DD251663A1 - METHOD FOR DETECTING PERFORMANCE HAZARDOUS FAULTS IN COMMUNICATION DEVICES - Google Patents

Abstract

The invention relates to a method for improving the effectiveness of the malfunction detection on connection-specific switching devices electromechanical switching systems and terminals, preferably Muenzfernsprechern. The fault detection criterion "average occupancy time" is compared with a variable limit value, which makes it possible to adapt to the traffic situation.

Description

Field of application of the invention

The invention relates to methods for detecting power-impairing interference in call processing equipment. Fields of application are electromechanical switching systems, in particular telephone exchanges on the basis of Hebdrehwählern and coordinate switches, in which circuit arrangements for the detection of disturbances are present in an indirect way.

Another advantageous application is the detection of interference to terminals of exchanges, preferably payphones.

Characteristic of the known technical solutions

In the known methods for indirect fault detection on connection-specific switching devices electromechanical telecommunications switching systems criteria for fault detection are formed from occupancy periods Tb, which are measured at the switching devices. Such a criterion is z. B. the average occupancy l _b . This can be approximately calculated by updating, after the measurement of the occupancy time Tb for a certain switching element of the switching system, an existing moving average i _{b of} the occupancy duration by correction by means of the factor a-weighted difference between t _b and T _b :

i _b : = f _b + a (Tb - tb) with a = ai for T _b <f _b and a = a ₂ for T _b > X _b

The disturbance detection criterion is compared to a fixed decision limit that is determined or corrected at discrete time intervals before using the method / de 2926697 and 2926604, Forvst, LI: "Analysis of Trunk Groups Containing Short Holding Times" Bell System Technical Journal 54 (1975 6, pp. 1127-1153 / Due to load-related fluctuations of the criterion in the undisturbed operating state of the switching devices, false statements can occur when the criterion is compared with the decision limit , which leads to quality losses on the one hand and unreasonable maintenance on the other hand.

Object of the invention

The aim of the invention is to improve the effectiveness of the detection of performance-endangering disorders on connection-specific switching devices efektromechanischer telecommunications switching systems and terminals. The improved efficacy is expressed in a shorter current detection time and a lower probability of making wrong decisions. Thus, the fault detection can be introduced more effectively in existing telecommunication systems more effectively.

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Explanation of the essence of the invention

The invention is based on the object, with particular consideration traffic-related fluctuations in the decision criterion used average occupancy improved method for the detection of faults connection individual switching devices electromechanical switching systems and terminals to find and thus increase the reliability of the occupancy based fault detection.

According to the invention the object is achieved in that with a known per se, microcomputer-based device that is used to measure the occupancy of the switching devices of the switching system, the occupancy durations of the switching devices are measured and determined for each of the switching devices after each occupancy of a moving average and a variable Limit g is compared. Falls below the variable limit by the moving average value of the microcomputer-based fault detection device is issued a fault message.

The variable limit value is now determined according to the invention by updating an existing limit value by correction by the factor-b-weighted difference between the existing limit value and a proportion T _b / x of the occupancy time.

The factor b can assume values between 0 and 1.

An embodiment of the invention provides for the formation of the variable limit value after each occupation of a switching device from a group of switching devices or terminals which are characterized by the same traffic behavior.

A further development of the invention prefers the different weighting of the difference to form the threshold value as a function of whether the fraction of the occupancy duration related to the threshold value formation is greater or smaller than the current threshold value.

b = bi for T _b / x <gb = b ₂ for T _b / x> g

The smoothing factor for increasing the limit value is greater than the smoothing factor for lowering the limit value b, <b ₂

A further development of the invention provides for the delimitation of the value range of the variable limit value upward (g ₀ ) and downward (g _u )

"g _u <g <g _o

embodiment

With reference to the embodiment of the invention will be explained in more detail.

A microcomputer for measuring and evaluating the occupancy times is connected to the payphones of an exchange. On the microcomputer an algorithm for calculating moving average values of the occupancy times of the payphones is implemented. In addition, the microcomputer receives an algorithm for implementing the method according to the invention for determining variable limit values.

For the determination of the variable limit values, the measurement results of the occupancy duration measurement are combined by payphones of the same type and a location area.

If a high traffic volume occurs in a location area, all payphones of the group formed for the formation of the variable limit value show a decrease in the average occupancy time due to the greater load on the switching system. At the same time, the variable limit of this group of pay phones decreases.

Occurs on a pay phone a disturbance, which affects the telephone traffic, the average occupancy of the disturbed payphone changes, but not the variable limit. This leads to falling below the variable limit by the average occupancy time of the disturbed pay phone and thus the failure message.

On the basis of the dynamic description of the method, the advantage according to the invention compared to the comparison of the moving average value of the occupancy time with a fixed limit value becomes clear since, in comparison with a fixed limit value, untimely error messages occur in the event of sudden changes in the traffic value.

Claims (4)

1. A method for detecting high-performance interference in switching equipment, the connection-specific switching devices, in particular of Telefonvermittlungsaniagen on the basis of Hebdrehwählern or coordinate switches and terminals, preferably payphones, occur, wherein the occupation times of the switching devices are measured and evaluated by a microcomputer-aided device, characterized in that the decision criterion average occupancy time is compared with a variable limit value which is determined by correcting an existing limit value by the directed difference of the limit value to a proportion of the occupancy time after each occupancy. 2. Method according to item 1), characterized in that the variable limit value is formed after each occupation of a switching device from a group operating under the same traffic conditions switching device. 3. The method according to item 1) and 2), characterized in that the weighting of the difference of the limit value to a proportion of the occupancy duration takes place depending on whether the proportion of the occupancy duration is less than or greater than the variable limit value. 4. Method according to item 1), 2) and 3), characterized in that the variable limit value is variable only within a predetermined range of values.