Multiplex communications – Duplex
Patent
1997-08-22
1999-08-10
Patel, Ajit
Multiplex communications
Duplex
370284, H04B 156, H04L 514
Patent
active
059369469
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to full-duplex transmission path interface measuring devices.
BACKGROUND INFORMATION
As described in U.S. Pat. No. 4,989,202, an ISDN (integrated services digital network) transmission path between the transmission line and a network has an interface. It is also known (see "Siemens KMT Report," no. 14, order no. E 80001-V331-W54, pages 6 and 7) that measurements can be performed on this interface and an appropriate measuring device can be provided for this purpose. For example, frequency-dependent measurements, functional tests and even jitter measurements can be performed with this measuring device. An ISDN data transmission line is a special form of a transmission line with full-duplex transmission in the common carrier duplex process.
According to European Patent Application No. 9,592 A1, a differential unit in a transmission and receiving device connected to a duplex line is provided for receiving signals. Two signals are sent to this differential unit, namely the transmission signal of its own transmission and receiving device and the complete signal that is transmitted on the duplex line and which consists of its own transmission signal plus a signal to be received from another transmission device. The task of the differential unit is to subtract its own transmission signal from the composite signal of the duplex line and in this way to make it possible to receive only the signal of the other transmission device. Thus, cross-talk from its own transmission signal to the received signal is suppressed.
SUMMARY OF THE INVENTION
The present invention relates to a measuring device for the interface of a transmission path with full duplex transmission in the common carrier duplex process, whereby a highly integrated interface unit is connected to the interface via a hybrid set and a transmitter on the one hand and a line termination (LT) or a network termination (NT) as the test object on the other hand.
An object of the present invention is to provide a means to accurately and simply perform physical measurements on the interface during transmission operation. This object is achieved according to the present invention by providing a device that simulates the arrangement consisting of a hybrid set, a transmitter and a line or network termination and which contains a high-resistance differential amplifier that is connected at the input to the transmission outputs of the highly integrated interface unit and at the output to an input of a subtractor via another high-resistance differential amplifier. Another input of the subtractor is connected to the interface via an additional high-resistance differential amplifier, and a measurement system of the measuring device is connected to the output of the subtractor.
An important advantage of the measuring device according to the present invention is that by using the simulating device and the subtractor, it is possible to analyze only the signal transmitted by the respective test object because the signals going to the test object and information in the subtractor are filtered out, so that only the signal sent by the measurement object is available and can be analyzed easily by a measurement system of the measuring device.
With the measuring device of the present invention, the device simulating the arrangement of a hybrid set, a transmitter and a line or network termination may have various designs. It is particularly advantageous--for the purpose of substantially eliminating the signals sent to the test object--if the simulating device has a hybrid set identical to the hybrid set of the transmission path, a transmitter identical to the transmitter of the transmission path and a termination with electric properties identical to those of the line or network termination of the transmission path.
To achieve the advantages of the measuring device of the present invention even when the transmission path has an attenuating device at the interface, it is advantageous for the simulating device of the measuring de
REFERENCES:
patent: 4604740 (1986-08-01), Gandini et al.
patent: 4638473 (1987-01-01), Cooperman et al.
patent: 5216667 (1993-06-01), Chu et al.
patent: 5502716 (1996-03-01), Rhebergen
patent: 5579336 (1996-11-01), Fitzgerald et al.
Lenihan Thomas F.
Mayer Richard L.
Patel Ajit
Tetronix, Inc.
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