Coverage enhancement of underwater and maritime multi-level communication networks
Underwater communication networks (UCNs) are considered a key-enabler to the underwater internet of things (UIoT). UCNs are regarded essential for various marine applications such as monitoring, exploration, and trading. However, large part of existing literature disregards the 3-dimensional (3D) nature of the underwater communication system. In this talk, we introduce a K-tier UCN that acts a gateway that connects the UIoT with the the Space-Air-Ground-Sea Integrated System (SAGSIS). The proposed network architecture consists of several tiers along the vertical direction with adjustable depths. On the horizontal dimension, the best coverage probability (CP) is computed and maximized by optimizing the densities of surface stations (SSs) in each tier. On the vertical dimension, the depth of each tier is also optimized to minimize inter-tier interference and maximize overall system performance. We also introduce and analyze, in this talk, a cooperative structure of SAGSIS to study the CP for SSs on a large-scale and far-reaching ocean surface. By incorporating the merits of onshore stations (OSs), tethered balloons (TBs), high altitude platforms (HAPS), and satellites (SATs), cooperative communication links between the terrestrial core connected base station and SSs are established via a relay station attached to an OS, TB, HAPS, or SAT. Considering the difference between each propagation environment, and the randomness distribution of SSs, we reconstruct the cooperative communication links and utilize in our analysis models of the point-to-area models recommended by the International Telecom Union (ITU). We concluded our talk by drawing multiple useful system-level insights that help optimize the design of underwater and maritime networks based on the given distribution of UIoT devices and SSs.