## 4 Partition Aware-RPL Protocol Overview
### Parent Selection Algorithm
This dynamic change in roles between nodes helps to balance the energy consumption between them, hence increasing the network lifetime. Although PA-RPL is conceived in order to give an appropriate answer for SF routing requirements, we believe this will be applicable for a number of other IoT applications. For instance, in smart large buildings and campuses, local information processing will be very likely required, hence requiring spatial decomposition of the LLN. ## 8 Conclusions and Future Work

In this paper, we propose a new variant of the RPL protocol that is suitable for Agricultural Low power and Lossy Networks. This protocol is intended to be used in a farmland with several parcels (or partitions). We called this protocol PA-RPL, standing for Partition Aware-RPL. This protocol ensures the creation of a tree-like structure, DODAG, where nodes located in a given parcel are gathered in a same sub-DODAG. We showed that when only few parcels are simultaneously monitored, the proposed algorithm performs high gain in energy, reaching up to 20%. Moreover, our results show that when parcel level in-network data aggregation is performed, energy saving substantially improves, up to 40%. PA-RPL is expected to induce longer paths. Consequently, one may anticipate higher latency. However, it is important to note that PA-RPL intrinsically reduces the number of channel contentions,

Figure 5:8 Intra-parcel message exchange with PA-RPL. which has a positive impact on the latency. A similar balance can be seen when considering the energy: longer paths are expected to induce higher energy consumption, while our PA-RPL helped gain up to 40% of energy consumption compared to RPL. On the other hand, in the context of our considered application, latency is not a very critical parameter: In all our considered scenarios, the data-sending period is set to at least 5 s, representing at least one order of magnitude higher than the expected end-to-end delay. Nevertheless, a deeper investigation of the impact of PA-RPL on latency will conducted as future work. Additionally, in this paper, the performance assessment of our proposal was solely made against RPL. This is justified by the fact that our proposal, PA-RPL, is an extension of RPL. Considering other protocols (Hierarchical, cluster-based, etc.) in the comparison is left as a future work, and would be beneficial and worth investigating. However, this would need further adaptation of these protocols to make the clusters/hierarchy reflect the geographical partition of the farmland into parcels. In fact, many of the hierarchical protocols that are already studied in agricultural applications (such as LEACH and APTEEN) are rather applied in different contexts (not used in the IoT context). Finally, the performance evaluation was limited to the simulation of different scenarios. To effectively measure the efficiency and robustness of our proposal in terms of the defined measures and metrics, we plan considering validation tests in real setup and in different situations. A testbed is currently under development and shall be used in future research. Conceptualization, K.F. and M.A.A. ; methodology, K.F. and M.A.A. ; software, K.F. ; validation, M.A.A and N.B.H.-A. ; formal analysis, K.F. and M.A.A. ; investigation, K.F. and M.A.A. ; resources, K.F. and M.A.A. ; data curation, K.F. ; writing--original draft preparation, K.F. and M.A.A. ; writing--review and editing, K.F., M.A.A, and N.B.H.-A. ; visualization, K.F. ; supervision, M.A.A and N.B.H.-A. ; project administration, K.F. and M.A.A; funding acquisition, N.B.H.-A. All authors have read and agreed to the published version of the manuscript. This research received no external funding. No conflicts of interest or state to declare. ## References

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