Abstract: A system and method for wireless data transfer between a computer and a telephone line using a remote media interface (RMI). The computer bidirectionally transfers the data to the RMI using an infrared (IR) signal. The RMI acts as an interface between the computer and the telephone line. The wireless data transfer system of the present invention includes an IR transceiver housed on the computer and an IR transceiver housed on the RMI. The RMI includes a data access arrangement (DAA) for converting the data received from the computer into a signal suitable for transmission over the telephone line and vice versa. The RMI also includes an external data interface connected to the telephone line that receives and transmits the signal over the telephone line. A soft modem is installed on the computer whereby at least part of the soft modem uses software to perform the function of a digital signal processor.

Abstract: In the transmitting node of an optical transmission system using wavelength multiplexing and including several channels the information content of each channel is transmitted onto its own wavelength (&lgr;1, &lgr;2, &lgr;3, &lgr;4) by modulating the laser transmitter producing the wavelength in question. The obtained optical signals are combined onto the same optical fibre. In the receiving node the sum signal is separated into different wavelengths by using a wavelength-selective optical separation component, whereby a predetermined wavelength and thus a channel is obtained from each output port of the separation component. In accordance with the invention, instead of using optical or electrical cross-connectors for re-routing a certain signal content to another destination, that transmission wavelength on which the signal content is transmitted is in fact changed at the signal transmission end.

Abstract: A method of optical pulse propagation via a dispersive optical fibre, the method comprising the steps of: launching the optical pulses into the fibre at a pulse intensity sufficient to provide non-linear dispersion compensation during propagation through a first portion of the fibre; and providing a counter-chirping device to substantially compensate for the dispersion of a remaining, second portion of the fibre.

Abstract: A wavelength division multiplexing transmission device includes a multiplexer part which multiplexes a plurality of first signals having a first bit rate and different wavelengths into a second signal having a second bit rate higher than the first bit rate and inserts wavelength data information concerning the different wavelengths into the second signal.

Abstract: An optical serial link may be formed of an optical transceiver and a reflective wavelength coupler. The coupler may reflect light beams of different wavelengths using an elliptical reflector and a dispersive element.

Abstract: A method and apparatus for low cost upgrading on demand of an optical fiber communication system from a single communication channel at one frequency to two communication channel systems at two different frequencies.

Abstract: A fiber optic communications link having PMD characterization across multiple optical channels to identify PMD problems. The communications link has adaptive PMD controls employed along the optical link, whereby PMD phenomena detected by instruments, such as PMD compensators, are interpreted as being either attributable to perturbation of fiber characteristics at large, or by failure of PMD equipment along the link. The present invention avoids taking unnecessary control or maintenance actions upon PMD related controllers and compensators. PMD notifications from various PMD compensators are correlated to identify which portion of the link has undergone a change in polarization characteristics to further identify PMD related errors and problems.

Abstract: An optical identification system for identifying a vehicle. The system comprises a laser source for generating a transmitted beam and a reflector in optical communication therewith. The reflector is operative to reflect the transmitted beam to thereby generate a reflected beam. The system further includes a shutter in optical communication with the reflected beam and operative to modulate the polarization of the reflected beam with identification information thereby generating a modulated reflected beam. The optical identification system of the present invention further includes a detector in optical communication with the modulated reflected beam. The detector is operative to pass the modulated reflected beam and decode the identification information modulated thereon.

Abstract: In an optical space communication system, a remote controller is provided at an arbitrary position remote from an optical space communication apparatus. The optical space communication apparatus is provided with an interface device for exchanging status information of the operating apparatus, operation start setup/manipulation information or operating setup/manipulation information of the apparatus with the interface device. Communication between the remote controller and the interface device is made for a transmission light power, a transmission signal power, a reception light power, a reception signal power, a light beam transmission angle, a temperature of a predetermined portion in the apparatus, an angular error between the reception light and an optical axis of a light reception unit in the apparatus, a transmission light beam divergence angle or the like.

Abstract: A communications network has a plurality of nodes interconnected by an optical transmission medium. The transmission medium is capable of a carrying a plurality of wavelengths organized into bands. A filter at each node for drops a band associated therewith and passively forwards other bands through the transmission medium. A device is provided at each node for adding a band to the transmission medium. Communication can be established directly between a pair of nodes in the network sharing a common band without the active intervention of any intervening node. This allows the network to be protocol independent. Also, the low losses incurred by the passive filters permit relatively long path lengths without optical amplification.

Abstract: A compact bidirectional module for multichannel use includes at least one transmitter and at least one receiver combined in a transmission/reception unit installed in a common housing, and at least one further such transmission/reception unit or at least one additional transmission unit or one additional reception unit provided in the common housing. In one preferred embodiment of the present invention, the transmission/reception unit is constructed in accordance with a bidirectional transceiver module which is described in German Published, Non-Prosecuted Patent Application DE 93 120 733 A1 and is also referred to as a TO-BIDI module, and additional transmission or reception units are likewise constructed by using the TO construction. Thus, a compact module that combines the assemblies of the known BIDI module and those of the TO-BIDI module, with their characteristics is provided.

Abstract: A self-configuring distributed switch has agile core modules connected by a plurality of channels to a plurality of large capacity edge modules. A core module controller selects paths through an associated core module and reconfigures the paths in response to dynamic changes in data traffic loads. Switching latency in the core modules is masked so that the source edge modules need not disrupt data transmission during reconfiguration. Surplus capacity is provided in the core modules to facilitate reconfiguration. Connection release and connection setup policies increase occupancy variance among the space switches in each core module to further facilitate reconfiguration. The reconfiguration functions of the data switch modules and the core modules are coordinated to keep reconfiguration guard time minimized. The advantage is a high capacity, load-adaptive, self-configuring switch that can be geographically distributed to serve a large geographical area.

