Network coding is a novel concept for improving network capacity. This additional capacity may be used to increase throughput or reliability. Also in wireless networks, network coding has been proposed as a method for improving communication. We present our experience from two studies of applying network coding in realistic wireless sensor networks scenarios. As we show, network coding is not as useful in practical deployments as earlier theoretical work suggested. We discuss limitations and future opportunities for network coding in sensor networks.

There exists a number of MAC protocols targeted for mobile scenarios. These include MMAC, MS-MAC and AM-MAC. These MAC protocols have in common that they seem to be evaluated only in simulation. This might indicate that these MAC are either too complex to use or they are not needed, at least for data collection, the major task of sensor networks. In this paper we show that extending a traditional data collection protocol with lightweight, carefully selected mechanisms is sufficient to provide reliable data collection at low energy cost for mobile sensor networks where both sinks and sources move.