Abstract: Optical transmission systems of the present invention include optical protection systems, apparatuses, and methods that provide increased reliability in the system. The optical system generally includes an optical switch having distinct, cooperating dedicated and shared protection sections. The shared protection sections in a plurality of nodes can be configured to provide a protection net, in which a plurality of traffic demands, or working channels, are commonly protected as protection group using one protection channels supported by the protection net.

Abstract: Optical transmission systems of the present invention include optical protection systems, apparatuses, and methods that provide increased reliability in the system. The optical system generally includes an optical switch having distinct, cooperating dedicated and shared protection sections. The shared protection sections in a plurality of nodes can be configured to provide a protection net, in which a plurality of traffic demands, or working channels, are commonly protected as protection group using one protection channels supported by the protection net.

Abstract: Optical transmission systems of the present invention include optical protection systems, apparatuses, and methods that provide increased reliability in the system. The optical system generally includes an optical switch having distinct, cooperating dedicated and shared protection sections. The shared protection sections in a plurality of nodes can be configured to provide a protection net, in which a plurality of traffic demands, or working channels, are commonly protected as protection group using one protection channels supported by the protection net.

Abstract: Optical systems of the present invention include at least one optical amplifier configured to provide partitioned amplification over the range of signal wavelengths carrying information between optical signal processing nodes. The optical amplifier is configured to partition the gain provided to a plurality of wavelength groups such that the gain in a wavelength group is only partly interdependent on, or independent of, the gain in the other wavelength groups. The optical system is further configured to transmit information using working wavelengths and one or more protection wavelength in different wavelength groups. The information can be transmitted simultaneously to provide a single fiber 1+N type protection. Similarly, the information can be switched from the first wavelength to the second wavelength upon a failure to provide single fiber M:N type protection.

Abstract: The present invention provides a device for performing wavelength add/drop multiplexing utilizing micromachined free-rotating switch mirrors. The free-space nature of the switch mirrors allow use of the front and back sides of the mirrors for reflecting signals. According to one embodiment of the present invention a WADM is provided in which micromachined switch mirrors are arranged in a polygonal (e.g., hexagonal) geometry, which allows full connectivity. According to one embodiment a WADM is provided for deployment in a unidirectional two-fiber optical network including service and protection fiber routes. According to this embodiment the WADM includes a first input port for receiving a WDM signal from the service fiber route and a second input port for receiving a WDM signal from the protection fiber route.

Abstract: The present invention provides a device and method for achieving protection in a free-space micromachined optical switching fabric. The present invention provides two protection schemes for mirror failures, which utilize either existing switching mirrors or additional integrated mirrors without extra fabrication effort or performance-degradation of the switch fabric. A switch fabric includes a plurality of micromachined free-rotating mirrors arranged in a rectilinear matrix configuration. The mirrors are reflective on both front and back sides. According to one embodiment of the present invention, upon the detection of a failed mirror associated with a transmission between an input and an output, a transmission path is determined that includes a backside of a pivot mirror. A transmission path is then established between the input and the output that utilizes the backside of the pivot mirror.

Abstract: Wavelength division multiplexing, spatial switching cross-connect structures which may be deployed as intermediate nodes of an all optical network to route any input channel on any source fiber to any destination fiber at any available wavelength to achieve full connectivity between the nodes of the network. The non-blocking cross-connect structure comprises a wavelength division demultiplexer for receiving multiple wavelength channels from each source fiber and for separating received channels into N wavelengths so that the wavelengths are organized according to a corresponding fiber of origin, a nonblocking optical structure for spatially and independently rearranging the received wavelengths so that wavelengths having a common destination fiber are grouped together, and a wavelength division multiplexer for multiplexing together wavelengths having the same destination fiber.

Abstract: A radiotelephone wrist device includes a case having a transceiver and a strap attached to the case for fastening the device to a user's wrist. The strap has a top layer and a bottom layer. The top layer is attached to the bottom layer by a pivot mechanism which facilitates rotating at least a portion of the top layer with respect to the bottom layer. A microphone is located on the strap and electrically connected to the transceiver. A speaker is located at an end of the top layer of the strap and electrically connected to the transceiver. A first antenna is located in the bottom layer of the strap. A second antenna is located in the rotatable portion of the top layer of the strap.

Abstract: There is disclosed the architecture for an all optic network which employs a three level hierarchy using wavelength vision multiplexing. At the lowest level of the hierarchy are Level-0 all optical networks. The Level-0 networks are "local" broadcast networks each of which supports a plurality of access ports and each access port can hear all the local traffic transmitted by all other access ports in the same Level-0 network. Each Level-0 network shares wavelengths internally, but there is extensive reuse of wavelengths among different Level-0 networks. The next higher level, which is the intermediate level, Level-1, is essentially a wavelength router coupled with one or more of the Level-0 networks to provide a wavelength path to one or more directly connect Level-0 networks or, in combination with a Level-2 network, a light path to one or more Level-0 network outside itself.

Abstract: In an optical arrangement for amplifying an input lightwave signal by a predetermined amount to a desired output level, an optical amplifier is connected to a loss element. The optical amplifier is pumped by an amount exceeding a nominal amount wherein the nominal amount is the amount of pumping needed to attain the desired output level at the optical amplifier output. By attenuating the signal output from the optical amplifier, the loss element generates an output signal from the optical arrangement at the desired output level. This optical arrangement is characterized by an improved noise performance (noise figure) over standard optical amplifiers.

