# A Comprehensive Survey on the Societal Aspects of Smart Cities
## 1 Introduction
It is worth noting that while smart cities can have a significant impact on various aspects that affect the quality of life of their citizens (e.g., safety, environment, or health conditions), even the most advanced adopters have not fully realized their potential and still have much work to accomplish [32]. However, all over the world, there are smart cities' projects whose implementations in real-world environments, become part of the body of knowledge that might be used as a foundation for other implementations. Smart cities are an incredibly complex endeavor and thus difficult to implement. They have different requirements according to each city's needs, services, and infrastructure, which are essential in one city may be irrelevant in another. For example, a city located in a hot environment would require infrastructure to help conserve water, while another in a humid environment would require infrastructure to prevent flooding. Any aspect of a city that can be enhanced by smart city technology can be implemented differently depending on each city's necessities, environs, and priorities. Furthermore, there is the human element to consider. A smart city's governance would ostensibly be performed by the public government of a city. However, they are not the only stakeholders who have an interest in the governance of a smart city [33]. Due to the cost and complexity of implementing a smart city, governments may require financial help from private companies and industries, research and technological assistance from universities and research institutions, and negotiate and achieve compromises with other cities' governments [34]. All these entities have a stake in the smart city and have interests they will want fulfilled, and thus will want to have a voice in the decision-making process [35]. Furthermore, all these systems once implemented will have to work in conjunction with each other, and the data collected will have to be analyzed and used without compromising the security and privacy of the citizenry. This will require even more systems (e.g., middleware, AI, and security), which will increase the complexity even more. This complexity is why implementing smart cities is so difficult, and thus it is important to define each dimension of a smart city and how they can be implemented and the stakeholders appeased. Considering all these recent developments, several surveys were published focusing on specific aspects related to the implementation of smart cities, such as the application domains of smart cities [36; 37], the role of disruptive technologies (e.g., IoT, blockchain technology, or big data) [38], the application of IoT [39; 40; 41; 42; 43], blockchain technology [44; 45], machine learning and artificial intelligence [46; 47; 48], multi-agents [49], fog computing [50], edge computing [51], open data [52], federated learning [53], the use of crowdsensing [54] data analytics [55; 56; 57], the systematization of privacy and security issues [58], or the proposal of a research agenda for public-private partnerships [59]. In turn, this article reports a survey of the dimensions of interest for a city and how smart city technologies can be applied to these dimensions to improve them. Subsequently, we present these technologies and how they are used, as well as their advantages and disadvantages. An additional topic will be how to classify and rank smart cities. In this article, we aim to show that smart cities and their associated technologies are still in their infancy when it comes to implementation in a real-world environment and that the field has various challenges to overcome, namely in how research is still very insular and there is not sufficient knowledge sharing, and there is a lack in the uniformization and standardization of that knowledge into a consistent base from which to progress, and the difficulty to transition from research endeavors to real-world applications.