Abstract: A system includes an optical transmitter that outputs an optical signal having a substantially Gaussian waveform and an optical receiver that is optically coupled to the optical transmitter and has an impulse response essentially matching the waveform. The impulse response and waveform preferably match in the time domain. The transmitter and receiver may be average-power-limited, using, for example, an erbium-doped fiber amplifier. To achieve a high signal-to-noise ratio, the waveform may be designed to minimize jitter, sample duration, matching parasitics, and inter-symbol interference (ISI). Such a waveform may be a return-to-zero (RZ) Gaussian or Gaussian-like waveform and may be transmitted in a variety of modulation formats. Further, the system may be used in WDM or TDM systems. A method for characterizing the time domain impulse response of an optical element used in the optical receiver is provided, where the method is optionally optimized using deconvolution and/or cross-correlation techniques.

Abstract: An optical, multi-channel, Differential Phase Shift Keying (DPSK) receiver demodulates multiple Wavelength Division Multiplexed (WDM) channels using at least one interferometer. This distributes expense of the interferometer(s) over all channels of an optical signal, allowing for deployment of cost-effective, scalable, wideband, WDM DPSK systems. For example, for an 80 channel WDM link, the receiver uses a single interferometer instead of eighty interferometers and associated stabilization hardware, dramatically reducing size, weight, power, and cost. The receiver is architecturally compatible with existing interferometer technologies so previous development and qualification efforts can be leveraged. This allows for expedited technology insertion into existing optical communications networks, including terrestrial and space-based optical networks.

Abstract: A polarization independent (PI) interferometer design that can be built from standard optical components is described. Based upon a Michelson interferometer, the PI interferometer uses a 50/50 splitter and Faraday Rotator Mirrors (FM's). The interferometer achieves good optical characteristics, such as high extinction ratio (ER) and low insertion loss (IL). Lack of polarization sensitivity reduces interferometer construction tolerances and cost, enhances performance and utility, and expands the scope of interferometric based devices. Such characteristics can be used to construct flexible, high performance, polarization insensitive, multi-rate, self-calibrating, optical DPSK receivers, power combiners, optical filters and interleavers, all-optical switches, and cascaded interferometers. Since polarization is not maintained in standard fiber optic networks, a PI-DPSK receiver allows for use of more sensitive DPSK communications over fiber, without need for costly polarization control hardware.

Abstract: An optical, multi-channel, Differential Phase Shift Keying (DPSK) receiver demodulates multiple Wavelength Division Multiplexed (WDM) channels using a single interferometer. This distributes expense of the interferometer over all channels of an optical signal, allowing for deployment of cost-effective, scalable, wideband, WDM DPSK systems. For example, for an 80 channel WDM link, the receiver uses a single interferometer instead of eighty interferometers and associated stabilization hardware, dramatically reducing size, weight, power, and cost. The receiver is architecturally compatible with existing interferometer technologies so previous development and qualification efforts can be leveraged. This allows for expedited technology insertion into existing optical communications networks, including terrestrial and space-based optical networks.

Abstract: A high capacity motorized rack holds a plurality of jewel case enclosed CDs in holders flexibly inter-connectable with each other to form a rotatable continuous loop. The loop is rotatably retained within a vertical rack housing and is driven by a motor, disposed within the housing, under user control such that the loop is rotated until a desired CD is moved to the top region of the belt. A rack may hold two or more such loops of inter-connected holders. In one embodiment a holder retains a single jewel case, and comprises two independent loops that are rotated with a single motor. A lamp and/or barcode scanner may be disposed on the housing for ease of CD selection. The housing base preferably is detached during shipping to permit transporting the rack in a smaller volume container. User control can include voice commands to direct loop rotation and speed.

Abstract: Methods and systems for load balancing a plurality of entities, such as firewalls, in a network environment are disclosed. In particular, the load balancing of firewalls on a bidirectional traffic path is performed using a single device that controls both incoming and outgoing traffic through the firewalls. The single device may include virtual routers for controlling the bidirectional traffic through the firewalls. A first virtual router may control incoming traffic to the firewalls and the other virtual router may control outgoing traffic to the firewalls. The virtual routers are logical partitions of the device layered on the physical resources of the device. The virtual routers share all or portions of the physical resources of the single device.

