## 5 Performance Evaluation  
### Simulation Model and Method  
The performance of the proposed DMQoS routing framework is studied and compared with three other localized and QoS-aware routing protocols DARA [15], LOCALMOR [16] and MMSPEED [12] using simulations based on ns-2 [5], which supports the simulation of multihop wireless networks complete with physical, data link, and MAC layer models. The configuration of network parameters is shown in Table 1. The delay and reliability constraints for each packet class are listed in Table 2. Note here that the constraints for a candidate application may vary depending upon the values generated by the sensors. For instance, BP or body temperature readings may produce CP traffic flows if the values cross certain thresholds.  
For performance studies, we used five different sets of source traffic loads \(S_{1}\) through \(S_{5}\), listed in Table 3, each consisting of a certain number of traffic flows for each packet classes. For instance, traffic input set \(S_{1}\) consists of 5 CP traffic flows, 10 DP flows, 20 RP flows and 30 OP flows.  
To prevent buffering packets indefinitely, packets are dropped if they wait in the send buffer for more than their remaining lifetimes. All packets sent via the routing layer are queued at the interface queue until the MAC layer can transmit them. The interface queue has a maximum size of 60 packets and is maintained as a priority queue with four priorities, each served in FIFO order. Routing packets get higher priority than data packets.  
The average result of 10 simulation runs is calculated for each graph point. For each simulation run, the active nodes are randomly selected, and the source node for each of the flows is also randomly selected. Thus, the variations in the obtained results mainly occur due to the randomness of the topology.  
\begin{table}
\begin{tabular}{|l|l|l|} \hline \multirow{2}{*}{**Packet Class**} & \multirow{2}{*}{**Delay constraint**} & **Reliability** & **Candidate** \\  & & **constraint** & **applications** \\ \hline CP & 0.25 s & 0.90 & ECG, EEG \\ \hline DP & 0.30 s & - & Video imaging, Motion sensing, EMG \\ \hline RP & - & 0.95 & BP, PH and respiration monitoring \\ \hline OP & \multicolumn{2}{|l|}{Only energy-aware} & Glucose, SPO2, Body temperature \\ \hline \end{tabular}
\end{table}
Table 2: QoS requirements for different applications.  
\begin{table}
\begin{tabular}{|l|l|l|} \hline \multirow{2}{*}{**Deployment**} & Area & 2,000 m \(\times\) 2,000 m \\ \cline{2-3}  & Deployment type & Random \\ \cline{2-3}  & Number of nodes & 1,000 BSMs \\  & & 6,000 BMSs \\ \cline{2-3}  & \
\begin{tabular}{l} Sink locations \\ (3 sinks) \\ \end{tabular} &
\begin{tabular}{l} (1000, 300) \\ (200, 1700) \\ (1700, 1800) \\ \end{tabular} \\ \cline{2-3}
**Deployment** & Initial node energy & 100 Joules \\ \cline{2-3}  & Buffer size & 60 \\ \cline{2-3}  & Radio range & 100 m \\ \cline{2-3}  & Link layer trans. rate & 1 Mbps \\ \cline{2-3}  & Transmit power & \(7.214e^{-3}\) Watt \\ \cline{2-3}  & Rcv. signal threshold & \(3.65209e^{-10}\) Watt \\ \cline{2-3}  & Bit error rate & \(10^{-4}\) \\ \hline \multirow{3}{*}{**Task**} & Application type & Event-driven \\ \cline{2-3}  & Packet size & \(<=\) 32 Bytes \\ \cline{2-3}  & Traffic type & CBR \\ \hline MAC & IEEE 802.15.4 & Default values \\ \hline
**Simulation** & Time & 1,000 seconds \\ \hline \end{tabular}
\end{table}
Table 1: Configuration of Parameters.  
The error bars in the graphs parallel to the y-axis indicate the variations in the obtained results from the presented average values and, thus, show the minimum and maximum values obtained from the runs.