System and method for measuring characteristics of the communication line

 

(57) Abstract:

Offers the method and the device 3, 60, 202 and 300 for measuring the dynamic characteristics or characteristics of the AC current and the static characteristics or characteristics DC cable pair 2, 10,0, 24 and 133 with one local, the end with the element 1,1, 19 and 20 having a known non-linear electrical characteristics, United with the other, remote end, and the methods and devices 30 and 111 for connection of a nonlinear element 1 with the remote end of a cable pair 2, 10, 24 and 133 and detach the nonlinear element 1 by means of an electric voltage, served on a cable pair 2, 10, 24 and 133 at the local end. Relevant to the invention the method and system test set near the end of 3, 60, 202 and 300 electrically transformed to the far end of a cable pair 2, 10, 24 and 133, so that in all respects it can be considered that it is at the far end, but actually physically remains on the near end. Nonlinear element 1 is in its non-linear region, but as a convenient way excited two or more variables of signals of different frequencies 4, 12, 13, 41, 42, 133 and 114 creates dopolnitelnaya characteristics of a cable pair 2, 10, 24 and 133. By choosing certain excitatory frequencies and measure the characteristics of the additional returning frequencies 6, 22, 52 and 200 it is possible to obtain the characteristics of a cable pair 2, 10, 24, 133. 3 S. and 42 C.p. f-crystals, 6 ill., table 1.

The invention relates to the measurement of characteristics of a cable pair, AC and DC, as is usually required for the maintenance of communication, information and computer networks and communication networks and cable television.

Finding cost-effective ways to test cables used in networks with distributed parameters (for example, for telephone systems), has been a problem from the very beginning of their use. All prior to the invention of testing methods can in General be represented by the shown in Fig. 1 scheme. The test rig had to connect to the cable at each end. Then, using the exchange of signals between these units have passed the test. Usually setting the far end of the 1 had to pass the signal, and the installation near the end of 2 was supposed to measure. Then the data were recorded by the person in the middle end. Test set 1, which was on da is taken from the near end of the automatic device. As a typical telephone network usually consists of many cables, diverging from the near end (the Central telephone station) on many of the far ends (subscribers), these methods of the prior art typically required many different test sets the far end.

It was recognized that walking to the far end for testing is not desirable, so I used various known methods for connecting the test set the far end control it automatically, to eliminate the necessity of walking to the far end for testing. The principal drawback of these methods of the prior art was that they are expensive and complex, and at the same time require the test set and the controller or operator waiting on each far end.

The invention overcomes the disadvantages of the known prior art relating to the need to have at the far end as staff and/or complex and expensive equipment, and uses the method that electrically converts the test setup of the near end to the far end of the cable, so in all respects can be considered, ctet be used to test a variety of cables, diverging from the near end, one test installation, thereby eliminating the need for the far end of complex and expensive equipment at the far end, used to connect and remote control.

The invention relates to a method and system for measuring characteristics of AC and DC cable pairs, such as pair telephone cable or pair cable used for signal transmission in local networks or similar signals completely from one end of the cable to another using United with him nonlinear devices. Such devices, being appropriately stimulated with two or more AC signals of different frequencies, creating additional frequencies. In accordance with the invention a non-linear device is placed on the remote or far end of the cable pairs and excited frequencies, served on a cable pair from another (local) or the near end. Excitatory frequencies are the length of the cable in the direction from local or near-end to the remote or far end and modified as the characteristics of the cable, and additional frequencies produced by what are the characteristics of the cable. Due to the special choice of exciting frequencies, and measuring the characteristics of returning additional frequencies with high precision to calculate the characteristics of the cable.

In one embodiment of the invention the non-linear device is permanently connected to a cable pair and designed in such a way that it becomes non-linear only in the presence of variable voltages in excess of those normally present on the cable pair during normal operation, and measurement are caused by the feed cable with a couple of local or near-end voltages in excess of normal voltage.

In another embodiment of the invention the non-linear device is isolated from the cable pairs of the second nonlinear device, such as a Zener diode or anoperational trinistor, so that it can be made to connect to the cable pair only when it is applied a DC voltage of appropriate magnitude and polarity, and the measurements are caused by the simultaneous feeding on cable a couple of combinations of DC and AC voltages.

In any case, the measuring device can be placed only at the local or near end, therefore, all of the I measurement systems of the prior art; in Fig. 2 is a block diagram corresponding to the invention the preferred measuring system of Fig. 3 is a block diagram, which, being partially principle, illustrates relevant to the invention the method and system in which the nonlinear element is connected with one end of a cable pair, and is excited by two known variables signals of different frequencies and amplitudes, while the result returned frequency is filtered and measured to determine the losses in the cable on one of the two incident frequencies; Fig. 4 is a block diagram, which, being partially principle, illustrates an alternate implementation of the method and system of Fig. 3, in which the access to the test cable pair, the nonlinearity is connected with another by supplying a constant voltage, and then measured dynamic characteristics of the cable; Fig. 5 is a block diagram, which, being partially schematic diagram that illustrates another alternative implementation of the method and system of Fig.3, in which the access to the test cable pair, the non-linear element is connected to a remote end through actuation using different pulse voltage troop the data; in Fig. 6 is a block diagram, which, being partially schematic diagram that illustrates an alternate implementation of the system of Fig. 5, in which the oscillator driving signal is at the far end.

