Telefonaktiebolaget Lm Ericsson (Publ)

Ericsson Ab

Marconi Communications Gmbh

Pierpaolo Ghiggino

Fabio Cavaliere

Stefan Dahlfort

Ernesto Ciaramella

Marco Presi

Alberto Bianchi

Roberto Proietti

Piergiorgio Sessarego

Giampiero Contestabile

Antony Thorley

Nicola Calabretta

Francesco Poletti

Giovanni Razzetta

Alfredo Palagi

The invention relates in general to a method, an apparatus and a unit for operating a Wavelength Division Multiplexing Access Network, and in particular to unbundling wavelengths in the network. Embodiments of the invention disclose monitoring a plurality of wavelengths of the Wavelength Division Multiplexing Access Networkto determine at least one available wavelength that is free for use. The transmitter then automatically transmits data to at least one user devicevia at least one available wavelength.

Apparatus and method for operating a wavelength division multiplexing access network

An optical network terminal (ONT) for use in an optical access network and comprising: an optical transceiver arranged to communicate with an optical line terminal using a wavelength which is modulated to carry sub-channels; a second transceiver arranged to communicate with a number of subscriber equipment using respective subscriber equipment channels; the ONT arranged to automatically map each subscriber equipment channel to a respective sub-channel of the wavelength without using an address associated with the respective subscriber equipment.

Optical access network and nodes

An optical network includes a first passive optical network optical line terminal, coupled to a first port of a first optical filter arrangement, and a second passive optical network optical line terminal, coupled to a second port of the first optical filter arrangement. An optical coupler is connected between the second passive optical network line terminal and the second port of the first optical filter arrangement. A passive optical distribution node is coupled to a third port of the first optical filter arrangement.

Passive optical network with plural optical line terminals

An optical PON network comprises a central office which generates N DPSK modulated optical signals, where N is an integer greater than 1, an optical coupling which connects the N signals to at least one optical fiber, a passive distribution node located remotely from the central office which has at least one input port that is coupled to the fiber and a plurality of output ports, the node being arranged to transmit a first wavelength of the N signals to at least one of its output ports, and at least one optical network unit connected through a respective optical fiber to the first output port of the passive distribution node. The passive distribution node comprises an arrayed waveguide grating which provides a passive optical connection between its input port and the first output port and which for that connection functions as a bandpass filter having a profile and bandwidth selected such that the DPSK optical signal passed to the input node is converted to an intensity modulated signal at the output port.

Optical PON network using passive DPSK demodulation

A ringed optical transmission system comprises along the ring rare earth doped fiber amplifiers. The system has a gain peak with a &#x3bb;wavelength outside the &#x3bb;-&#x3bb;band of the channels transmitted along the ring, the wavelength corresponding to an ASE emission peak of the amplifiers in the ring. In this manner a lasing peak forming a gain stabilization signal is produced.

Amplified optical ring transmission system

In an optical data transmission system, high frequency pulsed optical signals are transmitted along an optical fiber. These pulses are attenuated and distorted by transmission over long optical fibers making detection of data difficult at the receiving end. The allowable pulse profile is determined by an eye diagram which is non-symmetrical with respect to logic 1 and 0 levels. By positioning the eye diagram closer to the logic 0 level, detection in the presence of noise introduced during transmission of the optical pulses, can be significantly improved.

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Leamington Spa, United Kingdom

Pierpaolo Ghiggino