## 2 Related Work
The observation is that AODV performs well under RD compared to the other mobility models, and their major conclusion is that AODV can be used for applications that tolerate a small amount of packet loss. Unfortunately, be it in [20] or in [21], no clear explanation is provided as to what feature or statistical behaviour of a given mobility model actually influences which aspect of the protocol. The authors in [22] study the impact of mobility patterns on multicast routing protocols for MANET. A better analysis (compared to a few aforementioned papers) is provided that shows that the mobility pattern influences the connectivity graph, which, in turn, influences the protocol performance. It is also found that routing protocols perform better under unrealistic RWP. Yet, among the considered models is the Manhattan grid, which is not applicable to UAANET, not to mention that the speed of the nodes in the models can go as low as zero, which again is a problematic value when considering UAANET. A comparative analysis of various common routing protocols under various mobility models is also provided in [23]. A wide range of routing protocols of different types (reactive, proactive and hybrid) are considered. For mobility, group, file and RWP mobility models are considered. The simulations show that the mobility model has a significant impact on the performance of the routing protocols. Plus, RWP once again shows better performance for the protocols. However, there are a few problems with the simulations. For example, the simulations run for 30 s, which is problematic, since we know that RWP, for instance, needs a certain time in order to reach its steady-state spatial distribution [24]. Therefore, the conclusions drawn in [23] might well be skewed due to a transitory state. From our experience, it takes about 600 s to observe a steady-state-like behaviour in the performance metrics. We might have formulated similar reservations with the analysis in [25], where the simulation only lasts 500 s, but they specifically consider a different version of RWP. In fact, they use the random way point-steady state (RWP-SS) [26], where the initial speed and the stationary distribution location are sampled in order to overcome the problem of discarding the initial simulation data. In [25] also, AODV is used as the underlying routing protocol for simulation. The authors reached the conclusion that a mobility model should be selected based on the type of application scenario. Yet, they recognized the lack of evaluating multiple distinct routing protocols in their analysis. Furthermore, the speed range they used, with a maximum of 25 m/s, is considered relatively low in the context of UAANET. AODV is also the underlying routing protocol in the comparative simulation study of RWP and GM mobility models on the performance of MANET presented in [27]. The results show that both mobility models are not different at speeds representative of human mobility. In this case, which is of no interest for UAANET, the authors advise using RWP, because it has less computational overhead compared to GM. When the speed of the nodes is as high as fast automobiles, the performance result using RWP is significantly different from GM, and the authors advise to use GM instead. Then again, there is no in-depth analysis or comparison of the two mobility models based on routing-protocol-independent metrics. Such an analysis would provide a better understanding of the effects of the models on AODV, for instance. Not to mention that, once again, there is a lack of evaluating multiple routing distinct protocols in [27], as well. In [28], the performance of DSDV (destination-sequenced distance-vector) and AODV under the realistic mobility model is analysed and compared. The realistic mobility model is obtained based on spatial and temporal information about each and every node in a healthcare environment and based on personal behavior modelling [29].