Abstract: Systems and methods for implementing a memory-efficient fault tolerant computing system are provided. A generic backup process may provide fault tolerance to multiple working processes. The backup process need not include a copy of the code segments executed by the working processes, providing very large savings in memory needed to implement the fault tolerant system. Alternatively, multiple backup processes provide fault tolerance but need not include duplicated code segments for the working processes they support.

Abstract: An add/drop node used in an optical network having two fiber paths for carrying light corresponding to a plurality of channels in opposite directions may include a pair of add/drop modules that correspond to one of the plurality of channels. This arrangement advantageously provides a simple approach for connecting the components of an add/drop node.

Abstract: A method of generating language specific code comprising the steps of extracting neutral code from a knowledge base, preprocessing the neutral code, providing a code generator with the preprocessed neutral code and a target language in to which the preprocessed neutral code is to be translated, and processing the preprocessed neutral code by translating the neutral code into a target language code.

Abstract: A method of monitoring congestion within a data path having a queuing node located therein and a plurality of downstream nodes positioned downstream of the queuing node. The method includes monitoring congestion at the plurality of downstream nodes and setting a congestion notification flag by one of the downstream nodes when the node is congested. The transmission of data packets from the queuing node is stopped and packets received at the queuing node are queued when the flag is set. The method further includes transmitting packets from the queuing node when the congestion notification flag is cleared. A system for monitoring congestion on a data path is also disclosed.

Abstract: Techniques for searching for best matches in tables of information are provided. A first tree is traversed according to a first value for a first field and as information is encountered at each node, the information is written to a second tree. The second tree is traversed according to a second value for a second field to determine the best match for the first and second values. By utilizing the first and second trees, efficient searching for best matches can be achieved while allowing for dynamic modification of the data.

Abstract: Systems and methods for providing digital video teleconferencing over a network that allows a user to view the event in a manner more closely approximating live viewing are provided, while not requiring excessive use of bandwidth. Low resolution and high resolution of a videoconference event are obtained, preferably by using two cameras at the event. A whole eye view is sent to clients at low resolution. A user at the client can select one or more areas of interest to him (“attention windows”). High resolution data from the attention window(s) selected by each user is sent to the respective client. The client displays the whole eye view and the attention window data.

Abstract: A modularized network component system that includes a transceiver module and a separate accessory module, and enables the transmissions range of the transceiver module to be augmented by the accessory module, is disclosed. According to one aspect of the present invention, an optical network includes a fiber, a first device, and a second device. The first and second devices are coupled to the fiber such that the second device is in communication with the first device through the fiber. The second device includes a first modular subsystem that is arranged both to transmit data and to receive data through the fiber. The first modular subsystem is substantially physically decoupleable from the second device and from the fiber such that the first modular subsystem may be readily replaced within the second device by another modular subsystem.

Abstract: A method for evaluating a test fluid as a fabric care composition or as a component thereof. The method includes providing a test sheet of fabric comprising a plurality of test regions and simultaneously contacting each of the plurality of test regions with a different test fluid. The method further includes screening the plurality of test regions or the contacted test fluids for a fabric property of interest to evaluate the relative efficacy of the different test fluids.

Abstract: A method for forming an adaptive phased array transmission beam pattern at a base station without any knowledge of array geometry or mobile feedback is described. The approach is immune to the problems which plague methods which attempt to identify received angles of arrival from the mobile and map this information to an optimum transmit beam pattern. In addition, this approach does not suffer the capacity penalty and mobile handset complexity increase associated with mobile feedback. Estimates of the receive vector propagation channels are used to estimate transmit vector channel covariance matrices which form objectives and constraints in quadratic optimization problems leading to optimum beam former solutions for the single user case, and multiple user case. The new invention in capable of substantial frequency re-use capacity improvement in a multiple user cellular network.

Abstract: Methods and apparatus for tightening an erased bit threshold voltage distribution are disclosed. According to one aspect of the present invention, a method for processing erased bits associated with an erased bit distribution which includes an over-erased bit which has a first value that is less than a first threshold voltage value and a bit that has a second value that substantially exceeds a second threshold voltage value includes inhibiting the fast bit. The method also includes applying a soft program pulse to the erased bits such that inhibiting the fast bit substantially prevents the second value from changing and applying the soft program pulse to the over-erased bit substantially causes the first value to increase. In one embodiment, applying the soft program pulse to the over-erased bit substantially causes the first value to increase to a value that is greater than or equal to the first threshold voltage value.

