Architecture modularisation for next generation mobile networks

The journey towards the deployment of next generation networks has recently accelerated, driven by the joint effort of research and standards organisations. Some key innovative design concepts have been recently consolidating and are going to characterise the notable discontinuity between 4G and 5G systems. Among those, Architecture Modularisation, discussed in this paper, is regarded by the authors as the essential design principle to build a flexible network architecture natively supporting Network Slicing. According to this concept, conventional monolithic network functions, often corresponding to physical network elements in the existing systems, are to be split into basic building blocks defined with the proper granularity, allowing the definition of different logical architectures, tailored to 5G use cases. In this paper, a modularisation methodology is presented as a criterion to define the ‘right’ set of basic building blocks. Defined through this proposed methodology, the set of basic building blocks and the relating interfacing models are discussed. The paper concludes by proposing a candidate modular 5G network architecture, and comparing it with alternatives currently discussed within 3GPP standard working groups.