In Fig. 2 presents the basic structure of the invention. As shown in Fig. 2, to transform the test set of the near end to the far end, it is preferable to use sensitive to the voltage non-linear device 1, connected to the cable pair 2 at the far end. This non-linear device 1, such as a pair of diodes 19 and 20 (Fig. 3), fairly cheap. It can easily connect and disconnect, requires no power, the presence of the operator and does not require the remote control device. In the relevant invention system and method equipment near the end of the 3 consists preferably of three devices: generator 4 of the excitation signal, which preferably excites sensitive to the voltage non-linear device 1, causing it to become to some extent nonlinear; generator 5 of the control signal, which preferably generates the control signals used to measure cable characteristics cable pair 2 Uch is itmer.

Preferred in this case the principle of operation is shown in Fig. 2 system is as follows.

The generator excitation preferably generates a signal amplitude which is sufficient for entering sensitive to the voltage non-linear device 1 in the non-linear region of its characteristics. The required voltage level, preferably higher voltage levels, normally used for transmitting signals on a cable pair 2. Preferably, in a time when non-linear device 1 is in the nonlinear region, the generator 5 of the control signal simultaneously with the excitation signal was generated one or more signals of low level are necessary to measure the frequency. The level of these control signals is preferably much lower than the level of the excitation signal generated by the generator 4 excitation, and does not make a significant contribution to the nonlinearity sensitive to the voltage non-linear device 1. The resulting nonlinearity arises at the far end of a cable pair 2 as a result of the excitation signal from generator 4 excitation, preferably causes the far end of a cable pair 2 new generation chastota measured selective to the frequency measuring device 6. Preferably, in order to obtain a known initial characteristics of the system before it could be used a known calibration signal. In the described preferred system could identify the characteristics of a cable pair 2, as the characteristics of the measured signal is a product of its known initial characteristics of the produced excited sensitive to the voltage non-linear device 1, and the characteristics of the cable pair 2. Thus, the measurements obtained in accordance with preferred for the invention system and method, give the characteristics of the cable pair 2 in exactly the same way as if the generator 5 of the control signal have been physically present at the far end. Let us consider Fig. 3, which shows the basic scheme of the invention, designed to measure the attenuation depending on the frequency characteristics of the cable pair 10, in which the nonlinear element 1 preferably consists of two diodes 19 and 20, connected in parallel, but in opposite directions, and this diode pair 19 and 20 are connected in parallel to the resistor 9 with one end of a cable pair 10. A pair of resistors 14 and 15, each of which preferably is s 12 and 13 of the cable 10. In addition, preferably, the opposite end of the cable pair 10 was connected selective to the frequency of the voltmeter 22, preferably consisting of a bandpass filter 16, an amplifier 17 and a voltmeter 18. The voltmeter 18 is preferably sensitive only to signals with a predetermined frequency F3. Selective to the frequency of the voltmeter 22 and the signal generators 12 and 13 preferably comprise a control circuit 300.

Preferably, the sinusoidal signal generator 13 has been properly configured to have a large amplitude signal of frequency F1, so that the nonlinear element 1 is preferably introduced in the nonlinear region of its characteristics, and the sinusoidal signal generator 12 is preferably normally configured at a small amplitude, so that it is preferable not to introduce the element 1 in the non-linear region of its characteristics.

In preferred in this case the conditions of the signal generators 12 and 13 are two primary signal produced by a nonlinear element 1 and return to the bandpass filter 16. The frequencies of these two signals can be calculated by the following formulas:

F3 = N(F1) + F2, F3 = N(F1) - F2,

where

N is an odd integer.

Any of these two frequencies can pradipat very low frequency, so the weakening of the cable pair 10 at these frequencies was so small that they could be neglected, then the frequency F2 would represent the frequency at which the measured attenuation. Thus, the impedance of the cable pair 10, which can simply be determined by measurement or calculation that uses the length of the cable pair 10 and section lived, frequency response and resistive losses of a cable pair 10 can be determined from measurements with a voltmeter 18 reverse signal at a frequency F3.

For example, for measuring losses in the pair telephone cable 10, when the frequency F2 is equal to 304, 1004 and 2804 Hz, using the above formulas obtained are given in the results table.

It should be noted that in accordance with the invention, it is preferable that the frequency of the feedback signal F3 was constant and low enough that it did not affect the frequency response of a cable pair 10. Thus, it is lost when passing from a non-linear element 1, where it is produced, to selective to the frequency of the voltmeter 22 can be calculated by the well-known impedance of the cable pair 10 and the known values of the termination resistors 14 and 15.

