... applied to GSM, PSTN and Internet environment. Support the access of GSM, PSTN,telephone to realize GSM, PSTN, Internet integration. ... CDMA), PSTN, Phone.2,Supports GSM, CDMA two kinds of wireless communication standard.3,Support GSM: 850M/900M/1800M/1900M, CDMA: ... deviation to happened by the external world to influence the communication,the system can reset to the clock automatically, resume normal ...