# A High-Robust Sensor Activity Control Algorithm for Wireless Sensor Networks
## 5 Evaluations and Results
### Energy-Efficiency Analysis  
Numerous studies define the network life cycle as follows: the system starts execution until the first sensor dies. The literature defines the network life cycle as follows: the system begins to execute until the number of active sensors cannot maintain the target value of 6. In many cases, we are concerned with the capability of the system to monitor environmental information. We adopted the latter definition in this study. The main purpose of this experiment was to illustrate the sink through individual transmission and broadcast transmission of QoS packets, as well as to analyze these two methods in terms of the effect of power consumption on network systems. We will take the win nodes developed by the Rockwell Research Center as an example. Table 2 lists the various functions of the win nodes relative to the power consumption information. In this case, the sensor status can be divided into (a) transmission, (b) receiving, and (c) idle modes. In transitions between modes, which also exhibit varying power consumption, the power consumed by the conversion between the transmission mode and the receive mode is 19.35 mW, and that consumed by the conversion between the transmission mode and the idle mode is 14.75 mW [16; 17]. Sensors can load battery types, such as lithium ions, NiMH, NiCd, and alkaline. In this experiment, 1100 mAh NiMH batteries were used to enable the network system to provide a total power of 1131 W. The total number of sensors \(m\) was set as 100, the target value \(Q_{0}\) was set at 35, and the evoke parameter of SACA was set to 0.001. The execution results of the SACA and ACK approaches are shown in Figure 12(a),b. The ACK approach is unstable compared with SACA in terms of maintaining the target value, which indicates that the number of active sensors is higher. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**State Mode** & **MCU Mode** & **Sensor Mode** & **Radio Mode** & **Power (mW)** \\ \hline Transmission & Active & Active & Tx, Rx & 1139.4 \\ \hline Receive & Active & OFF & Rx & 409 \\ \hline Idle & OFF & OFF & OFF & 40.7 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Power consumption of [PERSON]’s wins nodes. Figure 13: Variations of the number of active sensors for the (**a**) SACA, (**b**) ACK approach. Although the Gur Game approach enables stable convergence for the target value, the number of active sensors cannot be maintained at the target value after 1000 rounds, as shown in Figure 14a. Figure 14b shows the power consumption of the three approaches. The Gur Game approach is faster than the ACK and SACA approaches in terms of power consumption. The system power is exhausted by the Gur Game algorithm after approximately 2000 rounds. In the SACA and ACK approaches, the system power is exhausted at approximately 2700 rounds. The initial power of each sensor is \(E_{i}\) and the total number of sensors is \(m\). Thus, Equation (4) can be used to calculate the total power of the entire network system as \(E_{max}\). Equation (5) shows the ideal value \(E_{G}\) of power consumption for the Gur Game approach, where \(E_{T}\) is the power consumption of the sensor in the transmission mode, \(E_{R}\) is the power consumption of the sensor in the receive mode, and \(t\) is the number of rounds. \(E_{TR}\) is the power consumption of the conversion of sensors between the transmission and receive mode. Equation (6) gives the power loss ideal value \(E_{A}\) of the SACA and ACK algorithms. \(E_{TI}\) refers to the power consumption of the conversion of sensors between the transmission status and idle status, where \(E_{G}\) and \(E_{A}\) are not greater than \(E_{max}\). Equations (5) and (6) illustrate that SACA is better than the Gur Game approach in terms of energy savings because sensors in sleep mode no longer receive any QoS packet from the sink. Moreover, the power consumption of the conversion of sensors between transmission status and idle status is less than that of the conversion of sensors between transmission status and receive status.