More preferably, otobusu signal F2, was known from the design of a nonlinear element 1. In addition, it is preferable that the amplitude of the frequency F1 was insignificant, as it always is preferably large enough to enter the nonlinear element 1 in the non-linear region of its characteristics. Thus, the weakening of the cable pair 10 at the frequency F2 can be calculated by the level of F2, which is served in a cable pair 10 sinusoidal signal generator 12, and the measured level of the returned signal F3 by the following formula:

The attenuation at the frequency F2 = (Vm/Vi(1/K)((Rt+Rs)/Rt),

where

Vm is the measured level F3;

Vi - imposed level F3;

K - conversion coefficient of the nonlinear element 1 using values of N;

Rs - series resistance of a cable pair 10;

Rt - characteristic impedance of a cable pair 10.

Let us consider Fig. 4, which shows the preferred embodiment of the invention, in which the nonlinear element 1 is connected in series with a blocking condenser 33, which serves to isolate from any of the applied constant voltage, and the resulting scheme is then connected with the far end of the cable pair 24 through normally open relay contacts 27, Engl is the present of the winding of the relay 34, resistor 32 and two Zener diodes 35 and 36 included in opposite directions, which are connected with the remote end of the cable pair 24. The capacitor 25 is designed to shunt the winding of the relay 34, so that she had a small impedance for AC signals. The normally closed contact 27 of the relay 34 are connected in series normally remote load 38 pair cable 24, which may consist of a telephone, a modem, a local area network, multiplexer, or any other device commonly used with cable pair 24. Preferably, in order to interchange any constant voltage cable pair 24 of the elongated load-38 was an additional capacitor 26.

According Fig. 4 local end of the cable pair 24 ends with the switch 39 access well-known type. In normal use this switch 39 access preferably is in position and connects the local end of the cable pair 24 with normal local load 40. This local load 40 preferably consists of a device, normally used for communication with the device that loads the remote end of the cable pair 24 and is also well known. In accordance with sistemista its transfer position C. This disconnects the normal load 40, replacing the test circuit 60. The test circuit 60 preferably consists of two separate sinusoidal generators 41 and 42 connected in parallel with the cable pair 24, a pair of resistors 43 and 44, each of which is preferably equal to twice the characteristic impedance of a cable pair 24, which is preferably used for reconciliation of the signal generators 41 and 42 with the cable 24, and a pair of capacitors 45 and 46, which are preferably block any DC voltage of the sinusoidal signal generators 41 and 42. In addition, as part of the test circuit 60 is connected selective to the frequency voltmeter 52, preferably consisting of a bandpass filter 47, amplifier 48 and voltmeter 49. In addition, to block any DC voltage bandpass filter 47 preferably includes a capacitor 50.

Preferably, during normal operation of a variant embodiment of the invention shown in Fig. 4, the local load 40 connected to the remote load 38 through the cable pair 24, since the normal operating voltage is preferably not enough to make any Zener diode 35 and 36 otkachenko delivers a constant voltage to the cable pair 24 through the protective current-limiting resistor 63. This voltage is preferably displaces in the forward direction, one of the two Zener diodes 35 and 36, and the other causes to be opened, then the resulting current flows through the ammeter 62, both of the Zener diode 35 and 36, the relay coil 34 and resistor 32. Thus, the relay contacts switch, disconnecting the normal remote load 38 from the cable pair 24 and connecting the nonlinear element 1 with the cable pair 24, thereby allowing to measure characteristics of the cable 24 as described with reference to Fig. 3. Additionally, since the resistance winding of the relay 34, the resistor 32 and the current-limiting resistor 63 known, as well as the voltage drop on a pair of Zener diodes 35 and 36, the serial impedance of the cable pair 24 can be easily calculated via the well-known Ohm's law. This allows us to solve the equations shown in the embodiment of Fig. 3, and therefore, to get all the results you need without any external information about the cable pair 24.

Let us consider Fig. 5, there is shown another preferred embodiment of the invention, in which the nonlinear element 1 is connected to the resistor 103 through a blocking capacitor 102, but nevertheless, the overall function of this option ousecall different. In this regard, the resulting circuit is preferably connected to a remote end of the cable pair 133 through the circuit consisting of the serial diode 104 and anoperational trinistor 105. This scheme will be conductive only when the polarity of the applied DC voltage is such that the anode of the diode 104 is shifted positively, and when the applied voltage is large enough to cause the Zener diode 106 to open and switch anoperational trinistor 105. As soon as anoperational trinistor 105 is switched, the circuit preferably becomes a low impedance and continues to pass current until, until you removed the applied voltage or will not change its polarity. The orientation of the diode 104 and the rest of the circuit is preferably changed to the opposite relative polarity of DC voltage on the cable pair 133, present during normal circuit operation. The resistor 108 and the capacitor 107 are designed to maintain the impedance required for the control input anoperational trinistor 105, so that it was not opened until opened Zener diode 106. The Zener diode 106 is preferably chosen so as to open when the voltage slightly greater than the greatest inany through the cable pair 133 and work normally. Thus, the polarity of the applied DC voltage and the change in its value, while the Zener diode 106 is open, preferably opens anoperational trinistor 105. As soon as anoperational trinistor 105 is opened, it preferably becomes a low impedance and connects the non-linear element with the cable pair 133 and allows to measure characteristics of the cable, as described above for Fig. 3.

