# Evaluation of Green Strategies for Prolonging the Lifespan of Linear Wireless Sensor Networks
## 3 Classification of Energy Management Techniques for Prolonging WSN's Lifetime
### Energy Consumption Analysis of WSN
#### 3.1.2 Parameters Influencing Energy Consumption of WSN  
There are several parameters that affect the energy consumption of a WSN. These parameters can have an influence on the energy consumption of the WSN, either at the node level or at the network-wide level [54]. In this subsection, we present the parameters that affect the energy consumption of a WSN at both the node and network-wide levels and the sources of energy waste in a WSN.  
The parameters that affect the energy consumption of the WSN at the sensor node level are parameters that have a direct influence on the energy consumption of the sensor node. These parameters belong to the physical layer and basically operate on individual nodes. They encompass both hardware and software parameters [55]. Understanding and optimizing these parameters is essential for designing energy-efficient WSNs that can prolong the network's lifespan and enhance its overall performance [56]. Table 1 presents a list of parameters and the components of the sensor node that is affected.  
The parameters listed in Table 1 are focused at the node level and thus have a similar effect on both traditional WSNs and LWSNs. However, we recognize that the parameters influencing energy consumption at the network-wide level pertain to the entire network rather than individual nodes. Optimizing these parameters at the network-wide level is  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Component Affected** & **Parameter** \\ \hline Sensing unit & Sensor duty cycle, sampling frequency, sensor resolution, sensor radius, sensor type \\ \hline \multirow{6}{*}{Processing unit (MCU, algorithms, protocols, OS, and applications, memory unit)} & Supply voltage, operational frequency, MCU duty cycle, MCU operating modes, number of processed bits \\ \cline{2-3}  & Channel time slot allocation, MAC duty cycle, message size, channel sampling interval \\ \cline{2-3}  & Application parameters \\ \cline{2-3}  & OS scheduling \\ \cline{2-3}  & Number of stored bits, number of memory reads and writes, duration of storage \\ \hline \multirow{6}{*}{Communication unit} & Transceiver duty cycle, transceiver operational modes, transmission power \\ \cline{2-3}  & (transmission distance), modulation scheme, data rate, packet size, packet \\ \cline{1-1}  & transmission interval, antenna direction \\ \hline \hline \end{tabular}
\end{table}
Table 1: Parameters affecting energy consumption in a sensor node.  
crucial for enhancing energy efficiency and extending the lifespan of WSNs while also meeting the application requirements and ensuring reliable data delivery. However, their optimization may be less effective in LWSNs. Table 2 outlines the parameters that influence energy consumption at the network-wide level, identifies the corresponding network layers involved, and assesses their impact in the context of LWSNs.  
Non-optimal tuning of these parameters at both the node and network-wide levels can lead to energy wastage in WSNs. Therefore, careful consideration and optimization of these parameters are essential to maximize energy efficiency and prolong the network's lifetime. The main sources of energy wastage in WSNs (and LWSNs) include idle listening, overhearing, over-transmitting, packet collision, interference, control packet overhead, redundant data, etc. [57; 58].  
Now that we have analyzed the energy consumption of a sensor node and identified the parameters influencing WSN energy consumption at both the node and network-wide levels, our next step is to review the existing taxonomies for classifying the energy management techniques aimed at prolonging the WSN's lifetime.