Patent Number: 6,480,487

Title: Digital loop carrier remote terminal having integrated digital subscriberplug-in line cards for multiplexing of telephone and broadband signals

Abstract: A fiber-based digital loop carrier (DLC) system provides multiplexedoptical transport for telephone line circuits between a terminal in acentral office and a remote terminal. The remote terminal performs themultiplexing and demultiplexing for interfacing channels on the fiber(s)to individual subscriber line circuits. To expand the capacity of DLCsystems to carry broadband services, fibers are run from broadbandterminations in the central office to the remote terminal. The remoteterminal includes interfaces for coupling to optical fibers, for two-waytelephone communications and for broadband communications. This terminalalso includes a line card rack, for mounting various line cards andproviding appropriate connections of the cards to the channels through thefiber interfaces. Some of the line cards provide normal telephone typeservice connections for one or more telephone lines. One or more of theline cards supports xDSL technology, for example Asymmetric DigitalSubscriber Line (ADSL) type service. An ADSL line provides multiplexedtransport of two-way telephone service signals, and one or more downstreamand corresponding upstream digital broadband channel. The ADSL line cardconnects to one or more narrowband channels for telephone service andsignaling communications and connects to a broadband channel, throughbackplane buses of the remote terminal. The ADSL line card also performsthe digital encoding and multiplexing/demultiplexing of the narrowband andbroadband communications for transport over a wire pair together withanalog or ISDN type telephone signals.

Inventors: Wegleitner; Mark A. (Vienna, VA), Brooks; Kenneth R. (Middletown, MD)


International Classification: H04M 3/00 (20060101); H04J 001/02 ()

Expiration Date: 11/12014