# Body-to-Body Cooperation in Internet of Medical Things: Toward Energy Efficiency Improvement
## 5 Simulation and Discussion  
In this section, we evaluate the performance of the proposed inter-WABN cooperation of IoMT health-based systems via computer simulations. In the simulations, random topology, various wireless body sensors are located in a \(3\times 3\) m, and two human bodies are assumed to coexist in the same range. The distances are assumed to be variable in the simulations, and all links are assumed to have the same distance which is denoted as \(d_{o}\). The transmission rate of all the links is assumed to be \(\beta_{o}\) (b/s/Hz). The path-loss exponent, \(\alpha\), is \(4\), \(Ml=40\) dB and \(Nf=10\) dB, the total antenna gain is \(G=5\) dBi, the carrier frequency is \(fc=2.5\) GHz, and \(N_{o}=-70\) dBm. In what follows, we denote the power consumption of circuitry for amplifying, transmitting and receiving as \(P_{o}\) (mW). Figure 4 shows the comparison of outage probabilities of DT-IoMT, TH-IoMT and IWC-IoMT as a function of the inter-node distance, \(d_{o}\). In general, the outage probabilities of all communication reduced as the inter-nodes distance increases. As shown in the figure, the proposed protocol achieved  
better performance compared to both protocols. As expected, the performance of the TH-IoMT is better compared to the DT-IoMT because the data are transmitted over two independent links. Figures 5 and 6 show the comparison of outage probabilities of DT-IoMT, TH-IoMT and IWC-IoMT as a function of the inter-node distance, \(d_{o}\). In both figures, an asymmetric transmission rate is assumed. In Figure 5 and for the first phase (i.e., from the sensors to the \(\CN\)) is set to \(5\,\mathrm{b/s/Hz}\) and for the second phase (i.e., from the \(\CN\) to \(T2\)) is set to \(2\,\mathrm{b/s/Hz}\). While, the transmission rates of the DT-IoMT and TH-IoMT are set to \(5\,\mathrm{b/s/Hz}\). As shown in the figure, the performance of IWC-IoMT is outperformed the DT-IoMT and TH-IoM protocols at distance less than \(1.5\) m, while the performance of the IWC-IoMT is degraded at distance more than \(1.5\) m. In the Figure 6 and for the first phase (i.e., from the sensors to the \(\CN\)) is set to \(2\,\mathrm{b/s/Hz}\) and for the second phase (i.e., from the \(\CN\) to \(T2\)) is set to \(5\,\mathrm{b/s/Hz}\). While the transmission rate of the DT, THC and ICC is set to \(5\,\mathrm{b/s/Hz}\). As shown in the figure, the performance of the IWC-IoMT is less than DT-IoMT and TH-IoMT for all cases and the inter-nodes distance. Figure 7 shows the comparison of energy efficiencies of DT-IoMT, TH-IoMT and IWC-IoMT as a function of the inter-node distance, \(d_{o}\). As shown in Figure 7, the energy efficiency values of all protocols are decreased as the inter-node distance increased. This performance of all protocols decayed due to the greater transmission power required to guarantee a certain transmission rate. Figure 4: Outage probability versus internode distance, \(d_{o}\). For all cases and links, the transmission rate and power consumption, \(P_{o}\), are \(2\,\mathrm{b/s/Hz}\) and \(10\,\mathrm{dBn}\). Figure 5: Outage probability versus internode distance, \(d_{o}\). For all cases and links, power consumption, \(P_{o}\), is \(10\,\mathrm{dBn}\). Nevertheless, IWC-IoMT performs best among all protocols because the IWC-IoMT utilised four independent transmission links and MRC at the destination (T2). Figure 8 shows the comparison of energy efficiencies of DT-IoMT, TH-IoMT and IWC-IoMT as a function of the power consumption, \(P_{o}\). From Figure 8, we can see that the energy efficiencies of DT-IoMT, TH-IoMT and IWC-IoMT increase as the power consumption increases. The reason is that the energy efficiencies are inversely proportional to the power consumption. In comparison, IWC-IoMT has greater energy efficiency compared to the DT-IoMT and TH-IoMT because its data is transmitted over four independent paths and the \(T2\) utilized MRC. The energy efficiency of the DT-IoMT is generally less than that of the TH-IoMT.