Open Cell-less Network Architecture and Radio Resource Management for Future Wireless Communication Systems

In recent times, the immense growth of wireless traffic data generated from massive mobile devices, services, and applications results in an ever-increasing demand for huge bandwidth and very low latency, with the future networks going in the direction of achieving extreme system capacity and ultra reliable low latency communication (URLLC). Several consortia comprising major international mobile operators, infrastructure manufacturers, and academic institutions are working to develop and evolve the current generation of wireless communication systems, i.e., fifth generation (5G) towards a sixth generation (6G) to support improved data rates, reliability, and latency. Existing 5G networks are facing the latency challenges in a high-density and high-load scenario for an URLLC network which may coexist with enhanced mobile broadband (eMBB) services. At the same time, the evolution of mobile communications faces the important challenge of increased network power consumption. Thus, energy efficient solutions are expected to be deployed in the network in order to reduce power consumption while fulfilling user demands for various user densities. Moreover, the network architecture should be dynamic according to the new use cases and applications. Also, there are network migration challenges for the multi-architecture coexistence networks. Recently, the open radio access network (O-RAN) alliance was formed to evolve RANs with its core principles being intelligence and openness. It aims to drive the mobile industry towards an ecosystem of innovative, multi-vendor, interoperable, and autonomous RAN, with reduced cost, improved performance and greater agility. However, this is not standardized yet and still lacks interoperability. On the other hand, the cell-less radio access network (RAN) was introduced to boost the system performance required for the new services. However, the concept of cell-less RAN is still under consideration from the deployment point of view with the legacy cellular networks. The virtualization, centralization and cooperative communication which enables the cell-less RAN can further benefit from O-RAN based architecture. This thesis addresses the research challenges facing 5G and beyond networks towards 6G networks in regard to new architectures, spectral efficiency, latency, and energy efficiency. Different system models are stated according to the problem and several solution schemes are proposed and developed to overcome these challenges. This thesis contributes as follows. Firstly, the cell-less technology is proposed to be implemented through an Open RAN architecture, which could be supervised with the near real-time RAN intelligent controller (near-RT-RIC). The cooperation is enabled for intelligent and smart resource allocation for the entire RAN. Secondly, an efficient radio resource optimization mechanism is proposed for the cell-less architecture to improve the system capacity of the future 6G networks. Thirdly, an optimized and novel resource scheduling scheme is presented that reduces latency for the URLLC users in an efficient resource utilization manner to support scenarios with high user density. At the same time, this radio resource management (RRM) scheme, while minimizing the latency, also overcomes another important challenge of eMBB users, namely the throughput of those who coexist in such a highly loaded scenario with URLLC users. Fourthly, a novel energy-efficiency enhancement scheme, i.e., (3 × E) is designed to increase the transmission rate per energy unit, with stable performance within the cell-less RAN architecture. Our proposed (3 × E) scheme activates two-step sleep modes (i.e., certain phase and conditional phase) through the intelligent interference management for temporarily switching access points (APs) to sleep, optimizing the network energy efficiency (EE) in highly loaded scenarios, as well as in scenarios with lower load. Finally, a multi-architecture coexistence (MACO) network model is proposed to enable inter-connection of different architectures through coexistence and cooperation logical switches in order to enable smooth deployment of a cell-less architecture within the legacy networks. The research presented in this thesis therefore contributes new knowledge in the cellless RAN architecture domain of the future generation wireless networks and makes important contributions to this field by investigating different system models and proposing solutions to significant issues.Programa de Doctorado en Multimedia y Comunicaciones por la Universidad Carlos III de Madrid y la Universidad Rey Juan CarlosPresidenta: Matilde Pilar Sánchez Fernández.- Secretario: Alberto Álvarez Polegre.- Vocal: José Francisco Monserrat del Rí

Radio Resource Management Scheme for URLLC and EMBB coexistence in a Cell-Less Radio Access network

