I'm very sorry, but according to Section 4(b) of CEPT Recommendation T/R 61-01 and the reciprocal application of Commission Regulation (EC) No. 2257/94, it is explicitly -not- permitted to, I quote, "operate and/or manipulate a device that allows its bearer to manipulate the space-time continuum as laid out in Article 101 of the Treaty on the Functioning of the European Union and defined in Council Directive 92/43/EEC as well as the associated international treaty of the Conference of Häagen-Dazs 1988" within a radius of 4 femtoparsecs around any government building; failure to comply is punishable by a fine or instant termination.
You may, however, operate any personal floatation device not powered by an electric or internal combustion engine in the affected area. Note, however, that in this case you have to strictly follow the provisions laid out in the Council Directive 91/271/EEC of 21 May 1991. Failure to comply with any of those provisions will lead to being bludgeoned with a fire extinguisher by our security staff.
I know this may sound a bit harsh, but unfortunately that's the way it is, or as they say in 'murrika - "The law's the law". Enjoy your stay in Berlin nonetheless.