Abstract: A high capacity motorized rack holds a plurality of jewel case enclosed CDs in holders flexibly inter-connectable with each other to form a rotatable continuous loop. The loop is rotatably retained within a vertical rack housing and is driven by a motor, disposed within the housing, under user control such that the loop is rotated until a desired CD is moved to the top region of the belt. A rack may hold two or more such loops of inter-connected holders. In one embodiment a holder retains a single jewel case, and comprises two independent loops that are rotated with a single motor. A preferred embodiment employs inter-connectable holders that each retain two jewel cases in a side-by-side configuration. A lamp and/or barcode scanner may be disposed on the housing for ease of CD selection. The housing base preferably is detached during shipping to permit transporting the rack in a smaller volume container. User control can include voice commands to direct loop rotation and speed.

Abstract: A high capacity motorized rack holds a plurality of jewel case enclosed CDs in holders flexibly inter-connectable with each other to form a rotatable continuous loop. The loop is rotatably retained within a vertical rack housing and is driven by a motor, disposed within the housing, under user control such that the loop is rotated until a desired CD is moved to the top region of the belt. A rack may hold two or more such loops of inter-connected holders. In one embodiment a holder retains a single jewel case, and comprises two independent loops that are rotated with a single motor. A preferred embodiment employs inter-connectable holders that each retain two jewel cases in a side-by-side configuration. A lamp and/or barcode scanner may be disposed on the housing for ease of CD selection. The housing base preferably is detached during shipping to permit transporting the rack in a smaller volume container. User control can include voice commands to direct loop rotation and speed.

Abstract: A variable-bit-rate communication system is described. The communication system includes a variable-bit-rate transmitter that generates digital data at a first or a second bit rate and a variable-bit-rate receiver that receives the digital data. The digital data comprises a sequence of signaling waveforms having a first or a second duty cycle, respectively, wherein each signaling waveform has the same shape.

Abstract: A high capacity motorized rack holds a plurality of jewel case enclosed CDs in holders flexibly inter-connectable with each other to form a rotatable continuous loop. The loop is rotatably retained within a vertical rack housing and is driven by a motor, disposed within the housing, under user control such that the loop is rotated until a desired CD is moved to the top region of the belt. A rack may hold two or more such loops of inter-connected holders. In one embodiment a holder retains a single jewel case, and comprises two independent loops that are rotated with a single motor. A preferred embodiment employs inter-connectable holders that each retain two jewel cases in a side-by-side configuration. A lamp and/or barcode scanner may be disposed on the housing for ease of CD selection. The housing base preferably is detached during shipping to permit transporting the rack in a smaller volume container. User control can include voice commands to direct loop rotation and speed.

Abstract: A high capacity motorized rack holds a plurality of jewel case enclosed CDs in holders flexibly inter-connectable with each other to form a rotatable continuous loop. The loop is rotatably retained within a vertical rack housing and is driven by a motor, disposed within the housing, under user control such that the loop is rotated until a desired CD is moved to the top region of the belt. A rack may hold two or more such loops of inter-connected holders. In one embodiment a holder retains a single jewel case, and comprises two independent loops that are rotated with a single motor. A preferred embodiment employs inter-connectable holders that each retain two jewel cases in a side-by-side configuration. A lamp and/or barcode scanner may be disposed on the housing for ease of CD selection. The housing base preferably is detached during shipping to permit transporting the rack in a smaller volume container. User control can include voice commands to direct loop rotation and speed.

Abstract: A high capacity motorized rack holds a plurality of jewel case enclosed CDs in holders flexibly inter-connectable with each other to form a rotatable continuous loop. The loop is rotatably retained within a vertical rack housing and is driven by a motor, disposed within the housing, under user control such that the loop is rotated until a desired CD is moved to the top region of the belt. A rack may hold two or more such loops of inter-connected holders. In one embodiment a holder retains a single jewel case, and comprises two independent loops that are rotated with a single motor. A preferred embodiment employs inter-connectable holders that each retain two jewel cases in a side-by-side configuration. A lamp and/or barcode scanner may be disposed on the housing for ease of CD selection. The housing base preferably is detached during shipping to permit transporting the rack in a smaller volume container. User control can include voice commands to direct loop rotation and speed.

