Realistic PHY Modeling for Accurate Wireless Simulations

Abstract

The importance of simulation has diminished in wireless networking despite the advantages of simulation in developing and evaluating new protocols, such as repeatability and scalability. This is due to constant questioning of the validity of the wireless simulation results by the wireless networking community. As an alternative, testbed evaluations, have become popular since they provide more confident results. However, adopting this approach is typically more time consuming and challenging. This thesis takes a step forward in improving the confidence of simulating IEEE 802.11 wireless networks. To this end, we introduce a site-specific IEEE 802.11 Physical (PHY) layer model for wireless networks, which is representative of an actual testbed. It uses testbed measurements as input to the model. As the main advantage of this model, we gain the ability to run realistic and repeatable experiments. The main contributions of this thesis are empirical propagation, frame error, frame detection and interference models. These contributions are based on a thorough analysis of which wireless parameters impact the accuracy of the simulation results. Then, we evaluate their impact both at PHY and transport layers, in different environments (indoor vs. outdoor) and set-ups (e.g., single flow, multiple concurrent flows, multi-hop scenarios). Our results show that environmental conditions and device specifications have a major impact on the wireless communication. Moreover, the site-specific approach for modeling wireless networks significantly improves the simulation results in comparison to the typical simulation models. Thesis: “Realistic PHY Modeling for Accurate Wireless Simulations”