Abstract: Systems and methods for efficient multiplexing of multiple access requests from disparate sources within a single OFDM burst. Each of multiple subscriber units employ non-overlapping groups of OFDM frequency domain symbols within a single burst for upstream transmission of their access requests. In one embodiment, the OFDM frequency domain symbols are differentially encoded to eliminate the need for transmission of upstream training information. In an alternative embodiment, the group of frequency domain symbols within the burst employed by any particular subscriber unit are contiguous to one another. Channel training for a give subscriber unit need only be performed over the subband occupied by its group of frequency domain symbols. This greatly reduces the number of training symbols required for reception.

Abstract: A modular interleaved Raman amplifier structure is exploited to reap the advantages provided by the high Raman gain coefficient and small effective area of highly nonlinear fibers without incurring penalties caused by nonlinear effects and double-Rayleigh backscattering noise. Very tight WDM channel spacings may be accommodated. The amplifier structure may be implemented at very low initial cost and with high reliability, scalability, and modularity.

Abstract: Systems and methods for converting a baseband OFDM signal to an IF signal while minimizing lengthening of the impulse response duration experienced by the OFDM signal. A conversion technique according to the present invention provides sufficient filtering to limit the effects of spurious frequency domain components caused by transitions between successive OFDM bursts. In one embodiment, the filtering is provided by a combination of a finite impulse response (FIR) filter having non-linear phase characteristics and a cyclic convolution filter. Conversion from the frequency domain into the time domain, upsampling, and cyclic filtering may be combined into one operation.

Abstract: Systems and methods for optimally receiving differential encoded OFDM signals via multiple antennas. These techniques may exploit spatial diversity without knowledge of channel characteristics. Further systems and methods are provided for exploiting frequency diversity within an OFDM burst where differentially encoded symbols are repeated to assure optimal performance. The output of differential decoding systems may also be used to provide soft decision values for individual bits of multibit symbols to facilitate use of bitwise channel decoding systems.

Abstract: Systems and methods for sharing a single decoder among data streams originating with multiple sources. Error correction coding techniques are modified to facilitate decoding of data from multiple sources multiplexed in the time domain at the decoder input. A single decoder accommodates multiple sources that have been encoded using disparate code rates. One application is an OFDM point to multipoint system.

Abstract: Four-wave mixing crosstalk between co-propagating Raman amplification pump sources and WDM channels is suppressed. Therefore, co-propagating pumping may be applied to Raman amplification without incurring penalties due to four-wave mixing crosstalk. Pump power need not be substantially increased to accommodate use of the present invention. Also, the use of lower cost Fabry-Perot pump sources is facilitated. In one implementation, the advantageous suppression of four-wave mixing crosstalk between pump signals and WDM channels is accomplished by imposing chromatic dispersion on the co-propagating pump sources.

Abstract: A method is provided for displaying chromatographic data using a graphical user interface. This method is preferably implemented as a software package which takes chromatographic data generated by varying fluorescence levels in a sample.

Abstract: A receiver transponder that is implemented in an optical add/drop multiplexer (OADM) is disclosed. The OADM is used in short haul type networks and receives light signals from two opposite directions on input fibers (21, 23). The optical input signals are converted to electrical signals by optical-to-electrical (O/E) converters (51, 53). The output terminals of the converters are connected to an electronic switch (61), which provides protection switching in a protected ring type network. The output signal of the switch can be monitored (65) before the signal enters a reshaping circuit (67), where the signal is reshaped, filtered from a supervisory channel, and adjusted to a proper drive level for a laser (69). The optical signal from the laser can travel a significant distance through a fiber (71) to a client receiver or sustain other forms of attenuation and still have sufficient signal power for reliable detection. An electrical output signal can be provided (73) by the reshaping circuit.

Abstract: Systems and methods for remotely monitoring the execution of computer programs are provided. Monitoring instructions are added the computer program so that during execution of the program, data may be collected regarding the program execution. The collected data may be automatically sent to a remote system or site for analysis. The monitoring instructions create little or no performance impact on the client yet provide valuable information to the developer of the program. Additionally, the monitoring instructions may be changes during computer program development.

Abstract: Systems and methods for precisely controlling the amount of redundancy introduced by a turbo encoding process. Bits having predetermined values are introduced into the turbo encoding input stream and then deleted from the turbo encoding output stream. At the receiver end, the bits having predetermined values are reintroduced into the encoded information stream as having been received with a maximum confidence level. Coding rate may be varied by varying the number of bits having predetermined values which are inserted at the encoder input. This scheme permits the amount of redundancy to be varied according to system requirements.