Direct-to-mobile Gateway. This type of SMS gateway has a built-in GSM or Global System for Mobile Communication connectivity. This permits sending and receiving SMS text messages via email, web pages and other software apps through the use of a SIM (Subscriber Identity Module) card. Direct-to-mobile gateway differs from SMS aggregators as it is installed in its own organization's network and has the capacity to connect to a local mobile network. This mobile works by the use of SIM card which will be acquired from the network provider for the SMS gateway to be installed.