Maritime Wireless Communication: From Propagation to Multi-User Network Topoplogies

海上无线通信具有战略意义;因此，它具有悠久的科学努力历史。在过去的几年里，我们已经被许多合作伙伴，如加拿大海军，要求提供可靠和高速的海外通信。通过使用精明的多天线方案，我们已经提高了数量级的可实现的数据速率在水上。 然而，大多数远程测量活动，由他人和我们进行，显示接收功率预测和实际测量之间的显着差异。一个研究充分，但仍然有些难以捉摸，管道效应的传播是由折射率梯度引起的蒸发层以上的海洋。例如，在澳大利亚的大堡礁，非视距链路为70公里，年平均功率比预测的功率小1000倍，变化甚至与风无关，正如理论预测的那样。在NSERC超电子椅的最后一次活动中，我们也有一个意想不到的和令人难以置信的良好的非视距连接在66公里。 如果希望设计一个海上网络，通过增加功率来补偿未知影响是不可能的，因为它还涉及对全球网络的更多干扰。因此，在这个问题上，必须回到RF传播基础。因此，我们建议对无线链路和反射过程中的波的影响进行深入观察。事实上，我们认为，当距离很长时，掠射角很低，只有少数海浪有效地产生反射和衍射。这一假设与通常的散射区假设形成鲜明对比。我们建议计算次度放牧和随机生成的定向海浪的传播。将建立一个实际的无线电测量，通过将海浪高度的实时波浪测量值与接收信号功率相关联来确认结果。 在网络层次上，随机几何和各种网络拓扑结构进行检查，以预测网络的整体性能与可变的节点密度。它建议评估可实现的吞吐量为不同分布的船舶位置和天线高度，在多个海况。在拓扑结构方面，将考虑网状或Ad-Hoc、点对点和点对多点系统的组合，以最大限度地提高可能的异构网络（HetNet）性能。 海洋对加拿大和魁北克至关重要，两国政府最近在海洋战略上投资了2 B$。值得一提的是，Ultra electronics TCS由Giuseppe Marconi爵士于1903年创立，前身为加拿大马可尼公司，以与泰坦尼克号进行海外无线通信而闻名，并成为第一个获得无线电相关诺贝尔奖的公司。这一提议完全符合我们历史上的无线创新能力。

Maritime wireless communication is strategic; as such it has a long history of scientific endeavors. In the past years, we have been solicited by numerous partners, such as the Canadian Navy, to provide reliable and high-speed oversea communications. By using astute multiple antenna schemes, we have enhanced by orders of magnitude the achievable data rates overwater. However, most long range measurement campaigns, performed by others and us, show significant discrepancies between received power predictions and actual measurements. A well-studied, but still somewhat elusive, ducting effect on the propagation is caused by the gradient of refraction index induced by the evaporation layer above the sea. For example, on the great barrier reef in Australia, with a non-line-of-sight link of 70 km, the yearly average power is a thousand times less powerful than predicted, the variations are not even correlated with the wind, as the theory predicts. In the NSERC Ultra Electronics chair's last campaign, we also had an unexpected and unbelievably good non line-of-sight link at 66 km. If one wishes to design a maritime network, a compensation of unknown effects through increased power is not possible since it also involves more interference on the global network. Going back to RF propagation basics is thus imperative on this issue. We thus propose to have an in-depth observation of the wireless link and the effect of waves in the reflection process. In fact, we believe that when the range is long, the grazing angle is so low that only a small number of sea waves effectively produce reflection and diffraction. This hypothesis is in stark contrast to the usual assumption of a scattering area. We propose to compute the propagation with sub-degree grazing and a random generation of directional sea waves. An actual radio measurement will be set-up to confirm the results by correlating real-time wave measurements of sea wave heights and the received signal power. At the network level, stochastic geometry and various network topologies are examined to predict the overall performance of networks with variable node densities. It is proposed to evaluate the achievable throughput for different distributions of ship positions and antenna heights, over multiple sea conditions. In terms of topology, a combination of meshed or Ad-Hoc, point-to-point and point-to-multipoint systems will be considered to maximize the possible Heterogeneous Network (HetNet) performance. The sea is of central importance to Canada and Québec as emphasized recently by both governments investing 2 B$ in maritime strategies. It is worth noting that Ultra electronics TCS has been founded as the Canadian Marconi Company by Sir Giuseppe Marconi in 1903, renowned for oversea wireless communication with the Titanic and as the first recipient of a Radio related Nobel Prize. This proposal is completely aligned with our historical wireless inventiveness.