For a sensor network to be reliable and useful, sensor data must sustain high Quality of Information (QoI). While QoI depends on many factors, the most crucial is the integrity of sensor data sources themselves. Sensor data quality may be compromised by causes such as noise, drifts, calibration, and faults. On-line detection and isolation of such misbehavior are crucial to assure high QoI for t...

The unexpected change in user equipment (UE) velocity is recognized as the primary explanation for poor handover quality. In order to resolve this issue, while limiting ping-pong (PP) events we carefully and dynamically optimized handover parameters for each UE unit according to its velocity and the coverage area of the access point (AP). In order to recognize any variations in velocity, we app...

One of the key issues in the design of personal communication service (PCS) systems is the efficient management of location information. The current IS-41 and GSM schemes use a two-tier system of home location register (HLR) and visitor location register (VLR) databases. In a two-tier system, the success of a call requires the HLR and the callee’s current VLR to be failure-free. A VLR failure a...

The authors study the design of heterogeneous two-tier wireless sensor networks (WSNs), where one tier of nodes is more robust and computationally intensive than the other tier. The authors find the ratios of densities of nodes in each tier to maximise coverage and network lifetime. By employing coverage processes and optimisation theory, the authors show that any topology of WSN derived from r...

Sink mobility brings new challenges to large-scale sensor networking. It suggests that information about each mobile sink’s location be continuously propagated through the sensor field to keep all sensor nodes updated with the direction for forwarding data reports. Unfortunately frequent location updates from multiple sinks can lead to both excessive drain of sensors’ limited battery power supp...