# A Real Case of Implementation of the Future 5G City
## 1 Introduction  
The evolution of technologies to capture, deliver, and elaborate data with the goal of monitoring, analyzing, and managing the environment is changing our way of living and empowering a wide range of applications and business models that span among different contexts such as smart systems, Industry 4.0, e-Health, intelligent transport systems, and energy management. In the near future, the quality of life of billions of people will depend on the capability of cities of to save energy, reduce harmful emissions, provide smart mobility, improve health services and the living conditions, and increase safety. This poses various challenges that can be overcome in the context of smart systems by adopting disruptive information and communications technologies. In particular, new communication systems should be able to provide ubiquitous access to information and broadband as well as critical services, along with a large variety of scenarios, to a massive number of heterogeneous devices, supporting a huge amount of data: everything will be connected following the Internet of Thing (IoT) paradigm [1]. This is paving the way for a novel and disruptive fifth generation (5G) communication network, whose challenge is to overcome the fundamental limits of the existing cellular networks, with the aim of guaranteeing a thousand-fold communication capacity increase, extremely low latency, and a massive number of connections in a cost and energy-efficientmanner [2; 3]. 5G systems will be challenged to simultaneously scale up and improve the efficiency of current mobile networks, but also accommodate a wide range of use cases with different and, in some cases, contradictory requirements in terms of coverage, latency, resilience, bandwidth, reliability, mobility, and energy consumption [3]. Indeed, the key difference between 5G and previous generations is the adoption and in-depth integration of a network of verticals, thus enabling the development of new digital services and models. As a consequence, future 5G networks are faced with the challenge of supporting three main categories of use cases [4]: (i) enhanced mobile broadband (eMBB), which delivers gigabytes of bandwidth on demand, (ii) massive machine-type communication (mMTC), which connects billions of machines, and (iii) ultra reliable and low-latency (URLL) communication, which allows immediate feedback with high reliability for critical services. In order to satisfy all these diverse use cases and their demands, 5G networks call for such qualities as adaptation, scalability, re-reconfigurability, virtualization, and self-organization.  
The Third Generation Partnership Project (3 GPP) started the 5G standardization process with initial study items as part of Release 14. The standardization was divided in two phases: (i) Phase 1--Release 15--provides the set of features, functionality, and services needed for deploying a commercially operational system, (ii) Phase 2--Release 16--will incorporate more functions to extend the 5G capabilities progressively, to support more services, scenarios, and higher frequency bands (to be completed in 2019). The aim of this division in two phases is to complete initial specifications on time and allow for commercial deployment and service launch in 2020 [3]. Together with standardization, field tests under real-world conditions are a significant step toward the launch of 5G networks. Indeed, these allow one to determine how to best leverage the new capabilities of users and to evaluate the key performance indicators (KPIs). In particular, KPIs represent the performance requirements that must be met in each application scenario, such as cell and user peak data rate, data and control plane latency, mobility capabilities, reliability, availability, and density of devices [4].