According Fig. 5 local end of the cable pair 133 terminates on the switch 111 of the access well-known type. Preferably, during normal use are shown in Fig. 5 system this switch 111 access was in position and connected the local end of the cable pair 133 with normal local load 113, which preferably consists of a device such as the equipment to the telephone network, which normally is used with a remote load device 123, such as a telephone or a modem, which loads the remote end of the cable pair 133 and is also well known. Preferably, during normal operation of the local load 112 created on the cable pair 133 DC voltage, which is normally used to with the direction of the diodes 109 and 110, becoming a low-impedance, connecting through remote load device 123 to the cable pair 133, thus allowing normal operation. This voltage is also preferably shifts the diode 104 in the opposite direction, isolating the test circuit from the cable pair 133, with local and remote load device 112 and 123 work normally.

When in accordance with the invention is required to test the cable pair 13, the switch 111 access is driven by a translation in the position of the Century. It detaches the normal load 112, replacing the test circuit 202. The test circuit 202 preferably comprises two separate sinusoidal signal generators 113 and 114 connected in parallel with the cable pair 133, a pair of capacitors 117 and 118, which are preferably block any DC voltage of the sinusoidal signal generators 113 and 114. In addition, with the opposite end of the cable pair 133 is preferably connected selective to the frequency voltmeter 200, which preferably consists of a bandpass filter 119, amplifier 120 and voltmeter 121. This voltmeter 121 as described in the above embodiments, the implement preferably sensitive only is tra 119.

In addition, as shown in Fig. 5, a constant voltage is applied to the local end of the cable pair 133 with a pair of power sources 124 and 125, which may be a battery or any other suitable well-known constant power source, through the polarity reversal switch 126, which is used to change the polarity of the applied voltage, and through the selector switch voltage 127, whereby the magnitude of the applied voltage can be set equal to one or two values. First potentiometer 130 is preferably installed in the middle of its range, so that the voltage supplied were balanced with respect to earth. Another shows a pair of inductance coils 128, connected with polarity reversal switch 126 having a high impedance at the frequency of voltage variables used to measure characteristics of the cable pair 133 in the manner described above with reference to Fig. 1, and with a pair of current-limiting resistors 129 provided for as a protective current limiters.

Preferably, first, after actuation of the switch 111, detaches normal local load 122 and, hence, relieving obesity DC voltage with the same polarity and magnitude what is used during normal operation, and that both they, and the switch 126 polarity, and the selector switch 127 voltage would be in the position C. Then preferably observe the readings of the ammeter 138. If current no, it's all right. If you notice the flow of current, then there are two possibilities: either the cable pair 133 is a short circuit or remote load device 123 passes current.

Then actuates the switch 126 polarity that when you change the polarity of the applied voltage is switched to position a, which changes at a reverse bias of the diodes 109 and 110. Thus the diodes 109 and 110 become high-impedance, disconnecting remote load device 123 from the cable pair 133. The resulting voltage is not high enough to operate the Zener diode 106, so anoperational trinistor 105 does not switch, and the test circuit 202 does not conduct any current. Then preferably observe the meter readings 138 current. If the current is still flowing, the cable pair 133 briefly closed. This was reported as a fault, the device 11 of the access is returned to the normal position, the test stop is prodoljayutsya.

Then the selector switch 128 voltage is driven so that instantly increase the applied voltage to a value large enough to cause the Zener diode 106 to open, and then returning the applied voltage by the same amount that was used during normal operation. This preferably is accomplished using a translation of the selector switch 127 voltage position And followed by a return to the situation, switching, thus anoperational trinistor 105. Then preferably again observe the meter readings 138 current. If you notice the flow of current, it's all right, and the impedance of the cable pair 133 is calculated on current values and known values of the serial resistors 129, applied voltage, the known voltage drop on the diode 104, anoperational trinistor 105 and the known value of the load resistor 103 using well-known Ohm's law. If current is not present, the cable pair 133 should be open. This was reported as a fault, the device 111 access is returned to normal position, and the tests are terminated.

As will be calculated consistent resistivity is written with reference to Fig. 3. The balance of the cable pair 133, i.e., the presence of any unbalanced resistance earth leakage from one or two lived pair 133, can be measured by adjusting the position of the arm 130 so that the readings of the voltmeters 131 DC and 132 are the same. The degree of deflection of the arm 130 from the centre is an indicator of the magnitude of the unbalance. This test procedure ends, and the switch 111 access is released from the on condition, returning the circuit to normal operation.

