## 6 Simulation Results and Discussions
### Performance Tradeoffs Made by DEADS  
DEADS is a reactive routing protocol in which data is transmitted only when certain predefined thresholds are met. Hence it is not suitable for applications where continuous data monitoring and reception are required.  
DEADS achieves improved network lifetime by introducing sink mobility in the network. In DEADS, cooperative routing is performed and high throughput is achieved at the cost of increased energy consumption and control overhead. Two to three times more energy consumption is involved when cooperative routing is performed in a network as shown in Figure 11. Along with this, control packet exchange for selection of cooperative partner nodes increases control overhead.  
An optimized value of \(d_{th}\) in accordance with Equation (4) is attained at the cost of control packet exchange. Nodes require their one-hop neighbor information in order to select their \(d_{th}\).  
There is a tradeoff between the network's stability period and data reliability. The stability period is compromised in order to attain reliable data transfer as shown in Figure 10. Data reliability refers to the authenticity of received data and it is affected by the damage caused by link impairments. The greater the effect of link impairments on the received data, the less reliable it is and increased are the chances of it being dropped by receiving node and vice versa. Whereas, the link state varies from node to node. Higher energy consumption causes nodes to die at the start of the network compromising stability period, however, because of transmission via alternate paths data reliability is achieved.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Evaluation Metric**} & \multirow{2}{*}{**Protocol**} & \multicolumn{2}{c}{**DEADS-SRC**} & \multicolumn{2}{c}{**DEADS-MRC**} \\ \cline{3-6}  & & **Linear** & **Elliptical** & **Linear** & **Elliptical** \\ \hline \multirow{4}{*}{**Network lifetime**} & DBR & 40\% & 45\% & 40\% & 45\% \\  & EEDBR & 40\% & 45\% & 40\% & 45\% \\  & CoDBR & 40\% & 45\% & 40\% & 45\% \\  & iAMCTD & 0 & 0 & 0 & 0 \\ \hline \multirow{4}{*}{**Throughput**} & DBR & 76\% & 69\% & 75\% & 71\% \\  & EEDBR & 76\% & 69\% & 75\% & 71\% \\  & CoDBR & 63\% & 51\% & 60\% & 55\% \\  & iAMCTD & 6.4\% & –23\% & –1\% & –13\% \\ \hline \multirow{4}{*}{**Packet drop**} & DBR & –41\% & –29\% & –51\% & –31\% \\  & EEDBR & –37.5\% & –25\% & –48\% & –27\% \\ \cline{1-1}  & CoDBR & –15\% & 1.5\% & –30\% & –1.5\% \\ \cline{1-1}  & iAMCTD & –35\% & –22\% & –46\% & –24\% \\ \hline \hline \end{tabular}
\end{table}
Table 2: Performance comparison of DEADS-SRC and DEADS-MRC with counterpart techniques.  
Reliable data transmission results in high throughput, as shown in Figure 12 because chances of successful data reception at sink are increased. Hence, there is a tradeoff between throughput and energy consumption.  
Reliable data transfer is attained at the cost of increased processing overhead (in terms of MRC and AF) and increased delay. Data is transmitted from source to relay and destination node. Relay node after performing AF at the received data forwards it to destination node. Destination node performs MRC at the received copies, selects appropriate relay and destination node and then forwards the data. In all this processing, a certain overhead is involved. Delay is also introduced because of which the proposed protocol is not suitable for delay sensitive applications.  
DEADS achieves reduced packet drop as shown in Figure 13 at the cost of multiple transmissions. Greater number of transmissions increase reliability at the cost of extra energy consumption. Tradeoffs are shown in Table 3.