  In energy constrained wireless sensor networks, it is significant to make
full use of the limited energy and maximize the network lifetime even when
facing some unexpected situation. In this paper, all sensor nodes are grouped
into clusters, and for each cluster, it has a mobile cluster head to manage the
whole cluster. We consider an emergent situation that one of the mobile cluster
heads is broken down, and hence the whole cluster is consequently out of work.
An efficient approach is proposed for recovering the failure cluster by
selecting multiple static sensor nodes as the cluster heads to collect packets
and transmit them to the sink node. Improved simulated annealing algorithm is
utilized to achieve the uniform deployment of the cluster heads. The new
cluster heads are dynamically changed in order to keep balanced energy
consumption. Among the new cluster heads, packets are transmitted through
multi-hop forwarding path which is cost-lowest path found by Dijkstra's
algorithm. A balanced energy consumption model is provided to help find the
cost-lowest path and prolong the lifetime of the network. The forwarding path
is updated dynamically according to the cost of the path and residual energy of
the node in that path. The experimental results show that the failure cluster
is recovered and the lifetime of the cluster is prolonged.
