# Realistic Simulation for Body Area and Body-To-Body Networks
## 4 Performance Evaluation
### Results  
The simulation results are presented for three performance metrics, this includes the packet delivery ratio (PDR), packet delay and energy consumption. Along with the two presented approaches, we also consider IEEE 802.15.6 channel models. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Common/Shared** & **Configuration** & **Values** \\ \multicolumn{2}{c}{**(Models)**} & **Parameters** & **Values** \\ \hline Application Layer & destination ID, data transmission interval, & Coordinator, 100 ms, \\ (Constant bit rate (CBR) & size, start time & 310 bytes, 0 s \\ \hline MAC (IEEE 802.15.6 & User priority, BAN size, & 2, 3 \\ CSMA/CA with ACK) & sleep management, ACK type & 1, immediate \\ \hline Modulation (DQPSK) & Highest data rate & 971.4 kbps \\ \hline Radio (IEEE 802.15.6) & Tx power, channel, sensitivity & 0 to 15 dBm, 0, \(-\)85 dBm \\ \hline Noise & AWGN & \(-\)95 dBm \\ \hline Antenna & & Monopole \\ \hline Interference & & Orthogonal \\ \hline
**Different** & **Configuration** & **Values** \\ \multicolumn{2}{c}{**(Models)**} & **Parameters** & **Values** \\ \hline Path loss & IEEE 802.15.6: CM3-B & 2450 MHz, Table 6 \\  & enhanced IEEE 802.15.6 (E-CM3-B) & 2450 MHz, \\  & path loss-BAN-mixed & 2450 MHz, \\ \hline Mobility & IEEE 802.15.6: Static & Fix distances (_i.e.,_ 0.26 m and 0.34 m) \\  & Enhanced IEEE 802.15.6 Dynamic: & file-time-varying: space and time \\  & walking, running, standing, _etc._ & varying distances, LOS/NLOS factors \\  & Semi-deterministic: & mobility-BAN group \\  & Dynamic (walking) & \\ \hline
**Additional** & **Configuration** & **Values** \\ \multicolumn{2}{c}{**(Models)**} & **Parameters** & **Values** \\ \hline Shadowing & Semi-deterministic & Shadowing-BAN mixed \\ \hline Fading & Semi-deterministic & Fading-BAN mixed \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Models and their corresponding configurations. DQPSK, differential quadrature phase shift keying. First of all, the results of PDR are presented as shown in Figure 13. It can be noticed that the IEEE 802.15.6 standard has almost no impact on the performance, even by reducing the transmission power to \(-15\) dBm. To understand this behavior, Table 9 shows the average received power for ear-belt and right wrist-belt links. We can clearly see that CM3-B (IEEE channel model) has a significant difference in the actual received power at varying transmission power levels, and it is not always constant. However, since the radio sensitivity (_i.e._, \(-85\) dBm being used from the IEEE 802.15.6 standard) is much higher than the received power, therefore CM3-B has a higher packet delivery ratio, even at \(-15\) dBm. Now, the question of the slight increase in PDR, while reducing the transmit power, is mainly due to the distributed MAC layer. In the CSMA/CA MAC, there is always randomness, and this is visible in the IEEE CM3-B results. Whereas, the enhanced CM3-B has a significant difference, and it is much closer to the radio sensitivity, even starting from \(-5\) dBm. As a result, the PDR is much lower, as can be seen in Figure 13. Consequently, E-CM3-B is more realistic. While comparing the results between the IEEE 802.15.6 channel model and the enhanced IEEE 802.15.6 channel model, Our deterministic approach is more pessimistic; the best performance is achieved at 0 dBm, whereas the PDR constantly decreases with reduced transmission power. A similar trend can be seen for the case of multiple BANs. It is to be noted that additional path loss factors (as mentioned in Section 4.1) make the enhanced version more realistic; especially for time varying links, since it provides the dynamic distance with reference to the coordinator which, is not the case in the IEEE 802.15.6 proposed channel models. Further, this has been previously validated specifically against time varying links in [66]. The variations of the PDR results in the deterministic approach while moving from one BAN to three BANs is 6% to 7%.