# Open Radio Access Networks For Smart IoT Systems: State of Art and Future Directions
###### Abstract  
The Internet of Things (IoT) constitutes a vast network comprising various components such as physical devices, vehicles, buildings, and other items equipped with sensors, actuators, and software. These components are interconnected, facilitating the collection and exchange of copious data across networked communications. IoT empowers extensive monitoring and control over a myriad of objects, enabling them to gather and disseminate data that bolster applications, thereby enhancing the system's capacity for informed decision making, environmental surveillance, and autonomous inter-object interaction, all without the need for direct human involvement. These systems have achieved seamless connectivity requirements using the next-generation wireless network infrastructures (5G, 6G, etc. ), while their diverse reliability and quality of service (QoS) requirements across various domains require more efficient solutions. Open RAN (O-RAN), i.e., open radio open access network (RAN), promotes flexibility and intelligence in the next-generation RAN. This article reviews the applications of O-RAN in supporting the next-generation smart world IoT systems by conducting a thorough survey. We propose a generic problem space, which consists of (i) _IoT Systems_: transportation, industry, healthcare, and energy; (ii) _targets_: reliable communication, real-time analytics, fault tolerance, interoperability, and integration; and (iii) _artificial intelligence and machine learning (AI/ML)_: reinforcement learning (RL), deep neural networks (DNNs), etc. Furthermore, we outline future research directions concerning robust and scalable solutions, interoperability and standardization, privacy, and security. We present a taxonomy to unveil the security threats to emerge from the O-RAN-assisted IoT systems and the feasible directions to move this research forward. O-RAN; smart IoT systems; machine learning +
Footnote †: journal: _Future Internet_  
The advancement of IoT technology heavily depends on its three pillars of computing, communication, and things (sensors and actuators). As evident by Figure 1, smart IoT systems have diverse quality of service (QoS) and reliability requirements [15; 19]. For example, healthcare wearables and energy grid smart meters are massive-connectivity-intensive. At the same time, self-driving vehicles and remote surgery are latency-intensive, while telemedicine and industrial control and monitoring systems are broadband-intensive [20; 21; 22; 23]. In the last two decades, mobile technology has opened the wildest imaginations regarding innovation and creativity in the telecom sector by drastically changing how we communicate from the perspective of distance and geographical divide. As a result, the total user experience has been consistently and substantially improved by new technology generations launched on average every ten years [24]. In a report published in 2022 by Dell'Oro, it was predicted that the global Radio Access Network (RAN) industry will surpass $40 billion by 2026 and that Open-RAN deployment will represent more than 15% to 20% of RAN worldwide [24; 25]. Traditional cellular networks such as 3G and 4G are built on monolithic, inflexible infrastructure, unlike 5G, which supports heterogeneity, allowing O-RAN to run on software-defined radio (SDR), an open loop instead of traditional analog hardware-based systems, which are closed-loop control [26]. The practical implementation of 5G systems requires drastically reworking existing plug-and-play methodologies instead of flexible, new, and open paradigms for network management, deployment, and control [27]. In this scenario, the cellular arena welcomes ground-breaking and cutting-edge networking solutions based on softwarization, openness, resource sharing, virtualization, and mobile edge-computing [28; 29]. O-RAN technology aims at maximizing possible resource usage and sharing infrastructure, providing a unique market opportunity such as infrastructure leasing and connectivity-as-a-service (CaaS) technology.