Space-air-ocean integrated networks (SAOINs), composed of low earth orbit (LEO) satellites, unmanned aerial vehicles (UAVs), and unmanned surface vehicles (USVs), have been advocated to provide seamless, high-rate, and reliable wireless transmission services for USVs. However, due to the restrictions of limited resources (e.g., spectrum bandwidth, transmission power, etc.), diverse demands of USVs, and selfishness of both UAVs and LEOs, there comes a significant challenge to provision high-quality wireless data rate for USVs to achieve their satisfied quality of experience (QoE). To this end, in this paper, we propose a hierarchical on-demand wireless data rate provisioning scheme to provide ubiquitous transmission services for USVs. Specifically, we first devise a hierarchical wireless data rate provisioning framework. The LEO satellite with an extensive wireless coverage is utilized to provide LEO satellite-to-UAV (L2U) data rate for UAVs with a certain L2U data rate price. Each UAV is employed to provide UAV-to-USV (U2U) data rate for covered multiple USVs with a certain U2U data rate price. We then propose a modified three-stage Stackelberg game to model the wireless data rate assignments among LEO satellites, UAVs, and USVs, where the time-varying data rate demands of USVs are considered to formulate the utility maximization problem. Afterwards, the backward induction approach is leveraged to attain the Stackelberg equilibrium as the solution of the formulated problem, where the closed-form expressions on the optimal strategies of both USVs and UAVs under different data rate budgets are obtained by the nonlinear programming method. Besides, an accelerated conjugate gradient descent (ACGD) based iteration algorithm is also designed to obtain the optimal strategies of the LEO satellites on the L2U data rate prices. At last, extensive simulations are carried out to demonstrate that the proposed scheme can significantly increase the utilities of USVs, as compared to other benchmark schemes.

中文翻译：

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泛在传输服务：空海一体网络中的分级无线数据速率配置

由低地球轨道 (LEO) 卫星、无人机 (UAV) 和无人水面飞行器 (USV) 组成的天海一体网络 (SAOIN) 被提倡提供无缝、高速率和可靠的无线为 USV 提供传输服务。然而，由于资源有限（如频谱带宽、传输功率等）的限制、USV的多样化需求以及UAV和LEO的自私，为USV提供高质量的无线数据速率面临着重大挑战。以达到他们满意的体验质量（QoE）。为此，在本文中，我们提出了一种分层的按需无线数据速率配置方案，为 USV 提供无处不在的传输服务。具体来说，我们首先设计了一个分层的无线数据速率配置框架。具有广泛无线覆盖的 LEO 卫星用于为具有一定 L2U 数据速率价格的无人机提供 LEO 卫星到无人机 (L2U) 数据速率。每个 UAV 用于以一定的 U2U 数据速率价格为覆盖的多个 USV 提供 UAV 到 USV (U2U) 数据速率。然后，我们提出了一个改进的三阶段 Stackelberg 博弈来模拟 LEO 卫星、无人机和 USV 之间的无线数据速率分配，其中考虑了 USV 的时变数据速率需求来制定效用最大化问题。之后，利用反向归纳法获得 Stackelberg 均衡作为公式化问题的解，其中通过非线性规划方法获得了 USV 和 UAV 在不同数据速率预算下的最优策略的闭式表达式。除了，还设计了一种基于加速共轭梯度下降 (ACGD) 的迭代算法，以获得 LEO 卫星在 L2U 数据速率价格上的最优策略。最后，进行了广泛的模拟，以证明与其他基准方案相比，所提出的方案可以显着提高 USV 的效用。