RU2045774C1 - Communication system simulating device - Google Patents

Abstract

FIELD: communication engineering. SUBSTANCE: quantity of busy (free) channels is simulated by reversing counter 5. Pulses of request generator 1 arrive at adding input of reversing counter 5 through AND gates 2 and 6. AND gate 2 is open when at least one free channel is available and AND gate 6 passes current when called subscriber is not busy. Processing of requests is simulated by random stream sensor 10 whose pulses go to subtracting input of reversing counter 5. EFFECT: enlarged functional capabilities and provision for simulating operation of communication system with unassigned channels including consideration of whether called subscriber is busy or not. 2 cl, 2 dwg

Description

 The invention relates to specialized means of computer technology and is intended to simulate a communication system operating in the mode of loose channels.

A device for simulating a communication system containing two counters, a pulse generator, a display board and series-connected random pulse stream generator, an element NOT and an element AND [1]
However, this device does not provide the ability to simulate the operation of a communication system over loose channels with checking the busyness of the called subscriber.

Closest to the proposed technical essence is a device for modeling a communication system containing two AND elements, an NOT element, an OR element, a reverse counter, a request generator and a random pulse flow sensor, the output of the application generator being connected to the first input of the first AND element, the output of which connected to the first input of the second element And [2]
The disadvantage of this device is that it does not allow to simulate a connection request service mode in a communication system with loose channels, taking into account the busy of the called subscriber.

 The purpose of the invention is to increase the accuracy of simulation of the device by reproducing the service mode of the connection request, taking into account the busyness of the called subscriber.

 This goal is achieved by the fact that in a device containing two AND elements, an NOT element, an OR element, a reversible counter, a request generator and a random pulse flow sensor, the output of the request generator being connected to the first input of the first AND element, the output of which is connected to the first input of the second of AND element, two And elements are introduced, a pulse generator with a random duration and a clock pulse generator, the outputs of the reverse counter being connected respectively to the inputs of the third AND element and the OR element, the output of the third element And connected to the input of the element NOT, the output of which is connected to the second input of the first element And, the output of the pulse generator with a random duration is connected to the second input of the second element And, the output of which is connected to the summing input of the reverse counter, the output of the OR element is connected to the first input of the fourth element And the output of which is connected to the input of the random pulse flow sensor, the output of which is connected to the subtracting input of the reversible counter, the output of the clock generator is connected to the second input of the four of the second element I.

 The introduction into the prototype of the new distinguishing features of the two And elements, a pulse generator with a random duration, a clock pulse generator and their new connections allows the device to simulate the operation of a communication system over loose channels when servicing a connection request taking into account the busyness of the called subscriber.

 It is known that, as a first approximation, communication systems with loose channels are modeled as queuing systems. In this case, only the presence or absence of a free communication channel is taken into account. The employment or freedom of the called parties is not taken into account. Taking this factor into account is important at the stage of designing communication systems, which determines the importance of introducing such a regime into the proposed device.

 Due to the fact that the proposed device has distinctive features from the prototype, it meets the criterion of "Novelty."

 The distinguishing features introduced are the two And elements, a pulse generator with a random duration, a clock pulse generator and their connections are found in other analogues, however, there they serve to achieve other goals. The goal set in the proposed device is achieved only through the introduction of the proposed distinctive features. Therefore, the proposed device meets the criterion of "Significant difference".

The industrial reproducibility of a random flow sensor is known and described in [3]
The industrial reproducibility of the AND, NOT, OR elements is due to the presence of the element base.

 The pulse generator with a random duration is non-standard and includes a pulse shaping unit, two AND elements, a totalizing counter and an RS trigger, the output of the pulse forming unit being connected to the first inputs of the first and second AND elements, the output of the first AND element connected to the counting input of the totalizing counter, output which is connected to the R-input of the RS-trigger, the direct output of which is the output of the generator and connected to the second input of the first element And, the output of the second element And is connected to the S-input of the RS-trigger, inverse output which is connected to the second input of the second element I.

