Research Article
Construction of Quality Virtual Backbones with Link Fault Tolerance in Wireless Sensor Networks
Input: A 2 edgeconnected graph , a colored subgraph of and , where .  Output: The set consisting of all 2Eblocks in .  1 Construct a BFS tree in , and let be the set of edges in . Let , .  2 for to do  3 Select a node with the smallest in .  4 ifthen  5 if is a white node then  6 Color blue, and .  7 end if  8 else  9 Let  10 for each edge do  11 Find a simple circle , whose edges are all in the edge set , and let be the set of all nodes in .  12 if there are no red nodes in then.  13 Let be the minimum ID of nodes in .  14 For each , let .  15 Color all nodes in red.  16 else  17 Let . Let and .  18 For each , .  19 Color all nodes in red.  20 for each do  21 For each node with , .  22 end for  23 end if  24 end for  25 .  26 end if  27 .  28 end for  29 Let and . Let  30 return. 
