Wireless access network optimization for 5G

Student thesis: Doctoral ThesisDoctor of Philosophy


The goal of expected 5th Generation (5G) wireless networks is to bring ultra high data rates, network throughput and service quality to mobile users in near future. Regarding to these expectations, the present virtualized and softwarized network architecture such as Cloud-Radio Access Network (C-RAN) and Software Defined Networks (SDN) is responsible for performing multiple key tasks such as allocating radio resources efficiently, providing Network Function Virtualization (NFV) and intelligent inter-network control/coordination, and flexibly sharing network resources among different network tenants and etc. Although these mentioned techniques and approaches already achieved certain progresses but also face various challenges because of the realistic engineering constraints and complicated network scenarios. To this end, this thesis contributes a series of 5G wireless networks optimization frameworks and efficient algorithms tackling different network problems in both theoretical and practical ways. The specific works of the thesis include the following proposals: a deep research of control plane in future SDN architecture, which is capable to provide intelligent control functions. Furthermore, based on such SDN based architecture, a control plane signal optimization framework is defined and solved, which optimally reduces the potential handover signals and balances control load between multiple control planes in the SDN enabled networks. On the other hand, by introducing network virtualization technologies, this thesis further proposes an optimization framework to flexibly share radio resources between network operators by using both intra-tenant and inter-tenant management entity. In addition, downlink signal transmission power control is also introduced to the framework to engage further resource reuse among tenants and achieve certain degrees improvement in energy efficiency during network operations. Due to the high complexity of the proposed optimization problem, various algorithms are proposed to solve this inter-tenant resource sharing problem efficiently, and numerical results demonstrate a satisfying improvements in various network performance. Finally, a service rate aware resource sharing optimization framework is proposed to bring the previous inter-tenant sharing framework to a more realistic network architecturing level by considering fronthaul limitation and potential multi-cell coordinated resource transmission. Since the high complexity of this optimization problem, novel algorithm is also designed and numerical result demonstrates satisfying gains in a very complicated 5G networks environment.
Date of Award1 Jun 2019
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorVasilis Friderikos (Supervisor) & Arumugam Nallanathan (Supervisor)

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