DE2541092C3 - Circuit arrangement for assigning a type of authorization in private branch exchanges - Google Patents

Description

2. Circuit arrangement according to claim 1, characterized in that the check is carried out by a time step (Z 2) which is triggered with the pulse of the applied time pulse following the message pulse and is matched to the shortest time interval between the clock pulses of the respectively permitted tariff range and the separation (TR) is triggered depending on the further clock pulse arriving within this ten-year period.

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It is known that the Fernsp -editeilnehmer a private branch exchange through the allocation of types of authorization only certain voice connections to jammed. For example, a participant can only feel of calls in the local area or in addition to the local area only in part of the remote area be entitled. This blocking or release of certain speech connections can now be done by a one or multi-digit control of the number dialed by the subscriber can be carried out. You can do this mechanical locking systems adjustable in the manner of a voter are used. By manipulation of the subscriber on the telephone set and special properties of a private branch exchange system there are now possibilities for bypassing such locking devices. To the security against such Increase bypasses, it is known for a tampered remote connection that is considered by a non remote authorized subscriber is set up, the arriving at the beginning of a long-distance call to use the first charge interval pulse for the forced release of this connection. Such a control is however in systems in which the required charge pulse for a connection in the local area already sent at the beginning of the conversation is excluded. The transfer of the billing pulse to The conversation would start, for example, in the area of the Deutsche Bundespost with the planned introduction from local traffic areas. Call connections in such a local transport area should with the facilities of the self-dialing remote service are processed, but subject to a fee Local call.

The security against bypassing the locking device due to the compulsory triggering with the first charge pulse, it cannot then be used either if there is no general blocking of self-willingness remote service is provided, but a certain remote area should be accessible by the subscriber.

55 A similar case exists if, with the planned introduction of local time counting, counting pulses are also sent out during a local call with a predefined time interval during the call for charging purposes and a subscriber is to be able to make such local calls.

It is now the object of the invention to provide a sounding arrangement for allocating a counting pulse-dependent Type of authorization for a call station that can be set up in private branch exchanges and via American broadcasts to create running connections through the call connections for the subscriber within a freely selectable tariff range to be specified and at the same time a security against circumvention of this respective authorization is given.

This is achieved in that the due to a Established connection to determine the charge is then checked whether it is within a tariff range released exclusively for this intercom that an im Compared to this predetermined limit value having a higher clock frequency clock cycle the separation of the connection is effected immediately.

According to the invention, there is an evaluation of the time cycle output for an established connection, whereby the authorization of the subscriber for such a conversation can be determined immediately can. The arrangement for checking the timing is in this case every exchange transmission of a private branch exchange assigned. Different tariff areas can therefore easily be used for the individual microphone units can be assigned, with one free connection option within each of these areas given is. Since the time interval to be charged for the connection is selected as the criterion for this, there is a reliable control option, so that the earliest time can be recognized at the time is, the forced release can be initiated for an unauthorized connection. aside from that This gives a high level of security against bypassing that of the known locking device in The connection with the evaluation of the first registered counting pulse does not correspond to the principle of the There is synchronicity between a blocking device and the voters of the exchange system Compared to this known arrangement, none was caused by a deliberate disturbance of this synchronization Bypass possibility, so that without additional measures an increased security even with only one Part of the remote area including clearance is available.

According to a further development of the invention, you do the following: Verification by a with the Meldeimpuk following pulse of the applied clock cycle and the shortest time interval of the Clock pulses of the respectively permitted tariff area in a coordinated time step, with the separation in Depending on the further clock pulse arriving within this period of time is triggered.

A monostable can be used as a time stage in a simple manner Flip-flop or a counting stage switched by an internal clock are used. This can then each the time span which corresponds to the smallest interval between the clock pulses of the clock pulse assigned to the released tariff area can be specified. Meets! now no further bar during this period of time

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pulse, it is a sign that the connection is released for the intercom and therefore no forced release is required.

In the drawing is an embodiment of the Invention shown in the form of a block diagram.

