  Virtual backbone trees have been used for efficient communication between
sink node and any other node in the deployed area. But all the proposed virtual
backbone trees are not fully energy efficient and EVBTs have few flaws
associated with them. In this paper two such virtual backbones are proposed.
The motive behind the first algorithm, Most Minimal Energy Virtual Backbone
Tree (MMEVBT), is to minimise the energy consumption when packets are
transmitted between sink and a target sensor node. The energy consumption is
most minimal and optimal and it is shown why it always has minimal energy
consumption during any transfer of packet between every node with the sink
node. For every node, route path with most minimal energy consumption is
identified and a new tree node is elected only when a better minimal energy
consumption route is identified for a node to communicate with the sink and
vice versa. By moving sink periodically it is ensured the battery of the nodes
near sink is not completely drained out. Another backbone construction
algorithm is proposed which maximises the network lifetime by increasing the
lifetime of all tree nodes. Simulations are done in NS2 to practically test the
algorithms and the results are discussed in detail.
