Abstract: A head end terminal for a communication system using multicarrier modulation is described. The head end terminal includes a multicarrier modem adapted to receive upstream signals and to demodulate the upstream signals modulated on a plurality of orthogonal carriers in a first frequency bandwidth, the multicarrier modem including a polyphase filter adapted to selectively filter the received upstream signal to provide protection against narrowband ingress for the modulated orthogonal carriers and allow for scalable bandwidth usage in the upstream transmission, and a controller operatively connected to the multicarrier modem for controlling receipt of signals.

Abstract: A video and telephony signal distribution network is provided. The network includes a head end for transmitting to a plurality of remote units. The network further includes at least one optical/electrical converter unit that transmits to the remote units over at least two coaxial cables coupled to a common optical/electrical converter unit. Each remote unit transmits upstream electrical data signals over its associated coaxial cable to the optical/electrical converter unit using a common bandwidth. The optical/electrical converter unit converts and frequency shifts the upstream electrical data signals from at least one remote unit to form an optical upstream data signal for transmittal to the head end such that the frequency spectrum used for the upstream communications is simultaneously used on each of the coaxial cables of to optical/electrical converter unit.

Abstract: A fiber termination block including a frame structure adapted to be connected to a fiber distribution rack. The frame structure includes a front end and a rear end. A front fiber optic adapter array is positioned adjacent the front end of the frame structure. A plurality of rear modules are mounted at the rear end of the frame structure. Each of the rear modules defines a front opening. At least one coupler is mounted within each of the rear modules. A plurality of fiber optic cables are provided for transmitting fiber optic signals between the front fiber optic adapter array and the couplers. The fiber optic cables extend through the front openings of the rear modules to access the couplers.

Abstract: A method for initializing a service unit in a communication system. The method includes receiving a synchronization signal from a head end at the remote unit. Further, an identifier is received specifying the remote unit. The method further receives an upstream frequency band and control channel designation at the remote unit, wherein the frequency band includes a number of subbands with at least one control channel in each subband. The method tunes to the designated frequency band and a reference signal is transmitted on a selected channel to the head end. The method receives adjustment signals based on the reference signal transmitted to the head end to allow signals transmitted from the remote unit to be orthogonal at the head end to signals from at least one other remote unit. The method adjusts parameters at the remote unit based on the adjustment signals.

Abstract: Circuits and methods are described which reduce waiting time jitter at a synchronizer/multiplexer by using a “sub-bit” comparison of a clock associated with an unsynchronized data stream and a clock associated with a synchronized data stream to generate a threshold level for use in determining when to stuff bits into the synchronized data stream. The term “sub-bit” means that the phase difference, as measured by, for example, the location of pointers associated with the two clocks, is precise to a fraction of a bit.

Abstract: A switching coax jack module and jack component provide for a removable DSX jack which can be slid into and out of the front of a jack module housing without disconnecting other internal jacks and without disconnecting the module from a chassis.

Abstract: A method for controlling gain in a network is provided. The method includes receiving signals for transmission over a network and adjusting the level of the received signals. The method further includes inserting an additional signal indicative of the level adjustment and transmitting the signals and the additional signal over the network. The method also includes extracting the additional signal after transmission over the network and compensating for the level adjustment based on the extracted signal.

Abstract: An apparatus that has housing for containing objects. The housing has two heat-conducting partial-boundaries having an interface between them. The apparatus also has a medium for enhancing heat transfer across the interface.

Abstract: Optical circulators can be formed with one or more adjustable components to facilitate the optimization of light coupling into the ports of the circulator. In particular, an optical circulator includes one or more adjustable mirrors positioned in the propagation path of a light beam travelling from a first port to a third port, typically via a second port, through the circulator. The one or more adjustable mirrors permit the deviation of the propagation path of the light beam to achieve better input precision into the circulator. One example of a method of circulating light from a first port to a third port includes propagating light from a first port through a reflective polarizer to a second port. The light then propagates from the second port into the reflective polarizer and is reflected from the reflective polarizer to a first mirror.

Abstract: A cable storage cartridge and assembly for storing an excess length of cable. The cartridge includes a rectangular carriage frame and a spool rotatably disposed inside the carriage frame. The spool is comprised of a first spool member having a radius protection loop channel on its top surface and a second spool member. Together the first spool member and second spool member define a storage chamber. The storage chamber lies in a different plane than the loop channel of the first spool member. The first spool member defines transition openings for allowing the cable to pass from the loop channel to the storage chamber. Carriage frame includes detent and catch tabs for retaining the cartridge inside a cartridge housing.

