The present Recommendation describes two types of systems on coaxial cable pairs providing 300 telephone channels in the approximate frequency band 0.06 to 1.3 MHz. The length of the elementary cable section is about 6 km for the first type of system and about 8 km for the second. The first is to be preferred when it is planned to equip the cable with 6 MHz repeaters later on, the second when it is planned to install systems belonging to the other family on the cable later on, i.e. the 4 MHz system, 12 MHz system or 18 MHz system.
ITU-T G.341 FRENCH-1993 Referenced Document
ITU-T G.222 NOISE OBJECTIVES FOR DESIGN OF CARRIER-TRANSMISSION SYSTEMS OF 2500 km