Industrial reproducibility of AND elements, totalizing counter and RS-trigger due to the presence of the element base, the unit for generating random pulses is described in [3]
In FIG. 1, 2 shows the electrical block diagram of the proposed device for modeling a communication system.

 In FIG. 1 is indicated: 1 request generator, 2, 3, 6, 9, respectively, 1, 3, 2, 4 elements AND, 4 elements NOT, 5 reverse counter, 7 pulse generator with random duration, 8 element OR, 10 random flow sensors pulses, 11 clock pulses.

 In FIG. 2 is an electrical block diagram of a pulse generator with a random duration.

 In FIG. 2 indicated: 12 pulse forming unit, 13, 14, respectively, the 5th and 6th elements of And, 15 totalizing counter, 16 RS-trigger.

 A device for modeling a communication system contains a request generator 1, a reverse counter 5, a clock pulse generator 11, a pulse generator with a random duration of 7, a random pulse flow sensor 10, respectively, the first 2, second 6, third 3, fourth 9 elements AND, element NOT 4 , element OR 8, and the output of the generator of applications 1 is connected respectively through the first 2 and second 6 elements And with the summing input of the reversible counter 5, the control input of the second element And 6 is connected to the pulse generator with a random duration of 7, and the second input of the first element And 2 through the element NOT 4 is connected to the output of the third element And 3, the outputs of the reverse counter 5 are connected to the corresponding inputs of the third element And 3, and through the element OR 8 with the fourth elements And 9. The output of the clock generator 11 through the second the input of the fourth element And 9 is connected to the input of the sensor of the random pulse stream 10, the output of which is connected to the subtracting input of the reversible counter 5. In this case, the device 7 includes a pulse generating unit 12, respectively, the fifth 13 and sixth 14 of the And elements, a totalizing counter 15, an RS-trigger 16, and a random pulse generating unit 12, a fifth element And 13, a totalizing counter 15, an R-input of the RS-trigger 16, the direct output of the RS-trigger 16 is the output of the generator and connected to the second the input of the fifth element And 13, the inverse output of the RS trigger 16 is the second input of the sixth element And 14, the control input of which is the output of the random pulse generating unit 12, and the output of the sixth element And 14 is connected to the S-input of the RS trigger 16.

 A pulse generator with a random duration of 7 is designed to generate random long pulses with random short pauses. The device 7 operates as follows.

 In the initial state, at the direct output of the RS-flip-flop 16 there is a logic level “1”. Therefore, the pulse coming from the pulse forming unit 12 through the open element And 13 will be fed to the input of the summing counter 15, which counts the number of pulses received from the pulse forming unit. As soon as the totalizing counter 15 is full, the next pulse will reset it and put the RS-flip-flop 16 in an inverse state. The next pulse will pass through the open element And 14, since at the inverse output of the RS-flip-flop 16 there will be a logic level “1” and will transfer the RS-flip-flop 16 to its initial state. Next, the pulse generator operates as described above.

 Thus, this pulse generator with a random duration can simulate the busy and free time of the called subscriber, respectively, by a random short pause (logical level zero) and a random long pulse (logical unit level) at the direct output of the RS flip-flop 16. Changing the duration of a subscriber's busyness can be done by changing the capacity counter 15.

 The proposed device for modeling a communication system works as follows.

 In a communication system with loose channels there are n working channels, each of which can be used to serve an incoming request to connect one subscriber to another. The total number of working channels available in the communication system in the device is determined by the capacity of the RS-reversible counter 5. Thus, the device can simulate three possible situations that occur in the simulated communication system when a connection request is received.

 Situation 1. The system has at least one loose communication channel. The called subscriber is free (not occupied by other subscribers). An incoming connection request arrives for service.

 Situation 2. There are no free loose channels in the system. The called party can be both free and busy. An incoming connection request is not received and is lost.

 Situation 3. The system has at least one free communication channel. The called party is busy. An incoming service connection request is not received and is lost.