We address the latency challenges in a high-density and high-load scenario for an ultra-reliable and low-latency communication (URLLC) network which may coexist with enhanced mobile broadband (eMBB) services in the evolving wireless communication networks. We propose a new radio resource management (RRM) scheme consisting of a combination of time domain (TD) and frequency domain (FD) schedulers specific for URLLC and eMBB users. We also develop a user ranking algorithm from a radio unit (RU) perspective, which is employed by the TD scheduler to increase the efficiency of scheduling in terms of resource consumption in large-scale networks. Therefore, the optimized and novel resource scheduling scheme reduces latency for the URLLC users (requesting a URLLC service) in an efficient resource utilization manner to support scenarios with high user density. At the same time, this RRM scheme, while minimizing the latency, it also overcomes another important challenge of eMBB users (requesting an eMBB service), namely the throughput of those who coexist in such highly loaded scenario with URLLC users. The effectiveness of our proposed scheme including time and frequency domain (TD and FD) schedulers is analyzed. Simulation results show that the proposed scheme improves the latency of URLLC users and throughput of the eMBB users compared to the baseline scheme. The proposed scheme has a 29% latency improvement for URLLC and 90% signal-to-interference-plus-noise ratio (SINR) improvement for eMBB users as compared with conventional scheduling policies.This work was supported by the European Union H2020 Research and Innovation Programme funded by the Marie Skłodowska-Curie ITN TeamUp5G Project under Grant 813391

Energy-Efficient Sleep Mode Schemes for Cell-Less RAN in 5G and Beyond 5G Networks

In 5G and beyond 5G networks, the new cell-less radio access network architecture is adopted to overcome the extreme network capacity challenges generated by massive wireless devices used for diverse scenarios and various applications. At the same time, the evolution of mobile communications faces the important challenge of increased network power consumption. To fulfill user demands for various user densities and meanwhile reduce the power consumption, we present a novel energy-efficiency enhancement scheme, i.e., (3×E) to increase the transmission rate per energy unit, with stable performance within the cell-less radio access network (RAN) architecture. Our proposed (3×E) scheme activates two-step sleep modes (i.e., certain phase and conditional phase) through the intelligent interference management for temporarily switching access points (APs) to sleep, optimizing the network energy efficiency (EE) in highly loaded scenarios, as well as in scenarios with lower load. An intelligent control over underutilized/unused APs is considered, taking their interference contribution into account as the primary main criteria in addition to load-based conditional criteria. Therefore, our proposed scheme assures a stable performance enhancement and maintains an efficient power saving when the number of UEs increases, improving existing works not addressing this performance stability in peak-traffic hours. Simulation results show that the network EE is improved up to 30% compared to the reference algorithm and up to 60% with respect to the baseline algorithm in which all APs are active all the time.This work was supported by the European Union H2020 Research and Innovation Programme funded by the Marie Skłodowska-Curie Innovative Training Network (ITN) TeamUp5G Project under Grant 81339

Efficient radio resource management for future 6G mobile networks: A Cell-Less Approach

Existing mobile communication systems are unable to support ultra high system capacity and high reliability for the edge users of future 6G systems, which are envisioned to guarantee the desired quality of experience. Recently, cell-less radio access networks (RAN) are exploited to boost the system capacity. Therefore, in this letter we propose a cell-less networking approach with an efficient radio resource optimization mechanism to improve the system capacity of the future 6G networks. The simulation results illustrate that the proposed cell-less NG-RAN design provides significant system capacity improvement over the legacy cellular solutions.This work was supported by the European Union H2020 Research and Innovation Programme funded Marie Skłodowska-Curie ITN TeamUp5G Project under Grant 813391

MOOC on "Ultra-dense networks for 5G and its evolution": challenges and lessons learned

Proceeding of: 31st Annual Conference of the European Association for Education in Electrical and Information Engineering (EAEEIE 2022), Coimbra, Portugal, 26 June-1 July 2022Many of the new mobile communication devices will be things that power and monitor our homes, city infrastructure and transport. Controlling drones thousands of miles away, performing remote surgeries or being immersed in video with no latency will also be a huge game changer. Those are some of the few things that make the fifth generation (5G) a revolution expected to be a thrust to the economy. To that end, the design and density of deployment of new networks is also changing becoming more dense, what introduces new challenges into play. What else will it add to previous generations? The MOOC about Ultra-dense networks for 5G and its evolution has been prepared by the researchers of an European MSCA ITN, named TeamUp5G, and introduces the most important technologies that support 5G mobile communications, with an emphasis on increasing capacity and reducing power. The content spans from aspects of communication technologies to use cases, prototyping and the future ahead, not forgetting issues like interference management, energy efficiency or spectrum management. The aim of the MOOC is to fill the gap in graduation and post-graduation learning on content related to emerging 5G technologies and its applications, including the future 6G. The target audience involves engineers, researchers, practitioners and students. This paper describes the content and the learning outcomes of the MOOC, the main tasks and resources involved in its creation, the joint contributions from the academic and non-academic sector, and aspects like copyright compliance, quality assurance, testing and details on communication and enrollment, followed by the discussion of the lessons learned.This work has received funding from the European Union Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie ETN TeamUp5G, grant agreement No. 813391

