One of the most widely used techniques for solving the famous localization problem in wireless sensor networks (WSNs) is the Trilateration. This paper introduces an enhanced version of the Trilateration algorithm entitled Fuzzy Based Trilateration (FBT). The main objective is to estimate the position of sensor nodes in WSNs accurately with a cheap, low power and simple technique. FBT achieves i...

Link quality estimation of reliability-crucial wireless sensor networks (WSNs) is often limited by the observability and testability of single-chip radio transceivers. The estimation is often based on collection of packer-level statistics, including packet reception rate, or vendor-specific registers, such as CC2420’s Received Signal Strength Indicator (RSSI) and Link Quality Indicator (LQI). T...

For automatic monitoring systems and user oriented services, crowd density estimation becomes an important research topic. There are existing methods like the camera based crowd density estimation or the RFID based counting systems. However, these methods need deployment cost and enough spaces to set the sensors. In this paper, we therefore present a passive estimation system that could be easi...

In this paper, we propose a distributed transmission power control algorithm which cannot only prolong the lifetime of sensor nodes by saving the energy consumption but enhance the performance of packet delivery ratio. Besides, it can also reduce the interference between transmitting nodes. Before designing our algorithm, we firstly investigate the impact of link quality when utilizing differen...

Deployment of a hybrid wireless and local area network (LAN) system is a feasible solution for smart grid communication. In this paper, a combination of fixed worldwide interoperability for microwave access (WiMAX) at 2.4, 3.5 and 5.8 GHz and Ethernet LAN is proposed for monitoring and control of energy meters in a smart grid. Communication signal quality is an important factor to consider as i...

The nature of packet loss of wireless links at 2.4G band was analyzed and a wireless link quality prediction algorithm for wireless sensor networks was proposed. In the proposal, RSSI (Received Signal Strength Indicator) and LQI (Link Quality Indicator) were utilized to produce a couple of metrics of wireless link quality, named Sm and delta respectively, and their distributions were studied. B...