Unified Network Modeling for Six Cross-Layer Scenarios in Space-Air-Ground Integrated Networks

TL;DR

An algorithm to generate node distributions under spherical coverage regions, which can assist in testing SAGINs before practical implementations is developed, which can assist in testing SAGINs before practical implementations.

Abstract

The space-air-ground integrated network (SAGIN) can enable global range and seamless coverage in the future network. SAGINs consist of three spatial layer network nodes: 1) satellites on the space layer, 2) aerial vehicles on the aerial layer, and 3) ground devices on the ground layer. Data transmissions in SAGINs include six unique cross-spatial-layer scenarios, i.e., three uplink and three downlink transmissions across three spatial layers. For simplicity, we call them \textit{six cross-layer scenarios}. Considering the diverse cross-layer scenarios, it is crucial to conduct a unified network modeling regarding node coverage and distributions in all scenarios. To achieve this goal, we develop a unified modeling approach of coverage regions for all six cross-layer scenarios. Given a receiver in each scenario, its coverage region on a transmitter-distributed surface is modeled as a spherical dome. Utilizing spherical geometry, the analytical models of the spherical-dome coverage regions are derived and unified for six cross-layer scenarios. We conduct extensive numerical results to examine the coverage models under varying carrier frequencies, receiver elevation angles, and transceivers' altitudes. Based on the coverage model, we develop an algorithm to generate node distributions under spherical coverage regions, which can assist in testing SAGINs before practical implementations.

Figures (4)

• Figure 1: Spherical geometry in six transmission scenarios ($\mathbb{S}_{i,j}(\forall i \in \{1,2,3\}, j\in\{\mathrm{u},\mathrm{d}\})$) of SAGINs, where $\mathrm{Rx},\mathrm{Tx},\mathrm{Tx}_e,\mathcal{O}(\mathrm{Tx})$ are the receiver, the transmitter, the edge point on $\mathcal{A}_{i,j}$, and the sphere surface on which all transmitters with the same altitude distributed.
• Figure 2: Spherical coordinate system in SAGINs, where $\mathrm{G}$, $\mathrm{A}$, and $\mathrm{S}$ represent three reference nodes on ground, air, and space.
• Figure 3: The vertex angles $\varphi_{i,j}$ and the coverage area sizes $\mathrm{Area}(\mathcal{A}_{i,j})$ versus the carrier frequency $f_{i,\mathrm{u}}$, the receiver's elevation angle $\alpha_{i,\mathrm{d}}$, and the transmitter/receiver's height $H_t,H_r$ in six cross-layer scenarios $\mathbb{S}_{i,j}$ ($\forall i \in \{1,2,3\},j\in\{\mathrm{u},\mathrm{d}\}$). In $\mathbb{S}_{2,j}$ ($\forall j\in\{\mathrm{u},\mathrm{d}\}$), $H_{\mathrm{a}}=50$km.
• Figure 4: Simulations of node distributions in six cross-layer scenarios. In (a), $f_{1,\mathrm{u}}=2\mathrm{GHz},f_{2,\mathrm{u}}=40\mathrm{GHz},f_{3,\mathrm{u}}=40\mathrm{GHz}$. In (b), $\alpha_{2,\mathrm{d}}=10^{\circ},\alpha_{2,\mathrm{d}}=30^{\circ},\alpha_{2,\mathrm{d}}=10^{\circ}$. In (b), the enlarged result of $\mathbb{S}_{2,\mathrm{d}}$ hides the satellite distribution to show $\mathcal{A}_{2,\mathrm{d}}$ from multiple aerial vehicles.

Theorems & Definitions (4)

• Lemma 1
• Proposition 1
• proof
• Theorem 1