... GSM900 - Class 1 (1W) for GSM18006, SIM Application Toolkit7,Control via AT commands (Hayes, 3GPP TS 27.007 and 27.005 ... )8,TCP/IP stack access via AT commands9,Internet Services TCP server/client, UDP, ICMP, DNS ... Microsoft® Windows 7™, Windows XP™ and Windows Vista™2,Firmware update via serial interface3,Real time clock with alarm functionality MC52i GSM ...