Dummy load / direct wire connection concept

Hi folks, In order that a rogue GSM-BTS can cause a lot of trouble with the regulation offices there is a need for a dummyload solution. I have 2 ideas in mind: The first one uses attenuators to set up a direct wired connection: http://root.runningserver.com/pub/desktop-gsm1.png The second one uses parasitic coupeling in a shilded box: http://root.runningserver.com/pub/desktop-gsm2.png The second solution in my opinion the most save one because the BTS does not send directly in its own receiver as well as the MS do not send directly into the BTS. But i also think that this solution is too crappy, i think there must be a more accurate way. The first solution fullfilly my demands in accurateness. The impedance is 50 Ohms and attenuators ensure that the signal that is transmitted between two points are attenuated enough - in theory... I have no experience in those things, i never connected a sender and a receiver directly for measurement proposes. I am afraid to damage BTS and/or MS by trying the first solution. What do you think, what would you do? How do you ensure that you do not interfere with the with the official GSM networks? I think sometimes it would be very nice to make 100% sure that no HF signals leave the desktop. PS: One of my inspirations: http://www.comlab.hut.fi/Resources/GSM.html regards. Philipp