## 6 Performance Evaluation
### Power Consumption in the Network  
In this section, we evaluate the energy-consumption of network nodes in D-MSR and WirelessHART. The simulation runs for 1,000 s. We measure the total consumed energy at every node during the simulation period. We consider two states of network operation, namely operation in (1) a static and (2) a dynamic environment (e.g., link failures). In the static environment we measure the energy needed to exchange network management messages (periodic updates), as well as application data messages (from sensors to actuators). For the dynamic environment we measure the energy consumed for the network maintenance. The periodic management messages generated by each device in the WirelessHART network are network health reporting and status commands (_i.e._, WirelessHART command 779, 780, and 787) and advertisements. In the D-MSR, each device broadcasts the advertisement packets, and the RPL periodically sends controlling messages to maintain routes. Management and application data messages for both D-MSR and WirelessHART are listed in Table 5.  
Table 6 shows the energy-consumption (in this simulation we assumed the energy-consumption in Tx/Rx turnaround, and the processing energy can be neglected) required for each type of transaction. In addition, the idle listening energy at an unused scheduled link is shown. This is the energy that is consumed by the receiver while it is waiting for a message to arrive. Values of the parameters used in Table 6 formulas are listed in Table 7. \begin{table}
\begin{tabular}{c c c c} \hline \hline
\begin{tabular}{c} Acknowleded unicast \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Periodic messages rates. The distribution map of energy consumption for network management traffic and application traffic in the case of static environment is illustrated in Figure 29. The total energy consumption over the network for management and application traffic is provided in Table 8. The total energy consumption for network management is higher in D-MSR than in WirelessHART, which can be explained by the higher data rate of control messages in RPL. From the network management energy map we can see that the distribution pattern for WirelessHART is symmetric, reflecting the regularity of the multi-path routing graph, with bottlenecks being the nodes close to the access points. The distribution pattern in the D-MSR management energy map, is also reflecting the structure of the RPL routing tree, with bottlenecks created at nodes close to the access points. The application traffic energy map of WirelessHART shows bottlenecks close to the access points, which is due to the fact that all traffic should pass through the gateway. The energy consumption at bottleneck nodes in WirelessHART is higher than in D-MSR bottlenecks. The total energy consumption in WirelessHART is also higher than in D-MSR, which is due to the fact that RPL routing in D-MSR forwards traffic through shorter routes that do not necessarily pass via the gateway. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Notation** & **Formula** & **Value** \\ \hline Acknowledged Tx & TxCCA\(\ast\)_Listen power_ + _TsMaxPacket_\(\ast\)_Transmit power_ + _TsAck_\(\ast\)_Receive power_ & 303 \(\upmu\)J \\ Acknowledged Rx & _TsMaxPacket_\(\ast\)_Receive power_ + _TsAck_\(\ast\)_Transmit power_ & 311 \(\upmu\)J \\ Broadcast Tx & TxCCA\(\ast\)_Listen power_ + _TsMaxPacket_\(\ast\)_Transmit power_ & 252 \(\upmu\)J \\ Broadcast Rx & _TsMaxPacket_\(\ast\)_Receive power_ & 264 \(\upmu\)J \\ Idle Rx & _TsRxWait_\(\ast\)_Listen power_ & 136 \(\upmu\)J \\ \hline \end{tabular}
\end{table} 
Table 6: Energy-consumption per transaction and its formula.