# An Energy-Efficient Routing Protocol for Reliable Data Transmission in Wireless Body Area Networks
## 5 Experimental Results  
This protocol is simulated on MATLAB platform. The node deployment is shown in Figure 2. Assuming that there are 10 sensor nodes and 1 sink node, the location of the node will not change after deployment. Detailed parameter values are shown in Table 1. In order to verify the performance of the proposed protocol, this paper compares it with the minimum hop routing protocol PERA [15] and the mulit-hop routing NEW-ATTEMPT [19], since the two protocols are similar to our proposed routing. There are many evaluation criteria defined for performance evaluation. We selected four criteria: network lifetime, throughput, residual energy and reliability transmission of emergency data. The network lifetime is defined as time taken in rounds from the beginning of network up to the last node dies [35]. The time duration from the start of the network up to the first node runs \begin{table}
\begin{tabular}{c c} \hline \hline
**Input:** \(S\): source node, _Sink_: coordinator, \(M_{i}\): cost function of node \(i\), _NT_: neighbor table; \\
**Output:**\(N\)-_best (\(i\))_: the best next hop node for \(i\) \\ Process: \\
1: Start \\
2: for \(S\) has packets to transmit with _Sink_ then \\
3: Select the best next hop from _NT_; \\
4: for each record in _NT_ to \\
5: Calculate \(M_{i}=\alpha*\gamma_{i1}+\beta*\gamma_{i2}+\theta*\gamma_{i3}+\lambda*(1- \gamma_{i4})\); \\
6: List the set of \(L\)\(\leftarrow\)\(M_{i}\) value of each record in _NT_; \\
7: _N-best (\(i\))\(\leftarrow\)_max [\(L\)] \\
8: end for \\
9: end for \\
10: end \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Simulation parameters. out of battery is the stability period of the network. Figures 4 and 5 depict the network lifetime comparison of the proposed routing protocol with PERA and NEW-ATTEMPT. We can see that the proposed protocol is superior to the other two protocols in terms of network lifetime by analyzing the experimental data. The PERA protocol selects the node with the smallest hops to sink as the best next hop. The advantage of the PERA protocol is that it can effectively reduce the transmission delay. However, this protocol creates additional energy losses due to the large transmission distance. Based on the above situation, the PERA protocol is not the best choice in WBAN with limited energy resources. Moreover, the NEW-ATTEMPT protocol constructs a cost function to select the best next hop node. The function takes some network parameters into account, such as the remaining energy of the node, the average data rate, and the distance from the sink node. However, the cost function does not fully consider the reliability transmission between nodes. Therefore, the probability of data transmission failure and retransmission is large. This will bring more additional energy consumption, and thereby affect the network lifetime. The maximum benefit function is constructed in this paper, and we consider multiple parameters to improve the efficiency of energy utilization and prolong the network lifetime. Figure 5 shows that the first dead node appears after 3548 rounds in the proposed protocol, while PERA and NEW-ATTEMPT protocols appear in the first dead node after 2604 and 2852 rounds respectively. The network stability period of this protocol is 1.36 times and 1.24 times as much as PERA and NEW-ATTEMPT, respectively. This shows that the proposed protocol improves the energy efficiency and prolongs the network lifetime. The network throughput refers to the successful data transmitted to the destination [36]. Figure 6 shows that the throughput of the proposed protocol in contrast to PERA and NEW-ATTEMPT. It can be seen that the line trend of this protocol is higher than the other two protocols. The throughput achieved by the proposed protocol, PERA and NEW-ATTEMPT are nearly 2200, 2510 and 3550 respectively. The higher throughput achieved by this protocol is to construct a maximum benefit function, which takes multiple parameters into account.