Due to the forecasted fast increasing cellular traffic and the already highly congested licensed spectrum, it is critical to exploit and utilize the unlicensed spectrum resources for the fifth-generation (5G) and beyond networks. A challenging problem is the coexistence of 5G and other networks with fair, reliable, and efficient sharing of the unlicensed spectrum. In this paper, we propose a blockchain-enhanced distributed spectrum sharing scheme for coexisting multiple operators and multiple WiFi APs. We design a novel lightweight and efficient consensus mechanism, named Proof of Strategy (PoG). In this consensus mechanism, the problem of spectrum sharing is used as a consensus puzzle, and the part of the unlicensed spectrum is used as the ‘fee’ of miners. With such a design, the computing overhead of the consensus process is expected to be reduced significantly. We develop a non-cooperative game to analyze the behavior of the miners and obtain a symmetric Bayesian Nash equilibrium under the uniform distribution of mining cost estimation. It can be found mathematically and experimentally that the strategy of the winner tends to maximize the system revenue by sharing the unlicensed spectrum resource. Furthermore, to reduce the impact of heavy interactions on system throughput, the operation of WiFi APs in the proposed scheme can be adaptively switched between ‘contention mode’ and ‘blockchain mode’ according to the network traffic load. The dynamic behavior is constructed as an evolutionary game, and the existence and uniqueness of equilibrium points are proved by theoretical analysis. Simulations demonstrated the fairness and effectiveness of the proposed blockchain-based scheme and the mode switching method for distributed spectrum sharing by heterogeneous wireless networks.

中文翻译：

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区块链增强了非授权频谱上异构网络的共存


由于预计蜂窝流量将快速增长且授权频谱已经高度拥塞，因此开发和利用第五代 (5G) 及更高版本网络的非授权频谱资源至关重要。一个具有挑战性的问题是 5G 与其他网络的共存，并公平、可靠、高效地共享非授权频谱。在本文中，我们提出了一种区块链增强型分布式频谱共享方案，用于共存多个运营商和多个 WiFi AP。我们设计了一种新颖的轻量级高效共识机制，称为策略证明（PoG）。在这种共识机制中，频谱共享问题被用作共识难题，而未授权频谱的部分则被用作矿工的“费用”。通过这样的设计，共识过程的计算开销有望大幅降低。我们开发了一个非合作博弈来分析矿工的行为，并在挖矿成本估计均匀分布下获得对称贝叶斯纳什均衡。从数学和实验上可以发现，获胜者的策略倾向于通过共享非授权频谱资源来最大化系统收益。此外，为了减少大量交互对系统吞吐量的影响，该方案中的WiFi AP的操作可以根据网络流量负载在“竞争模式”和“区块链模式”之间自适应切换。将动态行为构造为演化博弈，并通过理论分析证明了平衡点的存在性和唯一性。 仿真证明了所提出的基于区块链的方案和异构无线网络分布式频谱共享的模式切换方法的公平性和有效性。