The growing capabilities of wireless communication technologies such as WLAN-based systems enable their successful adoption in an ever-increasing range of applications. Particularly in the domain of the internet of things, the trend towards wireless interconnection is driven by its improved scalability and flexible, low-cost deployment compared to wired systems such as Ethernet. To handle the growing complexity of their design, developers need a process for early performance evaluation of these communication-intensive networked embedded systems. For this, established network simulation frameworks like ns-3 and ${OMNeT}++$ are often utilized. These frameworks require developers to model every part of their system, including the protocol stack and the target application they are developing. From the developers’ perspective, a workflow that would enable them to use real target software as much as possible is desirable. The available solutions to couple real target software with a network simulation, however, often exhibit several limitations. These range from a lacking detail level of the channel simulation to the requirement of access to the source code of every part of the system under design, and often prevent adoption of these coupling solutions. In this paper, we propose a data interface for the established simulator ns-3 that allows coupling to the Linux kernel at a very low level of the protocol stack, namely the lower WLAN MAC layer. This interface allows the performance evaluation of WLAN-based systems, in which real target code of almost the entire software stack can be used. With such an interface, developers can write real target software and test it under different wireless network scenarios and channel conditions, powered by a simulation using ns-3. We show the practicality of our interface by comparing it to a simulation solely performed in ns-3, as well as to another framework for coupling real target software to a channel simulation.