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7620318 Optical transceiver using heterodyne detection and a transmitted reference clock  
A heterodyne communication system uses coherent data modulation that is resistant to phase noise. In particular, a pilot tone and reference clock signal are transmitted along with the modulated...
7609974 Data transmission method and a system thereof  
An optical transmitter generates a transmission signal having a frame as a unit, the frame including a signal pilot signal with fixed amplitude and phase and two data bits to output the generated...
7583902 Module to module signaling utilizing amplitude modulation  
A method and apparatus configured to incorporate system data for transmission as part of or concurrently with network data. The system data may comprise communication system data for use in...
7580632 Method and apparatus for managing lightpaths in optically-routed networks  
A system and method that utilizes digital coding techniques to combine a high-rate data stream with a lower rate side data stream to produce a combined data stream in such a way that the side data...
7577358 Apparatus, system and method for optical packet switching using frequency header  
In the present invention, a single-frequency tone is used as addressing header for each optical packet. The frequency of the single-frequency tone is situated within the baseband of the digital...
7551858 Signal identification in optical communications networks  
Signals in an optical communications network, such as optical channels in an optical WDM network for example, are each identified by at least two low frequency dither tones with which the signal is...
7542678 Method and apparatus for a supervisory channel in a WDM fiber-optic communication system  
A method and apparatus for providing a supervisory channel in a wavelength division multiplexing (WDM) fiber-optic communication system uses a controlled optical attenuator disposed in an optical...
7539413 Observation apparatus and observation system  
The present invention discloses a submarine observation system in which a plurality of carrier lights assigned to each submarine observation equipment is transmitted from a land terminal apparatus...
7509047 System and method for subcarrier modulation in ISM band as supervisory channel  
Apparatus and method for transmitting a supervisory signal for optical network applications. The apparatus includes a subcarrier transmission system configured to receive a first supervisory signal...
7505685 Wavelength-division multiplex communication system and apparatus  
In the WDM communication system, in the absence of data to be transmitted on an optical channel, a pilot signal transmitting means transmits the channel-unique pilot signal data on the channel. A...
7457549 Sub signal modulation apparatus, sub signal demodulation apparatus, and sub signal modulation demodulation system  
A sub signal modulation apparatus, with the intention of stabilized transmission of a sub signal superimposed on main signal light irrespective of the intensity of the main signal light when used...
7418212 Electrical detection of optical symbols  
A system and method for detecting digital symbols carried in a received optical signal. The system comprises a functional element operative to receive a stream of samples of an electrical signal...
7412165 DCC loop plug  
Systems and methods are disclosed for testing the functionality of a synchronous optical network having a data communication channel therein. The system includes a testing device connected to a...
7412166 Pilot tones for optical signal wavelength identification and power measurement  
A method of optical communication includes providing a plurality of optical signals each associated with a distinct channel of a composite optical signal. A unique pilot tone signature is...
7389044 Method and system for providing a signature signal in an optical network in the event of loss of a client  
An optical network including multiple nodes is subject to intermittent faults that may raise alarms in the system. The invention focuses on an optical network based on the Any rate architecture. A...
7389045 Apparatus and method for monitoring and compensating an optical signal  
Optical communication apparatuses and optical communication methods are provided. According to one aspect, an optical communication apparatus includes a communication path configured to communicate...
7376350 Methods and apparatus for optical network management using pilot tones  
Methods and apparatus for managing an optical network using pilot tones are provided. One method includes selecting an optical path having a plurality of nodes from a database defining an expected...
7369763 Apparatus and method for monitoring an optical transmission line  
An apparatus and a method for monitoring an optical transmission line. An optical pilot signal of a predetermined duration is transmitted along said optical transmission line and a return signal is...
7356261 Optical wireless communications system  
An optical wireless communications system has a first optical wireless communications apparatus for transmitting a pilot beam and a second optical wireless communications apparatus for receiving...
7346279 Optical transceiver using heterodyne detection and a transmitted reference clock  
A heterodyne communication system uses coherent data modulation that is resistant to phase noise. In particular, a pilot tone and reference clock signal are transmitted along with the modulated...
7336903 Optical wireless transmission apparatus  
There is disclosed an optical wireless transmission apparatus in which a pilot light emitting section of a receiving/emitting section sends a pilot light in a wavelength region of 930 nm to 960 nm...
7321728 Optical waveform for use in a DWDM optical network and systems for generating and processing same  
An optical signal occupying one or more wavelengths. An optical data signal on each wavelength is modulated with a respective overhead (dither) signal, resulting in a respective dithered optical...
7321730 Method and apparatus for the transmission fault detection in an access network  
An optical network unit (ONU) interconnected by passive optical network (PON) equipment to an optical line terminal (OLT) is identified using secondary modulation of the optical carrier to impress...
7313326 Method to inject pilot tone into microcontroller-supervised DWDM transmitters  
The power of a digital signal such as an optical data stream is set via digital-to-analog converter having a reference input for connection to a DC reference signal. The pilot tone is injected into...
7302182 Methods and apparatus for sensing multiple wavelengths simultaneously in a single wavelength sensing device  
A method and system provide for sensing multiple wavelengths simultaneously in a single wavelength sensing device. The system may have a plurality of laser signals and a plurality of identifiable...
