In my country, BTS is built by one Telecommunication Company and use GSM 1800, and another BTS is built by another company and use GSM 900 in ONE place or one village. Why they are not use only one BTS to operate GSM 1800 and 900 althought different company. Or it can make interferent when signal transmite from sector.
hi;
in the theory ,
for interference, two beams must have one frequency.
But in nonlinear phenomena, it is possible that a wave of main frequency INTERFERE with another of harmonic frequency ( twice of main or more ... ) .
this is a rare phenomenon and often Not mentioned .
Does it help you ?
BYE.