["The Yeastar TG series connects GSM/3G/4G networks directly to VoIP networks, enabling bi-directional communication: GSM/3G/4G with VoIP and VoIP with GSM/3G/4G. The TG series is the best solution available for connecting IP-based telephone systems and offers a softswitch connection to a GSM/3G4G network. It is also the best fallback solution if the landline connection fails. *You can order either GSM or 3G or 4G channel. TG100 and TG1600 do not support 4G LTE. **Click here to check the frequencies/bands and mobile operators supported by TG GSM VoIP Gateway", "Connect telephone system systems to GSM or 3G-WCDMA or 4G-LTE networks", "Send and receive SMS messages via web interface, supports bulk SMS", "Save significant phone costs with mobile-to-mobile calls and SIP trunks", "Everything can be set up effortlessly in the web-based administration", "Cost-effective backup if the landline network fails", "Easy to integrate: high compatibility with established IPPBX and Softswitch"]