LEACH-SM: A protocol for extending wireless sensor network lifetime by management of spare nodes

After a wireless sensor network (WSN) is deployed, its operational lifetime depends on its energy resources. Available results reveal that significant improvement in WSN lifetime can be achieved by making WSNs redundant, that is, by adding to WSNs spare nodes that are initially asleep but are ready to be switched on when any primary node (i.e., a node that is not a spare) uses up its energy. We propose the LEACH-SM protocol - a modification of LEACH. It adds the spare selection phase to LEACH.