base band hopping involves all the nbcch trxs radiating at a fixed frequency as opposed to frequency hopping…the limitation for base band hopping is that the number of frequencies in the NBCCH can only be equal to the number of TRXs which is a limiting factor as far as interference reduction is concerned…also as compared to that, the conversation has to jump from one timeslot on a trx to another timeslot on another trx thereby increasing the probability of bit error rate..
there is a lot of flexibility in frequency hopping as compared to base band in the size of the MA list, the hopping sequence etc…which give it an added advantage..