Abstract: A system, method and computer readable medium comprising instructions for sending a message from an Optical Network Terminal (ONT) to an Optical Line Terminal (OLT), if the ONT does not receive an expected OLT action or an expected OLT response to the message within a period, considering the non-receipt of the expected OLT action or the expected OLT response a failure, and if a certain number of consecutive failures have occurred, considering by the ONT that it has entered an uncontrolled state.

Abstract: A system, method and computer readable medium comprising instructions for sending a message from an Optical Network Terminal (ONT) to an Optical Line Terminal (OLT), if the ONT does not receive an expected OLT action or an expected OLT response to the message within a period, considering the non-receipt of the expected OLT action or the expected OLT response a failure, and if a certain number of consecutive failures have occurred, considering by the ONT that it has entered an uncontrolled state.

Abstract: In an Optical Network Termination (ONT), a software controlled system, method and computer readable medium includes measuring a modulation current of an upstream laser transmission. The measured modulation current is processed to determine if a continuous transmission state is present, in response to which, a processor of the ONT sends a signal to shut down the upstream laser transmission. The software solution allows reconfigurable parameters including sample rate and shut down procedure.

Abstract: Redundant facility payload signals (12, 14) received by redundant interface modules (16, 18) are redundantly provided (28, 30; 32, 34) to redundant downstream modules (24, 26) in an equipment (10). A non-symmetrical facility protection algorithm is resident in the B interface module (18). Symmetrical equipment protection algorithms are independently resident and operative in each module of pairs of identical A and B modules at each stage of the data stream. Module or data failures result in switchover only of the disabled data path or module so that the ability to transport payload is maintained and other modules or data paths are unaffected. Facility switchover is effected by detecting a working line failure and transmitting commands to switch the protection line to the A path modules. Equipment switchover is effected by checking for a working or protection module failure independently in each path and independently communicating independent switchover decisions to the other side and downstream.

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.

Abstract: A transfer strobe delay stage selector insures accurate transfer of data from high speed circuitry to low speed circuitry through use of a delay stage module comprising a plurality of delay stages, and an associated multiplexor for selecting one of the delay stages so as to provide accurate reception of parallel data by the low speed circuitry from the high speed circuitry. The transfer strobe delay stage selector incorporates a synchronization channel identification module for detecting synchronization channel information in the frames of data transferred from the high speed circuitry to the low speed circuitry and also includes control circuitry for adjusting the selected delay stage until synchronization channel identification is detected.

Abstract: A serial transport frame format is described which transfers data between two locations. The serial transport frame format comprises a fixed number of channels per frame, each channel having a predetermined size. One channel per frame contains frame synchronization information and each channel which conveys data, contains a first portion for the transfer of data and a second portion which contains associated control information.

Abstract: A parallel time slot interchanger, particularly for use in telecommunication switching, comprises a plurality of switch groups, with each switch group containing a second plurality of channels. The parallel time slot interchanger incroporated a matrix-type architecture, with each module of the matrix comprising a switch block which in turn incorporates a switch memory, connect memory and associated control circuitry. The connect memory of each switch block is controlled by the control circuitry of that block. The data stored in the connect memory contains switch memory address information for reading channel data stored within the switch memory of the same switch block so as to be able to perform a time slot switching function during any given time slot of the parallel time slot interchanger. Each switch block is uniquely identified within its corresponding switch group so that only one switch memory address location is read and output during any time slot for each switch group.

Abstract: A low speed channel bypass apparatus is described for reprovisioning the time slot multiplexer associated with an add/drop multiplexer so as to insure that particular low speed channel(s) within a high speed channel are passed through the add/drop multiplexer via the time slot multiplexer when the operation of an associated network controller is determined to be faulty. The low speed channel bypass apparatus is particularly directed for use with a high speed channel conforming to the synchronous optical network communication standard (SONET). A watchdog timer is used to monitor the performance of the network controller. The watchdog timer when timed out not only prevents further operation of the network controller, but instructs an associated reprovisioning apparatus to instruct the time slot multiplexer to connect through selected channel(s) from the east high speed interface to the west high speed interface.

Abstract: Real-time conversion between two different A/B signal coding schemes based on the DS1 time division multiplex format is achieved by time sharing a programmable state machine. The time sharing is accomplished synchronously with the DS1 superframe such that each of the 24 DS1 channels have signalling translated once every superframe. Programmability of the state machine is facilitated by the use of an EPROM. A RAM is used for real-time storage of signal states, machine states and processor provisioning for each channel, thereby facilitating time sharing of the state machines. Flexibility is provided through the unique use of an EPROM, which can be modified to directly change the signalling translation response depending on the type of telephony service being provided and the coding scheme used for the signalling. Processor provisioning of the RAM selects a service type translation for each of the 24 DS1 channels.

Abstract: A generalized data interface for transmission of asynchronous data from a transmitting terminal to a receiving terminal at a different transmission rate is described. In accordance with the present invention, the high data transmission rates normally associated with synchronous transmission are achievable between asynchronous data terminals using novel asynchronous to synchronous and synchronous to asynchronous converters.