Industries in the Telecommunications subsector group establishments that provide telecommunications and the services related to that activity (e.g., telephony, including Voice over Internet Protocol (VoIP); cable and satellite television distribution services; Internet access; telecommunications reselling services). The Telecommunications subsector is primarily engaged in operating, and/or providing access to facilities for the transmission of voice, data, text, sound, and video. Transmission facilities may be based on a single technology or a combination of technologies. Establishments in the Telecommunications subsector are grouped into four industry groups. The first three are comprised of establishments that operate transmission facilities and infrastructure that they own and/or lease, and provide telecommunications services using those facilities. The distinction among the first three industry groups is the type of infrastructure operated (i.e., wired, wireless, or satellite). The fourth industry group is comprised of establishments that provide support activities, telecommunications reselling services, or many of the same services provided by establishments in the first three industry groups, but do not operate as telecommunications carriers.