IEEE Access (Jan 2024)
Rapidly Deployable Satellite-Based Emergency Communications Infrastructure
Abstract
Communication infrastructure is crucial during emergencies because it ensures reliable coordination and information dissemination for effective search and rescue missions. However, these systems rely on physical structures, making them vulnerable to failures caused by disasters like fires and flooding. To enhance resilience, redundant infrastructure is commonly practiced. For instance, redundant systems ensure continuous operation in space missions where repairs are not feasible. A major gap exists, however, as redundancy is not a viable solution for remote areas without existing communication infrastructure. Additionally, victims may need to evacuate to safety zones not covered by mainstream communication systems. In such cases, alternative infrastructure that is easy to deploy is required to address emergency communication challenges fully. This paper presents a framework to analyze the deployability of current satellite communication infrastructure for this purpose. The analysis focuses on deployability dynamics, elements, and applications. We start by discussing the evolution of satellite ground stations into mobile and software-defined systems. In the analysis, we find that, despite these advancements, current infrastructure fails to provide a single device that meets low power and low-cost rapid deployment requirements based on our deployability framework. The product that almost fulfils this is the satellite phone. However, satellite phones are prohibitively expensive for large-scale deployments, with a single device costing over 600 United States Dollars (USD), more than ten times the cost of Internet of Things (IoT) devices supporting similar technologies. Additionally, they are not power efficient. The high cost of satellite applications is associated with spectrum licensing and satellite infrastructural costs. We have analyzed satellite communication frequency bands and architectural design, such as antenna designs, communication protocols and standards, modulation techniques, and signal processing methods, to understand the important factors toward full deployability. Our comprehensive analysis reveals a gap in addressing interoperability issues caused by disparate communication standards, processing power and energy requirements. Further analysis reveals promising open-source initiatives that offer potential solutions, such as low-data rate modulation schemes, low-bitrate voice codecs, and low-power encryption techniques. Additionally, advancements in Artificial Intelligence(AI) and robust cybersecurity techniques provide a solid foundation for future developments of rapidly deployable satellite-based emergency communication infrastructure. Consequently, we have identified opportunities for developing low-power, frequency-agile architectures that integrate satellite and terrestrial network infrastructure. Specifically, the next-generation Cospas-Sarsat Search and Rescue system provides a pathway for eliminating spectrum licensing costs, making deployable systems affordable for mass adoption. Future work should leverage advancements in low-bitrate technologies to enhance emergency systems, ensuring secure and resilient two-way voice, messaging, and distress signalling capabilities for critical communications.
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