Date Added: Oct 2010
One fundamental task of Wireless Sensor Networks (WSNs) is to collect useful information from the sensory field or response users query. In such scenario, the gigantic amount of individual sensor readings will converge to the Base Station (BS) of the network. Thus, the "Funnelling effect" which describes the convergence of data traffic towards data sinks remains a major threat to the network lifetime. In particular, those sensors near data sinks need to relay data for nodes that farther away and burn energy faster with the result that the network may become disconnected or dysfunctional.