# A Study of MANET Routing Protocols in Heterogeneous Networks: A Review and Performance Comparison
## 6 Conclusions and Future Directions  
In this paper, we studied and compared the performance of four selected routing protocols--AODV, OLSR, BATMAN and DYMO--in a heterogeneous MANET network setting comprising nodes with varying capabilities, including fixed, mobility, data transmission rates, and power consumption. The system performance was evaluated by an extensive OMNeT++-based simulation model. We measured QoS parameters such as the packet delays, throughput, and packet delivery ratios. Our research findings are discussed below.  
Of the four routing protocols we studied, DYMO was the best-performing routing protocol in heterogeneous network environments with fixed as well as mobile nodes. Across all three performance metrics (i.e., delay, throughput, and packet drop ratio) that we evaluated, DYMO achieved lower delays, higher throughputs, and higher packet delivery ratios. AODV proved to be stable with respect to packet delays, but DYMO performed much better. This establishes that reactive and hybrid protocols demonstrate the capability of handling delays much better than proactive protocols do. We observed that DYMO was more efficient in achieving higher throughputs than the other three routing protocols as it delivered more packets over the network. Therefore, it is recommended that the DYMO routing protocol would be the best one to use in heterogeneous networks. Developing a new technique to improve the performance of multi-hop routing for post-disaster recovery in MANETs is suggested as one of the future works. This study also opened up several avenues for future research. First, machine learning techniques could be integrated into DYMO to fine-tune the routing decisions in real time, further enhancing its performance in dynamic environments. Second, the performance of these protocols in 5G-integrated MANETs should be evaluated to assess their compatibility with next-generation wireless technologies. Finally, the security vulnerabilities introduced by heterogeneous nodes in IoT deployments must be addressed to ensure robust and reliable communication. These directions will contribute to the development of more efficient and resilient MANETs for real-world applications.  
Conceptualization, N.I.S.; methodology, N.I.S.; software, N.I.S.; validation, N.I.S. and M.J.A.; formal analysis, N.I.S. and M.J.A.; investigation, N.I.S. and M.J.A.; resources, N.I.S. and M.J.A.; data curation, N.I.S.; writing--original draft preparation, N.I.S.; writing--review and editing, N.I.S. and M.J.A.; visualization, N.I.S. and M.J.A.; supervision, N.I.S.; project administration, N.I.S. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The original contributions presented in the study are included in the article. Further inquiries can be directed to the corresponding author.  
We would like to thank [PERSON], [PERSON], and [PERSON] (Auckland University of Technology) for conducting the simulation and [PERSON] (Auckland University of Technology) for mentoring this project.  
The authors declare no conflicts of interest.