# Internet of Things (IoT) Operating Systems Management: Opportunities, Challenges, and Solution
## 5 A Brief Review of Articles of This Special Issue  
Proliferation of IoT devices leads to the dense wireless network deployments. Further, availability of sub-1 GHz bands for the communication requires standard to fully explore the potential. Thus, IEEE 802.11 ah [27] standard is released. In 802.11 ah, a single Service Access Point (SAP) can support and serve maximum of 8191 stations with a minimum of 100 kbps data rate within the range of 1 km. In [28], authors explored Cognitive Radio (CR) based 802.11 ah networks and proposed new distributed MAC protocol named as carrier sense Restricted Access with Collision and Interference Resolution (RACIR). Its the hybrid MAC protocol based on CSMA/CD and CSMA/CR protocols. It resolves the scalability and hidden primary terminal problem. Each station enable contention free grouping access by estimating the active stations in the group by using split algorithm.Therein, it access the channel in random access contention based manner to avoid interference with the Primary User (PU) receiver. RACIR is compared with CR-CSMA/CA and the results showed that it considerably improves performance in terms of throughput, delay and energy consumption. IIoT is revolutionizing the industry. It is used to collect, analyze and apply the information from numerous sensors to further improve the overall efficiency of the system. The network design and topology plays a crucial role on the performance of the system. The proper handling of massive data generated by the sensors and security are the key to run the system efficiently. Therefore, [PERSON] et al. [29] addressed the topology design by considering uncertain factors in production process and sensor demands. Moreover, they proposed big data analysis model along with the security protection system. They used Analytic Hierarchy Process (AHP) to analyze the intelligent evaluation index model. They applied and evaluated the proposed solution to the diesel engine enterprise. According to the results, the proposed network topology deployment interconnect all the production units, efficiently process, handle and share the information among different units, and increased the system security. Consequently, it makes the enterprise more robust, adaptive and flexible. Smart homes with efficient Home Energy Management System (HEMS) provides reliability and consequently energy conservation. These systems are specifically designed to cater challenges like user comfort, and cost reduction etc. In [30] [PERSON] et al. presented Fuzzy Inference System (FIS) by considering humidity level as an additional parameter. They also used indoor room temperature variation as a feedback to FIS to manage the energy consumption and user comfort. They also automate the FIS using automatic rule based generation method using the combinatorial method. The results showed that the proposed scheme improves the overall system and considerably reduced the energy consumption without compromising the user comfort. Underwater Wireless Sensor Networks (UWSNs) is useful for aquatic monitoring, pollution monitoring and mineral extraction etc. Highly challenging UWSNs communication environment makes it very difficult to route the packets from sensor nodes to the sink. These devices are mostly battery operated and highly resource constrained. Hence, inefficient routing method consumes more energy and inevitably results in node failures. These sudden node failures results in creating void node problem. [PERSON] et al. in [31] proposed four schemes namely Adaptive transmission range in WDFAD-Depth-Based Routing (DBR) (A-DBR), Cluster-based WDFAD-DBR (C-DBR), Backward transmission-based WDFAD-DBR (B-DBR) and Collision Avoidance-based WDFAD-DBR (CA-DBR) to increase energy efficiency, decrease void node problem, decrease end-to-end delay, fall back recovery mechanism and reduce collisions. A-DBR dynamically adjust the transmission range to cater void node problem and consequently save energy with higher successful packet delivery.