A site-specific indoor link model for realistic wireless network simulations

Abstract

Compared to testbeds, the efficiency and accuracy of wireless networking simulations are constantly questioned by the network community. It is widely accepted today that the current network simulators are not able to fully represent the real wireless characteristics, especially at the physical (PHY) layer. This affects the trustability of simulation-based performance evaluations. On the other hand, testbed experiments require taking a tedious and time-consuming implementation path. This path could be significantly reduced by using realistic network simulators as a first step to test novel algorithms or protocols. Therefore, we took on the challenge of representing the link characteristics of the indoor testbed of the Berlin Open Wireless Lab (BOWL) project in the ns-3 simulator. Our extensive measurements study of the link characteristics, namely received signal strength (RSS), frame detection ratio (FDR) and frame error ratio (FER), produced several guidelines for modeling our testbed with satisfying accuracy in the simulator. More importantly, the proposed empirical models take into account several crucial properties related to the radio hardware and the environment, which are shown to have a significant impact on the simulation accuracy. We validate our model against testbed results and show that, unlike the existing models in ns-3, our model shows high agreement with the measurement results for any pair of nodes in the testbed.