Crosstalk Considerations for a 48 Channel PCM Repeatered Line

Extension of the 24 channelT1carrier concept to a 48 channel system requires a careful investigation of the limitations imposed by the increased crosstalk noise susceptibility of 48 channel regenerators. Results of this paper demonstrate the feasibility of dual cable and single-screened cable operation of 48 channel lines at repeater spacings comparable toT1spacing. Operation over singlecable facilities is limited by NEXT to cables with a large cross section and is further restricted to only selected conductors in such a cable. A final result establishes thatT1and 48 channel systems may operate simultaneously in facilities engineered according to 48 channel crosstalk requirements.