Phototelegraph Transmissions on Telephone-Type Circuits - Line Transmission of Non-Telephone Signals - Transmission of Sound-Programme and Television Signals (Study Group XV) 1 pp
Telephone circuits or cables used for various types of telegraph transmission or for simultaneous
transmissions
Recommendation H.32
SIMG'LTANEOUS COMMUNICATION BY TELEPHONY AND TELEGRAPHY
ON A TELEPHONE-TYPE CIRCUIT