As described in Fig. 6, it is easy to predict that the generator 114 driving signal can be located on the far end of the cable with a non-linear element without any change in the operation of the device.

If necessary, instead of measuring the characteristics of a cable pair, the invention can be used simply to detect the presence of sensitive voltage non-linear device 1 at the far end of a cable pair, where it is used as a "shortcut" because should provide a reflection of the unique known frequency in response to the control signal being initiated excitation signal, intended to introduce into the nonlinear region of its connected to the cable, or to determine, for example, cable type or specific application.

Nonlinear device, such as described in the invention a pair of diodes may be any device, instantaneous impedance which is a function of the applied voltage or current flowing through it, and also both. Such devices are specially manufactured to create new signals of known frequency generated by two or more specific signals.

The nonlinear element is inserted into its nonlinear region ( i.e. the point at which the impedance of the nonlinear device will change with a change in voltage), when it is applied excitation signal of sufficient magnitude. When the driving signal generates the non-linear element by a time varying voltage, it causes the nonlinear impedance element to vary in such a way that it defines a specific characteristic of this device nonlinearity and the change of the driving signal in time. Excitation signal causes the impedance of the nonlinear device to change in time synchronously vozbujdayuschego signal.

Similarly, the control signal also knew is much more than the control signal, so that its impact was major.

Of the changes of the nonlinear impedance element caused by the energizing and control signals generated two different phenomena. First, the nonlinear current flow caused by these signals, leads to a distortion of the shape of their voltage. This distortion causes the appearance of harmonics of the signal frequency current flowing through the nonlinear device, therefore, the current flowing through the nonlinear device contains not only the base frequency excitation and control signals, but also new harmonic frequencies. The magnitude of these new frequencies is predictable and reproducible function of the amplitudes of the excitation and control signals. Secondly, because all the components cause changes in the impedance of the nonlinear device, each of the components is modulated by the amplitude of all the others. Amplitude modulation creates sidebands on the displacement of one of the signal modulating the frequency of another. These sidebands appear as a new series of sum and difference signals in the current flowing through the nonlinear device. The frequency of these new signals are associated with different amounts and the differences between vosbmidesyatyh and distributed in the cable as echoes.

The reflected signals generated by the nonlinear device, have frequencies though predictable, but different from the frequency of the supplied signals, and are able to measure to separate filters. The amplitude of these echoes depend on the characteristics of the cable pairs, so that the characteristics of the pair can be determined from the amplitudes of the reflected signals, making possible the characterization of cable pairs.

The invention, which is sensitive to the voltage non-linear device used at the far end of the cable, can be actuated from the near end to enter it in the test order in the nonlinear region, has a wide range of applications of the nature and scope of the invention and not go beyond them.

1. System for measuring the characteristics of the line containing sensitive to the voltage non-linear medium with nonlinear region, coupled with the far end of the line, the tool will generate the excitation signal and the means for generating the control signal, coupled with the near end of the line, and measuring means connected to the near end of the communication line, characterized in that the measuring means is designed as smerovania of the excitation signal with the amplitude sufficient to transfer sensitive to the voltage non-linear means in its nonlinear region with a voltage level higher than normal voltage levels used for transmission of communication signals through the communication line, means for generating a control signal made with the possibility of the formation of the control signal, without introducing significant nonlinearity in sensitive to the voltage non-linear means, and exciting, and the control signals generated in such a way that is sensitive to the voltage non-linear means, generating harmonics of the excitation signal and mixed harmonics of the excitation signal and the control signal for generating a new frequency at the far end of the communication line, moreover, the new frequency is a predetermined frequency sufficiently low magnitude, are not affected by communication lines.

2. The system under item 1, characterized in that the means of generating the excitation signal is located in the middle end of the line.

3. The system under item 1, characterized in that the means of generating the excitation signal is located at the far end of the line.

4. The system under item 1, characterized in that the specified line contains five cable TV systems.

6. The system under item 1, wherein the communication line comprises a pair of cable data network.

7. The system under item 1, characterized in that the measuring means includes means for measuring characteristics, which is the product known initial characteristics specified excited, sensitive to the voltage non-linear means corresponding to the known calibration signal, and characteristics of the communication line.

8. The system under item 1, characterized in that the measuring means includes selective to the frequency voltmeter.

9. The system under item 7, characterized in that the measuring means includes selective to the frequency voltmeter.

10. System p. 1, wherein said nonlinear means comprises a pair of diodes connected in parallel in opposite directions, and a pair of diodes connected in parallel resistive impedance.

11. The system under item 9, wherein said nonlinear means comprises a pair of diodes connected in parallel in opposite directions, and a pair of diodes connected in parallel resistive impedance.

12. The system under item 1, characterized in that the non-linear means the UDA driving signal is not sufficient for to invoke the call connection to the phone line.

