The use of RSSI (Received Signal Strength Indicator), obtained automatically with the received messages in most sensor radios, is the popular way for estimating the location of the mobile wireless object. The great variation of RSS (Received Signal Strength), which may result in inaccurate estimations, is compensated by the fact that RSS does not require… (More)
As wireless sensor networks (WSNs) are being developed for a wide range of application fields of real-time monitoring and control, a design overview seems important so as to investigate alternative communication aspects while treating the WSN as a whole system. As applications become more demanding the need to consider also deployment constraints and… (More)
In the present work, we propose a practical RF propagation model – Free-space Outdoor Model – suitable for WSN due to the fact that it considers the most important WSN constraints and RF signal propagation path loss factors. The model is based on combining four path loss factors, which cause distortion and weakening of the RF signal, i.e.… (More)
Critical characteristics of wireless sensor networks, as being autonomous and comprising small or miniature devices are achieved at the expense of very strict available energy related limitations. Therefore, it is apparent that optimal resource management is among the most important challenges in WSNs development and success.
In the present study, we investigate the variability of the RF signal, measured as Received Signal Strength (RSS), in outdoor unobstructed environment aiming at modeling of the RSS uncertainty for the needs of the outdoor RSS-based localization and tracking applications. The modeling approach is based on determining empirically the relation between the RSS… (More)
Many factors have to be considered when RSS-based localization applications are designed, starting from selection of the proper propagation model, which has to represent in a relatively accurate way the interaction between the RF signal and the environment. The topology parameters, such as the number of beacons, the beacons' heights from the ground and the… (More)
Deployment of senor nodes brings the challenging question on how to place the sensor nodes in order to achieve a particular coverage degree with optimum number of nodes. An important factor, which deployment process also should take into account is the radio signal propagation to guarantee reliable communication links among the network. In the present work,… (More)
As tracking applications for moving objects become more challenging, demands for accurate and reliable tracking methods using wireless sensor networked devices increase. The use of received signal strength (RSS) of the propagated signals, provided by most sensor radios, is the popular means of achieving such a task. Despite the great RSS variation, which… (More)