation,the scalability score of the fragmentation blockchain generated by this design method can reach 1.28 to 3.06 times that of the other two design methods,and the security score can reach1.46 to 3.35 times.