Abstract: In a wireless local area network, predetermined interference-detection sequences of signal points, known at both the transmitter and receiver, are transmitted over a plurality of hopping frequencies along with a sequence of data signal points taken from a modulated code exhibiting built-in diversity. In the receiver, the extent to which there are errors in the received interference-detection signal points is used as a mechanism for identifying the likely occurrence of strong interference. If there are no, or few, errors, decoding proceeds normally. However, if the number of errors is above a predetermined threshold, it is assumed that the transmitted signal was subjected to significant interference and an erasure is declared. This is used as "side" information by the decoder to improve its ability to accurately recover data in the presence of interference.

Abstract: An optical equalization receiver for countering the effects of delay distortion is realized by utilizing dynamically controllable Fabry-Perot etalon structures. By dynamically adjusting the frequency response of an etalon that is in a feedback loop configuration, the associated delay characteristic of the etalon may be used to counter the effects of delay distortion, thereby allowing higher transmission rates and transmission distances to be achieved. In one exemplary embodiment, an optical receiver comprising a reflective Fabry-Perot etalon and a piezoelectric transducer is used in a feedback loop configuration wherein a feedback control circuit monitors an output signal from the etalon for generating a control signal representing the amount of delay needed to compensate for distortion in an optical signal incident on the etalon.

Abstract: An improved optical amplifier is disclosed with reduced signal-induced, deleterious, nonlinear effects, such as crosstalk, inter-modulation distortion and other saturation-induced effects. The invention comprises an optical amplifier with a compensation loop, such as a feed-forward or a feed-backward loop. This loop provides additional pumping to the gain medium associated with the amplifier, thereby compensating for what would otherwise be deleterious, signal-induced variations in the gain of the optical amplifier.

Abstract: The present invention relates to a N.times.N single-mode optical coupler employing evanescent wave coupling between mutually adjacent optical waveguides sufficiently close to one another to facilitate coupling among all the waveguides. An optical signal of a narrow frequency band, e.g. appreciably less than 100 gigahertz, introduced to an input port of one of the waveguides is found to be nonuniformly distributed among the output ports of the coupler. A first embodiment uses the nonuniform distributions of narrowband optical signals to the output ports of the coupler to enable the present invention to be used as essentially a selective switching device. A second embodiment introduces one or more predetermined broadband optical signals to one or more input ports of the coupler to produce an appreciably uniform power distribution among the output ports of the coupler.

Abstract: A star coupler for a single-mode-fiber optical local area network which reduces the amount of fiber required by a factor of two and diminishes the number of components by one-half. This savings in fiber and components is effected by "reflecting" signals which appear at various locations of the network back toward the input ports. The arrangement forms a broadcast-type of local area network where a message transmitted by any user can be received by all users.

Abstract: The present invention relates to an FET power amplifier whose transfer characteristics are parabolic or have a pronounced parabolic region. The amplifier is capable of linear operation due to a drain electrode bias network which includes a pair of serially connected quarter-wave transmission line sections connected at one end thereof to the drain electrode, and the interconnection point of the two quarter-wave transmission line sections is connected to both (a) a bias supply which causes the FET to operate over at least a portion of the parabolic region and (b) to a means which prevents envelope-induced drain bias voltage variations and presents a short-circuit to the drain terminal at a second harmonic of the input signal.

Abstract: The present invention relates to a linear, class A FET amplifier circuit capable of providing linear amplifier of input signals with a time-varying envelope function. An envelope detector (12) is responsive to an input signal (v.sub.i (t)) for extracting the envelope signal (V.sub.i (t)) therefrom. A gate controller (16) subsequently adds the envelope signal to a predetermined gate bias voltage (E.sub.G) and applies the sum (E.sub.G (t)) as the "d-c" gate input to the FET amplifier (14). Therefore, the gate bias voltage is dynamically controlled by the envelope of the input signal, resulting in a significant improvement in the power-added efficiency (.eta..sub.added) over prior art class A FET amplifiers.

Abstract: The present invention relates to an N-way non-hybrid power combiner arrangement for microwave amplifiers. In operation, sensing means (19.sub.1, 19.sub.2, . . . , 19.sub.N) are coupled in a one-to-one relationship with the individual amplifiers (12.sub.1, 12.sub.2, . . . , 12.sub.N) to monitor amplifier performance and sense amplifier failure. In one embodiment of the present invention, shorting devices (20.sub.1, 20.sub.2, . . . , 20.sub.N) are disposed adjacent to the outputs of the individual amplifiers and coupled to the associated sensing means in a one-to-one relationship. In an alternative embodiment, open-circuiting devices (30.sub.1, 30.sub.2, . . . , 30.sub.N) are disposed at a predetermined distance from the amplifier outputs along the transmission lines (24.sub.1, 24.sub.2, . . . , 24.sub.N) and coupled to their respective sensing means.

Abstract: The present invention relates to a class of adjustable microstrip and stripline tuners. An exemplary tuner comprises a pair of tuning elements, where each tuning element further comprises a pair of parallel spaced-apart conductive strips of equal length and at least one movable bridging wire connecting the two strips. The movement of the bridging wire will vary the output impedance of the tuning element, and a complementary arrangement of a pair of tuning elements will form a tuner capable of matching any impedance falling within the Smith chart.