Abstract:
An optical WDM transmission system including a plurality of first optical transceivers at a first end of an optical WDM transmission link, each including a tunable optical transmitter being adapted to create a first digital optical channel signal within the bandwidths of a set of first optical channels of the system according to tuning control information. The first channels are multiplexed in to a first WDM signal and supplied at the first end of the WDM link. Second optical transceivers at a second end link each include a transmitter adapted to create a second digital optical channel signal within a channel bandwidth of a second set of optical channels of the system. The second channels are multiplexed into a second WDM signal for transmission to the first transceivers, and demultiplexing there. A central tuning device creates the tuning control information for the first optical transceivers by tapping off an optical WDM detection signal from the first signal, extracting tuning status information from the optical WDM detection signal and determining tuning control information for at least one of the first transceivers. The central tuning device also supplies the tuning control information to the at least one first transceiver by modulating the second signal according to the tuning control information applying an amplitude modulation of the second signal using a dedicated WDM tone frequency.
Abstract:
The length of the optical fiber section under tension expands by a certain amount that is proportional to the level of tension applied to it. Monitoring the variations in the phase of the arriving signal allows to discover a fiber that is subject to a certain level of mechanical tension. With the method and apparatus according to the present invention it is possible to protect optical communication channels against failures in an optical transmission fiber that are caused by any kind of mechanical disturbances.
Abstract:
A method for bi-directionally transmitting digital optical signals over an optical transmission link in which a first optical transmit signal is created according to a first binary digital signal in such a way that the bit information of the first binary digital signal is included in first sections of the symbol interval of the first optical transmit signal. A second optical transmit signal is created by creating an optical wavelength reuse signal using the first optical transmit signal received at the second end of the optical transmission link, the optical wavelength reuse signal being modulated according to a second digital signal in such a way that the bit information of the second digital signal is included in second sections of the symbol interval of the first optical transmit signal received.
Abstract:
The invention relates to a method for monitoring a detachable fiber-optic connection, especially in a fiber-optic transmission device or system, comprising the steps of transmitting a wanted optical transmission signal carrying information data to be transmitted to at least one fiber-optic connection, a predetermined portion of the power of said optical transmission signal being reflected at the at least one fiber-optic connection depending on the status and properties of the at least one fiber-optic connection, creating a detection signal by detecting said reflected predetermined portion of the power of said optical transmission signal, monitoring and evaluating the detection signal as a function of time and creating a “DETECT” signal if the detection signal or a signal derived from the detection signal reveals a characteristic change in its course in time. Further, the invention relates to a corresponding device adapted to realize this method.
Abstract:
An optical line termination node has a first connection arrangement for connecting a working fiber, a second connection arrangement for connecting a protection fiber, a transceiver arrangement having first primary link and a first secondary link, and protection switching means configured for being switched either in a working operating state or in a protection operating state.
Abstract:
An asymmetrical network switch adapted to auto-discover and advertise into a traffic engineering, TE, domain a switch detailed connectivity matrix, SDCM, containing for each allowed switching combination of interfaces of said asymmetrical network switch at least one switch detailed connectivity matrix entry, SDCME, wherein each said SDCME represents an internal to said asymmetrical network switch potential connection interconnecting the interfaces of said interface switching combination, wherein a SDCME advertisement includes a switch detailed connectivity matrix entry cost vector, SDCME CV, which comprises a set of attributes describing cost penalties in terms of various service characteristics that a network service incurs if it selects a path or a tree traversing the asymmetrical switch in accordance with the SDCME.
Abstract:
Provided are methods and devices for determining the assignment of subsignals (S1, S2, S3, S4) transmitted by inverse multiplexing, particularly via an Optical Transport Network (OTN), to the transmission links (5a, 5b, 5c, 5d) carrying said subsignals. After a synchronization for the correct assembly of the subsignals (S1, S2, S3, S4) into the digital reception signal (E), the signal transmission via at least one transmission link (5a, 5b, 5c, 5d) is interrupted for a detection process in which the subsignal assigned to the interrupted link is determined. The process may be repeated to determine all subsignal assignments.
Abstract:
A method for providing an uplink over an access ring comprising access devices and at least one aggregation device, wherein each device of said access ring has ring interfaces connecting said device to neighboring devices in said access ring, wherein one access device of said access ring is configured as a ring master device which sends connectivity check messages on both its ring interfaces around said access ring to itself to detect a connectivity failure in said access ring, and wherein said ring master device changes a state of one of its ring interfaces depending on the detection result.
Abstract:
An optical fiber transmission system adapted to provide a remote passive identification of components deployed in said transmission system, wherein each component comprises an associated passive optical identification unit adapted to provide identification of a component type of the respective component on the basis of a received optical identification signature carried in an optical identification signal to said component.
Abstract:
A method and an apparatus for providing a flexible secondary data path control, said method comprising the steps of: detecting (S1) a primary data path failure of a primary data path between a customer premise site (3) and a central office site (4); initiating (S2) a corresponding secondary data path if a primary data path failure of said primary data path has been detected; initiating (S3) a measurement of data path characteristics of said initiated secondary path or utilizing constantly monitored data path characteristics of paths for an available secondary data path; and determining (S4) services to be provided via said secondary data path depending on the measured data path characteristics of said secondary data path.