# Validation of Wired and Wireless Interconnected Body Sensor Networks
## 5 Performance Evaluation
### Wireless DigiAID
Figure 15 provides a comparison of average transmitted power consumed before and after implementing the dynamic control based algorithm. Compared to maximum transmission power of IRIS mote, the node number 3, 5, 6, 7 and 8 has saved 3% to 8% of power. However, node 1 has saved 29% of power and node 2 and 4 has saved upto 90% of power. It proves this algorithm more energy efficient for routine body movement based communication. Figures 16 and 17 are showing results for sitting postures, maintained for 10 min. In contrast to walking, topological behavior maintained while sitting at \(TX_{1}\) (Figure 17a) and \(TX_{2}\) (Figure 17b)  
Figure 14: Packet Reception Ratio at various nodes while walking activity. Figure 15: Average TX power consumption while walking activity. is less complex because of the fact that body movements are not that frequent. At \(TX_{2}\) only 3 nodes have used a parent for few minutes. Whereas, all other nodes maintain direct connection towards sink which can be seen from Figure 16a. The main difference is observed for \(TX_{3}\) power level (Figure 17c) where more number of nodes has used other nodes as their parent to reach sink as estimated from greater number of nodes toward other nodes shown in Figure 16b. In particular, it is observed that node 6 change its behavior only once whereas the behavior of node 7 and 8 vary 3 times for successful packet transmission. At \(TX_{4}\) (Figures 16c and 17d), shows that again and again large number of nodes are changing their parents and only three nodes are making direct connection whereas all the remaining nodes have chosen a multi-hop route. Figure 16: No. of hops while sitting activity. (**a**) At \(TX_{2}\); (**b**) At \(TX_{3}\); (**c**) At \(TX_{4}\). Figure 17: Typical network topology while sitting activity. (**a**) At \(TX_{1}\); (**b**) At \(TX_{2}\); (**c**) At \(TX_{3}\); (**d**) At \(TX_{4}\). Figures 22 and 23 represents result for topological behavior while sleeping for 10 min. Result of \(TX_{1}\) (Figure 23a) shows single-hop transmission for a period of 10 min as in the \(TX_{1}\) of Sitting posture. It is because both body positions have less unusual movements. Furthermore, we have determined that for \(TX_{2}\) (Figure 23b) from the very start, some nodes are sending packets to BS using multiple hops, as shown in Figure 22a. It is also observed that for \(TX_{3}\) and \(TX_{4}\) (Figures 23c,d and 22b,c), nodes have changed their routes three times to perform reliable delivery of packets. All the results obtained till now proof that low transmit power results in multi-hop topology to maintain reliable transmission of packets. Figures 24 and 25 represents the results for RSSI reception when the patient sleeps down to rest on a bed. During this position the stability in receiving values of power is very noteworthy. The Figure 24 plots the RSSI over the entire period, at several time intervals. At maximum (\(TX_{1}\)) and medium (\(TX_{2}\)) transmit power levels, stable and high packet reception is achieved. Figure 21: Average TX power consumption while sitting activity. Figure 20: Packet Reception Ratio at various nodes while sitting activity. This can also be shown from the PRR graph, in Figure 26. The energy savings at minimum transmit power is also very significant with improved packet reception by most of the nodes. Except node 7 and 8, that is, of legs, which shows very poor PRR because while sleeping nodes comes over some hidden places as happened here and \(TX_{4}\) proved poor idea to be utilized here. For such conditions, mechanism is designed to perform dynamic power controlling for transmitting power to maintain high reliability with less power consumption. Therefore, different levels of powers are significantly used by most of the nodes to save energy.