Abstract: A subscriber equipment (210) is isolated (238, 234) at a line card (208) in a line shelf (200) and drop testing is conducted over a test-out bus (240) by a test unit (220) connected (236) to the subscriber equipment (210); the test unit (220) may be plugged into any line card slot in any of a plurality of line shelves (200, . . .

Abstract: In an optical fiber telecommunications network, an optical network unit is provided in the subscriber neighborhood for terminating the optical fiber transmission line and for providing electrical signals over metallic lines to the subscribers. The unit functions to convert the optical signal to an electrical signal and demultiplex the electrical signal to divide out baseband telephony signals from broadband video channels. The electrical signals are further demultiplexed and distributed to line cards serving each subscriber, while the broadband video channels are demultiplexed and provided to subscribers that have requested specific video channels. The system includes a test unit for performing metallic tests and also a means to gather subscriber channel requests to form a video control channel which is transmitted to a remote terminal via a baseband telephony channel.

Abstract: In fiber telecommunications network where an optical fiber is extended to the subscriber's neighborhood, mechanized loop testing is performed by a test unit located in a network unit in the subscriber's neighborhood. The test unit is responsive to commands from a controller located in the network unit to perform metallic line tests on the lines extending to the subscriber. Test results are stored in a memory associated with the controller in the network unit. Upon receipt of a test request from a central test controller, the controller within the network unit determines if there is sufficient time to perform the test; if so, a new test is performed and the results are conveyed back to the central test controller controller. If sufficient time is not available, the results of the last performed routine test contained in the memory are transmitted back to the central test controller.

Abstract: An optical line shelf formerly used exclusively for multiplexing broadband video with voice channels in a serial bus transport format is adapted for use with both optical line distribution units and a metallic distribution unit.

Abstract: A line unit, used in a line shelf having a line shelf processor and common logic, is provided with an EEPROM device for storing information relative to the line unit. The stored information includes line unit type identification codes, auto provisioning data, gain and equalization adjustment data and signaling translation tables. The data contained within the EEPROM may be utilized by the line shelf processor to provide automatic initialization and provisioning of the line unit when first inserted into the line shelf, and automatic signaling translation so that line unit signaling becomes compatible with a transmission facility connected to the line shelf. The need for factory preset resistors installed in the line unit may be eliminated by storing within the EEPROM a required gain setting.

Abstract: A heat generating means, such a resistive element, is serially connected in a current-carrying conductive line, and a fusible link carrying current from said line is serially mounted between the line and said resistive element and is positioned in proximity to the heat generating means, to be heated by the heat from the generating means and to melt in response thereto, thereby breaking the serial connection in the current-carrying line. A spring means may be provided to urge disconnection of the serial circuit when the fusible link melts.

Abstract: In an integrated telecommunications network adapted to provide narrowband telephony signals and broadband switched video signals, control signals for the broadband video signals are transmitted in the narrowband as baseband signals, which are frequency division multiplexed with the broadband switched video signals. The video control signals are transmitted over the same transmission lines as the broadband video signals and do not require the installation of additional transmission lines. Control signals from a plurality of subscribers are multiplexed together at a network unit and are transmitted as a channel on an optical fiber, after which the channels from a plurality of network units are further multiplexed together to form a frame of control channels which are transmitted to a video controller unit.

Abstract: A synchronous optical transmission system for interfacing SONET formatted channels to lower speed channels in either a SONET format or otherwise. The transmission system incorporates a fiber transmission system, terminal multiplexers and add/drop multiplexers that in turn incorporate a plurality of features, such as parallel scrambling circuitry, frame synchronization circuitry and the like.

Abstract: A terminal for a telecommunications system provides access to one or two high-speed synchronous transmission lines by both low-speed transmission lines and subscriber lines. A core module includes interfaces to the high-speed lines, a time slot interchanger, an interface to the low-speed transmission lines, processors and overhead circuitry for supporting the terminal. An access module includes a plurality of line shelves connected to subscriber lines, each line shelf includes a pair of processors and for time slot assignors. A multi-link serial bus connects the time slot interchanger to the access module and to the low-speed interface and provides close coupling between the processors in the core module and the line shelves. The processors cooperate to groom subscriber information from said subscriber lines to and from time slots in said high-speed feeder line and said low-speed transmission line.