## 4 Implementation and Discussion
### The Network Performance Result
#### 4.2.2 Signaling Overhead  
The signaling overhead parameter quantifies the signaling messages as the expense per temporal unit during which the vehicle engages in the handover process. This parameter is computed by the product of the distance to the Road Side Units (RSUs), the unit transmission overhead, and the size of the messages utilized in vehicular communication. We evaluate the signaling overhead by counting our system's signaling overhead and comparing it to other proposed schemes. It is compared with the group-based handover control scheme for mobile internet using partially distributed mobility management (GP-DMM) [42] and a secure blockchain-based group mobility management scheme in the VANET (SEBGMM) [43]. The methodologies employed for the calculation of signaling overhead within the framework of GP-DMM are delineated in the subsequent equation [42].  
\[C_{DMM}=~{}K[a(L_{Rs}+L_{RA})hop_{(v-RSU)}+2b(L_{PBA}+L_{PBU})hop_{(CMD-RSU)}] \tag{14}\]  
The signaling overhead associated with SEBGMM for K Vs' handover is demonstrated as follows [43]:  
\[C_{SEGBMM}=~{}K[a(L_{Rs}+L_{RA})hop_{(v-RSU)}] \tag{15}\]  
The signaling overhead for this proposed system (KBC) is shown as follows:  
\[C_{KBC}=~{}hop_{RSU-RSU}[a\times Trans_{u}\times L_{msg}] \tag{16}\]  
where \(hop_{RSU-RSU}\) represents the mean spatial separation between two Roadside Units (RSUs), \(a\) symbolizes the coefficient of weighting assigned to a particular link, \(Trans_{u}\) signifies the unit of transmission, and \(L_{msg}\) indicates the aggregate size of the message that is exchanged during the signaling procedure. The size of the selected messages in the signaling process in this study is delineated in Table 6, while the comparative outcomes with prior research are illustrated in Figure 10. All the schemes used blockchain-based security in VANETs. The initial methodology (GP-DMM) [42] exhibits the most substantial signaling overhead, attributable to its framework that inadequately addresses session key negotiation and the preliminary authentication phase of nodes. Our proposed framework and SEBGMM [43] exhibit parallels in differentiating between the initial authentication and handover phases. Nonetheless, the proposed framework demonstrates the minimal signaling overhead attributable to its more streamlined architecture, which does not employ a Control Mobility Database (CMD) and solely relies on the TAS and RSU.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Value** \\ \hline Session Key & 16 byte \\ Vehicle ID & 8 byte \\ TS & 4 byte \\ Ticket for initializing authentication & 8 byte \\ HMAC & 8 byte \\ Input bit length AES & 16 byte \\ Lifetime & 3 byte \\ IP Address & 16 byte \\ Service Name & 3 byte \\ \hline \hline \end{tabular}
\end{table}
Table 6: The size of messages in the signalling process.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Scenario** & **Authentication Delay** & **Handover Delay** & **End-to-End Delay** \\ \hline
1 & ✓ & ✓ & ✓ \\ \hline
2 & \(\times\) & ✓ & \(\times\) \\ \hline
3 & ✓ & ✓ & ✓ \\ \hline \hline \end{tabular}
\end{table}
Table 5: Network requirements fulfillment resume.