  The OMNeT++ simulator is well-suited for the simulation of randomized user
behavior in communication networks. However, there are scenarios, where such a
random model is unsuited to evaluate a communication system, and this paper
attempts to highlight such a case. Using this example of ad-hoc communication
between aircraft mid-flight, a tutorial-style description is attempted that
shall show how the OMNeT++ simulator can be used when a wealth of real-world
trace data is available. In particular, it is described how mobility trace
files can be directly used within OMNeT++, and how to link the generation of
data messages to this mobility data. This is explained via an example
simulation that evaluates a communication network in which an aircraft notifies
the ground control when it enters or leaves a specific geographic region.
Additionally, a novel trace-based application has been developed to achieve
this link between mobility and message generation. Furthermore, a new
TDMA-based medium access protocol for decentralized communication networks is
presented, which is oracle-based and thus allows a TDMA-like behavior of medium
access without causing any overhead; it can be useful when upper-layer
protocols should be evaluated under the assumption of TDMA-like behavior, but
isolated from the effects of a full-fledged TDMA protocol. Finally, physical
layer behavior is often either overly simplistic or overly computationally
expensive. For the latter case, when a detailed channel model is available but
its evaluation requires prohibitive computational effort, then averaging its
behavior into trace data can find a middle ground between efficient evaluation
and realistic representation. Hence, a novel trace-based radio model has been
developed that makes use of an SNR to PER mapping. In the spirit of open
science, all implementations have been made available under open licenses.
