# Open Radio Access Networks For Smart IoT Systems: State of Art and Future Directions
## 3 O-RAN in Smart IoT Systems
### Problem Space  
We propose a three-dimensional problem space, as detailed by Figure 3, where the \(X\)-axis indicates the IoT systems (e.g., STS, SMS, others), the \(Y\)-axis displays the targets (e.g., reliable communication, real-time analytics, fault tolerance, interoperability and integration), and the \(Z\)-axis covers the AI/ML techniques (i.e., RL, DNN). As shown in Figure 3, four targets were adopted to represent the research objectives achieved by O-RAN while supporting the smart IoT systems. The targets derived from the adopted research methodology and the diligent consideration of the objectives achieved by O-RAN in these domains. The dimension of targets (\(\gamma\)) are detailed below:  
* _Reliable communication (\(\gamma_{1}\)):_ It entails the achievement of reliable, optimized, and secure communication infrastructure for seamless connectivity and data exchange within and between these systems by addressing challenges related to latency, bandwidth, privacy, authentication protocols, interference, etc. For example, V2X communication represents optimal transmission latency [60], IoE beamforming represents optimized interference in the transmission medium [61], and telemedicine represents optimum end-to-end healthcare service delivery [62]. * _Real-time analytics (\(\gamma_{2}\)):_ It involves improving data collection, analysis, decision-making, and control by integrating edge computing, distributed analytics, and machine learning techniques to support extracting valuable insights and real-time monitoring. It also enables predictive maintenance, personalized services, etc. For example, resource allocation represents the dynamic assignment of network resources in real time [34], and edge intelligence represents data analytics close to where it is generated for improved performance [63; 64]. * _Fault tolerance (\(\gamma_{3}\)):_ It implies using the O-RAN concept to enhance IoT systems' resilience and self-healing capabilities by improving the robustness of fault detection and recovery mechanisms to ensure uninterrupted operation, quick response to disruptions and security threats to minimize downtime. Some of the examples are signaling storm detection [65] and Industrial IoT data security [66]. * _Interoperability and integration (\(\gamma_{\mathbf{\lambda}}\))_: It entails using the O-RAN concept to promote interoperability and integration among IoT devices, systems, and platforms using the standardized interfaces to enable seamless connectivity, data exchange, and integration of diverse components for efficient operations. For example, O-RAN can be used to facilitate interoperability between two or more IoT domains [59]. It is worth noting that to make O-RAN a viable wireless network infrastructure to support IoT applications, it is critical to perform quantitative analysis with performance metrics (latency, bandwidth, scalability, capacity, coverage, range, etc.) for IoT applications based on O-RAN. For example, related to smart manufacturing systems, to carry out monitoring capability of industrial systems, the latency range must be below 100 ms, bandwidth must be in the range of 0.1-0.5 Mp/s, and reliability needs to be larger than 99.9% [67]. In our prior study [15], we emphasized the importance of understanding the key parameters and performance requirements of smart manufacturing systems, including types of manufacturing applications, key parameters (network size, etc.) and performance requirements (latency, reliability, etc. ), discussed the challenges and limitations of existing static networking infrastructure to support applications in smart manufacturing systems with diversified performance requirements, and called for the necessity of developing dynamic and flexible/re-configurable networking infrastructures (e.g., software-defined networking) to support IoT applications with different performance requirements.