Development of a contact layer for LEO constellation /

Abstract

In addition to providing truly global coverage, LEO satellite constellations can have significantly decreased the end-to-end path delays compared to geostationary satellites through Inter Satellite Links (ISLs) that form a constellation network. The main challenge is the process burden on the satellites is selecting which satellite will act as network nodes or Host terminals, where each satellite performs both traffic forwarding, and its data downloading. This network is subjected to long delays, disruption, intermittent links, and network partitioning due to its dynamic nature. Delay Tolerant Network (DTN) protocol is recently proposed for different satellite-based networks in such server environment. It relies on strategies of traffic forwarding to expected satellite neighbors according to a contact plan. This gives rise to a concept of On-Board. Contact Plane (CP) to be in charge of forwarding tasks. The Thesis presents a model of a Layer 2 Contact Plane (CP) in charge of traffic management. The design of the CP is based on the multiprocessor system on chip (MPSoc) FPGA envisioned technologies to perform both Host and network node satellite tasks. The reason behind this choice is the need for On-Board Orchestrator to manage numerous tasks in two main categories: Network’s Management and Control Tasks (NMCTs), and Application’s Management and Control Tasks (AMCTs). Therefore, the design is fragmented in three domains using three Cortex-A53 processors of Zynq UltraScale MPSoC ZU3EG Xilinx ultra96-v2 kit. The first domain is the Orchestrator while the others are NMC for NMCTs and AMC for AMCTs. The Orchestrator uses Arm GIC-400 Generic Interrupt Controller (GIC) to perform these tasks.