Research On DSA Interference Threshold Management Method Based On Blockchain Technology

As a key technology to cope with spectrum shortage,dynamic spectrum access technology has received extensive attention from academia and industry.Dynamic spectrum access technologies comprise opportunistic spectrum access(OSA)and concurrent spectrum access(CSA).The former allows the secondary user(SU)to access the spectrum when the primary user(PU)is idle,and the latter allows the secondary user to share the spectrum with the primary user under the premise that the aggregate interference to the primary user does not exceed the interference threshold.The US Federal Communications Commission(FCC)proposed Citizens Broadband Radio Service(CBRS)as a solution for dynamic spectrum sharing,which stipulates that Priority Authorized License(PAL)and General Authorized Access(GAA)users can share spectrum with existing users on the premise that the aggregated interference to existing users is lower than the interference threshold.Meanwhile the aggregated interference from GAA users to PAL users also needs to be controlled below a certain interference threshold.Due to its advantages of decentralization,traceability,and non-tampering,blockchain technology can provide a more flexible and secure spectrum sharing mechanism for dynamic spectrum sharing.This paper combines the blockchain with the CBRS dynamic spectrum sharing scenario,and proposes a spectrum sharing mechanism based on the interference threshold management of the consortium chain,aiming to more fully utilize the interference threshold of existing users.In this mechanism,PAL users can provide GAA users with an interference threshold margin through the blockchain network,so as to ensure that the aggregated interference to existing users does not exceed the interference threshold,and to enable access to more GAA users.The simulation results prove that the mechanism can effectively improve the spectrum utilization.Based on Practical Byzantine Fault Tolerance(PBFT),this paper designs a consensus algorithm that is more suitable for dynamic spectrum sharing scenarios,which simplifies the consensus process and effectively reduces the communication complexity of the consensus process.In addition,aiming at the problem of interference protection between PAL users and GAA users in the CBRS system scenario,this paper designs a spectrum sharing framework based on hierarchical blockchain.It divides the authorized area into several local Area,builds a blockchain between users in the local area,and build a consortium chain among all PAL users in the authorized area.The paper proposes a Po R(Proof of Reliability)consensus algorithm that links mining difficulty with node reliability,provides incentives for nodes to participate in spectrum sharing,and reduces computing resource consumption.This paper proposes a Po R(Proof of Reliability)consensus algorithm,which links mining difficulty to node reliability,providing incentives for node participation in spectrum sharing,while reducing computational resource consumption.This paper also proposes the reliability value evaluation to ensure the safe and stable operation of the spectrum sharing process using the reliability value-based PAL user queuing mechanism,and maximizes the total transmission rate of GAA users using bipartite graph best matching.The simulation experimental results prove that this spectrum sharing mechanism can effectively improve the total transmission rate of GAA users.