Abstract: In an optical transmission system, a multiplexer frequency-division-multiplexes a plurality of signals, and outputs the resultant signal to an FM modularor. The FM modulator converts the frequency-division-multiplexed signal into an FM modulated signal through frequency modulation using the frequency-division-multiplexed signal as an original signal. A frequency-divider converts the FM modulated signal into a frequency-divided FM modulated signal whose frequency is ½n (n is an integer of not less than 1) the frequency of the FM modulated signal. An optical modulator has a predetermined input-voltage vs. output-optical-power characteristic, and is biased at the minimum point (voltage) about the output optical power. The optical modulator modulates an unmodulated light fed from a light source with the applied frequency-divided FM modulated signal to produce an optical signal whose optical carrier component is suppressed, and sends the optical signal to an optical transmission line.

Abstract: A wavelength dispersion compensation apparatus is provided which requires only a small number of dispersion compensation fibers for compensating for the wavelength dispersion of a wavelength multiplex signal caused in the transmission optical fibers. The dispersion compensation fibers are used for transmitting individual light signals which composes a wavelength multiplex signal, in order to give a wavelength dispersion in the opposite direction, the absolute value of which is the same as the dispersion which will be caused in the light signals during transmitting in the transmission optical fibers. At the output ends of the dispersion compensation fibers, a pair of two light signals with specific wavelengths is extracted by the light branching means composed of fiber gratings FG11 and FG12 and so on. The light signals extracted by the light branching means are multiplexed by the arrayed waveguide AWG2 and supplied to the transmission optical fibers after amplified by the light amplifiers AMP1 to AMP8.

Abstract: An OPC generates a pump light having the wavelength &lgr;s with a power larger than a threshold for generating a nonlinear effect in an optical fiber for a main signal having the wavelengths &lgr;1 through &lgr;4 transmitted from an OS, and wavelength-multiplexes the generated light with the main signal. When the pump light induces a nonlinear effect, a signal light having the wavelengths &lgr;1′ through &lgr;4′ is generated symmetrically to a main signal having the wavelength &lgr;1 through &lgr;4 about the pump light on a wavelength axis. Thus, in a wavelength multiplexing system designed based on an eight-wave transmission, a signal light can function as a compensation light even when only four waves are used at the initialization of the system, thereby compensating for the characteristics of the system operations. Furthermore, the system is effective in cost because it simply requires an OPC for generating a pump light regardless of the number of compensation lights to be generated.

Abstract: In a mobile data terminal having an infrared communication capability, a battery capacity detection 4 determines whether or not the remaining capacity of a battery 5 is smaller than a preselected threshold value. If the remaining capacity is greater than the threshold value, a data processing 1 causes a drive current control 3 to feed a first preselected drive current to a light emitting device 21 included in an infrared communication function 2. If the remaining capacity is smaller than the threshold value, the data processing 1 causes the drive current control 3 to feed a second preselected drive current smaller than the first drive current to the light emitting device 21. As a result, when the remaining battery capacity is small, a distance which infrared rays reach is reduced in order to maintain the infrared communication capability. A decrease in the above distance is reported to the user of the data terminal via an output 8 for thereby insuring convenient use.

Abstract: An optical transmission system comprises a number of optical terminals connected by optical waveguides such as optical fibers. Nonlinear processes occurring within an optical transmission medium of the waveguide or within the optical terminals is detected by a monitor which outputs monitored data representative of the products of nonlinearity. The data is used to control the power of the optical signal such that power is regulated to avoid the onset of the nonlinear process. The data may also be used to indicate an alarm condition to an operator. A monitor for four wave mixing detection utilizes dither signals applied to respective frequency components of a wavelength division multiplexed signal, products of the four wave mixing process being detected in the monitor by correlation between a sample of a received optical signal and reference data representative of dither induced modulation in the four wave mixing product.

Abstract: The present invention provides a wavelength division multiplexed optical communication system with dynamically stabilized wavelength selectors. To accurately correlate the wavelength of a wavelength selector to the wavelength emitted by an optical transmission source, the present invention uses an optical detector and feedback loop to optimize the wavelength of an optical selection element in accordance with a wavelength of an incident optical channel. In one embodiment, the optical selection element is a Bragg grating associated with a grating wavelength controller, such as a temperature regulator or strain tuning system, to adjust the wavelength band of maximum reflectivity of the grating. The feedback loop communicates with the optical detector and the wavelength controller to modify the grating's reflection wavelength band in accordance with the wavelength of an incident optical channel.

Abstract: Disclosed is a binary optical transmission system for transmitting and receiving a target transmit data to be transmitted as a binary optical transmit data composed of luminous part and non-luminous part, wherein the target transmit data is transmitted and received by a coding to use a transmission code that the ratio of time of luminous part to time of non-luminous part in a time section longer than one cycle of a transmission clock used to transmit the target transmit data is less than 1.

Abstract: An optical carrier drop/add transmission system and method using a same optical carrier to both drop traffic from an optical network and to add traffic to the optical network. An optical carrier signal is received by a transceiver and is subsequently split into a first and second optical signal. The first optical signal can be converted into an electrical signal for processing by the subscriber (i.e., data out). The electrical signal corresponding to the first optical signal is additionally inverted by the transceiver. The inverted electrical signal is subsequently modulated with the second optical signal in order to create a nominally flat signal (“optical chalkboard”). The subscriber's data is then modulated onto the flat signal and sent across the optical network.