1. Guest Editorial: Smart Cities and Smart Sensory Platforms

2. Designing learned CO2-based occupancy estimation in smart buildings

3.Swarm intelligence-based energy-efficient data delivery in WSAN to virtualise IoT in smart cities

4. Using Internet of Things and biosensors technology for health applications

5. Architecture design of the air pollution mapping system by mobile crowd sensing

6.WiFi-based passive sensing system for human presence and activity event classification

7. Design of a novel routing architecture for harsh environment monitoring in heterogeneous WSN

8. Survey on power analysis attacks and its impact on intelligent sensor networks

9. Smart and self-organised routing algorithm for efficient IoT communications in smart cities

10. GVANET project: an efficient deployment of a self-powered, reliable and secured VANET infrastructure

Over the past two decades Wireless Sensor Networks (WSNs) and their applications have been the topic of many studies. WSN is a network responsible for collecting, processing and distributing wireless data to the intended database storage center. Because these sensors are usually installed at remote sites, despite the recent advances. in the WSN technology, its applications still face significant challenges. Out of these, network security threats, network architecture, data collection, deployment and network coverage rise as the major concerns. Therefore, these five issues have been well studied in the literature. The main purpose of this paper is to detail these issues and elaborate on possible solutions.