1011 results about "Optical link" patented technology

A dual-band antenna is provided that combines two normally disparate communications modes into a single compact aperture minimizing overall mass and volume, while maintaining high performance efficiency and reciprocity of each individual mode. The antenna is compatible with both optical (near-IR/visible) and RF (microwave/millimeter-wave) transceiver subsystems for high bandwidth communications, applicable primarily to long- to extremely long-range (space-to-ground) link distances. The optical link provides high bandwidth while the RF provides a lower data-rate weather backup, accommodation for traditional navigation techniques, and assistance in cueing the extremely tight optical beam by matching the RF beamwidth to an optical fine-steering mechanism field-of-regard. The configuration is built around a near-diffraction-limited high performance primary mirror shared by both a direct-fed RF antenna design and a Cassegrain optical telescope. Material properties are exploited to combine the optical secondary mirror with the RF feed structure, providing a collimated optical beam interface at the antenna vertex.

A method of providing network services is described. The network includes a number of nodes, each one of which is coupled to at least one other of the nodes by at least one of a number of optical links. The network is preferably capable of supporting a number of virtual circuits. The method begins with the receiving of a request for a virtual circuit between a first node and a second node of the network. Preferably, the request specifies a quality of service of the virtual circuit. Next, the availability of network resources for supporting a virtual circuit at the requested quality of service is determined. Assuming sufficient network resources are available for support of the virtual circuit, the request is then serviced by provisioning (and maintaining) the requested virtual circuit. Servicing the request preferably includes actions such as provisioning, maintaining, and restoring the virtual circuit, using the requested parameters.

A distributed antenna system includes a master unit configured to receive at least one set of multiple input multiple output (MIMO) channel signals from at least one signal source. The master unit is configured to frequency convert at least one of the MIMO channel signals to a different frequency from an original frequency, and combine the MIMO channel signals for transmission. An optical link couples the master unit with a remote for transceiving the MIMO channel signals. The remote unit is configured to receive the MIMO channel signals to be transmitted over antennas and includes an extension port configured to transceive at least one of the MIMO channel signals. An extension unit is coupled to the remote unit and is configured to frequency convert at least one of the first and second MIMO channel signals from the different frequency back to an original frequency for transmission over an antenna.

A transceiver architecture for wireless base stations wherein a broadband radio frequency signal is carried between at least one tower-mounted unit and a ground-based unit via optical fibers, or other non-distortive media, in either digital or analog format. Each tower-mounted unit (for both reception and transmission) has an antenna, analog amplifier and an electro-optical converter. The ground unit has ultrafast data converters and digital frequency translators, as well as signal linearizers, to compensate for nonlinear distortion in the amplifiers and optical links in both directions. In one embodiment of the invention, at least one of the digital data converters, frequency translators, and linearizers includes superconducting elements mounted on a cryocooler.

In wireless local area networks (WLANS) with a large number of access points, the provisioning and capacity of the WLAN backhaul network connecting the access points to a core network becomes a major issue in network design. Some network services call for access points to be deployed in high densities in a wide range of environments, including outdoor environments. Traditional backhaul networks using fixed media such as twisted pair cable, coax cable, or optical fiber, in many instances are not physically or economically viable. Disclosed are method and apparatus for connecting access points via a mesh network using free-space optical links. The free-space optical links may be supplemented with mm-wave links to increase reliability and capacity.

A protective case for enveloping a smartphone incorporates at least one sensor for detecting stimuli arriving from outside of the smartphone. The case and the phone form an integral unit that possess extra features than the phone alone wouldn't have. The sensor is supplemented by a signal conditioning and interface electronic circuit for communicating the sensed information to the smartphone inner processor. The communication is via a wired connection to the smartphone's connector or wireless via a radio waves or optical link. For expanding versatility of the smartphone, the sensors may be adapted for detecting non-contact temperature, light, ultrasonic, smell, material composition, human vital signs, and other signals.

Apparatus and methods for transferring audio between a headset and electronic equipment over an optical link. The apparatus includes an electro-optical interface for electrically connecting to the electronic equipment, an optical link, and an electro-optical headset. Audio from the electronic equipment modulates a light source in the electro-optical interface. A modulated light signal is transmitted through the optical link to the electro-optical headset where it is demodulated and reproduced as the original audio in the ear of a user wearing the headset. Also, another audio from the user's mouth produces another modulated light signal in the electro-optical headset. The other modulated light signal is transmitted through the optical link to the electro-optical interface where it is demodulated to provide the other audio to the electronic equipment. The non-electrical optical link may improve audible communications between the electronic equipment and the headset in radio-frequency noisy environments. Also, the non-electrical optical link may prevent coupling with an aerial of the electronic equipment and improve radio propagation.