14. The system under item 1, characterized in that it further comprises a constant current source, located on the near end of the communication line to generate a constant loop current therein, and means of current measurement, located on the specified near the end to measure the loop current flowing through the communication line to determine its characteristics DC.

15. The system under item 10, characterized in that it further comprises means to prevent the passage of direct current, connected in series with the specified parallel diodes to prevent the passage of direct current, DC, located on the near end of the communication line to generate it a constant loop current flowing through the resistance, and a means of measuring current, located in the middle end of the line to measure the loop current is flowing through it, to determine its characteristics DC.

16. System on p. 11, characterized in that it further comprises means to prevent the passage of direct current, connected in series with the specified parallel is as specified near the end of the line to generate a constant loop current in it, flowing through the specified resistance, and a means of measuring current, located on the specified near the end of the line to measure the loop current is flowing through it, to determine its characteristics DC.

17. The system under item 14, characterized in that the said means to prevent the passage of direct current contains capacity.

18. System on p. 15, characterized in that the said means to prevent the passage of direct current contains capacity.

19. The system under item 1, characterized in that it further comprises first switching means located at the far end of the line for nonlinear switching means from the stand-alone state in which it is electrically isolated from the communication lines, in an isolated state in which it is electrically connected to the communication line, and the specified first switching means connects the nonlinear medium with a communication line in response to the excitation signal with a level corresponding to the switching level of the specified first switching means, and electrically isolates the specified non-linear means from the communication line, when the signal it is less than a specified level is switched situated at the far end of the line for nonlinear switching means from the stand-alone state, in which it is electrically insulated from the specified line in an isolated state in which it is electrically connected to the communication line, and the specified first switching means connects the nonlinear medium with a communication line in response to the excitation signal with a level corresponding to the switching level of the specified first switching means, and electrically isolates the nonlinear medium from the communication line, when the signal it is less than a specified level switch.

21. The system under item 14, characterized in that it further comprises first switching means located at the far end of the line for nonlinear switching means from the stand-alone state in which it is electrically isolated from the communication lines, in an isolated state in which it is electrically connected to the communication line, and the specified first switching means connects the specified nonlinear medium with a communication line in response to the excitation signal with a level corresponding to the switching level of the specified first switching means, and electrically isolates the nonlinear medium from the communication line, when the signal it is less than a specified level switch.

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23. The system under item 18, characterized in that it contains means of switching DC, located at the far end of the line for switching on and off of the constant current in response to a corresponding switch of the specified first switching means.

24. The system under item 19, characterized in that it contains means of switching DC, located at the far end of the line to activate and deactivate the specified constant current in response to a corresponding switch of the specified first switching means.

25. System on p. 20, characterized in that it contains means of switching DC, located at the far end of the line to activate and deactivate the specified constant current in response to a corresponding switch of the specified first switching means.

26. The system according to p. 22, characterized in that the means of switching DC contains anoperational trinistor.

27. The system under item 1, characterized in that it contains an isolation circuit connected to the communication line and located by its far end for electrical isolation of devices connected to the communication line at its far end in presets the scheme, connected to the communication line from its far end for electrical isolation of devices connected to the communication line at its far end in the presence of the specified driving signal, and the specified isolation circuit isolates the specified device from the specified driving signal, a specified control signal and the constant current when the measuring system is in test status, and transmits the call signal to a communication line, when the measuring system is in normal condition.

29. The system under item 18, characterized in that it contains an isolation circuit connected to the communication line from its far end for electrical isolation of devices connected to the communication line at its far end in the presence of the specified driving signal, and the specified isolation circuit isolates the specified device from the specified driving signal, a specified control signal and the constant current when the measuring system is in test status, and transmits the call signal to a communication line, when the measuring system is in normal condition.

30. The system according to p. 22, characterized in that it contains the STV, connected to the communication line at its far end in the presence of the specified driving signal, and the specified isolation circuit isolates the specified device from the specified driving signal, a specified control signal and the constant current when the measuring system is in test status, and transmits the call signal to a communication line, when the measuring system is in normal condition.

31. A method of measuring the characteristics of the communication line, comprising loading the far end of the line is sensitive to the voltage non-linear means having linear and non-linear region, the excitation is sensitive to the voltage non-linear tools excitation signal, applying at least one control signal of a low level on the communication line corresponding to the measuring frequency and the dimension of the measuring signal, wherein the level of the exciting signal is sufficient for the introduction of nonlinear tools in its nonlinear region and generation of harmonics of the driving signal and exceeds the normal voltage levels used for transmission of communication signals on the communication line, control signal formicoxenini contribution to the nonlinearity sensitive to the voltage non-linear means, when this control signal are mixed in a sensitive nonlinear voltage with harmonics of the driving signal that causes the generation of new frequencies in the far end of the line containing the measuring signal is a predetermined relatively low frequency, not confirmed the influence of the communication line, when the measuring signal is transmitted from the far end to the near end of the line, followed by comparison of the known calibration signal generated at a predetermined new frequency for determining on the basis of the characteristics of the communication line.

