Advancements in Secure Drone and Underwater Communication

The sixth-generation (6G) Internet of Things (IoT) networks are introducing new ways to connect devices. These networks use flying base stations, known as Drones, along with surfaces that can change their properties to improve coverage and security. This is important for both aerial and underwater communication. The integration of these technologies presents many new opportunities and challenges in IoT.

In this context, researchers are looking at how to keep communications secure when using radio signals from drones and underwater light systems. They study ways that outsiders, known as eavesdroppers, could try to intercept signals and how to prevent this. The aim is to create guidelines for designing networks that prioritize secure communication.

#The Role of Drones and Underwater Communication

Drones have become a key part of modern communication systems. They can provide coverage in areas where traditional ground stations cannot reach. By flying to various locations on demand, drones can support many types of devices that need to stay connected. They adapt well to changes, making them suitable for various applications such as monitoring and data collection.

In addition to air communication, underwater systems are vital for certain IoT applications. These may involve things like monitoring wildlife or checking the health of underwater environments. Combining drone technology with underwater communication systems helps to provide broader coverage for IoT networks.

#Intelligent Surfaces and Their Benefits

Reconfigurable Intelligent Surfaces (RIS) are emerging as a valuable tool in improving network performance. These surfaces can change how they reflect signals, helping to deal with issues like overcrowding or difficult propagation environments. They can be placed on walls or ceilings, making them flexible for various environments.

The ability to adjust the signals can significantly enhance both coverage and data rates. By combining RIS with drone technology, researchers are finding new ways to connect both land-based and underwater networks. This combination is paving the way for stronger security measures in communication systems.

#Literature Review

Recent studies highlight the promise of RIS in wireless communication. It has shown to be effective in enhancing performance and extending coverage. In various settings, such as relay systems, these surfaces help to amplify signals, making communication clearer and more reliable.

Dual-hop networks, which use a combination of radio and light signals, can also boost coverage and data rates. The use of drones in these networks is gaining attention, especially in areas where traditional infrastructure fails to provide adequate connectivity.

Researchers have been exploring different methods to enhance security in communication systems. Techniques such as using random noise, incorporating RIS, and applying drone technology have been discussed. Many studies have focused on static sources, highlighting a gap in research regarding dynamic sources like drones and satellites.

#Motivation and Objectives

The current literature has not fully addressed the role of moving sources in ensuring secure communication. There is a need to develop models that consider the dynamic nature of drones in communication networks. Additionally, while RIS has shown promise in improving security in some systems, its application in underwater communication is largely unexplored.

This study aims to fill these gaps by proposing a model that includes drones as dynamic sources and examines how RIS can enhance security in underwater settings. The research will also consider different scenarios where Eavesdropping might occur, allowing for a comprehensive understanding of potential threats.

#System Model

The proposed system involves a UAV as the source of communication, a relay, and eavesdroppers. In the first phase, the UAV sends signals to a relay above water, and in the second phase, the relay transmits the signals to a destination submerged underwater. The presence of eavesdroppers poses a risk, as they can intercept the communication.

Three distinct scenarios are explored. The first considers eavesdropping on the radio link, the second on the underwater signal, and the last combines both types of interception. Each scenario helps to identify vulnerabilities and test the security of the communication system.

#Problem Formulation

A critical aspect of communication systems is the signal-to-noise ratio (SNR), which helps determine the quality of the received signals. This study explores how SNR values change across different links and how these variations affect security.

The performance of both aerial and underwater links is modeled. The dynamics of the drones, the effects of environmental factors, and the characteristics of the RIS are all taken into account to understand their combined impact on communication.

#Secrecy Performance Metrics

Secrecy metrics are essential for evaluating how well a communication system can protect its data. Several key metrics include:

#Average Secrecy Capacity

This metric represents the average rate at which secure information can be transmitted over a channel. A higher capacity indicates a more effective communication system in maintaining security.

#Secrecy Outage Probability

This is the likelihood that the capacity for secure communication falls below a certain threshold. By analyzing different scenarios, the study seeks to quantify this probability and identify ways to reduce it.

#Probability of Strictly Positive Secrecy Capacity

This metric assesses the chances of having a positive rate of secure communication. It shows how likely it is to maintain confidentiality even under threat.

#Effective Secrecy Throughput

This reflects the rate at which secret information can be successfully transmitted while ensuring a required level of security.

#Numerical Results and Analysis

The research includes various simulations to see how different parameters affect the performance of the communication system. Factors like fading, the number of reflecting elements, and characteristics of the underwater environment are explored to determine their impact on secrecy.

#Impact of Parameters

Different variables, such as the distance between communication points and environmental conditions, play a crucial role in determining the effectiveness of the system. For instance:

• Fading Severity: An increase in fading severity generally leads to improved secrecy performance as it becomes harder for eavesdroppers to intercept communication.

• Distance: Greater distances can reduce the chance of successful interception, but they can also weaken signal strength.

• Diversity: Using multiple antennas can improve the quality of the received signal and enhance security measures.

#RIS in Underwater Communication

The incorporation of RIS in underwater communication shows promising results. Increasing the number of reflecting elements tends to lower the risk of eavesdropping, as it allows for better signal control.

Simulations also reveal that different methods of detection yield varying results in terms of secrecy performance. For example, using advanced techniques tends to lead to better outcomes than traditional methods.

#Design Guidelines

Based on the findings, several recommendations emerge for constructing secure communication networks using these technologies:

#For RF UAV-NTN Link

1. Consider Fading: Higher values of fading factors can help secure communications.
2. Link Distance: Optimize distances between communication points for better performance.

#For UOWC Link

1. Utilize RIS: Increasing the number of reflective surfaces helps in directing signals better.
2. Detection Methods: Choose advanced detection techniques to maximize secrecy.
3. Control Underwater Factors: Understand and mitigate the effects of underwater turbulence and environmental variations.

#Conclusion

This research highlights the importance of integrating drone and underwater communication systems while emphasizing the need for strong security measures. By addressing gaps in previous studies, it proposes methods for enhancing secure communication through intelligent technologies. The findings support a broader understanding of how to protect sensitive information against potential threats in modern communication networks.

Leveraging RIS technology can significantly improve the robustness of both aerial and underwater systems, paving the way for more secure communication practices in the future.