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The article analyzes the total cost of ownership (TCO) of 5G fronthauling solutions based on analog and digital radio-over-fiber (RoF) architectures in cloud radio access networks (C-RANs). The capital and operational expenditures (CAPEX, OPEX) are assessed, for a 10-year period, considering three different RoF techniques: intermediate frequency analog RoF (IF-A-RoF), digital signal processing (DSP) assisted analog RoF (DSP-A-RoF), and digital RoF (D-RoF) based on the common public radio interface (CPRI) specifications. The greenfield deployment scenario under exam includes both fiber trenching (FT) and fiber leasing (FL) options. The TCO is assessed while varying (i) the number of aggregated subcarriers, (ii) the number of three-sector antennas located at the base station, and (iii) the mean fiber-hop length. The comparison highlights the significance that subcarrier aggregation has on the cost efficiency of the analog RoF solutions. In addition, the analysis details the contribution of each cost category to the overall CAPEX and OPEX values. The obtained results indicate that subcarrier aggregation via DSP results in high cost efficiency for a mobile fronthaul network, while a CPRI-based architecture together with FL brings the highest OPEX value.

With the introduction of the next generation 5G systems, an unprecedented bit rate demand for optical transport infrastructure is expected, in addition to the need to ensure low costs, low power consumption, and low latency. With the current analog radio over fiber approach, high spectral efficiency is achieved, therefore, this is a fundamental technology for the next generation fronthaul system. This thesis addresses the possibility of using an analog radio-over-fiber system in a fronthaul of a Cloud Radio Access Network, avoiding the well-known bandwidth multiplication issue associated with the digitization of radio signals. Using a low-cost directly modulated laser and a standard PIN, we have experimentally demonstrated how to obtain a 5G-compliant EVM on all component carriers by optimizing power and bit loading between component carriers. Com a introdução dos sistemas 5G de próxima geração, é esperado uma demanda por taxa de bits sem precedentes para infraestrutura de transporte óptico, para além da necessidade de garantir baixos custos, baixo consumo de energia e baixa latência. Com a abordagem atual de rádio sobre fibra analógico, consegue-se alcançar uma alta eficiência espectral, portanto, esta é uma tecnologia fundamental para o sistema fronthaul de próxima geração. Esta dissertação aborda a possibilidade de usar um sistema analógico de rádio sobre fibra num fronthaul de uma Cloud Radio Access Network, evitando o conhecido problema de multiplicação de largura de banda associado à digitalização de sinais de rádio. Usando um laser diretamente modulado de baixo custo e um PIN padrão, demonstrámos experimentalmente como obter um EVM compatível com 5G em todas as portadoras, otimizando o power e bit loading entre as portadoras. Mestrado em Engenharia Eletrónica e Telecomunicações

Submitted by Manuel Jesus (albertojesus@ua.pt) on 2021-03-03T23:36:42Z No. of bitstreams: 1 Documento_Pedro_Loureiro.pdf: 7410117 bytes, checksum: 376044a73e22efb7f67185dcae4e2fc4 (MD5) Approved for entry into archive by Cristina Santos (cmaria@ua.pt) on 2021-03-04T15:54:54Z (GMT) No. of bitstreams: 1 Documento_Pedro_Loureiro.pdf: 7410117 bytes, checksum: 376044a73e22efb7f67185dcae4e2fc4 (MD5) Made available in DSpace on 2021-03-04T15:54:54Z (GMT). No. of bitstreams: 1 Documento_Pedro_Loureiro.pdf: 7410117 bytes, checksum: 376044a73e22efb7f67185dcae4e2fc4 (MD5) Previous issue date: 2020-12-18 Mestrado em Engenharia Eletrónica e Telecomunicações

This paper provides an assessment of the total cost of ownership (TCO) of a number of 5G fronthauling solutions based on digital and analog radio-over-fiber (RoF) architectures in cloud radio access network (C-RAN). We computed the capital and operational expenditures (CAPEX, OPEX) in the case of an optical fiber aggregation network based on a ring topology. Three different RoF architectures were considered: intermediate frequency analog RoF (IF-A-RoF), digital signal processing assisted analog RoF (DSP-A-RoF), and digital RoF (D-RoF) based on the common public radio interface (CPRI). A greenfield scenario considering both fiber deployment and fiber leasing was analyzed. The results presented in the paper show how the TCO changes with the number of aggregated carriers for the considered RoF architectures and fiber deployment strategy. They also reveal the impact that each cost category has on the overall CAPEX and OPEX value.