Evaluation of TCP Performance in MANETs using an Optimized Scalable Simulation Model

We present an optimized scalable simulation model for TCP, developed in OPNET, and investigate its performance in the case of OLSR mobile ad-hoc networks (MANETs). The key idea for the model´s construction is to represent each node by a subqueue, in the simulation model. Thus, the exchange of packets in the network is literally a set of enqueue/dequeue operations among the subqueues. The physical, channel access, routing, and transport protocols´ algorithms operate appropriately upon every such packet exchange, to simulate the different network levels. Such an approach for network modeling allows to reach very large simulation times, therefore letting the network reach its steady state and allowing to study the system´s long-term performance. We apply this model to study the performance of TCP in MANETs, and the interactions among the involved protocols. Compared to the existing models, it is fully scalable and optimized, as shown by the simulation results.