... 1 + SIM 2), 3 standby channels (GSM A + GSM B + PSTN) 5 working modes can be ... 106 KPa GSM parameters Frequency bands: GSM 850MHz, GSM 900MHz, GSM 1800MHz (7 kinds) GSM 1900MHz, GSM 850/1900MHz, GSM 900/1800MHz, GSM 900/1900MHz ... Frequency stability: < 2.5 ppm Receive sensitivity: < -100 dBm Transmit power: < 2W (850/900 MHz), < 1W (1800 ...