Abstract: A deformable connector incorporates first and second springs deflectable along multiple axis to compensate for misalignment. A connecting member is attached to the springs and includes perforations also to compensate for mis-alignment along an axis. EMI integrity is maintained with a deformable gasket that abuts the connecting member.

Abstract: An optical communication system comprising plural optical communication paths, a passive optical coupler, and at least one optical node. The passive optical coupler has a plurality of inputs coupled through the passive optical coupler to an output of the passive optical coupler, and each input is coupled in a corresponding one of the optical communication paths. Each optical node comprises plural optical line terminals, each of which is interposed in a corresponding at least one of the optical communication paths. Each optical line terminal is operable to either (a) substantially prevent an optical signal propagating in that corresponding at least one optical communication path from reaching a corresponding input of the passive optical coupler through the at least one optical communication path, or (b) permit the optical signal to propagate in that corresponding at least one optical communication path towards the corresponding input of the passive optical coupler.

Abstract: Techniques for providing communication services include provisioning a packet network connection that has packet channels, each of which is independently capable of carrying narrowband signals so as to emulate a private line circuit. A narrowband private line that traverses the packet network connection using a particular one of the packet channels is established. Delays that might otherwise be introduced as a result of packetizing the narrowband signals can be reduced. Private lines that traverse the packet network connection using other packet channels can be added or removed without adversely affecting the existing lines. Additionally, a narrowband communication line that traverses a channel in a first virtual circuit connection in a packet network can be rolled over to a channel in a second virtual circuit connection in the packet network. The latter technique can improve the use of available bandwidth and can be applied to non-private line applications as well.

Abstract: A reduced component optical switch module includes a plurality of ports wherein each port includes an optical input and an optical output. A plurality of switchable deflectors in combination with a plurality of non-switchable deflectors can be used to establish transmission paths between pairs of ports to support traffic reciprocity. In one embodiment, the ports and switchable elements are configured so as to provide substantially constantly transmission paths within the respective module. In another embodiment, additional deflector elements can be provided to implement loop-back functionality at one or more of the ports.

Abstract: An interconnect element incorporates a plurality of smaller, substantially identical, interconnect modules. Multiple identical elements can in turn be combined to form larger interconnect networks. Signal paths in the elements can be implemented with optical fibers or electrical conductors.

Abstract: The spectral shape of a communication signal is preserved by filtering it into a selected number of frequency band signals representing a selected number of the frequency bands. A calculator generates a plurality of initial gain signals having initial gain values for altering the gain of the frequency band signals. Each initial gain signal corresponds to one of the frequency band signals. Each initial gain value is derived from a measurement of the power of at least a portion of one of the frequency band signals. The calculator also generates a plurality of modified gain signals having modified gain values. Each modified gain signal corresponds to at least one of the frequency band signals and each modified gain value is derived from one or more functions of at least two of the initial gain values. The frequency band signals are altered in response to the modified gain signals to generate weighted frequency band signals which are combined to generate an improved communication signal.

Abstract: A multiple carrier communication system includes a primary impulse shortening filter that receives an output signal of an analog to digital converter and accepts coefficients. A secondary impulse shortening filter receives the output signal of the analog to digital converter, outputs an output signal, and passes coefficients to the primary impulse shortening filter. A reference signal generator outputs a reference signal. A comparator compares the output signal and the reference signal and outputs a resulting error signal. An adaptive processor computes coefficients for the secondary impulse shortening filter based on the error signal.

Abstract: A system and method for autonomous data path verification in a multi-module shelf configuration, such as in a digital cross-connect system, are disclosed. The system generally includes a source port module, a destination module, and optional n-stage network of mapping interface modules. The source port module is configured to reuse transport overhead bytes of received SONET or SDH signals by inserting data path verification data therefor. The destination module is configured to perform autonomous data path verification between the source port module and the destination module by examining the reused transport overhead bytes of the signals received from the source port module. The method generally includes reusing transport overhead bytes by inserting data path verification data into the overhead bytes of signals received by a first module, e.g., a source port module, and transmitting the signals with the data path verification data toward a second module, e.g., a destination port module.

Abstract: An optical line terminal determines an approximate location of impairment in an optical transmission path (e.g., optical fiber) without disconnecting the optical line terminal from the optical transmission path. The optical line terminal generates pilot tones that are modulated on an optical signal and used to make reflection and dispersion measurements in a frequency domain reflectometry manner, thus providing for in-vivo diagnostic testing of the optical transmission path. The dispersion can be automatically corrected by using a dispersion compensator.

Abstract: A multi-point communications system is set forth herein. The communications system includes a receiver and transmitter disposed at a primary site for communication with a plurality of remote service units disposed at respective secondary sites. The receiver of the primary site receives OFDM/DMT signals over a number of transmission bins. A transmitter at the remote service unit includes an improved transmitter architecture. The transmitter comprises a first circuit for converting a signal into a first serial digital data stream and a second circuit for generating a second serial digital data stream from the first serial digital data stream of the first means. The second serial digital data stream is a digital representation of an OFDM/DMT signal that is to be transmitted to the receiver of the primary site and is generated from the first serial digital data stream through a modulated direct digital synthesis thereof.

