# Validation of Wired and Wireless Interconnected Body Sensor Networks
## 5 Performance Evaluation
### Wireless DigiAID  
This section investigates the results achieved from wireless DigiAID design. The analyses of collected results provide an in-depth description of the packet reception at different power levels when a human body is performing routine movements. Here, the number of nodes is increased to nine for the application of other health parameters and dummy data is transmitted by each sensor node for the purpose of research. The increase in number of nodes is also intended to scrutinize the behavior of wireless system in a manifold structure. The evaluation of power results is performed using MATLAB with log data generated from IRIS motes. It proves \(TX_{1}\) as sufficient transmit power level to provide good enough packet reception. But the usage of \(TX_{1}\) means high energy consumption. Therefore, dynamic control based algorithm is simulated to provide a good percent of PRR with the prevention \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Activity** & \multicolumn{2}{c}{**Platform**} & \multicolumn{2}{c}{**Good**} & **Satisfactory** & **Not Satisfactory** \\ \hline Walking & DigiAID & RR & ✓ & & & \\  & & HR & & ✓ & & \\  & Hexoskin & RR & & & ✓ & \\  & & HR & ✓ & & & ✓ \\ Sitting & DigiAID & RR & ✓ & & & \\  & & HR & & & ✓ & \\  & Hexoskin & RR & & ✓ & & \\  & & HR & ✓ & & & \\ Sleeping & DigiAID & RR & ✓ & & & \\  & & HR & ✓ & & & \\  & Hexoskin & RR & & ✓ & & \\  & & HR & ✓ & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison between DigiAID and Hexoskin. Figure 9: Measurements during sleeping activity. (**a**) Respiratory rate; (**b**) Heart rate. Similarly, at medium transmit power (Figure 11b), node maintains single-hop toward sink for around 5 min and after 5 min, node 6 is following multi-hop behavior whereas all the remaining nodes are continuing single-hop transmission. The node 2 has also used multi-hop behavior and used a parent as shown in Figure 10b. After sometime, it again maintains single-hop connection toward sink. Figure 11c,d shows that due to minimum transmit power and trivial body movements of walking, from the very start most of the nodes are following multi-hop to reach the BS. Even some nodes maintain multihop behavior for all time as shown in Figure 10c,d. Figures 12 and 13 results are captured when a person is walking back and forth in a room for a time interval of 3-4 min. Figure 12 shows received power against time at BS calculated using RSSI values for different nodes. For the fixed maximum transmit power of 3 dBm graph shows that the received power is widely fluctuating around average values of \(-40\) dBm to \(-80\) dBm. Nodes at the wrists, thigh and legs show poor performance (received power is always less than \(-55\) dBm) as compared to nodes at the chest, abdomen and head (received power is always greater than \(-55\) dBm) due to movement while walking. The overall performance of the received power is very good for high transmit power and no loss in total number of received packets is observed. The results for \(TX_{2}\) show the variation between \(-50\) dBm to \(-80\) dBm with zero percent packet loss. This proves medium power to be more efficient for the wireless DigiAID network as compared to earlier case. Further evaluation of minimum transmits power (\(TX_{3}\)) shows the deviation between \(-70\) dBm to \(-90\) dBm. \(TX_{4}\) power level results depicts that even lesser power can be used for transmission of data packets (with losses) which would be helpful in escalating the battery life time. However, at the same time it provides very poor PRR (Figure 14), whereas \(TX_{1}\) to \(TX_{2}\) is showing a very good level of packet reception. Therefore, with adopting dynamic control based transmission there is always a use of \(TX_{1}\) or \(TX_{2}\) to provide a good level of received power (Figure 13) with the energy efficiency. This also shows a tradeoff between low power and data loss, if the patient's data is of great importance than extreme low power can never be advisable.