Inovação no Desenvolvimento do Curso Online Acessível a Todos (MOOC) sobre “Redes Ultra-densas 5G e sua Evolução”

Muitos dos novos dispositivos de comunicações móveis serão aparelhos que alimentam e monitorizam as nossas casas, infraestruturas urbanas e transportes. Controlar drones a milhares de quilómetros de distância, realizar cirurgias remotas ou estar imerso em vídeo com latência reduzida transformará certamente o acesso às tecnologias de informação e comunicação digitais. Estes são alguns dos aspetos que tornarão a quinta geração das comunicações móveis (5G) uma revolução, um impulso para a economia, e o foco de todos os intervenientes atuais na área das telecomunicações. Com este intuito, o planeamento e a crescente densidade de implantação destas novas redes introduzem novos desafios de otimização. Que elementos serão adicionados em relação às gerações anteriores? Baseados num Curso Online Acessível a Todos (MOOC) anteriormente desenvolvido na UC3M (UC3M Staff, 2022), o MOOC sobre redes ultra-densas 5G e sua evolução foi elaborado pelos investigadores da Marie Skłodowska-Curie Actions (MSCA) ITN/ETN Europeia (teamUp5G Reserachers, 2022), denominada TeamUp5G (Teamup5G, 2022; Pérez Leal et al., 2020) e apresenta as tecnologias mais importantes que suportam comunicações móveis 5G, com ênfase no aumento de capacidade e redução de energia, que facilitam o desenvolvimento de redes com pequenas células. Os conteúdos abrangem aspectos desde tecnologias de comunicação até casos de utilização, prototipagem e o futuro próximo, sem esquecer questões como a gestão de interferência, eficiência energética ou gestão de espectro. O objetivo do MOOC (TeamUp5G, 2022) é preencher a lacuna na aprendizagem ao nível dos estudos de graduação e pós-graduação, em conteúdos relacionados com tecnologias 5G emergentes e suas aplicações, incluindo a 6G futura. O público-alvo envolve engenheiros, investigadores, profissionais e estudantes. O artigo descreve o conteúdo e os resultados de aprendizagem do MOOC, as principais tarefas e recursos envolvidos na sua criação, as contribuições conjuntas do setor académico e não académico, e aspectos como a conformidade relativamente aos direitos de autor, garantia de qualidade, testes e detalhes sobre comunicação e inscrição, seguidos da discussão das lições extraídas.Este trabalho foi financiado pelo programa de investigação e inovação Horizonte 2020 da União Europeia através da Rede Europeia de Estágios (ETN) Marie Skłodowska-Curie TeamUp5G, acordo de bolsa N.º 813391, pela SNF Scientific Exchange - AISpectrum (projecto 205842) e UIDB/50008/2020. Os autores agradecem as contribuições da equipa audiovisual da UC3M responsáveis pela edição do MOOC, e da equipa responsável pelos direitos de autor e pela gravação na plataforma edX.info:eu-repo/semantics/acceptedVersio

Massive Online Open Course (MOOC) on ‘Ultra-dense Networks for 5G and its Evolution’

Many of the new mobile communication devices will be things that power and monitor our homes, city infrastructure and transport. Controlling drones thousands of miles away, performing remote surgeries or being immersed in video with no latency will also be a huge game changer. Those are some ofthe few things that make the fifth generation (5G) a revolution expected to be a thrust to the economy. To that end, the design and density of deployment of new networks is also changing becoming more dense, what introduces new challenges into play. What else will it add to previous generations? The MOOC about Ultra-dense networks for 5G and its evolution has been prepared by the researchers of an European MSCA ITN, named TeamUp5G, and introduces the most important technologies that support 5G mobile communications, with an emphasis on increasing capacity and reducing power. The content spans from aspects of communication technologies to use cases, prototyping and the future ahead, not forgetting issues like interference man agement, energy efficiency or spectrum management. The aim of the MOOC is to fill the gap in graduation and post-graduation learning on content related to emerging 5G technologies and its applications, including the future 6G. The target audience involves engineers, researchers, practitioners and students. This paper describes the content and the learning outcomes of the MOOC, the main tasks and resources involved in its creation, the joint contributions from the academic and non-academic sector, and aspects like copyright compliance, quality assurance, testing and details on communication and enrollment, followed by the discussion of the lessons learned.info:eu-repo/semantics/acceptedVersio