# IIoT System for Intelligent Detection of Bottleneck in Manufacturing Lines
## 2 Literature Review
### Technological Advances That Impact Data Flow and Data Integration  
Technological advancements in networking and industrial protocols are revolutionizing traditional control systems, enabling flexible information flow and communication within and between industrial layers. Notably, the optimization of industrial Ethernet protocols, such as Time-Sensitive Networking (TSN) with features such as Single-Pair Ethernet (SPE), consolidates diverse sensor and actuator data into a unified network. This not only reduces wiring but also supports data-driven manufacturing by facilitating increased sensor and I/O device installations, as highlighted in [13]. The growing adoption of 5G technology in industrial communications is enhancing the bandwidth capacity, reducing latency, and improving the overall efficiency. This technology, standardized for smart manufacturing applications, supports the Industrial Internet of Things (IIoT) and industrial wireless communications [14; 15]. The integration of Ethernet TSN and 5G offers increased potential for automation, sensor augmentation, and smart manufacturing. Additionally, the rise of devices with 5G interfaces proves advantageous in situations where cable usage is impractical, such as in hostile environments with chemical agents. The 2023 Industrial Network Market Share, as reported in [16], highlights substantial growth in industrial Ethernet, surpassing wireless technologies. Although traditional fieldbus is decreasing, it remains prevalent in industrial control. The study indicated a 68% market share and 10% annual growth for industrial Ethernet-related network technologies, while wireless technologies hold an 8% market share with an annual growth of 22%. In contrast, fieldbus accounts for 24%, experiencing a negative annual growth of \(-5\%\). These data reflect a shifting preference toward wireless and Ethernet networking for interconnecting field components. With the data acquired from sensors and actuators, advancements in network standards support both vertical and horizontal information flow, aligning with the Industry 4.0 paradigm [17]. Technologies such as MQTT [18] enhance message exchange, facilitating rapid data delivery to other software layers or the cloud. Protocols such as HTTPS and Modbus TCP improve communication latency over the industrial Ethernet network, enabling smoother interaction between devices, such as programable logical controller (PLC) and other clients, such as those using Web or Modbus, for information retrieval. The OPC protocol with UA mode [19] presents a service-oriented architecture that integrates components, incorporating features such as security and modeled information. This protocol facilitates the exchange of information with programmable controllers, middleware systems, and integrated cloud-based systems [20]. In summary, the ongoing changes in technology are transitioning from a monolithic focus on individual machine control to a flexible, integrative, and scalable approach. This shift brings forth various features and capabilities, as follows:  
* Establishes information connections between processes, workstations, factories, and remote sites. * Makes this information flow more accessible and expands the scope to analyze issues, such as those in this article, to obtain an effective detection of bottlenecks. * Provides higher-quality data [21], encouraging monitoring, measurement, and comparison with other key information, where we will be able to control deviations or trends. The 6G wireless technology, discussed in [22], promises future industrial scenarios based on the Internet of Verticals, emphasizing cloud manufacturing and the provision of resources as services. This approach allows for the sharing of solutions between workstations or similar machines. However, a significant challenge is ensuring the security of information flows due to increased mobility, leading to more frequent cyber-attacks. In [23], the authors underscored the importance of classifying cyber-attacks by layers in IIoT architectures.