# A Study of MANET Routing Protocols in Heterogeneous Networks: A Review and Performance Comparison
## 4 Results and Discussion  
### Delay Performance  
These graphs illustrate the results that are gathered in part from the OMNeT++ simulation tool. Each simulation is recorded, along with the events that took place during the running of a simulation. We measure the end-to-end delays of the mobile nodes over the amount of latency in the sending/receiving packets.  
The effect of various mobile node types on the end-to-end delays for the AODV routing protocol is shown in Figure 3. As the simulation progresses, the packet delays decrease, indicating improved route stability and efficiency. The performance variations among the heterogeneous nodes highlight the challenges in maintaining low latency in dynamic network conditions. AODV exhibits higher delays in high-mobility scenarios due to its reactive route discovery process. The blue line represents a mobile node that experiences significant delays until it moves within the transmission range of the gateway.  
The effect of various node types on the end-to-end delays for the BATMAN routing protocol is shown in Figure 4. Throughout the simulation, the delays tend to stabilize, reflecting the protocol's proficiency in handling dynamic network conditions. The performance uniformity observed among the heterogeneous nodes highlights BATMAN's ability to sustain low latency in diverse operational environments.  
Figure 4: End-to-end delays for the BATMAN routing protocol.  
Figure 3: End-to-end delays for the AODV routing protocol.  
The impact of the node types on the end-to-end delays for the DYMO routing protocol is shown in Figure 5. As the simulation advances, the packet delays experience a rapid decrease, indicating the protocol's efficiency in establishing stable communication paths. The consistent performance across the heterogeneous nodes underscores DYMO's effectiveness in maintaining minimal latency within dynamic networking scenarios.  
The effect of various node types on the end-to-end delays for the OLSR routing protocol is depicted in Figure 6. Throughout the simulation, the delays exhibit a gradual increase and eventual stabilization, illustrating the protocol's ability to maintain consistent communication despite the mobility of the nodes. The performance differences among the heterogeneous nodes highlight OLSR's strengths in managing routing efficiency in dynamic environments.  
The superior performance of DYMO in terms of the end-to-end delay can be attributed to its hybrid approach, which combines the strengths of proactive and reactive routing. Unlike OLSR, which floods the network with periodic control messages, DYMO dynamically adapts to network conditions, reducing the route discovery time and minimizing the latency. Similarly, AODV's reactive nature results in longer delays during route discovery, particu  
Figure 5: End-to-end delays for the DYMO routing protocol.  
Figure 6: End-to-end delays for the OLSR routing protocol.  
larly in high-mobility scenarios. BATMAN, while proactive, suffers from control overhead, leading to increased delays as the node mobility fluctuates. These insights highlight the importance of protocol design in addressing the challenges of heterogeneous networks.