A comprehensive review of wireless sensor networks: Applications, challenges, radio technologies, and protocols.

Recently, significant advances in digital sensing technology and wireless communications have led to the production of small-scale smart sensors that have the ability to sense physical changes in different environments and convert them into digital signals that are collected in one central location. These networks are called wireless sensor networks (WSNs) because they have the ability to wirelessly communicate with each other for the purpose of passing data between them and deliver it to the central station. Wireless sensor networks have great importance in human environments, as they are used to monitor and record physical changes in environments that are not accessible to humans, such as environments with very high temperatures, or in cases of chemical environmental pollution, in forests and seas as well as in deep layers of earth to monitor seismic and volcanic activity. In view of the great importance of wireless sensor networks and their obvious impact on human life, and for the purpose of providing researchers with brief and complete information about these networks, we have presented this paper that briefly reviews what sensor networks are, their specifications, applications and the challenges they face. This paper also included most of the radio communication techniques used in sensor architectures. As well as touching on the most important routing algorithms in "WSNs" and their classifications with a comparison of their performance. Finally, this paper provided an overview of research trends that could lead to significant technological development and beneficial growth to overcome the challenges of wireless sensor networks. [ABSTRACT FROM AUTHOR]