Siemens Aktiengesellschaft

Hans-Hermann Witte

Steven Moustakas

Michael Stockmann

Ralf T Kersten

Eckhard Storck

Viktor Bodlaj

Herbert Michel

Vaclav Kulich

Manfred Rohler

A switch mechanism for switching signals at inputs onto outputs and switching networks for interlinking first and second transmission media. Switching networks for interlinking first and second transmission media for the transmission of signals in frequency-division or space-division multiplex have a substantially simpler architecture in comparison to known switching networks. To that end, the switching networks are constructed with a new switch mechanism composed of a plurality of adjustable frequency converters of the input side, of a means for distributing the signals and of doubly adjustable frequency converters of the output side and/or of a plurality of doubly adjustable frequency converters of the input side, a means for distributing the signals and adjustable frequency converters of the output side. A simpler structure can be achieved in a known switching network of the Clos type in that shared-medium switches of two different types are employed. The switch mechanism can be used in electrical and optical switching systems.

Switch mechanism for switching signals at inputs onto outputs and

In an asychronously operating optical data bus:

Method and apparatus for recognizing data collisions in an optical data

An optical data bus with a statistical access method for the transmission of data between transmitters and receivers in the form of NRZ data provides that every transmitter of a subscriber contains a Manchester encoder which Manchester encodes the NRZ data and deposits such data onto the bus in a Manchester-encoded form. The receiver of every subscriber contains a Manchester decoder for the reacquisition of the NRZ data from the Manchester encoded data and contains a clock recovery device which recovers the clock contained in the Manchester-encoded data. Such a Manchester decoder with the clock recovery device can be constructed in a very simple manner and such a simple structure is disclosed. A very simply-constructed bus state recognition device is also included.

Optical data bus having a statistical access method

A method and outage recognition device for use with a redundantly designed optical transmission system having at least two receiver circuits at each station of the system with each receiver circuit having an input, an output and a separate transmission channel connected to the input characterized by the recognition device and method determining an outage of either one of the transmission channels by applying an output of each of the receiver circuits to a means for recognizing outages in the channel and determining the outage in the transmission channel by the occurrent data independent of statistical phase positions of the data in each channel. In a specific embodiment of the device, various logic elements are interconnected in a manner so that they not only reliably identify an outage of a channel but also indicate which channel has failed.

Method for the recognition of the outage of one or more transmission

A device for recovery of a synchronized clock signal from a signal sequence, in particular a random sequence, clocked at a specific frequency. The device includes a clock generator which by itself generates clock signals whose phase and frequency are tuned to the specific phase and clock frequency of the signal sequence, and which is triggerable externally by specific signals derived from the signal sequence in order to synchronize its phase and frequency with the phase and clock frequency of the signal sequence. The clock generator includes preferably a monostable multivibrator whose output signals are fed back delayed to the input serving as trigger input.

Device for recovering a synchronized clock signal from a signal sequence

A coupler network for coupling N subscriber transmitters to N (=n.multidot.m) subscriber receivers is disclosed. The system exhibits m star couplers each having respectively N transmitter-side input ports for the connection of the N subscriber transmitters and having respectively N receiver-side output ports for connection with respectively N/m subscriber receivers of the N subscriber receivers. In order to reduce the line attenuation of this echo-free coupler network, each subscriber transmitter is connected to a plurality of star coupler input ports and a detector of each star coupler receiver is connected to a plurality of star coupler output ports. A lens system or a fiber taper which make it possible for more light to be coupled in or out (than for individual fibers) is employed for coupling a plurality of star coupler input ports to a subscriber transmitter and/or for coupling a plurality of star coupler output ports to a detector of a subscriber receiver. The specific case N=64, m=4 is illustrated in the drawing.

Optical coupler network for coupling a plurality of subscriber

If data from more than one subscriber circulates on a bus link in an optical bus network structure in which access of the subscribers to the bus is not synchronously controlled, data collisions can occur. In order to guarantee a high data throughput on the bus, these data collisions must be avoided insofar as possible or must be quickly perceived. A circuit for identifying possible data collisions determines whether the bus is free for a subscriber wishing to transmit, and which permits collisions on the bus to be quickly identified and corresponding measures to be quickly initiated to prevent further collisions. The present invention enables a subscriber to a bus system to distinguish between a data collision and normal transmission errors. This distinction is made by concluding that a collision has occurred only when the bit error frequency is substantially higher than the probabilistically determined normal transmission error frequency.

