Evolution of WSN into WSN-IoT: A Study on its Architecture and Integration Challenges

Researchers have contributed a lot to the enhancement of wireless sensor networks (WSN). Various protocols have been designed for these networks to work with limited resources. However, we are leading toward a new era of innovation, and a new network of things (devices), known as Internet-of-Things (IoT), is evolving, where everything will be connected to the Internet. WSNs integration with the Internet will unleash the full potential of sensor networks, and the sensed data will be available to any user on the Internet at any time. However, their integration raises some challenges which need to be tackled. WSN protocols, designed for limited resources, may not be compatible to create a robust connection with the Internet. Also, the connectivity will make WSN accessible to the whole Internet that may influence the working of the sensor networks. In this paper, we have reviewed the evolution of WSN toward WSN-IoT. For this, we have studied the layered architecture of WSN and how various researchers have contributed to its lifetime enhancement. After that, we have compared the architecture of WSN with IoT to find out the architectural dissimilarities between them. Finally, to address the various challenges that emerge with WSN-IoT integration, we have reviewed the different approaches used for their integration, and then some solutions are given to deal with those challenges.