on the high temperature side, the EoS of hot and dense QCD matter is still not precisely known. For systems created in the RHIC energy region with high temperatures and low baryo-chemical potential, lattice quantum chromodynamics (lQCD) (see, e.g., Ref.[@Fodor:2001pe]) calculations predict a cross-over transition between the hadron gas and the QGP phase. The additional structures of the phase diagram are still under heavy debate, especially regarding the existence or non-existence of a critical endpoint [@deForcrand:2006pv].

The intermediate SPS energy regime still raises a lot of interest because the onset of deconfinement is expected to occur at those energies and the possibility of a critical endpoint and a first-order phase transition is not yet excluded. Several beam-energy dependent observables such as the particle ratios [@Afanasiev:2002mx; @Alt:2007fe], the flow [@Kolb:2000fha; @Bleicher:2000sx; @Petersen:2006vm], the HBT parameters [@Rischke:1996em; @Adamova:2002ff; @Li:2007yd] show a non-monotonic behaviour around $E_{\rm lab}=30-40A~$GeV and the interpretation remains still unclear. Therefore, future energy scan programs at RHIC, SPS and FAIR are planned to explore the high-$\mu_B$ region of the phase diagram in more detail.

To learn something about the hot and dense stage of the collision from the final state particle distributions, a dynamical modeling of the whole process is 