Abstract: An interconnect element incorporates a plurality of smaller, substantially identical, interconnect modules. Multiple identical elements can in turn be combined to form larger interconnect networks. Signal paths in the elements can be implemented with optical fibers or electrical conductors.

Abstract: A method and apparatus for interference suppression in wireless communication systems, especially Orthogonal Frequency Division Multiplexed (OFDM) systems. The array apparatus includes a two-tier adaptive array system which provides for both spatial diversity and beamforming at the uplink. The adaptive array is comprised of sub-arrays spaced at a distance sufficient to provide spatial diversity, ideally 5 to 15 wavelengths at the frequency of operation. Each sub-array is composed of at least two antenna elements spaced in proximity sufficient to provide effective beamforming or scanning, ideally less then one-half of one wavelength at the frequency of operation. The Direction of Arrival (DOA) of signals impinging upon the array can be calculated by comparing signals from sub-array elements.

Abstract: A switch core is set forth that comprises a plurality of duplex switches that are interconnected with a interconnection fabric to implement, for example, strictly non-blocking operation of the switch core for reciprocal traffic. In one embodiment, an N-way reciprocal switch is implemented. The N-way reciprocal switch comprises a plurality of duplex switches numbering N of at least a 1×(N−1) switch type (e.g., the duplex switches have at least N−1 ports available for connection to implement the interconnection fabric). The interconnection fabric interconnects the plurality of duplex switches so that each duplex switch is connected to every other duplex switch used in the interconnection fabric by a single connection. A similar architecture using switches numbering N of at least a 1×N switch type are also set forth.

Abstract: A multiple carrier communication system includes a primary impulse shortening filter that receives an output signal of an analog to digital converter and accepts coefficients. A secondary impulse shortening filter receives the output signal of the analog to digital converter, outputs an output signal, and passes coefficients to the primary impulse shortening filter. A reference signal generator outputs a reference signal. A comparator compares the output signal and the reference signal and outputs a resulting error signal. An adaptive processor computes coefficients for the secondary impulse shortening filter based on the error signal.

Abstract: A way of testing a wavelength division multiplexed (WDM) system without requiring connection to data source/sink equipment. A test signal is introduced onto a light path of interest in the system, and the test signal is monitored downstream for signal integrity. Lack of signal integrity is used to identify a fault in the lightpath. Alternatively, optical loopbacks may be used to localize and identify a fault in the lightpath. The lightpath includes a source optical node connected to a sink optical node via intermediate optical nodes. An optical signal introduced at the source node with a destination at the sink node may be looped back at any one of the intermediate nodes or the sink node to localize and identify a fault in the lightpath.

Abstract: A multi-point communications system is set forth herein. The communications system comprises a transmitter for transmitting OFDM/DMT symbols over a predetermined number of bins across a transmission medium. The OFDM/DMT symbols are generated using at least one timing signal. At least one of the predetermined number of bins includes a pilot tone sub-symbol having a frequency corresponding to the clock signal. The communications system also includes a receiver for receiving the OFDM/DMT symbols from the transmission medium. The receiver demodulates the received symbols using at least one timing signal. The receiver has a first pilot tone search mode of operation in which the receiver adjusts its timing signal to scan the frequency range of the predetermined number of bins looking for the pilot tone sub-symbol and identifies the bin including the pilot tone sub-symbol.

Abstract: An optical signal having optical energy is received at an optical amplifier. The optical signal may be separated into a low frequency segment and a high frequency segment. The high frequency segment and the low frequency segment may be processed in order to determine a low frequency error signal and a high frequency error signal. The low frequency error signal may be summed with the high frequency error signal in order to generate a total error change associated with the optical amplifier.

Abstract: In order to enhance the quality of a communication signal comprising speech signal components due to speech and noise signal components due to noise, a filter divides the communication signal into a plurality of frequency band signals representing the speech signal components and the noise signal components in a plurality of frequency bands. A calculator generates a plurality of weighting signals having weighting values corresponding to the frequency band signals. The weighting values represent at least approximations of the normalized powers of the noise signal components in the frequency band signals. The frequency band signals are altered in response to the weighting signals to generate weighted frequency band signals which are combined to generate a communication signal with enhanced quality.

Abstract: An electrical system comprises an electrical circuit board for mounting electrical components and a circuit board sub-rack. The board includes a pivotally mounted ejector member which pivots to insert and eject the board from the sub-rack. The ejector member carries two grounding contact surfaces for engagement with the ground plane of the board and chassis area of the sub-rack when the ejector member is pivoted to its closed position. The contact surface of the ejector member mates with the board to frictionally hold the board in fully inserted position. The ejector member also includes a retaining arm which mates with the sub-rack for providing an insertion or ejection force to facilitate insertion or ejection of the board relative to the sub-rack.

Abstract: Erroneous data due to faults are prevented from propagating through a distributed network node having diversely routed communications links by using a fault masking technique that eliminates the 60 ms of error propagation time associated with SONET networks. The fault masking technique can also prevent random bit errors from propagating through the distributed network node. A frame alignment technique used in the network node is scalable for very wide words (e.g., 128 bits) for use with high speed optical communications protocols, such as OC-192.