US 6,480,487 B1 · Digital loop carrier remote terminal having integrated digital subscriber plug-in line cards for multiplexing of telephone and broadband signals

Abstract

A fiber-based digital loop carrier (DLC) system provides multiplexed optical transport for telephone line circuits between a terminal in a central office and a remote terminal. The remote terminal performs the multiplexing and demultiplexing for interfacing channels on the fiber(s) to individual subscriber line circuits. To expand the capacity of DLC systems to carry broadband services, fibers are run from broadband terminations in the central office to the remote terminal. The remote terminal includes interfaces for coupling to optical fibers, for two-way telephone communications and for broadband communications. This terminal also includes a line card rack, for mounting various line cards and providing appropriate connections of the cards to the channels through the fiber interfaces. Some of the line cards provide normal telephone type service connections for one or more telephone lines. One or more of the line cards supports xDSL technology, for example Asymmetric Digital Subscriber Line (ADSL) type service. An ADSL line provides multiplexed transport of two-way telephone service signals, and one or more downstream and corresponding upstream digital broadband channel. The ADSL line card connects to one or more narrowband channels for telephone service and signaling communications and connects to a broadband channel, through backplane buses of the remote terminal. The ADSL line card also performs the digital encoding and multiplexing/demultiplexing of the narrowband and broadband communications for transport over a wire pair together with analog or ISDN type telephone signals.

Claims33

Dependent claims

A remote terminal for providing communication between a central office and subscriber premises equipment within a prescribed serving area, the remote terminal comprising:

a first bus for carrying digitally multiplexed narrowband data channels to and from the central office;
a second bus for carrying digitally multiplexed broadband data channels;
a set of first subscriber line circuits, connected to the first bus, for logically connecting first subscriber loops serving a first group of subscribers to the narrowband data channels;
a set of second subscriber line circuits, connected to the first bus and the second bus, for logically connecting second subscriber loops serving a second group of subscribers to the narrowband data channels and the broadband channels;
and
a terminal controller for controlling logical connections between the first subscriber loops and the narrowband data channels, and between the second subscriber loops and the narrowband data channels and the broadband channels.

3 more elements

A remote terminal for providing communication between a central office and subscriber premises equipment within a digital loop carrier serving area, the remote terminal comprising:

digital subscriber line circuits, each receiving digitally multiplexed narrowband data channels from the central office and digitally multiplexed broadband data channels from a broadband data source, each digital subscriber line circuit configured for selectively establishing a two-way narrowband data connection between the central office and at least one corresponding subscriber loop on a corresponding selected one of the digitally multiplexed narrowband data channels, and a two-way communication interface between the at least one corresponding subscriber loop and a broadband data source on one of the digitally multiplexed broadband data channels;
and
a controller for logically controlling establishment of the two-way narrowband data connections and the two-way communication interfaces by the digital subscriber line circuits.

A method of providing communication between a central office and central office subscribers in a digital loop carrier serving area, the method comprising:

receiving, by a remote terminal serving the central office subscribers, digitally multiplexed voice channels from the central office via an optical fiber;
receiving digitally multiplexed broadband data channels by the remote terminal;
and
selectively establishing in an integrated remote terminal line card, for each subscriber loop serving a corresponding subscriber premises equipment, at least one of a two-way communication interface between the corresponding subscriber premises equipment and the central office, a downstream broadband connection for supplying broadband data from one of the broadband data channels to the corresponding subscriber loop, and an upstream data connection for outputting data received from the corresponding subscriber loop to a service provider supplying the broadband data.

1 more element

An integrated digital subscriber plug-in line card comprising:

a multiplexer/demultiplexer for logically connecting a plurality of two-way narrowband data paths serving respective subscriber loops to a bus configured for carrying digitally multiplexed narrowband data between the integrated digital subscriber plug-in line card and a central office;
telephone line interface units for connecting the two-way narrowband data paths by sending/receiving telephone signals for the respective subscriber loops;
a broadband data terminal adapter configured for receiving a digitally multiplexed broadband data stream and outputting a plurality of demultiplexed broadband data streams for the respective subscriber loops, the broadband data terminal multiplexing upstream data streams, received from the respective subscriber loops, onto the digitally multiplexed broadband data stream;
a plurality of digital subscriber loop modems for modulating the demultiplexed broadband data streams into downstream analog signals, respectively, and demodulating upstream subscriber loop control signals received from the subscriber loops into the upstream data streams, respectively;
and
a plurality of subscriber loop multiplexer/demultiplexer circuits for transmitting the downstream analog signals and the telephone signals to the respective subscriber loops at first and second signal channels, respectively, and demultiplexing the upstream subscriber loop signals from the respective subscriber loops at a third signal channel.

3 more elements

Dependencies are inferred from the claim text.

Digital loop carrier remote terminal having integrated digital subscriber plug-in line cards for multiplexing of telephone and broadband signals

Life of this patent

Digital loop carrier remote terminal having integrated digital subscriber plug-in line cards for multiplexing of telephone and broadband signals

Life of this patent

Abstract

Claims33