 In situation 1, the proposed device works like this. The number of busy communication channels in the system is displayed as a binary number in the reversible counter 5. At the same time, the direct outputs of counter 5 corresponding to this number have a logical level of “1”. Since there are free communication channels, the output of the AND 3 element will be the logical level “0”, and accordingly, the output of the NOT 4 element and the input of the And 2 element will be the logical “1” level. The presence of "subscriber" of the subscriber or his "busyness" is modeled by a pulse generator with a random duration of 7, while the presence of a pulse at the output of the generator 7 corresponds to "free", and the absence of a pulse corresponds to "busy". Thus, the request received from the application generator 1 for the connection will go through the open elements And 2, And 5 and will go to the summing input of the reverse counter 5, the value of which will increase by one, thereby simulating the occupation of one working channel.

 Modeling the process of servicing applications is as follows.

 The random pulse flow sensor 10 operates as follows. The clock generator 11 through the open element And 9 gives out a high frequency to the input of the random stream sensor 10 pulses, while the first incoming pulse starts the sensor 10, and subsequent clock pulses ensure its operation.

 After a random number of pulses equal to the service time of the incoming connection request, the random flow sensor 10 generates a pulse at its output, which indicates that the service is completed and one of the busy communication channels is free. This pulse is fed to the subtracting input of the RS-reversible counter 5, and the capacity of the latter decreases by one. Thus, one busy working channel is released.

 We also note that the process of servicing busy communication channels is carried out according to the algorithm described above even in the absence of a new incoming connection request.

 In situation 2, the proposed device works like this. Since all channels are occupied in the communication system, then at all inputs of the AND 3 element there will be a logic level of "1", and therefore, at the output of the NOT 4 element and the input of the And 2 element there will be a logic level of "0". This means that the incoming connection request, regardless of the availability or busyness of the called subscriber, will be lost. At the same time, in the communication system, the simulation of the service mode of busy communication channels will be as described above.

 In situation 3, the proposed device works like this. Since the communication system has a free unsecured communication channel, the incoming connection request will go through the open element And 2 and will go to the first input of And 6. Since the called subscriber is busy, then at the second input of And 6 there is a logical level of "0" from the output of the pulse generator with a random duration of 7. Therefore, the incoming connection request, regardless of the "free" or "busy" working loose channels of communication will be lost. At the same time, in the communication system, the mode of servicing busy communication channels will be simulated as described above.

 By connecting various calculating devices to the corresponding elements of this device for modeling a communication system, one can obtain numerical characteristics of the quality of service for subscribers of a communication system with non-fixed channels.

 The advantage of the proposed device for modeling communication systems is the ability to simulate the service mode of the connection request with checking the busyness of the called subscriber. Such modeling of communication systems at the stage of their development allows to reduce development time while reducing the cost of the work itself.

Claims (2)

 1. DEVICE FOR MODELING A COMMUNICATION SYSTEM containing two AND elements, an NOT element, an OR element, a reversible counter, a request generator and a random pulse flow sensor, the output of the application generator being connected to the first input of the second AND element, characterized in that two element And, a pulse generator with a random duration and a clock generator, and the outputs of the reverse counter are connected respectively to the inputs of the third element And and the element OR, the output of the third element And is connected to the input of the element NOT, the output of which is connected to the second input of the first element And, the output of the pulse generator with a random duration is connected to the second input of the second element And, the output of which is connected to the summing input of the reverse counter, the output of the OR element is connected to the first input of the fourth element And, the output of which is connected to the input of the random pulse flow sensor, the output of which is connected to the subtracting input of the reversible counter, the output of the clock pulse generator is connected to the second input of the fourth element I.  2. The device according to p. 1, characterized in that the pulse generator with a random duration contains a pulse shaping unit, two And elements, a summing counter and an RS trigger, the output of the pulse shaping unit being connected to the first inputs of the first and second And elements, the output of the first element And is connected to the counting input of the totalizing counter, the output of which is connected to the R-input of the RS-trigger, the direct output of which is the output of the generator and connected to the second input of the first element And, the output of the second element And is connected to the S-input of RS-t iggera inverse output is connected to the second input of the second member I.