A density-awareness and delay-sensitive data collecting scheme for wireless sensor networks

This paper proposed a density-awareness and delay-sensitive (DADS) data collecting scheme for wireless sensor networks. This scheme exploits static sink and mobile sink simultaneously to collect data from the whole network. In this way, DADS can solve the premature network partition problem, resulting from the heavy traffic load in the static sink´s vicinity. On the other hand, the coexistence of static sink can guarantee the delay of data delivery for source nodes cannot wait to send their data until the arrival of mobile sink. Comparing with existing algorithms, the major contributions of DADS lies in, (1) mobile sink can adapt the TTL (broadcast depth) of new position announcement message according to the corresponding node density, such that performance can be improved significantly in terms of packet delay and packet delivery ratio without sacrifice of energy consumption balance in the whole network, (2) if a source node only has the route to static sink, packets originated from it may be redirected to the nearer mobile sink when pass through immediate node, this minor and unapparent upgrade can even further improve the state of the art in terms of the referring performance metrics. Finally, extensive simulations show that DADS outperforms the existing data collecting scheme in terms of packet delay, data delivery ratio and network lifetime.