... Interface: RS232, RS485 Standard and Band: GSM850/900/1800/1900MHz 3G modem. Designed with industrial grade, supports SMS, CSD, RS232, AT ... sending SMS, alarm system, data transmission, etc .Detailed information A. Wireless Specification1. UMTS/WCDMA/HSDPA/HSUPA 850/900/1900/2100MHz2. Quad ... UL)6. GPRS: 85.6Mbps(DL), 42.8Kbps(UL)7. Support SMS, CSD and data function8. Standard AT command interface B ...