Integrated Digital Loop Carrier (IDLC)




IDLC systems are the integration of Integrated digital terminal (IDT) and Remote digital terminal (RDT).



Integrated digital terminal (IDT) is a part of local digital switch (LDS) and it acts like a concentrator to put more channels on a digital communications line.



IDLC system moves some of the switching services from the local switches into RDTs to increase the efficiency of communication lines between customers and central office.





The above diagram shows how an integrated digital loop carrier (IDLC) system can be installed in a local telephone distribution network to allow a 24 channel T1 line(A T1 line refers to a specific type of copper or fiber optic telephone line that can carry more data than traditional telephone lines) to provide service up to 96 telephone lines.



A switching system has been upgraded to include an IDT and a RDT which has been located close to a residential neighborhood. IDT dynamically connects access lines (actually digital time slots) in the switching system to time slots on the communications line between IDT and RDT. RDT is a local switch that can connect up to 96 residential telephone lines.



When a call is to be originated, RDT connects (locally switches) the residential line to one of the available channels on the DS1 (Digital signal 1) interconnection line. IDT communicates with RDT using GR-303(GR-303 is a Bellcore specification that defines a set of generic interface requirements that allow Class-5 digital switches from one vendor to interface with access systems from another) standard.



Reference:

http://www.telecomdictionary.com/telecom_dictionary_IDLC_definition.html