# IoT-Enabled Smart Cities: A Review of Concepts, Frameworks and Key Technologies
## 3 Review of IoT-Enabled Smart City Components and Solutions
### Smart Governance  
Smart governance deals with the adoption of ICT into city governance practices in order to improve the decision-making process and speed up bureaucratic and administrative procedures through a smarter collaboration among different stakeholders and social actors [38], including public administrations, city officers, private companies and citizens. This can be successfully accomplished by providing innovative city services, dedicated channels and network integration for citizens. For instance, citizens can be engaged in participating with city governance activities and decisional processes through ICT-based tools and social media [39] as evidence of the mobile crowdsourcing paradigm [40], according to which citizens can act as \"users as sensors\" with their smartphones and mobile devices, participating as individuals and in groups in the acquisition process of data of interest for smart communities. IoT technologies are transforming traditional city governance transactions and processes into smart government resources on the basis of the different participating actors, i.e., government-to-citizen (G2C), government-to-business (G2B) and government-to-government (G2G) [41,42]:  
* Government-to-citizen (G2C) refers to the set of software solutions (typically web and mobile based) that support the relationships between public administrations and citizens, such as public administration web portals and/or mobile applications and social media channels employed for communication and interaction between local governments and citizens. In addition, IoT technologies, such as RFID and biometric sensors, are widely and increasingly adopted in electronic ID cards and mobile devices for identity recognition, electronic authentication and signature, according to different governmental standards, such as the European Community's electronic IDentification, Authentication and trust Services (eIDAS) [43]. These features are typically required to access services that are provided by public administrations and consult citizens' personal data related to public services, etc., thus simplifying a lot of the communication and interaction between governmental authorities and citizens;
* Government-to-business (G2B) regards the interactions between public administrations and businesses companies. In this model, e-procurement solutions are adopted, i.e., digital tools (mainly via the web), through which local governments publish ten  
Figure 3: The classification of smart city domains with related components and application areas. ders, projects, competitions, facilities for the purchase/sale of goods and other general services for and from private companies. IoT technologies are widely adopted in G2B activities, facilitating and enhancing the relationship between local governments and companies that provide public and private services to citizens. For instance, transportation companies use location-based sensors (usually exploiting GPS technology) and services, sharing them with local administrations and allowing the easier and more efficient urban planning for mobility and transportation [44]. In addition, it includes similar aspects involved in many other domains that provide public and fundamental services, such as waste management, water, energy, etc. To this end, the use of cloud computing is generally adopted to store and share data and results among the different stakeholders (city operators, companies and citizens);
* Government-to-government (G2G) is related to the software solutions that aim to improve communications between the different public administration entities and groups, thereby speeding up all processes that require the interaction of these actors. This implies the use of IoT technologies for data collection, storage and sharing, which exploits, for instance, cloud computing and web/mobile-based services.