Module Name GSM Module 3G UMTS (WCDMA) Module SIM5215E UC15 Module Type — UC15-E (For Europe) UC15-A (For America) UC15-T (For Thailand) Network Standard 2G GSM 3G UMTS (WCDMA) / 2G GSM 3G UMTS (WCDMA) / 2G GSM Frequency 850/900/1800/1900 MHz 900/2100 MHz (UMTS), 850/900/1800 MHz (GSM) 900/2100 MHz (UMTS), 900/1800 MHz (GSM) 850/1900 MHz (UMTS), 850/900/1800/1900 MHz (GSM) 850/2100 MHz (UMTS), 850/900/1800/1900 MHz (GSM) SMS Support MMS — Voice Call 2G Voice Call 2G Voice Call 2G/3G Voice Call 2G/3G Voice Call SIM Card 2G/3G/4G SIM Card (Backward Compatible) Data — Call Waiting Support Call Forwarding Support Supported Model S20, S50, S100, S300 A GSM/WCDMA Module provides 1 GSM/WCDMA channel for voice calls of S-Series VoIP PBX, supporting 2G/3G network standard and powerful SMS features. Yeastar GSM/WCDMA Module for S-Series VoIP PBX Specifications Click here to check the supported cellular operators.