Abstract: A method for controlling the data rate of a virtual connection. Data packets are received for transmission on the virtual connection. The method comprises buffering the data packets in a buffer. A counter signal is generated to indicate the beginning of timeslots in a measurement window. The number of timeslots needed to transmit the data packets with a selected data rate is determined. The method further accesses data from at least one table to determine the spacing between timeslots in the measurement window used to request access to a data bus based on the number of timeslots needed to achieve the selected data rate. Further, access to a data bus for the data packets in the buffer is requested based on the data accessed from the table. The method further transmits the packets when access to the bus is granted.

Abstract: A circuit for a cable modem termination system is provided. The circuit includes a backplane interface and a packet processing engine coupled to the backplane interface. The circuit further includes a plurality of media access control (MAC) circuits, each media access control circuit coupled to the packet processing engine, each MAC circuit supporting one of N contiguous downstream channels with a single upconverter and each MAC circuit also supporting a plurality of upstream channels.

Abstract: A system and method for electronically identifying connections established through a cross-connect system provides for identification of all hard-wired and temporary patch connections, and any modifications made to same. Connection identification and status information is acquired in near real-time and stored in a database which is accessible by a user through a graphical user interface (GUI). The TRACE or lamp wires which connect respective pairs of cross-connect circuits are utilized in an unconventional manner so as to form a scanning bus. The information signal paths established through the cross-connect circuits remain undisturbed. A scanning signal is communicated between each pair of cross-connected circuits over the TRACE conductor. In the event a patch cord is used to temporarily redirect a signal connection, the scanning signal is transmitted over the shield or sleeve conductor of the patch cord. The scanning signal provides identification and other information concerning the transmitting circuit.

Abstract: A monitor circuit for indicating whether a digital cross-connect bay has a cross-connect jack that cross connects equipment being tested that includes a non-intrusive sensor for sensing current changes in a power feed line of the bay being monitored. The non-intrusive sensor is operatively coupled to a sensor device that generates a signal to activate an external sensor if a current change is detected by the sensor. The sensor device is powered from the same power supply as the bay it is monitoring.

Abstract: A frequency estimate of an incoming data input is generated and transmitted with network traffic to a receiver. At the receiver, the estimate is recovered, decoded, and is used to seed an algorithm for locking the data access rate of the receiver to the incoming data. Data is buffered in buffers at each end of the system, and data flow out of the buffers is managed depending upon data rate.

Abstract: The present disclosure relates to a fixture for holding a plurality of fiber optic connectors. The fixture includes a holding plate defining a plurality of ferrule receiving openings spaced about a reference axis. The holding plate includes a plurality of movable portions with each of the moveable portions at least partially defining one of the ferrule receiving openings. The moveable portions are moveable between open positions in which the ferrules can be inserted in the ferrule receiving openings, and clamped positions in which the ferrules can be clamped within the ferrule receiving openings. The fixture also includes a drive member mounted to allow relative rotation between the drive member and the holding plate, and a plurality of retaining members spaced about the reference axis. The retaining members are positioned between the drive member and the movable portions of the holding plate.

Abstract: The present disclosure relates to a jack assembly including a jack mount having a front side and a rear side. A jack of the assembly is adapted to be slidably mounted in a jack receiving region of the jack mount. The jack assembly also includes a plurality of cross-connect contacts, and a rear interface assembly. The rear interface assembly includes a dielectric cover piece and a plurality of rear connectors that project outward from the dielectric cover piece.

Abstract: A telecommunications network is provided. The network uses a ring of ring switches to provide a transport mechanism for data packets that is transparent to the data and protocols contained in the data packets. This transport mechanism is simple and low cost to implement. Such networks can carry, for example, data to and from the Internet to a subscriber with a cable modem hook-up to a cable network or a DSL modem connection to a copper wire DSL enabled telephone network.

Abstract: An apparatus for containing objects, such as electronic circuit cards, and a method for making the same, the apparatus having a housing; at least one case disposed within the housing, the case adapted to confine the objects to different locations within the housing and comprising a frame, the region within the frame divided into two regions by a first partition, each of the two regions divided into a plurality of sections by a plurality of second partitions, each of the second partitions thermally coupled to the frame and the first partition, each of the sections divided into a plurality of slots, each slot having an object disposed therein for thermal contact between the first partition, a second partition, and one of a second partition and the frame; and at least one heat sink adapted to absorb heat from the case, the heat sink thermally coupled to the case and the housing.