The Short Message Service (SMS), often called text messaging, is a means of sending short messages to and from mobile phones. SMS was originally defined as part of the GSM series of standards in 1985[1] as a means of sending messages of up to 160 characters, to and from GSM mobile handsets.[2] Since then, support for the service has expanded to include alternative mobile standards such as ANSI CDMA networks and AMPS, satellite and landline networks.[3] Most SMS messages are mobile-to-mobile text messages, though the standard supports other types of broadcast messaging as well.