Lucent Technologies Inc.

Michael L Steinberger

David Gradl

Warren Clifton Trested, Jr

Peter B Busschbach

Blaine A McKenzie

A unique trace word is assigned to each incoming signal routed by a sliced switch fabric having two or more parallel switches. The unique trace word is encoded into each incoming signal following an overall format that ensures that each sliced trace word (i.e., the subset of bits in the overall format routed by each parallel switch) also uniquely identifies each incoming signal. In this way, the present invention ensures that the switch configuration of each and every parallel switch can always be verified. As such, any improper switch configuration can be detected, including those misconfigurations in which all but one of the parallel switches are correctly configured as well as those misconfigurations in which all of the parallel switches are identically, but incorrectly configured. In a preferred embodiment, the overall format is defined in terms of a table, in which each column comprises all of the bits of the unique trace word and the bits are shifted cyclically between pairs of columns to reduce the number of rows of the table that need to be processed before all of the bits in the unique trace word are available in the outgoing signal transmitted from the sliced switch fabric.

Trace format for a sliced switch fabric

A high speed digital signal connection interface with reduced cross talk includes a multiple pin connector with disconnectable header and receptacle portions. The header is attached to a first set of signal carrying wire pairs communicating with a first signal processing unit. The receptacle is attached to a second set of signal carrying wire pairs communicating with a second signal processing unit. Within each of the first and second wire pair sets is a first wire pair subset carrying digital signals travelling in a first direction between the signal processing units, and a second wire pair subset carrying digital signals travelling in a second direction between the signal processing units. The first and second wire pair sets are attached to the corrector such that adjacent pin pairs of the connector carry only signals travelling in the same direction and such that connector pin pairs carrying signals travelling in opposite directions are not adjacent to each other. An impedance matching circuit is provided for each signal-carrying wire pair of the first and second wire pair sets. Each impedance matching circuit has a first side connected to one of the signal processing units and a second side connected to one of the wire pairs at an impedance that substantially matches the wire pair impedance. The impedance matching circuits that connect to wire pairs carrying outgoing signals from a signal processing unit provide driver end impedance matching, and the impedance matching circuits that connect to wire pairs carrying incoming signals to a signal processing unit provide receiver end impedance matching.

High density multiple digital signal connection interface with reduced cross talk

A test system for a evaluating a digital signal link includes a data signal generator, a data signal receiver, a digital signal link to be tested and a test interference signal injection (TISI) network connected as part of the digital signal link. The TISI network includes a data signal input port for receiving digital data signals generated by the data signal generator, a data signal output port for providing the digital data signals to the data signal receiver, and a controlled impedance data signal path carrying the digital data signals between the data signal input port and the data signal output port. An interference signal input port receives interference signals over a range of frequencies from an interference signal generator. One or more directional couplers directionally couple the interference signals into the data signal path toward either the data signal output port or the data signal input port at an impedance that substantially matches the impedance of the digital signal link. The directional couplers are configured to maintain d.c. isolation from ground to facilitate the transfer of d.c. coupled data signal logic through the TISI network.

Test system with signal injection network for characterizing interference and noise tolerance in a digital signal link

A system provides automatic protection switching in case of failure or degradation in a function. For example, a system node may have a working server function, a protection server function, one or more client functions, and a control function. In its baseline configuration, the working server function is active, meaning that it is operating on-line with respect to the client functions, while the protection server function is standby, meaning that it is either inactive (i.e., cold standby) or operating off-line with respect to the client functions (i.e., hot standby). The control function monitors the operations of the working server function, and, if a failure or degradation is detected, or if an externally generated switch command is received, the control function will (1) instruct the working server function to change its status from active to standby and (2) instruct the protection server function to change its status from standby to active. In addition, the control function instructs each server function about a protection switch override condition. Each server function communicates its active/standby status as well as the override condition to the client functions (e.g., using in-band signaling). In addition to monitoring the active/standby status and the override condition transmitted from each server function, each client function also performs its own independent monitoring of the status of the server functions to detect failures or other degradation in the server functions. Each client function then applies a specific set of rules to this information to determine which server function to select for its operations. The set of rules are designed to handle race conditions and other ambiguous states.

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Woodenville, WA, United States of America

Michael L Steinberger