828414.fig.007a
(a)
828414.fig.007b
(b)
828414.fig.007c
(c)
828414.fig.007d
(d)
Figure 7: Aggregation example. The subfigures from left to right represents the consecutive steps of an average computation: (i) the measured data is ready to send. It is stored in a format of actual average; number of data. Non-CDS nodes sends the average to their parents. (ii) The CDS nodes start to send the aggregated value to its parents. (iii) A CDS node receives an aggregate from all of its neighbors, and starts to broadcast the final aggregated value. Nodes willing to store the value can do so. (iv) Other CDS nodes receiving the final value rebroadcasts it. Nodes willing to store the value can do so.