32. The method according to p. 31, characterized in that the phase of the excitation includes a stage of excitation of the specified sensitive to voltage nonlinear funds from the near end of the line.

33. The method according to p. 31, characterized in that the phase of the excitation includes a stage of excitation of the specified sensitive to voltage nonlinear funds from the far end of the line.

34. The method according to p. 31, wherein the communication line comprises a pair of telephone cable, the phase excitation includes a stage of excitation of the specified sensitive to the voltage non-linear tools excitation signal and the telephone signal at a specified telephone cable pair, and the specified driving signal has a voltage sufficient to cause you to call the phone connected to the specified telephone cable.

35. The method according to p. 31, wherein the communication line comprises a pair of television cable and the specified phase excitation includes a stage of excitation of the specified sensitive to the voltage non-linear tools excitation signal having a voltage level in excess of the normal voltage levels used for transmitting signals of cable television on the specified television cable pair.

36. The method according to p. 31, wherein the communication line comprises a pair of cable data network, and the specified phase excitation includes a stage of excitation of the specified sensitive to the voltage non-linear tools excitation signal having a voltage level in excess of the normal voltage levels used for transmission of information signals at a specified telephone pair cable data network.

37. The way of measuring on p. 31, characterized in that it further includes the following steps: feeding a line of constant current corresponding to its conturn is="ptx2">

38. The method according to p. 37, characterized in that it includes a step of switching the specified sensitive to the voltage non-linear means of a stand-alone state in which it is electrically isolated from the communication lines, in an isolated state in which it is electrically connected to the communication line, and the specified stage switching ovative connection is sensitive to the voltage non-linear means with the communication line in response to the excitation signal with a level corresponding to the switching level of the specified first switching means, and electrical isolation of the specified sensitive to the voltage non-linear means from the communication line, when the signal it is less than a specified level switch.

39. The method according to p. 31, characterized in that it includes a step of switching the specified sensitive to the voltage non-linear means of a stand-alone state in which it is electrically isolated from the communication lines, in an isolated state in which it is electrically connected to the communication line, and the specified stage switch covers the connection specified sensitive to the voltage non-linear means with a specified communication line in response to the excitation signal with ulatio specified sensitive to the voltage non-linear means from the communication line, when the signal it is less than a specified level switch.

40. The method according to p. 37, characterized in that it contains step on and off the specified constant current in response to a corresponding switch of the specified first switching means.

41. The method according to p. 31, characterized in that it contains step isolation device connected to the communication line at the far end, in the presence of the specified driving signal.

42. The method according to p. 39, characterized in that it contains step isolation device connected to the communication line at the far end, in the presence of the specified driving signal.

43. The method according to p. 40, characterized in that it contains step isolation device connected to the communication line at the far end, in the presence of the specified driving signal.

44. System for detection of nonlinear devices in the line containing sensitive to the voltage non-linear medium with nonlinear region, coupled with the far end of the line, the tool will generate the excitation signal and the means for generating the control signal, coupled with the near end of the line, and measuring means connected with livanou frequency, a means of generating the excitation signal is configured to generate excitation signal with an amplitude sufficient to transfer sensitive to the voltage non-linear means in its nonlinear region with a voltage level higher than normal voltage levels used for transmission of communication signals through the communication line, means for generating a control signal made with the possibility of the formation of the control signal, without introducing significant nonlinearity in sensitive to the voltage non-linear means, and exciting, and the control signals generated thereby, to be sensitive to the nonlinear voltage means generating harmonics of the excitation signal and mixed harmonics of the excitation signal and the control signal for generating a new frequency at the far end of the communication line, and a new frequency is a predetermined frequency sufficiently low magnitude, are not affected by communication lines.

45. The system according to p. 44, wherein the specified sensitive to the voltage non-linear means comprises a pair of diodes connected in parallel in opposite directions, and the specified pair of diodes are connected to the computers

 

Same patents:

The invention relates to the field of telecommunication and can be used to check the quality of the communication channels of tone frequencies used for transmission of discrete information signals

The invention relates to the field of radio, namely to control the technical state of the communication systems

The invention relates to measuring technique and can be used to adjust and control the parameters of the radios and high-frequency blocks in serial and mass production of radio and television equipment

The invention relates to telecommunications, in particular, to devices of the test channels of the primary network connection

The invention relates to telecommunication and can be used to perform automated measurements of amplitude-frequency characteristics (AFC) of the group and of linear channels of transmission systems on cable, radio and other communication lines

The invention relates to telecommunication and can be used in transmission systems with frequency division multiplexing (CRC)

FIELD: radio communications.

SUBSTANCE: pulse noise is detected upon conversion of signal received into intermediate frequency, noise active time is determined, information signal is disconnected from amplifier incorporated in superheterodyne receiver, noise-affected part of information signal is recovered by eliminating simulator signals during extrapolation, and superheterodyne receiver is checked for serviceability at intermediate frequency.