It is now assumed that an extension subscriber from the intercom Sp, for which there is to be a connection possibility limitation recorded in a corresponding authorization evaluator, sets up a chargeable exchange call A via the coupling network KN and the exchange transmission AUE only part of the remote area is released for this call station, which is defined in the time pulse counting by the smallest possible interval between the individual clock pulses of the time pulse for this area Γ5

Assuming a local time count, the same way for this call station could only making local calls, which in turn is assigned a predetermined time, is permitted will.

The device provided with the reference sign LJ and assigned to an office transmission is now used to check whether the subscriber is crossing the area specified for him or is establishing a connection within this area

The clock pulses incurred for the call connection are fed via the addition Z assigned to the exchange transmission to the facilities available for billing and at the same time to facility U. In order to enable an exact assessment of the clock rate, the start pulse triggered with the reporting of the called subscriber and evaluated at the same time as the first counting pulse is used not used for evaluation. The evaluation should only be carried out with the second charge pulse, so that an unauthorized call connection incurs a maximum of two charge units. This means that the time stage in the form of the counter Z 2, which is matched with the internal clock supplied by the clock generator TG , is only released when this second charge pulse arrives.

This is now done in the following way. The counter Zi, which represents a binary counter, for example, is intended to assume the logic potential H or L with the first pulse at the two outputs Q 1 and Q 2, which is supplied via the coincidence gate G 4. The output Q 3 is intended to supply the potential L corresponding to the output potential in the idle state, so that the coincidence gate G4 is permeable to the pulses applied to its input Ei via the inverter i / 2. With the second charge pulse, the counter Zi should assume the logic potential L at its output Q i and the logic potential H at its output <? 2. As a result, logic potential Wan is present via the reversing stage Ui at input E2 and at input £ "3 of gate G 1. As a result, the gate is opened with the charge pulse applied to input Ei of this gate and a pulse is given to input 5 of the counter Z2 used as a timer This is supposed to assume the logic potential H at its output A. This enables the coincidence gate G 3 via the input Ei so that the clock pulses supplied by the clock generator TG are fed to the counter Z2 as incremental pulses . the counter Z2 is preset such that it reaches this input clock thereby predetermined end position in a time corresponding to the smallest time interval of the clock pulses for the shared collective area to the end of this fixed predetermined period of time is triggered by the second charge pulse at the output a of Counter logic potential H, which is also at the same time Input E of the bistable flip-flop FF is pending These tipping .ufe can, triggered by the actuation of the Gabeiumscha'tekontaktes GU are brought to the drawn starting position. In the case of a predetermined period of time in the range of minutes, two stages can be provided for the counter Z2, assuming a driving second cycle, of which the second then receives the transmission pulse triggered, for example, at a full minute

If a further charge pulse arrives during the specified period of time, this is a sign that a call has been set up to which the respective subscriber is not authorized. By this third pulse to both the output Qi and the output Q 2 accept the counter Zi logic voltage H, which is then at the inputs E2 and E3 of the gate circuit G 2 is applied, the applied yet at the input Ei of the gate circuit G2 pulse then performs the release this gate to a signal fed to the clock input T of the flip-flop FF , so that the flip-flop is switched to the other stable position. The resulting signal at output A then z. B. the isolating relay TR is activated and in a manner not shown causes the forced release of the established connection. This can happen after a short delay in which the extension participant is prompted by an alert to end the call. If no further charge pulse arrives within the specified period of time, this is to be interpreted as a sign that the call connection has been set up in the tariff range permitted for the intercom. In this case '.vi / d accept output A Logil »potential L after the time span has elapsed, ie when the preset end value of counter Z2 is reached , whereby gate G 3 is blocked via input Ei.

1 sheet of drawings

Claims (1)

Patent claims: 1. Circuit arrangement for the allocation of a counter pulse-dependent Type of authorization for and Connections in telephone systems via office transmissions, characterized in that that the created due to a connection established to determine the fee Timing is checked to see whether it is within an exclusively released for this call station The tariff range is that at a limit value given in comparison to this a time cycle having a higher clock frequency immediately disconnects the connection is effected.