Metric-Based Cooperative Routing in Multihop Ad Hoc Networks

Algorithm 2

function modified Dijkstra (G, S, D):

 for each vertex v in Graph:

//Initializations

  cost [v]:= infinity;

//Unknown cost function from S to v

  previous [v]:= undefined;

//Previous node in optimal path from S

 end for;

  cost [S]:= 0;

  Q:= the set of all nodes in Graph;

  while Q is not empty:

 u:= vertex in Q with smallest cost [];

   if cost [u] = infinity:

    break;

//remaining vertices inaccessible from S

 fi;

  remove u from Q;

 for each neighbor v of u:

 //where v has not yet been

        removed from Q.

temp:= 1− (1−cost [u]) linkmetric(u,v);

  //link cost for PDR

temp:= cost [u] + 1/linkmetric(u,v);

  //link cost for Throughput

        or Energy Efficiency

      if alt < cost [v]:

         cost [v]:= temp;

         //Update new metric

         previous [v]:= u;

         //Update new path

     fi;

  end for;

end while;

return cost [];

path:= empty sequence

//find shortest path between S and D

 d:= D

 while previous [d] is defined:

   insert u at the beginning of path

   d:= previous [d]

 end while

 return path;

end modified Dijkstra.