An Enhanced Energy Saving Approach for WSNs

Wireless sensor networks are used today in a wide range of applications, all of which employ a large number of sensors. In large scale sensor networks, sensor nodes are often not easily accessible. Because of this, the energy consumption of wireless networks is an important matter as well as a popular topic of research. A sensor node consumes energy while collecting, processing, transmitting and receiving data. Each of these processes could be the focus of research, so there are many investigations into these subjects, centering on ways of reducing energy consumption and extending the lifetimes of networks.In this paper we study data processing schemes that define the distribution of decision making, which affects system accuracy and energy consumption. The two typical detection schemes are the centralized and distributed schemes. In a centralized scheme, nodes collect samples from the environment and send them to a “fusion center”, where the samples are used to arrive at a final decision. This scheme provides optimal decision accuracy; however, it consumes considerable energy. In contrast, distributed schemes allow nodes to make local 1-bit decisions, which are sent to the fusion center to make the final decision. In a hybrid scheme the network specifies the level of accuracy required for the whole system. This can be achieved by manipulating the scheme to work sometimes as centralized other times as distributed. We propose an energy-saving hybrid scheme that focuses on optimizing transmission energy, since most of the energy consumed is in the transmission process. In the proposed scheme each node alternates between centralized and distributed according to its location and path length. Nodes with longer path lengths are classified as acting more as distributed than those with shorter path lengths.