US 6,886,181 B1Granted

Extended distribution of ADSL signals

AssigneeCritical Telecom Corp.

InventorsDavid E. Dodds, Oliver Cruder, Mark Labbe

Life of this patent

Estimating the term…

Loading patent…

Abstract

A plurality of metallic telephone lines carrying both baseband POTS (plain old telephone service) and DSL (digital subscriber line) or ADSL (asymmetric digital subscriber line) signals originate at customer premises and pass through a common field cabinet enroute to a telephone central office. Baseband POTS signals flow in an undisturbed manner through the field cabinet and maintain the normal, highly reliable, communication between the subscriber premises and the central office telephone switch. At the field cabinet, DSL/ADSL signals are removed from the metallic telephone line and are then communicated between the field cabinet and the central office using fiber optic broadband transmission. Fiber optic transmission increases the allowed distance between the ADSL transceiver located at the customer location and the respective ADSL transceiver located in the telephone central office. In the optical fiber, DSL and ADSL signals are retained in their 2B1Q, DMT, QAM or CAP analog format and are simply frequency translated in the process of frequency division multiplex (FDM) transmission. The arrangement allows the provision of ADSL service to customers beyond the distance limit normally imposed by a completely metallic telephone line. It is understood that this arrangement is equally applicable to a variety of DSL (digital subscriber line) signals.

Claims21

Dependent claims

Apparatus for distributing ADSL signals to customer premises from a central office, comprising:

a central office having a POTS switching system and ADSL terminals that connect to a data network;
a plurality of customer locations at least some of which have at least one voice frequency POTS terminal and at least one ADSL terminal;
a field cabinet remote from the central office associated with the plurality of customers;
a plurality of individual metallic telephone lines each extending from a respective one of the customers to the field cabinet;
a trunk cable containing a large number of metallic telephone lines and extending from the field cabinet to the central office;
the field cabinet including a plurality of connections for connecting the individual telephone lines to the trunk cable for connection of signals between the customer locations and the central office;
the individual metallic telephone lines each being arranged to transmit both voice frequency POTS signals and ADSL signals between the respective customer location and the field cabinet;
a bi-directional link separate from the trunk cable for the broadband transmission of ADSL signals in a modulated analog form in pre-selected frequency bands between the central office and the field cabinet;
the ADSL terminals at the central office including ADSL modems arranged to communicate the ADSL signals in their modulated analog form over the bi-directional link;
a splitter and interface module at the field cabinet, remote from the central office having:
a plurality of signal splitting coupler units each associated with a respective one of the individual telephone lines and each arranged to separate the ADSL signals and the voice frequency POTS signals from the respective telephone line;
a plurality of connectors each arranged to connect the separated voice frequency POTS signals between the respective individual telephone line and the trunk cable;
a plurality of interface and frequency translation units each associated, with a respective one of the coupler units for receiving the separated ADSL signals from the coupler unit and for communicating the bi-directional ADSL signals in their analog form on the bi-directional link between the central office and the respective individual telephone line in a pre-selected one or more of the frequency bands that are associated with the respective individual telephone line;
and
a plurality of frequency translation and interface units at the telephone central office each of which is associated with the pre-selected band or bands on the bi-directional link associated with a respective individual telephone line and each of which provides an interface between the respective ADSL signals on the bi-directional link and the ADSL modem of the ADSL terminal of the central office.

12 more elements

Apparatus for distributing ADSL signals to customer premises from a central office, comprising:

a central office;
the central office having a POTS switching system;
the central office having ADSL connection terminals that connect to a data network;
a plurality of customer locations at least some of which have at least one voice frequency POTS terminal and at least one ADSL terminal;
a field cabinet remote from the central office associated with the plurality of customer locations;
a plurality of individual metallic telephone lines each extending from a respective one of the customer locations to the field cabinet;
a trunk cable containing a large number of metallic telephone lines and extending from the field cabinet to the central office;
the field cabinet including a plurality of connections for connecting the individual telephone lines to the trunk cable for connection of signals between the customer locations and the central office;
the individual metallic telephone lines each being arranged to transmit both voice frequency POTS signals and ADSL signals between the respective customer location and the field cabinet;
a bi-directional link separate from the trunk cable for the transmission of ADSL signals in a modulated analog form between the field cabinet and the central office for connection to the data network;
and
the ADSL terminals at the central office including ADSL modems arranged to communicate the ADSL signals in their modulated analog form over the bi-directional link;
a splitter and interface module at the field cabinet, remote from the central office having:
a plurality of signal splitting coupler units each associated with a respective one of the individual telephone lines and each arranged to separate the ADSL signals and the voice frequency POTS signals from the respective telephone line;
a plurality of connectors each arranged to connect the separated voice frequency POTS signals between the respective individual telephone line and the trunk cable;
and
a plurality of interface units each associated with a respective one of the coupler units for receiving the separated ADSL signals from the coupler unit and for communicating the bi-directional ADSL signals on the bi-directional link between the central office and the respective individual telephone line.

14 more elements

Dependencies are inferred from the claim text.