Abstract: An existing network configuration is assessed, and potential changes to the existing configuration are identified that provide the greatest incremental improvements to the performance of the network. In a preferred embodiment, the user of the system identifies the maximum number (N) of changes that may be implemented in an existing network, and the system provides a set of possible reconfigurations, each requiring fewer than N changes. The user is presented a display of the potential improvement provided by each set as a function of the number of changes in the set, so that the relative incremental gain can be easily visualized. The objective function of the optimization may include conventional load-balancing objectives, or other objectives, such as a global minimization of path lengths.

Abstract: A receiving system allows for the coherent detection of a spread-spectrum transmission at any point in time during the transmission, thereby avoiding the need to identify the start of the transmission during the transmission-detection process. An input buffer captures the transmissions on a communication channel using a moving time-window. A detector processes a time-slice from the input buffer and identifies all of the simultaneously transmitting transmitters during that time-slice. As each transmitter is identified, the demodulator traces back-in-time to identify where the message can first be detected in the input buffer. The transmission includes suitable characteristics to facilitate detection and demodulation of the message content, but need not contain a preamble to allow the detection process.

Abstract: A distributed network monitoring system includes a central monitoring device configured to fetch network traffic information from one or more remote monitoring devices in response to receiving a notification from the remote monitoring devices that the network traffic information is available, the remote monitoring devices being communicatively coupled to the central monitoring device. The network traffic information is associated with a timestamp which indicates a time period at which the network traffic information was collected by the remote monitoring devices. The central monitoring device further synchronizes the network traffic information from the remote monitoring devices by comparing the timestamp of the network traffic information with a system timestamp provided by a system clock or network time protocol (NTP) server. The network traffic information is identified as unavailable if the timestamp cannot be located when compared to the system timestamp.

Abstract: A system and method for determining a common time base among nodes in a network by iteratively propagating timing constraints among the nodes, and determining a time-shift to apply to the time base of each node that conforms to these constraints. “Trace” files record the time of transmission or reception of packets at each node, based on the time base at the node. A fundamental constraint in a common time-based system is that the time of reception of a packet at a destination node cannot be prior to the time of transmission of the packet from a source node. A further constraint in a common time-based system is that the time of reacting to an event cannot be prior to the time of the event.

Abstract: A control node of a communication network is operated at a packet bandwidth determined according to observations of performance metrics of the network at the control point. These performance metrics may be one or more of throughput, average fetch time and packet loss. The control node is operated so as to set a control bandwidth to corresponding resonance points of the performance metrics. The resonance points are determined by scanning across a range of control bandwidths, until one or more of the performance metrics is/are optimized. The packet bandwidth is set by varying an inter-packet delay time over selected communication links at the control node.

Abstract: An integrated RC filter comprises a first resistor being coupled to a first capacitor through a first node and a signal input of said integrated RC filter is coupled through one of the first resistor and the first capacitor to the first node. To allow for an increase in the RC time constant of the RC filter without losing signal transparency, amplification means are included between said signal input and said one of the first resistor and the first capacitor having a gain factor substantially larger than unity, said first node being coupled through attenuation means to a signal output, said attenuation means having an attenuation factor substantially.

Abstract: Multiplier device comprising first to nth multipliers M1 to Mn for multiplying a carrier modulated information signal with first to nth mutually phase shifted and identical, substantially square wave mixing signals MS1 to MSn with 50% duty cycle. In order to eliminate fifth or higher order interferences from the output of said multiplier device according to the invention, n is greater than 2, outputs of said multipliers M1 to Mn are respectively coupled through weighting circuits W1 to Wn with respective fixed weighting factors WF1 to WFn to an adder circuit, said mixing signals MS1 to MSn having respective phase angles ?i corresponding to ?i=i*??, said weighting factors WFi corresponding to the sine value of said respective phase angles ?i=i*?? with ?? being the mutual phase difference between each two phase consecutive mixing signals corresponding to ?/(n+1) and i varying from 1 to n.