Abstract: A high capacity motorized rack holds a plurality of jewel case enclosed CDs in holders flexibly inter-connectable with each other to form a rotatable continuous loop. The loop is rotatably retained within a vertical rack housing and is driven by a motor, disposed within the housing, under user control such that the loop is rotated until a desired CD is moved to the top region of the belt. A rack may hold two or more such loops of inter-connected holders. In one embodiment a holder retains a single jewel case, and comprises two independent loops that are rotated with a single motor. A lamp and/or barcode scanner may be disposed on the housing for ease of CD selection. The housing base preferably is detached during shipping to permit transporting the rack in a smaller volume container. User control can include voice commands to direct loop rotation and speed.

Abstract: A high capacity motorized rack holds a plurality of jewel case enclosed CDs in holders flexibly inter-connectable with each other to form a rotatable continuous loop. The loop is rotatably retained within a vertical rack housing and is driven by a motor, disposed within the housing, under user control such that the loop is rotated until a desired CD is moved to the top region of the belt. A rack may hold two or more such loops of inter-connected holders. In one embodiment a holder retains a single jewel case, and comprises two independent loops that are rotated with a single motor. A preferred embodiment employs inter-connectable holders that each retain two jewel cases in a side-by-side configuration. A lamp and/or barcode scanner may be disposed on the housing for ease of CD selection. The housing base preferably is detached during shipping to permit transporting the rack in a smaller volume container. User control can include voice commands to direct loop rotation and speed.

Abstract: A motorized rack for holding the jewel cases or containers of CDs (or the CDs themselves) in a very compact manner includes a continuous loop formed of holders for the CD cases or other retainers which is driven by a pair of sprockets on which the holders are mounted for rotation. High density storage is provided by spacing the holders and their associated CD containers contiguously to one another and then removal is facilitated by allowing the holders and containers to fan out at the top the vertical tower for manual removal.

Abstract: A high capacity motorized rack holds a plurality of jewel case enclosed CDs in holders flexibly inter-connectable with each other to form a rotatable continuous loop. The loop is rotatably retained within a vertical rack housing and is driven by a motor, disposed within the housing, under user control such that the loop is rotated until a desired CD is moved to the top region of the belt. A rack may hold two or more such loops of interconnected holders. In one embodiment a holder retains a single jewel case, and comprises two independent loops that are rotated with a single motor. A preferred embodiment employs inter-connectable holders that each retain two jewel cases in a side-by-side configuration. A lamp and/or barcode scanner may be disposed on the housing for ease of CD selection. The housing base preferably is detached during shipping to permit transporting the rack in a smaller volume container. User control can include voice commands to direct loop rotation and speed.

Abstract: A high capacity motorized rack holds a plurality of jewel case enclosed CDs in holders flexibly inter-connectable with each other to form a rotatable continuous loop. The loop is rotatably retained within a vertical rack housing and is driven by a motor, disposed within the housing, under user control such that the loop is rotated until a desired CD is moved to the top region of the belt. A rack may hold two or more such loops of inter-connected holders. In one embodiment a holder retains a single jewel case, and comprises two independent loops that are rotated with a single motor. A preferred embodiment employs inter-connectable holders that each retain two jewel cases in a side-by-side configuration. A lamp and/or barcode scanner may be disposed on the housing for ease of CD selection. The housing base preferably is detached during shipping to permit transporting the rack in a smaller volume container. User control can include voice commands to direct loop rotation and speed.

Abstract: A motorized rack for holding the jewel cases or containers of CDs (or the CDs themselves) in a very compact manner includes a continuous loop formed of holders for the CD cases or other retainers which is driven by a pair of sprockets on which the holders are mounted for rotation. High density storage is provided by spacing the holders and their associated CD containers contiguously to one another and then removal is facilitated by allowing the holders and containers to fan out at the top the vertical tower for manual removal.