TT-1866GSMPayphoneisanoutdoorICCardpayphone.ItsupportsGSM900MHzandGSM1800MHzdualfrequency,andallowsusertomakeandreceivephonecallviaGSMnetwork.Nomatterinremotedistrictorsomewherewithouttelephoneinfrastructure,TT-1866GSMpayphonestillenabletoofferphoneserviceviaGSMnetwork. FeatureSupportGSM900/1800MHzdualbandserviceReliableoperationfrommicroprocessorcontrolWithflashmemorysystemcanbeeasilyupgratedAutomaticresendofPINnumberforGSMSIMcardauthenticationonpowerreset.ICcardwithSAMCardauthenticationEnabletoremoteupgradesettingortariffthroughTTICpayphonemanagementsystemCircuiterrordetectionwarnserrorcodeandsuspendservice