Abstract: A simulation method and system partitions network traffic into background traffic and explicit traffic, wherein explicit traffic is processed in detail, and background traffic is processed at a more abstract level. The packets of explicit traffic are modeled in complete detail, so that precise timing and behavior characteristics can be determined, whereas large volumes of traffic are modeled more abstractly as background flows, and only certain aspects, such as routing through the network, are simulated. Tracer packets are used to model the background traffic and carry a number of characteristics of interest for generating simulation results. In this manner, the effect of the background traffic on the explicit traffic can be modeled at each network element. The abstract processing of background traffic is facilitated by techniques that include multi-variate table look-up, neural networks, and the like.

Abstract: Tunable low noise amplifier using an RF current feed back loop (L) coupled between input (IM) and output (OM) means and including first (CAI) and second (CA2) serially coupled first order lowpass RF current amplifiers as well RF current inverter means (INV). To obtain narrow bandpass selectivity within a relatively wide tuning range e.g. from 40 MHz to 1000 MHz said first RF current amplifier is being provided with a current gain larger than that of the second RF current amplifier, and a 3 dB cut off frequency lower than the 3 dB cut off frequency of said second RF current amplifier, a tuning control signal being supplied to both first and second RF current amplifiers to vary the respective 3 dB cut off frequencies thereof.

Abstract: A receiving system dynamically searches a communications band for transmissions of messages having the same nominal communications parameters, including the use of the same spreading code, but having potentially different specific frequencies and code-phases. The receiver samples the communications band at each code-phase of the spreading code over a span of down-converted transmission frequencies. When a message element is detected at a particular code-phase and frequency, it is forwarded to a demodulator that demodulates the message and sends it to its intended destination. This technique allows each transmitter to be independent of the receiver. In a preferred embodiment of this invention, a Fast M-Sequence Transform (a Walsh-Hadamard Transform) is used to determine the power level at multiple code-phases at a given frequency in parallel, thereby substantially reducing the time required to search for transmissions at each discrete code-phase.

Abstract: Control system for programmable filters, master-slave calibration system and fully programmable high precision filter for use in such control system, such filters being provided with a filter input and a filter output including a first, first order low pass filter section comprising first and second mutually identical operational transconductance amplifiers (OTAs), having a controllable transconductance Gm from a differential voltage input having first and second differential voltage input terminals to a single current output carrying a single phase current output signals, said first and second OTAs being provided with first and second control inputs, respectively, said filter input being coupled to the first differential voltage input terminal of said first OTA.

Abstract: A system is installed in the subsurface to control the hydraulic gradient between the area within a containment system and the area outside the containment system, and provides an easy-to-maintain treatment system. Preferably, the treatment system includes a sufficiently sized conduit between the inside-area and the outside-area that is accessible via a manhole. This conduit can be filled with remedial material or other treatment equipment, the manhole-sized access providing a relatively easy means of providing, maintaining, and replacing this material and equipment. Because the conduit is appropriately sized, hydraulic pressures on either side of the open conduit can be expected to be substantially equal, thereby reducing the potential of leakage of contaminants caused by hydrostatic pressure. Gates and screens are provided on either side of the conduit, to facilitate flow control, with manhole accessways to facilitate maintenance of these gates and screens.

Abstract: Receiver comprising an RF input filter including a digitally controlled capacitor bank with n capacitors being controlled by a tuning control signal for varying the tuning frequency of the RF input filter within a tuning range. For an improvement of the receiver in price/performance ratio the n capacitors of the digitally controlled capacitor bank are monolythically integrated, whereas the bandwidth of the tunable RF input filter is being adjusted to the maximum relative spread of said capacitors. A continuous tuning control signal is being supplied through an analogue to digital (AD) converter to said capacitor bank and to a first input of a differential stage, an output of the AD converter being coupled through a digital to analogue (DA) converter to a second input of a differential stage, an output of the differential stage being coupled to a control terminal of a variable capacitance diode being arranged in parallel to the digitally controlled capacitor bank.

