EditorialRecent issues in wireless sensor networks Wireless sensor networks (WSNs) have become a highly active research area because of their potential of providing diverse services to a broad range of applications. The explosive growth of applications for the current and emerging user services creates a number of issues in WSNs. Emerging technologies and application services have posed various challenges to both academic and industry people, especially for the development of efficiency, scalability, and reliability in WSNs. These challenges motivate us to design and develop new protocols, architectures, and services for future WSNs.The goal of this special issue is to publish both state-of-the-art and prospective papers that present advances towards the performance enhancement of WSNs. The call for papers for this special issue attracted 15 submissions from different areas and countries covering a wide range of topics in the field of WSN. Each paper was carefully evaluated by at least two reviewers. This careful evaluation process has allowed us to select four high quality research papers. We strongly believe that the selected papers will make a significant contribution to researchers, practitioners, and students working in this field.The first paper, 'Secured Flooding Time Synchronization Protocol with Moderator' by Ding-Jie Huang et al., addresses the security vulnerability of the flooding time synchronization protocol (FTSP) and proposes several technologies to reinforce the structure of FTSP. Simulation results show that, by combining the root selection mechanism with the global time blacklist filter, the proposed mechanisms successfully defend against traitor attacks on FTSP.The second paper, 'On The Impact of Temperature on Path Selection for Wireless Ad-hoc Sensor Networks' by Chih-Cheng Tseng et al., takes the impacts of the temperature on the utilization of battery of mobile nodes into the problem of selecting paths in wireless ad hoc sensor networks. To address this issue, the authors propose a three-step systematic method to calculate the battery's utilization under different temperature of a mobile node's battery. Simulation results show that the battery's temperature is critical to the lifetime of ad hoc sensor networks if we let the method be applied to the power-aware source routing algorithm and the maximum path lifetime routing algorithm.The third paper, 'Performance Analysis of S-MAC Protocol' by Li-Wei Chang et al., investigates the design of energy-efficient medium access control (MAC) protocol for WSN. In this paper, the performance of the proposed sensor-MAC (S-MAC) is mathematically analyzed and verified by conducting extensive simulations. In addition, as compared with the conventional carrier sense multiple access/collision avoidance protocol, the simulation results show that the S-MAC protocol performs better in terms of power consumption, delay, and collision rate.Sensor nodes are usually unevenly distributed in real situations. Efficient spatial index is essential for querying spatia...

No abstract

No abstract

No abstract

No abstract