# Review of Smart-Home Security Using the Internet of Things
## 4 Analysis and Discussions of the IoT Setting  
### Architectural Structure of IoT Ecosystems  
In order to study the security of a smart-home environment deploying IoT technology, one should first describe the architectural structure of such systems. Ordinarily, devices are communicating at the edge system, directly or via a gateway, and can also interact through the Internet or a cloud. The layers of an IoT architecture are not defined by a single methodology or standard, but rather by a combination of industry best practices, architectural principles, and various standardization bodies. However, several organizations and standardization bodies provide guidance and frameworks for designing and implementing IoT architectures. Some of the most notable ones include the following:* International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC): The ISO and IEC have developed several standards related to IoT, including ISO/IEC 30141 [93] which provides guidelines for the architecture and interoperability of IoT systems. While the ISO/IEC standards may not explicitly define the layers of an IoT architecture, they offer principles and recommendations for designing scalable and interoperable IoT solutions. * Institute of Electrical and Electronics Engineers (IEEE): The IEEE has published numerous standards and guidelines for IoT, including IEEE P2413 [94] which defines an architectural framework for IoT. While IEEE P2413 does not prescribe specific layers, it outlines key architectural concepts and considerations for IoT systems. * Industrial Internet Consortium (IIC): The IIC has developed the Industrial Internet Reference Architecture (IIRA) [95], which provides a comprehensive framework for designing industrial IoT solutions. While focused on industrial applications, the IIRA can be adapted for other IoT use-cases and includes concepts related to layered architectures. * Open Connectivity Foundation (OCF): The OCF has developed standards for interoperability and connectivity in IoT devices and ecosystems [96]. While the OCF standards primarily focus on interoperability protocols, they also address architectural principles that may align with layered approaches. * National Institute of Standards and Technology (NIST): The NIST has published several documents related to IoT security and architecture, including the NIST Cybersecurity Framework [97] and NIST Special Publication 800-183 [98], which provide guidance on IoT device cybersecurity. While not explicitly defining layers, these documents offer principles and recommendations for designing secure IoT architectures. Overall, while there is no single methodology or standard that defines the layers of an IoT architecture, various organizations provide guidance and frameworks that can drive the design and implementation of IoT solutions. Architects and designers often refer to these resources to develop architectures that meet the specific requirements and objectives of their IoT projects. Nevertheless, based on these methodologies four conceptual levels are considered in IoT research (e.g., [19]):  
1. Application: smart environment, smart home, smart city;
2. Perception: movement sensors, smoke sensors, pressure sensors;
3. Network: nodes, servers, topologies;
4. Physical: smart phones, smart appliances, power supplies. These layers are detailed in the following subsections. A modern IoT system consists of various smart environments, such as smart homes, cities, hospitals, and transport, all of which are supported by applications that run on smart devices. The application layer [99] is the topmost layer in the IoT architecture and manages all these applications and their secure deployment on user's devices. It is responsible for ensuring the confidentiality, integrity, and availability of legitimate software and its data, as well as that the applications can interconnect and interact with the lower layer, which is the network layer.