Obtaining reliable estimates for the amount of gravitational radiation produced in transplanckian collisions in TeV gravity scenarios is an important task, to produce meaningful bounds from the LHC data (or other TeV scale experiments). In this talk, I will present a higher dimensional generalization (arXiv:1105.2298) of a method first studied by D'Eath and Payne, to obtain such an estimate. In the first part I will introduce the motivation for TeV scale gravity models focusing on the main arguments for using shock waves as a model for the colliding particles. In the remaining part I will show how to think about the problem as a perturbative expansion of flat space-time and how information can be extracted in such a framework. Finally I will present the numerical results from first order perturbation theory and will comment on how we are achieving the second order correction.