A method of providing network services is described. The network includes a number of nodes, each one of which is coupled to at least one other of the nodes by at least one of a number of optical links. The network is preferably capable of supporting a number of virtual circuits. The method begins with the receiving of a request for a virtual circuit between a first node and a second node of the network. Preferably, the request specifies a quality of service of the virtual circuit. Next, the availability of network resources for supporting a virtual circuit at the requested quality of service is determined. Assuming sufficient network resources are available for support of the virtual circuit, the request is then serviced by provisioning (and maintaining) the requested virtual circuit. Servicing the request preferably includes actions such as provisioning, maintaining, and restoring the virtual circuit, using the requested parameters.

Nonlinearity-induced signal distortions are compensated by processing an input communications signal, in the electrical domain prior to Electrical-to-optical conversion and transmission through an optical link of a communications system. According to the invention, a compensation operator is determined that substantially mitigates the nonlinearity-induced signal distortions imparted to an optical signal traversing the communications system. The input communications signal is then input to the compensation operator to generate a predistorted electrical signal. This predistorted electrical signal is then used to modulate an optical source to generate a corresponding predistorted optical signal for transmission through the optical communications system. With this arrangement, arbitrary nonlinearity-induced signal distortions imparted by the optical link can be compensated in such a manner that a comparatively undistorted optical signal is obtained at the receiving end of the optical link.

An optical fiber ring network includes a plurality of interconnected nodes, each pair of neighboring nodes being interconnected by a pair of optical links. Using coarse wavelength division multiplexing, data is transmitted in both directions over each link, using a first wavelength λ1 to transmit data in a first direction over the link and a second wavelength λ2 to transmit data in a second, opposite direction over the link. The two wavelengths λ1 and λ2 differ by at least 10 nm. Each of the data streams transmitted over the optical link has a bandwidth of at least 2.5 Gbps. Further, each data stream has at least two logical streams embedded therein. A link multiplexer at each node of the network includes one or more link cards for coupling the link multiplexer to client devices, and one or more multiplexer units for coupling the link multiplexer to the optical links. Each link card includes frame buffers capable of storing numerous Fiber Channel frames that are being transmitted to and from the client device(s) coupled to that link card. The link card also includes flow control logic for pre-filling the frame buffers with frames of data before the receiving client devices send flow control messages to request their transmission. The combined effect of the frame buffers and flow control logic is that the full bandwidth of the links can be utilized even when the network nodes are very far apart and the client devices have small input data buffers.

A system establishes a path for distributing data through an optical network (115). The system includes an optical switch (205a) and a data distribution endpoint (105a). The optical switch (205a) establishes a first encryption key distribution path through the optical network (115), the first encryption key distribution path including multiple optical switches and optical links. The data distribution endpoint (105a) determines whether eavesdropping has occurred on the first encryption key distribution path using quantum cryptography. The optical switch (205a) further establishes a second data distribution path through the optical network (115) responsive to the eavesdropping determination. The second encryption key distribution path includes multiple optical switches and optical links.

A first node (205) in a network includes a non-optical transceiver (415) and an optical subsystem (410). The non-optical transceiver (415) sends a request message to establish an optical link from the first node (205) to a second node via electrical signals over an electrically transmissive medium. The optical subsystem (410) establishes an optical link between the first node and the second node based on the receipt of the request granted message and transmits data between the first node and the second node via optical signals over the optical link.

A method and system to support secure booting and configuration. The mechanism employs an optical link comprising a quantum channel that is used to send data encoded as quantum bits (qubits) via respective photons. Qubits encoded using a first random basis at the client and are sent to the boot server, which processes the qubits using a second random basis to extract the encoded data. A public channel is used to send data indicative of the second random basis to the client. A symmetric quantum key is then derived a both the client and the boot server using a comparison of the random basis' and the original and extracted data. The scheme enables the presence of an eavesdropper to be detected on the quantum channel. A DHCP message exchange is employed to obtain a network address, and, optionally, be provided with a network address for one or more boot servers. A boot image request is made to the boot server by the client, and a subsequent boot image is downloaded via a secure channel facilitated by the symmetric quantum key.

The present invention discloses a transmitter and receiver for optical communications system, which provide compensation of the optical link nonlinearity. M-PSK modulating is used for data embedding in an optical signal in each WDM channel using orthogonal frequency division multiplexing (OFDM) technique. At the receiver side electrical output signals from a coherent optical receiver are processed digitally with the link nonlinearity compensation. It is followed by the signal conversion into frequency domain and information recovery from each subcarrier of the OFDM signal. At the transmitter side an OFDM encoder provides a correction of I and Q components of a M-PSK modulator driving signal to compensate the link nonlinearity prior to sending the optical signal to the receiver.

