Siemens Aktiengesellschaft

Siemens Aktiengesell Schaft

Mathias Bischoff

Joachim Charzinski

Bernd Stilling

J&uuml;rgen Burgmeier

Dominic Axel Schupke

An optical communication network, an optical information transmission method and network node devices for use in an optical communication network, in which optical signals are exchanged via a first data link between a first network node device and a second network node device with interposition of a number of further interconnected network node devices, in which, after a disturbance on the first data link, a third network node device sends a signaling signal to a fourth network node device connected to the third network node device for setting up a second data link which acts at least partially as a standby for the first data link, which signaling signal contains a parameter (NRR, n) determined by the third network node device on the basis of which it is determined whether the fourth network node device is responsible for setting up the second data link or not.

Device and method for restoring connections in automatically switchable optical networks

The access node for optical networks with variable access wavelengths can be connected to user devices via respective first optical conductors and can be connected to the optical network via second optical conductors. The novel access node has light sources which emit at the wavelengths defined in the optical network. The light of the light sources can be modulated in the user devices. This prevents that in each case a light source which must be able to emit light of a different wavelength in a dynamic optical network or the wavelengths of which must be subsequently converted must be arranged in the individual user devices. In addition, it also prevents circuit boards leading to a high logistical expenditure having to be provided in the user devices. Accordingly, according to the invention, it is possible to construct the individual user devices without light sources. This considerably simplifies their construction and the method of use.

Access node for optical networks with variable-access wavelengths, user device for connection to such an access node, method for feeding a number of signals from a number of users into an optical network and using an access node and at least one user device for carrying out such a method

In order to monitor the signal quality in transparent optical transmission paths, the signal is sampled asynchronously, the distribution of the sample results in recorded and a signal quality parameter is formed, in that only those flanks which are located away from the maxima of the distribution are evaluated.

Method for monitoring the signal quality in transparent optical networks

A method for transmitting an additional data signal and a useful data signal, via optical connections, in an optical network, wherein the additional data signal is transmitted on the same channel as the useful data channel and converted into code sequences which are, in turn, superimposed on the useful data signal with a small amplitude. At the reception end, the additional data signal is recovered by cross-correlation.

Method for transmitting an additional data signal and a useful data signal in an optical network

A first optical signal is generated via a first laser diode on which a low-frequency signal of small amplitude is superimposed. The first optical signal is conducted through a gas-filled galvanotron and the low-frequency signal emerges at two terminals of the galvanotron. The low-frequency signal is fed to a synchronous detector and emits a first output signal for generating a control signal. The first laser diode is controlled via the control signal and the low-frequency signal, the first optical signal passes through the gas-filled galvanotron and represents a first frequency reference signal. A second optical signal is generated via a second laser diode and emits the second optical signal via a first fiber-optic directing coupler to a signal output and to a second fiber-optic directing coupler. A microwave signal is generated by combining the second optical signal and the first frequency reference signal via an opto-electronic converter. The microwave signal is fed to a frequency control loop subsequent to opto-electric conversion and mixes the microwave signal with a quartz-based frequency synthesizer signal for generating a difference low-frequency signal. A phase comparison is provided of a signal of the quartz oscillator and the difference low-frequency signal resulting in a second output signal for generating a control signal for the second laser diode.

Method for generating an optical frequency reference signal

In a wavelength-division multiplex switching network having input wavelength-division multiplex (&lgr;) demultiplexers followed by a space switch and output wavelength-division multiplex multiplexers, wavelength-individual space switching matrices which are in each case connected, at the input end, via a number, corresponding to the number of wavelength-division multiplex multiplexers, of link lines to corresponding outputs of the space switch, lead to the wavelength-division multiplex multiplexers, some of the link lines leading to a space switching matrix directly connect the space switch to the respective space switching matrix and an adjustable wavelength converter is in each case inserted into the remaining link lines.

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Munich, Germany

Mathias Bischoff