Abstract
The advancement towards next-generation mobile networks necessitates the transition to higher frequency spectrum to leverage increased bandwidth for realizing superior network performance and innovative services. However, the deployment of heterogeneous networks (HetNets) and devices across different verticals introduces complexities in network management, configuration, and meeting demanding network performance and quality of service (QoS) requirements. These challenges are particularly exacerbated in indoor environments, responsible for 80%-90% of all mobile traffic, where building penetration losses (BPL) significantly degrade network coverage and capacity.Despite the success of network-sharing initiatives, the fiercely competitive and trustless operating environment faced by Mobile Network Operators (MNOs) hampers seamless interoperability across carriers. The emergence of Micro-operators (μOs) offers promise, but progress has been impeded by the lack of a framework facilitating business and technical agreements between key stakeholders – MNOs and μOs.
This thesis proposes a software-defined networking approach to enhance interconnectivity and cooperation between mobile network operators. The solution leverages software defined networks (SDN) and smart contracts running on blockchain to establish trust between operators and validate transactions, ensuring uninterrupted services and high availability for mobile subscribers switching between networks. This approach minimizes performance penalties and enhances the quality of experience for mobile subscribers. As a result, this research makes the following novel contributions:
• Intelligent Blockchain-enabled SDN Architecture: The proposed architecture integrates an intelligent SDN controller with a blockchain framework, facilitating dynamic switching of mobile subscribers between multiple operators during service disruptions. The SDN controller processes handover requests from mobile subscribers based on critical metrics such as radio signal quality, and communicates these requests to a smart contract on the blockchain. The smart contract utilizes consensus mechanisms to automate and authorize handovers between the base stations of different operators, in accordance with the service level agreements (SLAs). This model streamlines the complexities of manual SLA management and enhances trust and interoperability among MNOs. The performance of the architecture is validated through detailed simulations, demonstrating significant improvements in network availability and user connectivity, which outperforms traditional network models. This research highlights the potential for a significant shift in mobile network management, despite challenges such as scalability and integration with existing infrastructures.
• Analytical Modelling and Evaluation of System Performance Using Different Consensus Mechanisms: This research investigates the impact of three (3) different blockchain consensus mechanisms - Practical Byzantine fault tolerance (PBFT), Raft and Paxos - on mobility management operations across different MNOs, specifically handover performance. Using queuing theory, we develop analytical models to evaluate the average packet sojourn time and handover delays, which are then compared with simulation results. In addition, we look at the performance of these consensus mechanisms under different network design scenarios. Our findings reveal that the Raft consensus mechanism outperforms the PBFT and Paxos in terms of network performance figures, such as higher throughput (packet delivery and number of successful handovers) and lower latency (both E2E and handover delays). This research also offers valuable insights for network deployment, paving the path towards intelligent and dynamic mobility solutions that meet the demands of future multi-operator networks and various industry verticals.
• Real-World Use Case - Software-Defined Radios: Furthermore, we present one of the use cases of our research in dynamic spectrum management by extending the software-defined concept to software-defined radios (SDR). A cloud-based software defined radio testbed was developed as a proof of concept (PoC) to evaluate its performance in implementing ground station operations, specifically in transferring satellite data from the ground station to the cloud.
This thesis makes significant contributions to the field of telecommunications by proposing a scalable and trust-based architecture for next-generation network systems. This innovative framework is designed to enhance interoperability, streamline operational processes, and elevate the overall quality of services provided to mobile subscribers. Additionally, the thesis provides deep insights that have the potential to significantly enhance network efficiency and management. These contributions lay the foundation for the development of novel services and future advancements in network engineering and the telecommunications industry.
| Date of Award | 14 Jan 2025 |
|---|---|
| Original language | English |
| Supervisor | Kumudu MUNASINGHE (Supervisor) & Dharmendra Sharma AM PhD (Supervisor) |