Circuit for recognizing data collisions in an optical data bus and

An optical star coupler for use in optical systems with multi-mode optical fibers for interconnecting two groups of system fibers, characterized by the star coupler comprising a mixing element, two groups of optical fiber elements and an arrangement for positioning the mixing element and the groups of fiber elements in the same plane. The mixing element is a planar waveguide which has an input and output end which are interconnected to groups of the fiber elements with a packing density of each group of the fiber elements at the input and output ends being as high as possible. The planar waveguide has a thickness approximately equal to the diameter of the fiber elements and the diameter of each of the fiber elements is approximately equal to the core diameter of the system fiber to which it is connected and all of the fiber elements are selected to be of one type of fiber which are either gradient fibers or stepped profile fibers. To position the mixing element and the group of fiber elements in the same plane, a method includes forming a sandwich of the mixing element between a cover and substrate, forming a pair of sandwiches for each group of fiber elements between a substrate and a cover element, assembling these sandwiches on a support element with the polished end surfaces of the fiber element sandwiches engaging the polished end surfaces of the mixing element sandwich, and securing the sandwiches in the assembled position.

Optical star coupler and the method of making

A coupler which is used with light conducting system fibers of a fiber optical communication system to couple-out and couple-in a light signal to the system fibers characterized by the coupler having at least three optical coupler fibers for connection to the system fibers and an arrangement for holding the fibers in a plane with two of the fibers converging together to have a portion of each of the fibers adjacent the end face in parallel side by side relationship with the end faces being flush and holding at least the third fiber with its end face abutting against the end faces of the pair of fibers with each of the glass fibers forming the coupler having an overall diameter which is equal to the core diameter of the system fibers which are connected thereto. Preferably, the cladding of each of the coupler fibers is as thin as possible and the coupling fibers may be embedded in a material having an index of refraction which is less than that of the cladding of the fiber to reduce light losses.

Optical fiber coupler

Method and apparatus for an optical four-gate coupler wherein the junction between two large fiber optical waveguides of the same diameter are connected to a fiber optical waveguide having a smaller diameter and wherein a guide part is formed with a groove for engaging the small fiber optical waveguide and the distance from the center line of said groove to the edge of the guide is equal to the diameter of the larger waveguides so that the guide part and a detent can hold the two large waveguides and the smaller waveguide in aligned contacting positions and a cover plate fits over at least the two large waveguides. Such structure is then cut transverse to the center axis of the three waveguides and the ends are polished and then coupled together so as to provide an optical four-gate coupler. The modification comprises forming a groove having a width equal to the diameter of the larger fiber optical waveguide fibers and a depth which is equal to two times the diameter of a thick fiber plus one time the diameter of the smaller fiber and wherein a number of smaller fibers are placed in the bottom of the groove and the two larger fibers are placed into the groove on top of the smaller fibers and are pressed with a cover member against the smaller fibers so that at least one of the smaller fibers is in good aligned contact with one of the larger fibers.

Method and apparatus for an optical four-gate coupler

A three dimensional star coupler for interconnecting a first bunch of optical waveguides such as fibers to a second bunch of optical waveguides or optical fibers characterized by a mixing element being a planar waveguide having a thickness approximately equal to the fiber diameter and having input and output surfaces coupled to the incoming and outgoing fibers which are all supported in the same plane. The mixing element consists for example of an elongated rectangular plate but also can have a configuration of arcs of a circular configuration.

Optical star coupler for multi-mode light conducting fibers

A light distributor which is connected to an incoming light guide and a plurality of outgoing light guides for distributing a light arriving from the incoming light guide into the plurality of outgoing light guides characterized by the distributor comprising a disk member, which may be circular, of a material which has properties of a low absorption and low scattering, and the member has an abutting surface for both the incoming and outgoing light guides with the abutting surface of the incoming light guide being opposite to the abutting surface of the outgoing light guides. The disk member of the light distributor will have a thickness equivalent to the diameter of the cores of the light guides. The disk member may be of a material which is birefringent or which has a controllable index of refraction.

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Munich, Germany

Hans-Hermann Witte