EFFECT: enhanced precision of superheterodyne receiver serviceability check.

1 cl, 1 dwg

FIELD: radio engineering; diagnostics and repairs of radio equipment.

SUBSTANCE: proposed method includes recording of current criteria of radio and video communication channel conditions, their comparison with desired reference values, elimination of faults detected, and check tests for signals in electric and low-current circuits, replacement of faulty electric and low-current harnesses, units, and assemblies, checkup for signals in circuits of automatic-control, measuring, and recording system and checking-and-recording equipment, and checkup of circuits for normal functioning, whereupon pieces of equipment are subjected to accelerated aging by thermal and mechanical impacts.

EFFECT: enlarged functional capabilities and enhanced reliability of condition inspections.

1 cl

FIELD: instrumentation engineering; serviceability check of multichannel communication systems.

SUBSTANCE: proposed equipment includes personal computer, multiplexing switch, circuit checkup unit, control unit, multichannel comparison unit, virtual standard, switching unit, output signal shaper, multiplexer, and normalizing unit that has voltage meter and circuit meter.

EFFECT: enlarged functional capabilities of device.

3 cl, 1 dwg

FIELD: multi-channel communication systems.

SUBSTANCE: equipment has comparison block, virtual standard, input and output signal generators, commutator, voltage meter, circuit measuring means and control block.

EFFECT: broader functional capabilities.

2 cl, 1 dwg

FIELD: amplitude-frequency characteristics of quadripoles.

SUBSTANCE: control of quadripole is realized in two stages. At first stage, estimation stage, N counts of measurements results are received during length T of one signal period, and on second stage, analysis stage, during time T received signal estimation results are recognized with determining of class of technical state of object (like breakdown). To realize first stage of control, to present clock pulse generator, first counter, delay element, first register, first AND element, adder, additionally inserted are two keys, two analog-digital converters, second register and operative memory block for estimation results, to realize second control stage additionally to first and second comparison block, indication block, inserted are breakdowns signs memory block, breakdown counters and commutator, and for controlling control stages to present launch element, first counter, second AND element, key element is additionally inserted.

EFFECT: higher speed of operation.

5 dwg

FIELD: radio engineering; serviceability check of communication systems.

SUBSTANCE: proposed method is characterized in that serviceability of communication systems in frequency-adaptive range is evaluated by checking system response to noise situation simulated at its input and its comparison with desired value. To this end time required for tuning to optimal frequency is measured and compared with desired value, and also number of errors is counted and compared with that admissible.

EFFECT: enhanced reliability of estimating serviceability of communication system in frequency-adaptive range.

1 cl, 1 dwg

FIELD: systems for determining amount of available data transfer resources.

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EFFECT: possible determining of amount of available data transfer resources for certain connection.

3 cl, 4 dwg

FIELD: control technologies in packet telecommunication networks and data transfer networks.

SUBSTANCE: method is based on shortening down to minimal separate list (INS) of number of clients subject to control due to maximal statistical relations of data exchange inside network node in comparison to number of analogical network nodes in whole network, and also maximal productiveness of network node and during control input data packets are compared only in portion of address of incoming data packets with minimal separate list of number of clients subject to control, while received minimal separate list of number frequency clients subject to control is used for verification of each passing data packet.

EFFECT: decreased work amount of processor providing control over communication participants, while main problem is large number of relatively short data packets, which is necessary to compare to full, related to whole network, list of client inputs subject for control, and productiveness of computing devices connected thereto, which is necessary in each node for realization of this problem.

4 cl, 2 dwg

FIELD: method and device for measuring quality of signal shape.

SUBSTANCE: real signal, representing shape of signal, divided on separate channels by time and codes, is produced, for example, by means of standard communication system for high speed data transfer. Controlling-measuring equipment produces ideal signal shape, matching real signal shape. This equipment produces estimate of shifts between parameters of real signal shape and ideal signal shape, then performs estimation of different measurements of quality of signal shape using quality measurements of compensated real shape of signal. Examples of processing real signal shape and appropriate ideal signal shape by means of controlling-measuring equipment are given. Provided method and devices can be utilized with any shape of signal, separated on channels by time and codes, not depending on equipment, which produces signal shape.

EFFECT: increased precision of measurement of signals shape quality, which are separated on channels in temporal area and code area.

3 cl, 3 dwg

FIELD: communications engineering, possible use for classification of connections.

SUBSTANCE: in method and device by means of computing block one or several distance coefficients are determined, while distance coefficients show efficient length of network connection depending on distance by air. On basis of known data about network connections, distribution coefficient of weak portions is determined, showing mutual relation to each other of weaker portions of network connection. Data transfer resource is determined to determine maximal for data transfer capacity for different types of modems. On basis of efficient length of network connection, weaker portions distribution coefficient and data transfer resources by means of computing block classification is performed (of subject network connection in accordance to its maximal data transfer capacity).

EFFECT: possible quick and flexible determining of service quality parameters.

3 cl, 9 dwg

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