###### Abstract  
This paper presents a case study of Fog Computing, Edge Computing (EC) and Intelligent EC applied to Smart Buildings, focusing on the deployment of innovative services and smart IoT devices, discussing new architecture as Software-Defined Network (SDN). Specifically, a comprehensive solution of a Smart Building case is proposed to validate main statements and conclusions are drawn, providing a general guideline to address the problems of choosing between Edge or Fog Computing and the specific category of IoT devices. The methodology employed in this study is based on field research conducted in buildings within the metropolitan region of Sao Paulo, Brazil, that aim to enable their transformation into Smart Buildings (SBs). Moreover, principles of Electronic Systems Engineering and Cloud Computing such as reliability, scalability and security are applied. In that way, this study integrates advanced multimedia technical services to enhancing security and communication within the SBs through centralized control. The method focuses on identifying and analyzing the most common problems observed in field research within SBs in early stages of development, prior to the intensive implementation of IoT devices and Fog or Edge Computing technologies on the state of the art. The research adopts a comparative approach, investigating the best solutions for each application category. The results are consolidated in a main table within the article, correlating solutions to the four main problems identified in the field research, such as impairments in voice over IP and video communication using IoT devices; latency and delays in communication between SBs and the Cloud center; access security issues; and the Quality of Experience of video over IP communication, both in live transmissions and recordings between SBs. Regarding applications, this study considers the use of specific IoT devices and Cloud Computing architectures, such as Fog or IEC. Furthermore, it explores the implementation of new open network and communication models, such as SDN and NFV, to optimize communication between the various SBs and the SB's connection to the control center of a Smart City. E 2025 15 3805 10  
Fog and IEC are increasing their hold around the world for constrained applications by such factors as costly bandwidth, long latency and Quality of Experience (QoE) sensitivity or even needing high processing power and large storage for structured or unstructured data close to the place where data are generated or received by IoT devices. Smart Cities encompass a diverse range of services across numerous domains, including traffic management, public utilities, environmental sustainability, water and electricity provisioning, and the seamless integration of buildings and neighborhoods with transportation and energy distribution networks, particularly for electric vehicles (EVs). Furthermore, the application landscape extends to Industry 4.0, encompassing smart factories and precision agriculture, aimed at enhancing agribusiness productivity through the deployment of drones, IoT-enabled machinery, LoRa, WP-MEC networks, and advanced video and security surveillance systems. A significant portion of these broad technological advancements in IoT and Edge services is being leveraged within Smart Buildings (SBs). This includes granular control of water and electricity consumption, implementation of environmentally sustainable systems, and the utilization of LoRa, Wi-Fi 6, and Bluetooth for smart IoT devices. The integration of Edge Computing with these smart IoT devices within SBs facilitates enhanced operational efficiency and intelligent automation [1]. The core of this article is the site where the computational power is to be installed and supplied with reference to the Smart Buildings in order to make it possible to carry on the operational study. This computing power may be concentrated within the Fog or the IEC or even yet in a hybrid solution as in the two cases cited in _multi-cloud_, which could be extended to the traditional cloud.