To make sure that we get at least one CH in almost every grid, more than required number of CHs are preelected in the first phase of CH election.
In DUCA more number of CHs are needed to be preelected than eventually required; that is, we need to keep [p.sub.CH] > C/n.
The preelected CHs in phase 1 are not evenly distributed; therefore, the aim of this phase is to get an even distribution of CHs in the network Following are the steps taken.