## 2. Mobility Models and Related Work
### Related Work  
[PERSON] et al. [17] presented an evaluation analysis for different routing protocols in MANET with different mobility models. The mobility models used were Random Way Point (RWM), Reference Point Group Mobility (RPGM), and Column Mobility Model (CMM), along with different routing protocols such as AODV, DSR, DYMO, and DSDV. This study provides us with the guidelines for choosing routing protocols for different mobility models in different scenarios and has also shown the impact of different routings on different QoS parameters. In [18], performance analysis for MANET is performed with three different mobility models for on-demand and table-driven routing protocols. This study shows that on-demand routing performs well in terms of memory consumption as compared to table-driven routing protocols. This study only focused on two ad hoc routing protocols which makes it very limited to decide what protocol is best suited for which mobility model, and also, it does not cover the use and importance of sink nodes placement and its movement as well. [PERSON] et al. [19] reviewed different routing protocols for VANETs. According to this study, an increasing number of node size of routing tables for OLSR routing protocol increases which degrades its performance, and by increasing the number of nodes, AODV suffers the problem of route failure. Similarly, if we consider GPSR and CAR, it suffers the problem of packet loss with an increased number of nodes in VANET. This study has considered the packet loss and route failure as issues, but sink node exhaustion is not considered. Moreover, sink mobility is untouched. [PERSON] et al. [20] selected the clustering-based routing protocols for their evaluation with different mobility models. Different categories of position and non-position-based protocols were compared in this study and have concluded that position-based routing performs well as compared to non-position-based routing protocols. Different protocols such as DECA, DEMC, and DEMC-R were  
Figure 2: Movement of Mobile Nodes in RWM (**Left**) and RDM (**Right**). evaluated and were compared with MAR, GRC, and GRC-R with different mobility models. In [21], the author compared the performance of different routing protocols, such as AODV, DSR, DSDV, AOMDV, etc., for FANET (Flying Ad Hoc Networks). Through the analysis, HWMP was found to be the best protocol suited for FANET with different mobility patterns, and OLSR is the second-best for the same. Even though these protocols perform well in terms of packet loss, overall delay, and throughput but sink node placement still needs improvement as it keeps on being exhausted very early with an increased number of nodes. [PERSON] et al. [22] evaluated the outcomes of three routing protocols, i.e., AODV, DSR, and OLSR, by Varying the number and velocity of nodes. The analysis shows that OLSR was better than DSR and AODV in terms of average end-to-end delay and throughput with the increasing number of nodes in the network. [PERSON] and [PERSON] [23] evaluated AODV and DSR based on pause time and speed. The outcomes show, on the one hand, that AODV performs better than DSR when the speed of the node is low and the pause time is static. While the DSR has better results as compared to AODV as far as throughput and end-to-end delay are concerned. [PERSON] [24] has examined the performance of mobile ad hoc network (MANET) routing protocols concerning group and entity mobility models. The following three widely used routing protocols were studied and compared: DSR, AODV, and DSDV. Network simulator version two (NS2) and its tools have been used for animation, and an analysis of findings was used in the simulations. The authors [PERSON] et al. [25] examine the performance of DSDV, AODV, and DDSR, routing protocols based on data analysis from NS2 simulations with various load and mobility scenarios. Routing protocols function similarly in low-load and low-mobility environments. DSR, on the other hand, outperforms AODV and DSDV protocols as mobility and load increase.