PTP lab link

Hello everyone!
I’m trying to simulate a large radio link into a lab with NetMetal 5. I’ve read that it’s possible changing ‘‘Distance’’ parameter, this parameter it’s supposed to change all TDMA parameters automatically (I’m not pretty sure about it), but I try to modify it and it’s locked in ‘‘1 km’’, my scenario it’s as follows:
PC ↔ Bridge Station ↔ Access Point ↔ PC
wireless protocol: NV" | BW: 40 MHz

If I’m wrong, I’d like to know if it’s possible to simulate a large link into the laboratory. Thank so much!