Automated mapping of dataflow applications to state-of-the-art, heterogeneous Multiprocessor Systems on Chip (MPSoCs) with complex interconnects and communication means is an ongoing research endeavor. We implement, measure and analyze three different communication libraries for a representative, off-the-shelf platform of this kind. The results of the analysis are used to show the need of a new cost model to properly characterize inter-task communication. Afterwards, this paper presents an algorithm to solve the mapping problem jointly for computation and communication using this cost model. A case study with four real streaming applications shows that the obtained mapping is able to reduce the execution time. Compared to a mapping decision where all channels are mapped to shared memory, the makespan fell down up to 10 % due to an automated selection of a more appropriate communication library.