Alcatel N.v.

Alcatel

Rainer Fritschi

Rolf Heidemann

Heinz G Krimmel

Bernhard Junginger

Jurgen Otterbach

Rolf Rossberg

In a hybrid fiber/coax access network (NET) with downstream and upstream channels, the upstream channel serves to transmit voice and video signals as well as data signals from groups of customer locations (END) to a subcenter (HUB). A demarcation point (UP) provides the interface between the access network (NET) and the private network of the customer location (END). It contains at least two devices (BP,, BP,, BP,) for frequency-splitting received signals in the upstream frequency band, at least two switches (S,, S,, S,) following the at least two devices (BP,, BP,, BP,) and serving to block or unblock individual upstream frequency ranges, a measuring unit (MESS,) for measuring the amplitudes or intensities of the signals in the split frequency ranges, and a control unit (CTRL) for evaluating the measured values and controlling the at least two switches (S,, S,, S,). For a customer location (END), individual upstream frequency ranges can thus be telemetrically blocked for a limited time. Decentralized and autonomous monitoring of individual upstream frequency ranges is accomplished by a measuring unit which is controlled by the demarcation point (UP) itself.

Active demarcation point of an access network

In a fiber-optic amplifier, which consists of at least one pump coupler (2) with a pumping light source (1) and an erbium-doped fiber length (7) which is spliced to the pump coupler (2), at least one detector is located in the splice area (12) between the fiber length (7) and the outgoing transmission line, to monitor the amplifier by measuring the scattered light coming from this splice area (12). An electrical evaluating device follows the detector.

Fiber optical amplifier having a detector for measuring scattered light

A coupler (1) made of optical fibers is provided with a device for detecting the light that is carried in one of the fibers at the coupler output in operation. For that purpose, the coupler (1) embedded in an enclosure (2) has at the coupler output a lens body (8) enclosing the optical fiber (pigtail 6) and a detector (9) aimed at the lens body (8). With the detector, during coupler operation, lost light dissipated via the primary coating of the optical fiber is received by the lens body (8 ) and carried by the detector (9) to an electrical evaluator.

Growing community of inventors

Korntal-Münchingen, Germany

Rainer Fritschi