# MANET Routing Protocols' Performance Assessment Under Dynamic Network Conditions
## 4 Methodology  
We implemented eight routing protocols (OLSR, DSDV, AODV, DSR, AOMDV, TORA, ZRP, and GRP) using the OMNeT++ 6.0.1 simulation environment with INET-4.5.0 as seen in Table 4. When compared to NS2 and OPNET, which are frequently more complex and less flexible, OMNeT++'s modular architecture, user-friendly GUI, scalability, vibrant community, and cross-platform compatibility make it a popular choice for imitating the wide range of routing protocols that were mentioned [21]. The simulations were conducted  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Protocol** & **Description** & **Advantages** & **Disadvantages** \\ \hline \multirow{4}{*}{Ad Hoc On-demand Distance Vector (AODV) [16]} & Establishes routes to destinations on an as-needed basis using route request and route reply messages. & Lower overhead since routes are created on-demand. & Higher latency due to route discovery process. \\ \multirow{2}{*}{Dynamic Source Routing (DSR) [17]} & Uses source routing and maintains route caches for data transmission. & Efficient route discovery and maintenance. & High overhead with route caches and source routing. \\ \multirow{2}{*}{Ad Hoc On-demand Multipath Distance Vector (AOMDV) [18]} & Extends AODV to provide multiple redundant paths to enhance fault tolerance. & Improved reliability and fault tolerance. & Increased complexity and overhead. \\ \multirow{2}{*}{Temporally-Ordered Routing Algorithm (TORA) [7]} & Establishes a directed acyclic graph for routing based on link reversal. & High adaptability and fault tolerance. & High overhead in maintaining the directed acyclic graph. \\ \hline \hline \end{tabular}
\end{table}
Table 2: Reactive Routing Protocols.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Protocol** & **Description** & **Advantages** & **Disadvantages** \\ \hline \multirow{4}{*}{Zone Routing Protocol (ZRP) [19]} & Divides the network into zones and uses proactive routing within zones and reactive routing routing between zones. & Combines advantages of proactive and reactive approaches. & Complexity in managing zones. \\ \multirow{4}{*}{Geographic Routing Protocol (GRP) [20]} & Uses geographic information to improve routing decisions, combining proactive and reactive strategies. & Efficient use of geographic data for routing. & Requires accurate location information. \\ \hline \hline \end{tabular}
\end{table}
Table 3: Hybrid Routing Protocols.  
under four scenarios with varying node densities (20, 80, 200, and 500 nodes). The area size was set to 1000 \(\times\) 1000 units with a connectivity probability of 0.2. Each simulation involved 100 packets, a packet size of 1024 bytes, and an arrival rate of 1.0 packets per second. The selection of parameters in OMNeT++ simulations, such as a packet arrival rate of 1.0 s and a packet size of 1024 bytes, is crucial for ensuring consistency, relevance, and reproducibility. A packet arrival rate of 1.0 s creates a uniform and predictable traffic pattern, which helps evaluate routing protocols under controlled conditions and reflects real-world scenarios like sensor networks. A packet size of 1024 bytes matches common data sizes in network applications, allowing for meaningful performance assessments (e.g., throughput, delay, packet loss). Using these standard values ensures that the experiment is reproducible and provides relevant, consistent results for real-world MANET applications. The nodes in the simulation were configured to use the Random Waypoint Mobility model, which reflects the random movement patterns of nodes in an ad hoc network and allows for the evaluation of the routing protocols' performance under dynamic network conditions. The free-space propagation model is used, which is the default radio propagation model in OMNeT++ and follows the inverse square law. It assumes an ideal environment with no obstacles, reflections, or interference and is commonly used in theoretical and simplified simulations.