Abstract: Receiver comprising a cascade of first to N resonance amplifiers (SA1, SA2, SA3), an output thereof being coupled to signal processing means (TO, SD, PK, LP1, S) for deriving a baseband modulation signal. To improve the signal to noise ratio said cascade is included in an RF input stage of the receiver for a distributed selective amplification of an RF reception signal, preferably with an impedance level of the individual resonance amplifiers within said cascade of first to N resonance amplifiers increasing in signal downstream direction.

Abstract: A simulation system includes a cache structure that stores determined characteristics related to the propagation of an event. If a similar event occurs, and the factors affecting the determination of these characteristics have not changed, the characteristics associated with the new event are retrieved from the cache, rather than being re-determined from the underlying factors. In the example of mobile transceivers, if multiple transceivers share a common set of underlying factors, the determined characteristics of one transceiver can be shared among all of the other transceivers. If the underlying factors are dependent upon geographic area, mobile transceivers that enter a geographic area having associated cached characteristics can use the cached characteristics of other transceivers that are, or had been, in the area.

Abstract: Linked zones define the temporal and spatial relationships among multiple zones of a surveillance area, and are used to model an object's disappearance from one zone, for potential reappearance at another zone. One or more zones are defined within each camera's field of view. Two zones are linked if an object that disappears from one zone is capable of appearing in the other zone. Each link has an associated delay parameter or function that characterizes the time delay, if any, between a disappearance and subsequent appearance. For each zone, a set of other zones that are linked to this zone is maintained. When an object disappears from a zone, the set of other zones that are linked to this zone is used to reduce the search space for object appearances corresponding to this disappearance. When the corresponding object appearance is found, the tracking function is handed-off to the tracking module associated with the zone in which the object appeared.

Abstract: A mirror suppression circuit includes a first quadrature signal path coupled between quadrature signal input and output terminals and an error correction circuit for correction of amplitude and phase errors in a carrier modulated quadrature signal. To obtain a suppression of both amplitude and phase imbalance of the carrier modulated quadrature signal as well as signal amplitude variations, a quadrature output of the error correction circuit is coupled to an error detection circuit. The error detection circuit detects amplitude and phase errors and provides amplitude and phase control signals to the error correction circuit for a negative feed back of the amplitude and phase errors. The amplitude and phase control signals vary with products of components of the quadrature signal and components of a quadrature reference signal.

Abstract: A thermal management system for a spacecraft module includes a baseplate and wall system that is precharacterized to provide a given level of thermal performance regardless of an orientation of the spacecraft relative to a source of solar energy. The system is characterized at a worst-case hot orientation, and at a worst-case cold orientation. The characterization provides a maximum temperature and a minimum temperature of components mounted on the baseplate as a function of the height of the walls. The height of the walls is selected to provide a suitable temperature range for the components, based on the power dissipation of the components. The system is designed to be symmetric, so that this temperature range is assured regardless of the orientation of the spacecraft.

Abstract: AM receiver comprising an RF input circuit for receiving an RF AM signal, demodulation means providing an audio signal carried by said RF AM signal as well as automatic gain control means for stabilising an RF carrier dependent DC level at the output of said demodulation means at a substantially fixed stabilisation value. In order to improve the receiver performance in particular at low values of the RF reception fieldstrength, the RF input circuit is being provided with a cascade of N tuneable resonance amplifiers being tuned to said RF AM signal, said automatic gain control means controlling at least one of said cascade of N resonance amplifiers to increase in both gain and selectivity at a decrease of the fieldstrength of said RF input signal.

Abstract: A method and system for flow propagation analysis uses ‘tracers’ that are iteratively propagated through a simulated network between source and destination elements. These tracers are structured to contain traffic flow information from source to destination, and to reflect changes as the flow is affected by each element along the path from source to destination. The resultant flow information at the destination corresponds to the effective throughput from the source to the destination, and the flow information at the output of each intermediate element in the network corresponds to the potentially achievable throughput through that element for the given source-to-destination flow.