## 3 Proposed UGAVs-MDVR Protocol
### Level-Based Cluster-Head Election (LBCHE)  
In LBCHE, a single vehicle is elected from each cluster to manage the cluster members (CMs) and to develop communication with all adjacent clusters. The LBCHE scheme is specified as various levels, which adapt to the dynamic mobility of vehicles and scenarios, such that the IVC links remain stable. The LBCHE scheme is given as follows:  
1. The first level has low priority, in which the cluster head (CH) is elected based on the technology or resources of that UGV and is capable of handling the mine-detection function efficiently as specified in [45]. The priority is set as low because the UGVsare considered completely autonomous in this case. However, the preferences can be changed manually, also according to the desired requirements. The procedure is given in Algorithm 2. 2. The second level has medium priority compared to the first and is designed for scenarios where mines are detected and cleared without human involvement. In this level, the CH is elected based upon the vehicular speed because, in VANET, the speed mismatch causes weak IVC links, as analyzed in a survey of VANET protocols [14]. The speed-based cluster-head election (SBCHE) reduces the switching of CHs and CMs and increases the cluster's stability by reducing continuous maintenance. In addition, the SBCHE scheme is made flexible and adaptable by defining the average speed as the cluster threshold value (CTV) for the CH election. The maximum cluster speed limit (CSL) for UGVs is 60 m/s because the vehicles move slowly within the rough terrain, as shown in Equation (2). The CTV is given in Equation (3). \[\text{CSL}=\text{maximum}\;(60)\;\text{m/s} \tag{2}\]  
\[\text{CTV}=\text{average}\;(\text{CSL})\;\text{m/s} \tag{3}\]  
The CTV is further improved by introducing speed adjustment factor (SAF) 'u' as shown in Equation (4) so that the UGVs can adapt themselves to any scenario:  
\[\text{CTV}=\text{CSL}\pm\text{u} \tag{4}\]  
The value of 'u' can be varied to select the desired vehicle, specifically CH. For example, if the value of 'u' is increased, then the CH will be selected from the front vehicles of the cluster since the CTV exceeds the mobility of 30 m/s. Similarly, the CH can be elected from the last vehicles of the cluster by reducing the value of 'u' because the CTV will go below 30 m/s in this case. 3. At the third level, the manual cluster-head election (MCHE) is proposed with high priority to give the major and foremost control to mine disposal staff so that they can handle the situation concerning real-time scenarios and by considering the level of risk. In MCHE, the convoy's leader can elect any vehicle as CH. 4. The fourth level is introduced with UAVs as CH, where it is difficult to maintain IVC links of UGVs because of hilly areas and asymmetrical surfaces. Correspondingly, the UGVs cannot move together in some scenarios because of irregular trajectories where the inter-vehicular distance increases. Consequently, the UAVs are the best possible solution to disseminate the MDMs to incoming vehicles (IVs) by reducing the communication gap through the air-to-ground link, as shown in Figure 2.  
The flowchart of the UGAVs-MDVR protocol is shown in Figure 3. The flowchart elaborates on the steps of cluster creation, the level-based cluster-head election scheme, and multicast routing. The incoming cluster member joining and cluster joining process is also demonstrated along with the conditions of similar direction and speed. The cluster merging function is also illustrated in the flowchart, and finally, the multicast record updating function is executed to update the records. The cluster election process consists of the following steps, as demonstrated in Algorithm 2 below:  
1. Cluster-head election computation,
2. Resources comparison by sharing information with neighboring nodes,
3. Cluster-head election process execution,
4. Maintaining the cluster head and cluster. ```
1. TO complete Vw in \(\Phi\)(n) Implement // all UGVs
2.