# Worldwide Coverage Mobile Systems for
## 1 Introduction  
A Smart City is an area where information, technologies, infrastructures, and services are fostered to provide additional value to services that are aimed at improving the quality of life and the living-experience of inhabitants and business experience of companies. In this scenario, digital and telecommunication technologies play a major role in achieving a fully smart city. According to [1], Smart City can be taken in accordance with six characteristics: Economy, People, Governance, Mobility, Environment, and Living. The scope of a smart city is deeper than using information and communication technologies (ICT) to optimize resources' usage and drop current emissions. It means that all of the services and infrastructures, e.g., transportation, water and energy distribution, energy usage, street lighting, etc., are managed smartly, based on the information collected from a variety of sensors in a cooperative set. Furthermore, the interaction and response of the administration (the council) agents are required to provide the best services to different population segments, from babies to aged people, in order to guarantee a high performance and optimization. As society evolves, smart cities must improve to cope with new needs. Smart cities are not isolated entities and a supra-smart-cities entity is now identified, and their development will be supported by new advanced communication systems providing worldwide coverage. Some of those supportive communication systems and infrastructures are currently being developed in successive stages. To provide worldwide coverage, new satellites constellations consisting of many LEO satellites, which are being launched. Furthermore, to provide such worldwide coverage, including the poles, while keeping a small size factor in mobile devices, new antennas must be designed to face current and future Smart Cities communication needs. Despite the concrete definition we accept as most suitable or precise, a common component is a need for evolving and scalable communications. In [2], the authors highlight the key role of ICT in the development of real smart cities. Furthermore, smart cities cannot be conceived without ICT support. The authors identify an advanced global ICT infrastructure as one of the essential components of a smart city. Given that several types of wireless devices (smartphones, laptops, IoT, sensors, etc.) are being widely used and a large amount of contents is available on the Internet, network systems providing appropriate ubiquitous services, anytime, and anywhere, are needed [3]. The development of smart cities will benefit several areas of city life: education, health, environment, transportation, security, energy, business, and economy, and many research challenges are pointed out. Smart Cities need to be able to integrate themselves into national, regional, and international infrastructures. It is worthy to remark that, in order to achieve the overall goal of Smart Cities, several milestones must be reached and, in consequence, several technologies must be developed to support municipality services. The efforts should take into account both wireless infrastructures for mobile communication and wireless and wired infrastructures for fixed communication networks. Furthermore, the growing demand for ubiquitous communications to support the different services offered to the citizens in the smart city affects the technologies (WiFi, WiMAX, LTE, 4G, 5G, FITH, etc.). Several experiments have been developed in different locations without the expected results. However, one can expect that the focus on the network side will shift to Wireless Sensor Networks, allowing for the connection between locations, everyday objects, and devices. The need for provisioning ubiquitous connectivity and reliable and real-time communications identifies satellite communications as a promising solution to support the relevant services and applications.