1st - No you don't. Terrain-mapping, INS, Radio navigation, doppler, etc. don't rely on satellites. Besides, Iran has plenty of satellites, so no problem using GPS either. .
Do you mean Satellite*S* or Satellite .... as far as i know it has only launched one only and that too into low orbit .... i don't think Iran has yet the capabilty to send a satellite into geostationary orbit .... where you would normally place a communication satellite.