۱- Introduction

۲- Evolution of the mobile network architecture

۳- Roadmap of softwarization and virtualization in 5G environments

۴- Towards SDN & NFV in 5G: state of the art

۵- Future research

۶- Conclusion

References

Abstract

The promise behind the effective deployment of 5G networks is an architecture able to provide flexibility, reconfigurability and programmability in order to support, with fine granularity, a wide and heterogeneous set of 5G use cases. This dictates a radical change in the design of mobile systems which, being usually based on the use of static deployment of vendor equipment characterized by monolithic functionality deployed at specific network locations, fail in providing the above mentioned features. By decoupling network functionalities from the underlying hardware, softwarization and virtualization are two disruptive paradigms considered to be at the basis of the design process of 5G networks. This paper analyses and summarizes the role of these two paradigms in enhancing the network architecture and functionalities of mobile systems. With this aim, we analyze several 5G application scenarios in order to derive and classify the requirements to be taken into account in the design process of 5G network. We provide an overview on the recent advances by standardization bodies in considering the role of softwarization and virtualization in the next-to-come mobile systems. We also survey the proposals in literature by underlining the recent proposals exploiting softwarization and virtualization for the network design and functionality implementation of 5G networks. Finally, we conclude the paper by suggesting a set of research challenges to be investigated.

Introduction

The evolution of mobile networks from 2G to 4G has been mainly driven by the supporting applications, whose requirements defined the features of the network in terms of procedures (e.g., ) authentication, signaling, connection establishment) and functionalities (e.g., mobility management, anchoring, data forwarding, path computation). Once the application-related features have been defined, mobile networks have been deployed by exploiting the network technologies, which were well-consolidated [1]. As each generation of mobile networks has a design to deliver specific services, the introduction of novel applications to satisfy customers’ demands requires the re-design or the introduction of novel functionalities in the network in case the requirements of such applications differ substantially from those of the applications already supported [2]. From this point of view, the well-consolidated use from 2G to 4G networks of hardware implementing specific network functionalities has the following drawbacks [3], [4], [5]: (i) updating the already deployed network functions requires the introduction of novel hardware equipment; (ii) supporting novel applications could require totally disruptive network changes, and this dictates for a novel network design and thus the standardization of a novel generation of mobile networks. In addition to the mentioned limitations, high capital expenditure (CAPEX) in deploying new network architectures and operating expenditure (OPEX) when upgrading network functionalities have been extra barriers that consequently decreases the revenue of mobile operators [6].