... strength signal in given area signal shielding deviceMobile signal shielding device Tx Frequency (A)TX frequency 869-894MHz/925-960MHz (B ... /1900-1990MHz Available system Include analog (AMPS,TACS,NMT) and digital (GPRS,GSM, DCS,CDMA,PDC,TDMA,PHS,PCS,IDEN,W ...