# An Accuracy-Aware Energy-Efficient Multipath Routing Algorithm for WSNs
## 6 Evaluation  
### Simulation Configuration  
In this simulation, the configuration of the main parameters is listed in Table 1.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Configuration** \\ \hline CPU & Core I5 processor \\ Main frequency & 2.5 GHz \\ Sensing area range & 500 m \(\times\) 500 m \\ maximum communication range & 50 m \\ Initial energy of sensors & 2 J \\ Bit error rate \(e\) & random(0, 1) \(\times\) 10\({}^{-6}\) \\ Packet loss rate & random(0, 1) \(\times\) 10\({}^{-2}\) \\ Node Accuracy Loss \(\delta\) & 0.005 \\ MAC protocol & 802.15.4 \\ Packet length & 16 kbits \\ \hline \hline \end{tabular}
\end{table}
Table 1: The configuration of main parameters.  
The sensor energy consumption adheres to the classic model described in [38] (the sensors are powered by batteries and do not benefit from alternative energy supply, such as wireless-powered communication technology [39; 40]). The energy consumption by a node to transmit \(k\) bits of data over 1 meter is:  
\[C_{s}(k,l)=E_{elec}k+\varepsilon_{amp}kl^{2} \tag{25}\]  
where the radio dissipates \(E_{elec}=50\) nJ/bit to run the transmitter or receiver circuity and \(\varepsilon_{amp}=0.015\) nJ/(bit\(\cdot\)m\({}^{2}\)) is the transmit amplifier.  
For a receiving node, the energy consumption to receive \(k\) bits of data is:  
\[C_{r}(k)=E_{elec}k \tag{26}\]  
Hence, on the link \(e\) between two adjacent nodes, the energy consumption \(C(e)\) is the sum of the energy consumption for transmitting \(C_{s}\) and the energy consumption for receiving \(C_{r}\), which can be expressed as:  
\[C(e)=C_{s}(k,l)+C_{r}(k) \tag{27}\]  
Based on the energy consumption model, the following performance indexes are used to evaluate the performance of the EMRAR algorithm:  
* Average Accuracy Loss (AAL): the relative error between data sent by the source node and the data received and recovered by the destination node. The AAL value in this work is the average loss of \(m\) data received during the simulation time, which can be calculated as: \[AAL=\left(\frac{1}{m}\sum_{i=1}^{m}\frac{x_{i}-x_{i}^{\prime}}{x_{i}}\right) \times 100\%\] (28) where \(x_{i}\) is the data sent out by the source node, and \(x_{i}^{\prime}\) is the data received and recovered by the receiving node.
* Packet Delivery Rate (PDR): the ratio of the number of packets received by the destination node \(Num_{R}\) to the number of packets sent by the source node \(Num_{S}\), which can be calculated as: \[PDR=\frac{Num_{R}}{Num_{S}}\times 100\%\] (29)
* Network Residual Energy (NRE): the ratio of the residual energy of all the nodes in the network to the initial energy of the network, which can be calculated as: \[NRE=\frac{\sum E_{re}}{\sum E_{ini}}\times 100\%\] (30)  
The above indexes are evaluated under different densities of adjacent nodes (average number of neighbors of a node) or different data transmission rates. The experiments are performed in OMNet++ by means of the MiXiM framework. It uses the topology generator to generate random topologies for simulation each time. The experiments are repeated till the results can be achieved at a precision of 1% with a 90% confidence interval. The maximum number of iterations is set to 100.