A SONET network terminated by routers includes working paths and backup paths. The routers pre-establishes in their link state data bases the links in both for both the working and backup paths. However, the links involved in the backup paths are given higher costs, then the links working paths, that the routers select only the links in the working path. If there is a failure in a link in a working path, an APS arrangement provides rapid switchover of the optical links so as to substitute one or more links in the corresponding backup path. This is accomplished by changing the relative costs of the working and backup links involved, so that the routers select the backup links for their routing tables.

A system is provided for implementing PCI Express protocol signals over an optical link. A transmission circuit is used to provide an electrical-to-optical conversion, a receiving circuit provides an optical-to-electrical conversion, and a sideband circuit is used to provide and receive control information.

A method and system for generating and transmitting optical signals with only one sideband. Single-sideband optical signal transmission reduces the signal impairment effects associated with dispersion. Such transmission also increases the spectral efficiency of optical transmission systems. Single-sideband modulation also makes possible electrical compensation for optical link dispersion during transmission. Single-sideband modulation is generated using the modulating data signal and its Hilbert transform, which is approximated by a tapped-delay time filter. Line coding is used to remove the low-frequency content in the modulating data signal, avoiding the inefficiencies of tapped-delay-line filter approximated Hilbert transformers at low frequencies. Line coding can also help optical single side band signal generation and transmission using a simple optical filter instead of Hilbert transformers.

An optical version of USB is provided to enable PDAs and digital cameras to download data and media files to remote network servers. The PDA is plugged into an optical transceiver that communicates with a complementary transceiver located in a network terminal (for example a payphone) that is in communication with the network server.

A forward error correction (FEC) communication device that includes a transmitter photonic integrated circuit (TxPIC) or a receiver photonic integrated circuit (RxPIC) and a FEC device for FEC coding at least one channel with a first error rate and at least one additional channel with a second error rate, wherein the first error rate is greater than the second error rate. The TxPIC chip is a monolithic multi-channel chip having an array of modulated sources integrated on the chip, each operating at a different wavelength, wherein at least one of the modulated sources is modulated with a respective FEC encoded signal. The TxPIC also includes an integrated wavelength selective combiner for combining the channels for transport over an optical link.

A fiber optic system includes a transmitter configured to utilize a plurality of modulation formats and a receiver communicatively coupled to the transmitter and configured to utilize a plurality of modulation formats. The transmitter and the receiver are cooperatively configured to set a modulation format of the plurality of modulation formats based upon optical signal-to-noise ratio associated therewith. A flexible bandwidth adaptation method includes monitoring at least one aspect of an optical link at a network element, responsive to the at least one aspect, computing a new modulation scheme for the optical link, and, if a solution is found for the new modulation scheme, changing to the new modulation format.

An optical transmission network includes an optical transmitter photonic integrated circuit (TxPIC) chip, utilized in an optical transmitter and has a plurality of monolithic modulated sources integrated for multiple signal channels on the same semiconductor chip is provided with channel equalization at the optical receiver side of the network that permits one or more such integrated modulated sources in the TxPIC chip to be out of specification thereby increasing the chip yield and reducing manufacturing costs in the deployment of such TxPIC chips. FEC error counts at the FEC decoder on the optical receiver side of the network includes counters that accumulate a plurality of bit pattern-dependent error counts based on different N-bit patterns in the received data bit stream. The accumulated counts of different N-bit patterns are utilized to provide for corrections to threshold and phase relative to the bit eye pattern as well as provided for weight coefficients for the optical receiver equalization system. The deployment of this type of equalization in a digital OEO REGEN network substantially reduces, if not eliminates, the need for dispersion compensating fiber (DCF) or EDFAs in an optical link of the network and enhances the optical receiver tolerance to chromatic dispersion (CD) so that an increase in chip yield is realized for TxPIC chips not operating with acceptable operational parameters, particularly with a desired frequency chirp parameter relative to at least one of the TxPIC modulated sources.

A synchronization system in accordance with the principles of the invention includes a central synchronizing management unit, at least one synchronization distribution unit, and at least one network element. Each synchronization distribution unit receives synchronization and management information from the central synchronization management unit. This information may be transmitted directly from the central synchronization management unit, or it may be transmitted though another synchronization distribution unit in a group of a daisy-chained synchronization distribution units. The daisy-chained arrangement employs both active and passive optical paths. The central synchronizing management unit may query any synchronization distribution unit within the system to obtain performance statistics. Additionally, the central synchronizing management unit may detect faults within the system by setting performance monitoring thresholds and interrogating a synchronization distribution unit to determine whether a threshold has been exceeded. The synchronization distribution units are physically located in close proximity to the network elements they serve. Additionally, the management and synchronization information exchanged between the central synchronization unit and a synchronization distribution unit is carried over a bidirectional optical link.