# Multiparametric Monitoring in Equatorial Tomato Greenhouses (II): Energy Consumption Dynamics
## 4 Experiments and Results
### Energy Consumption Dynamics of DigiMesh Network
The change in the transmission rate for Nodes 2 and 3 did not influence the behavior of energy consumption, since the _pdf_, the margin of highest data concentration, and the narrow width of the CI were very similar at the three speeds. In contrast, the similarities of these parameters for Sensor  
Figure 2: Time signals for DigiMesh network in two example realizations: (**Left**) at 19,200 bauds; (**Right**) at 57,600 bauds; (**Top**) complete time signals; and (**Bottom**) signal sections with closer detail. Node 1 were evident at 9600 and 19,200 bauds, but the _pdf_ was multimodal, and the CI increased considerably at 57,600 bauds, due to the lag between realizations that was previously explained in the M-mode analysis of this node. The increase in the transmission speed in Node 4 did not significantly change the consumption range with higher data concentration, however, the number of modes of the probability distribution was reduced from three to two, and the CIs were reduced in both speeds, with the narrowest one being obtained at 19,200 bauds. Hence, the energy consumption behavior for this rate was less affected by factors such as the load effect given at low battery voltages or the delay in the CO\({}_{2}\) sensor activation. Figure 5 shows the estimation of the histograms for the DigiMesh network at 9600, 19,200, and 57,600-baud rates. The elements of the DigiMesh network for the three speeds have the same current ranges with higher occurrence probability. In addition, the current range with lower probability of the Coordinator Node decreases with increasing speed. Accordingly, we identify that the sensor nodes have higher average energy consumption than the Coordinator Nodes, especially Sensor Node 4. Figure 6 shows relevant aspects identified in the autocorrelation analysis using the M-mode and the CI at 19,200- and 57,600-baud rates. The plots of the Coordinator Node at 57,600 and 9600 bauds were similar, and corresponded to a non-seasonal time process, since the decrease of their SAFs was slow and exponential-like. In contrast, the first six realizations of this node at 19,200 bauds recorded slow and anti-persistent drops, and for increasing run number, the battery voltage was reduced and the consumption signals tend to be uncorrelated processes, because the falls were rapid and with slight persistence in the initial delays. The persistence and fast descend of SAFs in Nodes 1 and 3 were similar for the three speeds, hence, we conclude that the consumption signals in these nodes is seasonal, independently of the transmission rate. The autocorrelation variations in the signals of Nodes 2 and 4 were rapid in all the runs and the number of signals with relevance throughout the delay was greater than 19,200 bauds, but in general terms we can classify the consumption of these nodes as uncorrelated processes. Figure 3: M-mode of _pdf_ with distinctive characteristics for DigiMesh network. From left to right: Coordinator Node, Node 1, and Node 4. (**Top**) At 19,200 bauds; and (**Bottom**) at 57,600 bauds. Through the comparative study of the CI of the SAF for the three speeds, we identified relevant differences, which are shown in Figure 7. In the Coordinator Node, the consumption processes were on average seasonal for all speeds, as long as the battery was fully charged in each realization. In all cases, the widths of the CIs were greater with respect to the Sensor Nodes, and similarly at 9600 and 57,600 bauds. However, at 19,200 bauds the width decreased with increasing delay. In addition, the average SAF was higher at 57,600 bauds. The rapid and persistent drops, as well as the CI dimensions in the graphs of Nodes 1 and 3, were similar at all transmission rates, meaning that the consumption signals of these network elements are seasonal. The SAFs of Node 2 were uncorrelated at all speeds, as far as their values showed rapid drops without persistence with narrow CIs. Finally, the consumption signals from Node 4 were classified as non-correlated processes for all the tests.