7302178 System and method for measuring power of optical signals carried over a fiber optic link  
A pilot tone generator receives optical energy from an optical communication medium carrying a plurality of optical signals. Each optical signal carries data modulated at a unique wavelength and...
7274872 System and method for subcarrier modulation as supervisory channel  
An apparatus and method for processing a supervisory signal for optical network applications. The apparatus includes a subcarrier transmission system configured to receive a first supervisory...
7272308 Method of WDM channel tagging and monitoring, and apparatus  
Provided is an optical apparatus and method wherein power transfer coefficients arising from SRS are measured at a designated co-location point and the power of dithers, which are impressed on the...
7263287 Method and apparatus for assessing performance of optical systems  
An apparatus for accelerating assessment of an optical transmission system using Bit Error Rate (BER) tests calculates Q-factors for at least two different extinction ratios from measured test BER...
7248798 Method and system for identification of channels in an optical network  
A method and system for identification of a channel in an optical network is provided. The channel is identified by the use of unique combinations of two or more low frequencies, or tones,...
7242863 Method and system for coordinating and utilizing channel power information in an optical communications network  
A method of coordinating channel power information in a wavelength division multiplexed (WDM) optical communication system is disclosed. The method determines weighting values for each channel of...
7231146 Optical communication system  
Communicating a signal includes receiving the signal at a primary device of a switching system, where the primary device is associated with a primary path along which the signal is propagating. A...
7190897 Optical channel operating parameters monitoring  
In a communication system, channel operating parameter carrier frequencies are located in the vicinity of data nulls in a data spectrum. The operating parameter carriers are summed with the data...
7187862 Method of locating faults in optical telecommunication networks  
A method, a system and a module are proposed for detecting and locating faults in an optical multi channel network composed of network nodes. The method includes assigning different sub-carrier...
7184660 Method and system for monitoring performance of optical network  
The invention describes methods and systems for monitoring the performance of an optical network by marking a group of optical signals with a set of identification tags which are unique to network...
7174097 Method and an apparatus for signal transmission  
A method and apparatus for transmitting a plurality of signals having different wavelengths through a length of optical cable which is caused to provide distributed gain by being subjected to Raman...
7174108 Transmission device and repeater  
A transmission system is provided that recognizes occurrence of a fault efficiently so that the workability and quality of service can be improved. An optical amplifier part amplifies an optical...
7158723 Channel identification in communications networks  
Channels in an optical WDM network are each identified by at least two dither tones with which the channel is modulated, the dither tones alternating with a predetermined periodicity so that at any...
7151897 Optical clock phase-locked loop circuit  
This optical clock phase-locked loop circuit includes an oscillator 12 , an optical coupler 2 , an optical cross-correlation detection device 3 that outputs light containing the correlating...
7142783 Method and system for identification of channels in an optical network  
A method and system for identification of a channel in an optical network is provided. The channel is identified by the use of unique combinations of two or more low frequencies, or tones,...
7139486 Method and apparatus for optical add/drop multiplexing in optical networks  
An optical add/drop multiplexing (OADM) apparatus and method are disclosed for detecting pilot tones, removing ghost tones, and re-inserting pilot tones on WDM signals in an optical network. The...
7139476 Distributed fiber sensor with detection and signal processing using polarization state management  
Polarization effects are managed to provide differential timing information for localizing disturbances affecting two or more counter-propagating light signals on one or more optical waveguides...
7130544 Optical repeating system and optical amplifying repeater control method  
An optical repeating system includes an optical transmitter and an optical amplifying repeater. The optical transmitter transmits a supervisory command and a control command to the optical...
7127165 Method and system for compensating for side effects of cross gain modulation in amplified optical networks  
A method and system for compensating for side effects of cross gain modulation in amplified optical networks, which allows reliable identification of expected and unexpected channels in the network...
7127182 Efficient optical transmission system  
A transmitter for optical communication systems includes a source of optical radiation, a source of complex non-information signals, and a modulator unit in communication with the source of optical...
7123832 Methods and apparatus for optical network management using pilot tones  
Methods and apparatus for managing an optical network using pilot tones are provided. One method includes generating a list of pilot tones contributed by a selected node to each of its target...
7120358 Optical packet routing network system based on optical label switching technique  
An optical communication equipment comprises shared optical sources 88 a– 88 d to be shared by communication nodes 100 a– 100 d , the wavelengths of optical signals 76 a– 76 d are...
7113705 Methods and apparatus for sensing multiple wavelengths simultaneously in a single wavelength sensing device  
A method and system provide for sensing multiple wavelengths simultaneously in a single wavelength sensing device. The system may have a plurality of laser signals and a plurality of identifiable...
7110673 Optical communication system  
In networks carrying existing optical traffic on one wavelength band in combination with wavelength division multiplexed traffic carried on a second wavelength band, there is a need to enable...
7062166 First and second derivative processing of wavelength multiplexed optical signals  
A system and method for optimizing performance characteristics of optical networks. The system and method exploits a wavelength-locked loop servo-control circuit and methodology that enables real...
Matches 1 - 50 out of 132 1 2 3 >