Redundant trees for preplanned recovery in arbitrary vertex-redundant or edge-redundant graphs

We present a new algorithm which creates redundant trees on arbitrary node- redundant or link-redundant networks, These trees are such that any node is connected to the common root of the trees by at least one of the trees in case of node or link failure. Our scheme provides rapid preplanned recovery of communications with great flexibility in the topology design. Unlike pr evious algorithms, our algorithm can establish two redundant trees in the c ase of a node failing in the network. In the case of failure of a communica tions link, our algorithm provides a superset of the previously known trees .