SDN-based Flexible Resource Management and Service-Oriented Virtualization for 5G Mobile Networks and Beyond

This thesis examines how Software Defined Network (SDN) and Network Virtualization (NV)
technologies can make 5G and beyond mobile networks more flexible, scalable and programmable
to support the performance demands of the emerging heterogeneous applications. In this direction,
concepts like mobile network slicing, multi-tenancy, and multi-connectivity have been
investigated and their performance is analyzed. The SDN paradigm is used to enable flexible
resource allocation to the end users, improve network resource utilization and avoid or rapidly
solve the network congestion problems. The proposed network architectures are 3rd Generation
Partnership Project (3GPP) standards compliant and integrate Open Network Foundation
(ONF) SDN specifications to ensure seamless interoperability between different standards and
backward/forward compatibility. Novel mechanisms and algorithms to efficiently manage the
resources of evolving 5G Time-Division Duplex (TDD) networks in a flexible manner are introduced.
These mechanisms enable formation of virtual cells on-demand which allows diverse
resource utilization from multiple eNBs to the users. Within the scope of this thesis, SDN-based
frameworks to enhance the QoE of end user applications considering Time Division-Long Term
Evolution (TD-LTE) small cells have also been developed and network resource sharing scenarios
with Frequency-Division Duplex (FDD)/TDD coexistence has been studied.
In addition, this thesis also proposes and investigates a novel service-oriented network
slicing concept for evolving 5G TDD networks which involve traffic prediction mechanisms
and includes user mobility. An analytical model is also introduced that formulates the network
slice resource allocation as a weighted optimization problem. The evaluations of the proposed
solutions are performed using 3GPP standard compliant simulation settings. The proposed
solutions have been compared with the state-of-the art schemes and the performance gains
offered by the proposed solutions have been demonstrated. Performance is evaluated considering
metrics such as throughput, delay, network resource utilization etc. The Mean Opinion
Score (MOS) metric is used for evaluating the Quality of Experience (QoE) for end-user applications.
With the help of SDN-based network management algorithms investigated in this work,
it is shown how 5G+ networks can be managed efficiently, while at the same time provide
enhanced flexibility and programmability to improve the performance of diverse applications
and services delivered over the network to the end users.