Pius W. Q. Lee

Learn More
The use of wireless sensor networks (WSNs) for structural health monitoring is gaining popularity since it allows for a low-cost, rapid and robust assessment of structural integrity. Meanwhile, recent advances in ambient energy harvesting technology have made it a viable alternative source of energy for powering WSNs. WSNs powered by ambient energy(More)
—Energy harvesting wireless sensor networks (EH-WSNs) are gaining importance in smart homes, environmental monitoring, health care and transportation systems, since they enable much longer operation time as energy can be replenished through energy harvesting. This is unlike WSN nodes that use non-rechargeable batteries which need to be replaced once energy(More)
—Motion and intrusion detection are often cited among various Wireless Sensor Network (WSN) applications. A typical configuration comprises clusters of wireless nodes equipped with motion sensors to detect human motion. Currently, the performance of WSN is subject to several constraints, mainly the phenomenon of radio irregularity and finite on-board(More)
Wireless sensor networks are expected to be deployed in harsh environments characterised by extremely poor and fluctuating channel conditions. With the commonly adopted single-sink architecture, such conditions are exemplified by contention near the sink as a result of multipath delivery. This may be reduced by deploying multiple sinks spatially-apart e.g.,(More)
—The selection of a path in a network from one node to another is performed by a routing protocol, often using the shortest path approach. However, it has been shown that in wireless networks, the shortest path approach tends to select paths with wireless links that are only intermittently available and often unstable, resulting in extensive loss of packets(More)
—In wireless networks, it is important to determine the outcome of packet transmissions for networking protocols. In this paper, we design a transmission outcome classifier for IEEE 802.15.4 wireless networks based on received signal strength indicator and link quality indicator values. Our classifier performs loss differentiation by analyzing statistical(More)
In this demonstration, we implement and deploy a solar-powered wireless sensor network in an outdoor carpark to provide parking guidance to motorists. Combining energy harvesting, multi-hop opportunistic routing and adaptive duty-cycling technologies, the system provides low-cost, real-time, sustainable and eco-friendly operation. We make use of solar(More)
Topology control by means of transmit power adjustment is a well-studied technique for improving the network capacity and energy efficiency of wireless ad hoc networks. In this paper, we investigate the feasibility of connectivity and topology control in a real IEEE 802.11b testbed composed of inexpensive commercial off-the-shelf (COTS) routers. Although(More)
  • 1