Azea Networks Limited Patent applications |
Patent application number | Title | Published |
20090269068 | TRANSMISSION SYSTEM - A wavelength division multiplexing transmission system, the system comprising: a plurality of channels at different wavelengths, each channel comprising a transmitter, a receiver, and one or more amplifiers, the system further comprising an encoder for encoding data with a coding, and; a decoder for decoding transmitted data; prioritizing means for prioritizing the data on each channel; monitoring means for monitoring directly or indirectly, raw (uncorrected) bit errors on each channel; power adjusting means for, varying the power on a channel in response to the bit error rate. | 10-29-2009 |
20090154919 | PULSED HIGH LOSS LOOP BACK SIGNALLING SCHEME - An optical transmission system comprises two optical fibbers carrying optical signal traffic between two terminals, and a plurality of optical repeaters coupled to the two fibers each repeater having a permanently connected passive high loss loop back circuit between the two fibers. One terminal includes a transmitter, which launches a pulsed supervisory signal on a dedicated supervisory wavelength into one optical fiber, and a receiver, which detects a portion of the supervisory signal looped back from each repeater in order to identify the existence and location of faults in the transmission system. The pulsed supervisory signal is of sufficiently short duration such that portions of the signal returned from each repeater do not overlap with one another and interference with the counter-propagating traffic is avoided by utilising a dedicated supervisory wavelength. Each return pulse is integrated sequentially by a single detector and processed by heterodyne reception and synchronous demodulation. | 06-18-2009 |
20090067783 | METHOD OF TUNING AN ADJUSTABLE DISPERSION COMPENSATOR - In the present invention, a method of controlling a tuneable optical dispersion compensating device to act on an optical signal by automatically controlling a plurality of dispersion control settings of the device in a systematic way using feedback, thereby to adapt freely the optical group delay for the optical signal within a predetermined wavelength range including that of the optical signal. | 03-12-2009 |
20090028555 | OPTICAL FILTER - An apparatus and method are provided for filtering an optical signal by wavelength. An initially polarised signal is passed through a DGD element effective to alter the polarisation state of the components of the signal according to wavelength. A polarisation filter (polariser) is then provided to attenuate light having given polarisation states from the signal, thereby attenuating the wavelengths associated with said polarisation states. The invention finds particularly utility in the domain of vestigial sideband filtering, allowing the bandwidth of signals within a wavelength division multiplexed system to be reduced without introducing the deleterious effects associated with conventional wavelength filters. | 01-29-2009 |