Mac sublayer protocol design and optimization for aerial swarms

Abstract

The main objective of this thesis is to design and optimize a MAC sublayer protocol for ad hoc networks, with a primary focus on maintaining the reliabile communication. Ad hoc networks, comprising aerial swarms, provide benefits such as easy use and operation in diverse environments, thanks to their simple and economical deployment, along with their remarkable maneuverability. However, the communication standard used in these networks -IEEE 802.11 standard, widely known as Wi-Fi- is primarily designed for networks with limited mobility and minimal changes in network topology. As a result, the existing Wi-Fi standards have limitations in accommodating rapidly changing network topology. This limitation becomes particularly problematic for aerial swarms that require reliable and high-bandwidth multi-hop communication links, ultimately leading to an inability to meet the quality of service (QoS) requirements. Due to the dynamic and contested nature of ad hoc networks, ensuring reliable communication can be challenging at times. To address network management challenges in highly decentralized networks, a self-organizing TDMA-based protocol is proposed. This protocol is designed to tackle communication difficulties in ad hoc networks and optimize the overall communication process by incorporating intelligent topology management, dynamic slot assignment, slot migration, and slot releasing as key components. By integrating these features, the protocol aims to enhance communication reliability and address the specific requirements of ad hoc networks. Implementing this protocol at the data link layer allows for decentralized coordination among nodes, removing the requirement for a central unit and assuring continuous communication even in dynamically changing environments and conditions. In contrast to existing MAC-sublayer protocols, the goal of this research is to present and simulate a protocol that meets ad hoc network's specific requirements. The thesis begins with an examination and modeling of the current situation, which is followed by an outline of services, message formats, procedural rules, and sequence diagrams for the subsequent protocol design stage. The protocol's design incorporates a number of notable abilities, such as slot operations, frame size modifications, topology management, optimization in control packet exchange, and collision avoidance, all of which contribute to the protocol's successful operation. To validate the findings of this thesis, the suggested protocol is evaluated using the OMNeT++ simulation environment. In contrast to previous studies, the proposed S-TDMA protocol is assessed based on four key metrics: energy efficiency, control traffic, packet delivery ratio, and average channel utilization. The evaluation results indicate a substantial enhancement in overall channel utilization, reaching up to 55%, while also reducing control traffic overhead by approximately 13%. These outcomes highlight the effectiveness and benefits of the proposed protocol in improving network performance and resource utilization. The results of simulations provide important insights into the protocol's performance and ability to adapt to changing network conditions.