User:Darkstar8799/AN/TTC-39 Automatic Telephone Central Office

AN/TTC-39 Automatic Telephone Central Office

The AN/TTC-39 Automatic Telephone Central is a family of heavy mobile telephone switches developed for the U.S. military. It is part of the TRI-TAC series of strategic communications systems. TRI-TAC was intended to improve interoperability of communications systems between the services and reduce redundant acquisitions programs. In the program, each major component (voice switches, message switches, FM radios, satellite radios, etc.) is assigned to a particular military service to manage, but is available for use by all the services.

The AN/TTC-39 is a hybrid circuit switch, with a 744-line capacity (96 analog and 648 digital). The facility provides technical control functions including channel reassignment and multiplexing, line testing, engineering orderwire, atomic timing standard, and analysis or trouble reports, alarms, and system data. It signals and supervises analog and digital trunks and lines. This includes 20 Hz/1600 Hz ringdown, DC closure, dial pulse, DTMF, and 6-wire E&M using tone burst, confirmation, non-confirmation, common channel, and digital in-band-trunk signaling (DIBITS).