Browsing by Subject "Communications Research"

Now showing 1 - 2 of 2
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    Open Access
    Infrastructure sharing of 5G mobile core networks on an SDN/NFV platform
    (2017) Mwangama, Joyce Bertha; Ventura, Neco
    When looking towards the deployment of 5G network architectures, mobile network operators will continue to face many challenges. The number of customers is approaching maximum market penetration, the number of devices per customer is increasing, and the number of non-human operated devices estimated to approach towards the tens of billions, network operators have a formidable task ahead of them. The proliferation of cloud computing techniques has created a multitude of applications for network services deployments, and at the forefront is the adoption of Software-Defined Networking (SDN) and Network Functions Virtualisation (NFV). Mobile network operators (MNO) have the opportunity to leverage these technologies so that they can enable the delivery of traditional networking functionality in cloud environments. The benefit of this is reductions seen in the capital and operational expenditures of network infrastructure. When going for NFV, how a Virtualised Network Function (VNF) is designed, implemented, and placed over physical infrastructure can play a vital role on the performance metrics achieved by the network function. Not paying careful attention to this aspect could lead to the drastically reduced performance of network functions thus defeating the purpose of going for virtualisation solutions. The success of mobile network operators in the 5G arena will depend heavily on their ability to shift from their old operational models and embrace new technologies, design principles and innovation in both the business and technical aspects of the environment. The primary goal of this thesis is to design, implement and evaluate the viability of data centre and cloud network infrastructure sharing use case. More specifically, the core question addressed by this thesis is how virtualisation of network functions in a shared infrastructure environment can be achieved without adverse performance degradation. 5G should be operational with high penetration beyond the year 2020 with data traffic rates increasing exponentially and the number of connected devices expected to surpass tens of billions. Requirements for 5G mobile networks include higher flexibility, scalability, cost effectiveness and energy efficiency. Towards these goals, Software Defined Networking (SDN) and Network Functions Virtualisation have been adopted in recent proposals for future mobile networks architectures because they are considered critical technologies for 5G. A Shared Infrastructure Management Framework was designed and implemented for this purpose. This framework was further enhanced for performance optimisation of network functions and underlying physical infrastructure. The objective achieved was the identification of requirements for the design and development of an experimental testbed for future 5G mobile networks. This testbed deploys high performance virtualised network functions (VNFs) while catering for the infrastructure sharing use case of multiple network operators. The management and orchestration of the VNFs allow for automation, scalability, fault recovery, and security to be evaluated. The testbed developed is readily re-creatable and based on open-source software.
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    Open Access
    WiMAX spectrum virtualization and network federation
    (2017) Ogunleye, Babatunde Samuel; Murgu, Alexandru
    Spectrum management in wireless broadband networks as regards its cost and its efficient usage has posed a huge challenge for mobile network operators. Traditionally, network operators had exclusive rights to access the band of spectrum allocated to them, but with the high price of spectrum license, it is becoming necessary to find alternative ways to use and access spectrum more efficiently. Resource virtualization is a method which has been extensively adopted in hardware computing for creating abstract versions of physical hardware resources and it has proven to be a powerful technique for customized resource provision and sharing. This idea of resource virtualization is gradually being transferred into the domain of wireless mobile network resource management but the ideas around it are still evolving. Since spectrum is an important wireless network resource, it is imperative to provide an efficient and cost effective means for the resource to be accessed and utilized. Therefore the idea of spectrum virtualization is investigated in this research as a possible solution to this problem. To expand on the notion of spectrum virtualization, this research further explores the idea of network federation. Network Federation involves the interconnection of diverse network components to be operated as a single seamless network. This will enable them share their network resources while the networks are geographically dispersed and managed by different network operators. To fully implement these concepts there is a need for a well-developed network framework. This research proposes two novel architectures for spectrum virtualization and network federation using the WiMAX (Worldwide Interoperability for Microwave Exchange) wireless broadband technology. The proposed WiMAX spectrum virtualization architecture introduces a novel entity known as the Virtual Spectrum Hypervisor (VS-Hypervisor). This VS-Hypervisor bears the responsibility of spectrum management and virtualization within the WiMAX framework. In the implementation of WiMAX network federation, the novel architecture enables the cooperative existence of multiple WiMAX base-stations having virtualization capabilities with overlapping cellular coverage areas for the purpose of sharing their spectrum resources. In this architecture, a novel federation control plane known as the Virtual Spectrum Exchange Locale (VSEL) is proposed. The VSEL facilitates the VS-Hypervisors in the federated physical base-stations to be able to negotiate and exchange spectrum between themselves to match their spectrum needs. The architectures for WiMAX spectrum virtualization and network federation was modelled and implemented using the OPNET Modeler. Results obtained validated their efficacy with respect to the effective management of the wireless network spectrum. Therefore this proposed network architectures would help network operators optimize their radio networks.