... to realize wireless alarm(for security use)6) Strong signals with high gain antenna 7) Support SIM card (1.8V,3V) 8 ... 2) Frequency ranges: A) GSM 850 GSM 1900: I) Transmission: 869.2 ~ 893.8MHz I) Transmission: 1, 930 ~ 1, 990MHz Ii) Reception ... : 1, 850 ~ 1, 910MHz B) GSM 900: GSM 1800: I) Transmission: 890 ~ 915MHz I) Transmission: 1, 710 ~ 1, 785MHz Ii) Reception: 935 ...