GSM radio coverage bounces backward
A  characteristic of radio signals is that they reflect off surfaces. Not  startling or new news in itself, unless one considers its impact on  radio coverage propagated North, but due to reflection, can be detected  for instance in the South East or South West, behind the Sector of the  Mast. In yet another case, I am told that at the Central Criminal Court  evidence in a case confirmed that coverage in the opposite direction  from its angle of propagation was detected and useable. It is useful to  know this in cases for instance where the location of a mobile 'phone  and a Cell ID's radio coverage at a location are not compatible with the  investigation evidence. Importantly, the case does not set a universal  principle, as this phenomenon does not happen in every case due to flat  earth, no clutter etc. Tests will still need to be conducted on a case  by case basis. It does though cast doubt over simply conducting  spot-tests at one location.