Discrete event network simulators are used to evaluate the performance of a variety of designs in the wireless communication field. They enable researchers to build new network protocols and architectures in a simplified and organized development environment with adherence to the fundamental software engineering principles. However, even though they embody different mathematical models to simulate wireless medium, it is still far from taking an excessive number of channel conditions that directly affect wireless communication into consideration. In this study, we integrate the interface of the software-defined radio (SDR) USRP B210 into the physical layer model of the discrete event simulator OMNeT++ to create an integrated SDR (iSDR) framework. iSDR opens the way to easily develop new network protocols using various OMNeT++ modules and run simulations in wireless medium via the SDR interfaces for realistic performance results. We present working principles of iSDR and discuss significant design issues to support complex simulation scenarios.