Although the PLC technology is increasingly used mainly in low voltage networks, causes of interference of signal transmission have not been, as yet, sufficiently explained. It is very important for the wider use of this technology in practice. The paper presents and discusses the results of simulation analysis of transmission efficiency for narrow band PRIME standard obtained for specially developed for this purpose simulation model of the real low voltage network. This model allows both the mapping of the network parameters in the desired range as well as the modelling of physical phenomena occurring in it that may practically affect the narrow-band transmission quality. On the basis of the results the suitable conclusions for practical applications have been formulated.

The article presents an idea of building a widearea sensor network for monitoring the environmental state. The network combines different technologies for data acquisition and is heterogenic in that it is suited to use different data transmission technologies. A distinguishing feature, making this network different from its existing counterparts, is its easy expansion by adding new sensor types, as well as its scalability and functional universality.

In order to construct an effective wide-area sensor network, an optimal solution consists in dividing it into a local and a core segment. On the local side, the ZigBee technology is commonly applied to transfer sensor data as it offers effective mechanisms of self-organization and automatic reorganization in case of failure. Since ZigBee is claimed to be natively suited to multi-hop transmission, its performancein terms of throughput and delaywas quantitatively tested in a chain topology consisting of up to five hops. The achievable data rates were found to be exponentially decreasing with successive hops whereas the delay was growing linearly. A strong dependence was also confirmed between an antenna type used on ZigBee devices and the maximum achievable operating range.

No abstract