Hybrid Approaches to Address Various Challenges in Wireless Sensor Network for IoT Applications: Opportunities and Open Problems
International Journal of Computer Networks And Applications
Since the last decade, wireless sensor network (WSN) and Internet of Things (IoT) has proved itself a versatile technology in many real-time applications. The scalability, costeffectiveness, and self-configuring nature of WSN make it the fittest technology for many network designs and scenarios. The traditional WSN algorithms are programmed for fixed parameters without any touch of Artificial Intelligence as well as the optimization technique. So, they suffer from a trade-off between various
... parameters like network lifetime, energy efficiency, and others. To conquer the limitations of traditional WSN algorithms, machine learning has been introduced in wireless technology. But machine learning approaches also cannot solve all the problems in WSN solely. Some of the applications like target tracking, congestion control, and many more, do not give desired results even after applying the machine learning techniques. So, there is a need to introduce optimization in such cases. The paper gives an extensive survey on various optimization methods employed to solve many WSN issues from 2005 till 2020. It also gives a brief description of the usage of various machine learning techniques in WSNs from 2002 till 2020. The paper discusses the advantages, limitations, effects of these methods on various WSN techniques like topology, coverage, localization, network and node connectivity, routing, clustering, cluster head selection, cross-layer issues, intrusion detection, etc. This paper gives a lucid comparison of many state-of-the-art optimization algorithms and descriptive and statistical analysis for discussed issues and algorithms associated with them. It also elucidates some open issues for WSNs/IoT networks that can be solved using these approaches. SURVEY ARTICLE with IoT. It gives a huge coverage of radius for communication of several objects, offices, schools, homes, hospitals, etc. To connect the vast number of devices through the internet or any internet-based technology like fog computing, the system needs to follow several protocols  . These protocols work towards the efficiency of the system to make it reliable and withstand its complexity. IoT is classified into four aspects: Transmission, support, perceptive, and applications. Each aspect uses some technologies for its successful working, for instance, WSN, RFID, global positioning system (GPS) are under perceptive. Similarly, the transmission is controlled by technologies like Bluetooth, ZigBee, wireless local area network (WLAN), etc. for support system IoT uses data mining, cloud computing, etc. There are several applications of IoT in real-world scenarios. Despite being well equipped with updated and smart technologies, the IoT and WSN face some critical issues which are inevitable  . The paper covers literature centered on various technologies, schemes, and algorithms to address many problems coming in the way of coming-of-age wireless communication technologies for various applications. Some challenges in the way of IoT/WSN systems are discussed below- The data transmission in any wireless network plays a very dominant role since the whole network's main focus is to transmit data from one place to another. Energy scavenging/ harvesting is another aspect that should be considered before deploying the sensors. The sensors have limited battery power and are often not rechargeable. So, the technologies which can make use of solar energy or scheduling approaches to minimize the consumption of energy in the network should come up. Fault node detection or anomaly or intrusion detection is the major challenge for which much researches have been done and still taking place. The faulty/ outlier nodes affect directly the accuracy, energy wastage, throughput degradation, etc., of the network. The tracking of any object, event, or target is another challenge coming in the way of WSN/IoT applications. Some applications need nearly zero delays to detect any target or event like in the case of military application, fire detection, etc. Also, the coverage area should be maximum to avoid any left-out areas for tracking. Routing means the selection of a path that starts from the source and leads to the destination. The routing faces many issues like energy management, throughput, jitter, end-to-end delay, etc. This paper covers more than 100 applications in IoT which covers technologies like unmanned aerial vehicle (UAV), WSN, industrial WSN (IWSN), etc. in the last decade. The paper gives a survey of 13 WSN assisted IoT network challenges and their implementing technologies. We describe the number of surveys covering each issue, the percentage of the applications used for various issues, and the common issues. We also find some of the research gaps from the papers in the literature and give a possible solution to fill that gap.