Efficient Satellite-Ground Interconnection Design for Low-orbit Mega-Constellation Topology

Abstract

The low-orbit mega-constellation network (LMCN) is an important part of the space-air-ground integrated network system. An effective satellite-ground interconnection design can result in a stable constellation topology for LMCNs. A naive solution is accessing the satellite with the longest remaining service time (LRST), which is widely used in previous designs. The Coordinated Satellite-Ground Interconnecting (CSGI), the state-of-the-art algorithm, coordinates the establishment of ground-satellite links (GSLs). Compared with existing solutions, it reduces latency by 19% and jitter by 70% on average. However, CSGI only supports the scenario where terminals access only one satellite and cannot fully utilize the multi-access capabilities of terminals. Additionally, CSGI's high computational complexity poses deployment challenges. To overcome these problems, we propose the Classification-based Longest Remaining Service Time (C-LRST) algorithm. C-LRST supports the actual scenario with multi-access capabilities. It adds optional paths during routing with low computational complexity, improving end-to-end communications quality. We conduct our 1000s simulation from Brazil to Lithuania on the open-source platform Hypatia. Experiment results show that compared with CSGI, C-LRST reduces the latency and increases the throughput by approximately 60% and 40%, respectively. In addition, C-LRST's GSL switching number is 14, whereas CSGI is 23. C-LRST has better link stability than CSGI.

Figures (14)

• Figure 1: Satellite and Constellation.
• Figure 2: ISL mode of communication between ground terminals. One ground terminal (such as a user Dish) communicates with the other (such as a ground station) through only two GSLs, with multi-hop ISLs in between.
• Figure 3: Overview of C-LRST. When GSL switches, we can get a target access satellite through C-LRST. First, there are a series of visible satellites over the terminal. Through Classification operation, they are classified according to their flight directions. The output of this operation is the north set and the south set of satellites. Second, choose a flight direction that needs to be switched, such as the north. Then, calculate the visible time of all satellites in this set. Finally, select the satellite with the longest remaining service time as the target access satellite of the terminal.
• Figure 4: Satellite service time calculation demonstration. The circle $O$ represents the coverage area of the satellite, $R$ is the radius of the circle, $P$ is any point within the circle, and $D$ represents the remaining service time along the satellite flight direction.
• Figure 5: Visible satellites distribution of some ground stations. Visible satellites above the ground station fly in two directions, forming two sets. For example, the visible satellites of ground station 60 are labeled as two sets $s_1$ and $s_2$, and those of ground station 46 are labeled as two sets $s_3$ and $s_4$.

Theorems & Definitions (4)

• Proposition 1
• Proof 1
• Proposition 2
• Proof 2