Telecommunications have experienced a paradigm shift in the past decades with the advent of Internet or things (IoT). With this new huge market, a lot of several interesting challenges have emerged, particularly with the potential inclusion of the IoT world in the future fifth generation of cellular mobile communications (5G) and beyond. Indeed, wireless networks have been supporting unprecedented traffic due to the drastic growth of mobile devices, the development of various applications and the implementation of IoT. Consequently, beyond 5G (B5G) systems spotlighted diverse and often contradicting key performance indicators, such as high capacity, low latency, high reliability/user-rates, ubiquitous coverage, high mobility, massive connectivity. Since the available frequency spectrum is absolutely limited, next generations of wireless communications should be accompanied with the adoption of non-orthogonal frequency sharing. Non-orthogonal multiple access (NOMA) and successive interference cancellation (SIC) have been conceived as a breakthrough technology in the B5G networks because of its superior spectral efficiency. Indeed, even if spectrum sharing and non-orthogonal transmissions have been deeply investigated during the past decades, they are considered as the most promising multiple access techniques to be adopted since the BS cannot serve UEs in an orthogonal manner anymore. Moreover, energy efficiency at both network and terminal sides has to be enhanced for economical and ecological reasons. Indeed, energy efficiency has now become a key pillar in the design of communication networks. With the advent of the fifth generation of wireless networks, expecting millions more base stations and billions of connected devices, the need for energy-efficient system design and operation will be even more compelling. As network architecture becomes complex and the user requirement gets diverse, the role of efficient resource management has come to be a crucial task. Besides, the data protection and privacy of Machine Type Devices (MTDs) remain major challenges, mainly due to the massive scale and the distributed nature of IoT networks. Lack of security measures will result in decreased adoption among users and therefore is one of the driving factors in the success of the IoT. Note that the proposed solutions should not involve significant energy, delay, and computational overhead since they will be implemented in resource-constrained devices. The main objective of the project MOMENT is to explore innovative network architectures/topologies and investigate new multiple access techniques to ensure the fulfillment of these heterogeneous constraints and a high-level security in order to cope with the aforementioned challenges. Particularly, we will investigate some of the practical challenges of large-scale deployment of NOMA such as the inter-NOMA- interference (INI), inter-cell interference, and implementation complexity. Distributed security management protocols will be investigated to ensure the scalabity of the proposed solutions and enable the deployment of the IoT. The proposed solutions will be based on sophisticated coding and sparse signal processing concepts, advanced game theoretical tools, artificial intelligence and machine learning.