## 5 Performance Evaluation  
### Simulation Configuration  
In this subsection, we present the simulation configuration environment to simulate the proposed CoMP handover mechanism. We used an OMNeT++ network simulator [25], which runs on a Linux operating system. We compared the handover performances of MIPv6, HMIPv6, and CoMP.  
Figure 14 shows the network topology used in our simulations for MIPv6, HMIPv6, and CoMP. This topology has been used extensively for mobility management performance studies. The coverage of WSN BS was set to 50 m within a 200 m \(\times\) 200 m area. It is assumed that once a CoMP sensor node moves out of the coverage of WSN BS1 BS, the new T_Addr is available. The following configurations were used in simulation:  
* To stabilize the results, each simulation of the linear back and forth movement between WSN BS1 BS and WSN BS2 of the CoAP node lasted for 100 s.
* The IEEE 802.15.4-2006 standard is used for the MAC layer, and each WSN BS has a radio coverage area radius of approximately 20 m. The overlapping region between WSN BS1 BS and WSN BS2 is 5 m. The advertisement period of the HA/WSN BSs is 1 s, although the advertisements are not synchronized.  
\begin{table}
\begin{tabular}{c c} \hline
**Protocol** & **Total Packet Loss** \\ \hline P_MIPv6_ & \(\lambda\)p _DMIPv6_ \\ P_HMIPv6_ & \(\lambda\)p _DMIPv6_ \\ P_CoMP_ & Zero \\ \hline \end{tabular}
\end{table}
Table 4: Packet Loss Analysis.  
Table 5 shows the basic system parameters for evaluating the performance of the mobility management protocols. Most parameters in this analysis were set to typical values found in [21, 22, 23]. We use the parameters in Table 5 to analyze the mathematical performance evaluation of the handover latency and packet loss during the handover procedure described in Section 4.2.  
In Table 5, the _auto-configuration delay_ indicates the time interval during the duplicate address detection procedure, and the _movement detection delay_ indicates the time interval during which the CoAP node recognizes whether the current network domain is in the same domain. The L2 handover delay indicates the time interval during the link layer handover procedure. Section 4.1 provides further description of these parameters. It is assumed that the number of hops between the CoAP node and WSN BS, between the CN and HA, between the WMMS and WSN BS1 BS/WSN BS2, and between the HA/CN and WMMS are set to 1, 2, 2, and 2, respectively. In the performance evaluation, we used UDP-based Constant Bit Rate (CBR) traffic with bit rates of below 56 Kb/s, a packet size of 1024 bytes, and a packet arrival rate under 55 packets/s.  
Figure 14: Simulation topology and parameter.  
\begin{table}
\begin{tabular}{c|c|c} \hline
**Parameter** & **Symbols** & **Value** \\ \hline Auto-configuration delay & t\({}_{\text{AC}}\) & 500 ms \\ Movement detection delay & t\({}_{\text{MD}}\) & 100 ms \\ L2 setup delay & t\({}_{\text{L2}}\) & 50 ms \\ Wired-link bandwidth & B\({}_{\text{w}}\) & 10 Mbps \\ Wireless-link bandwidth & B\({}_{\text{nf}}\) & 20–250 kb/s \\ Average queuing delay & \(\sigma\) & 0.1 ms \\ Wireless-link delay & L\({}_{\text{nf}}\) & 15 ms \\ Wired-link delay & L\({}_{\text{w}}\) & 2 ms \\ Control packet size & \(S\) & 50 bytes \\ Tunnel packet & \(S_{\text{r}}\) & 80 bytes \\ Packet arrival rate & \(\lambda_{p}\) & Default value 10 packets/s \\ Average speed of node & \(V\) & 10 m/s \\ \hline \end{tabular}
\end{table}
Table 5: Simulation Parameters.