SU1661786A2 - Data transmission system simulator - Google Patents

Abstract

The invention relates to computing and can be used in simulating the operation of multicast data transmission systems. The purpose of the invention is to expand the functionality of the device by simulating multicast data transmission systems with targeted re-request of messages. The device contains a message pulse generator, a random noise flow generator, a random number sensor, three switches, three elements OR, a memory register, two groups of elements NOT, two groups of elements AND, a delay element and two decoders. 1 il.

Description

The invention relates to computing and can be used in the design and simulation of multicast data transmission systems and is an improvement to the device by author. No. 1451718.

The purpose of the invention is to expand the functionality of the device by simulating multicast data transmission systems with targeted re-request of messages.

The drawing shows a diagram of the device.

The device contains a sensor 1 random numbers, the first 2 and second 3 switches, the first group of elements is NOT 4, the generator 5 message pulses, the first 6 and second 7 decoders, the second group of elements HE 8, the first 9 and second 10 groups of elements And, the generator 11 random interference flow, outputs 12-15, memory register 16, first 17 and second 18 elements OR, third switch 19, third element OR 20, and delay element 21.

The device works as follows.

The random number sensor 1 generates K-bit parallel random codes arriving at the information inputs of switches 2 and 19. Each code models one message: the address portion of the message and the fact of the message itself. The number of addresses (subscribers) in the device to which the information is transmitted corresponds to the number of output bits of the decoder.

On a Start command, a trigger pulse is applied to the input of the generator of 5 message pulses operating in the standby mode. The generator 5 generates a pulse, which is fed to the control inputs of switches 2 and 19 and to the input of register 16. In this case, register 16 records for storing the address message code from the output of switch 19. Each pulse from generator 5 allows one message to pass through switches 2 and 19. From the switch output 2 code

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message arrives at the input of the decoder 6 and the information inputs of the switch 3.

The random noise generator 11, the HE 4 elements, and the switch 3 are designed to simulate the distortion of messages that occur in the transmission path. At random times specified by the generator 11, the parallel code from its outputs, after inversion by the elements NOT 4., is read into the control inputs of the switch 3. In this case, if the moment the code arrives at the switch 3 coincides with the moment the code arrives from generator 11, part message pulses do not pass into the transmission path, i.e. The message is distorted. If the arrival times of the codes do not match, then the message passes through the switch 3 without distortion. If all potentials of the switch 3 have low potentials, the message through switch 3 will not pass, i.e. in this case, the situation is simulated when the transmission channel goes out of order (the message is not valid) and the message is lost.

Decoders 6 and 7 are designed to analyze incoming codes at their inputs, i.e. to determine the address of the subscriber to whom the information is transmitted. Elements 9 and 10 and elements 8 are designed to accurately identify individual subscribers to whom information is addressed (output 12) and which is correctly received (output 14), and subscribers who, due to distortion, mistakenly receive other people's messages (output 13) . If the message code coincides with the subscriber code, the conditional number of which is assigned to one of the outputs of the decoder 6, a pulse appears at that output of the decoder, which arrives at the second input of the corresponding element AND 10 and through the corresponding element NOT 8 at the corresponding element 9.

Register 16, the OR elements 17, 18, and 20, the third switch 19, and the delay element 21 are designed to simulate the process of reshot the message by the subscriber in case of an erroneous reception of a message addressed to another subscriber. For definiteness, we assume that the message is addressed to the second subscriber. In this case, a pulse appears at the second output of the decoder 6, which arrives at the second input of the second element AND 10, and the second element NOT 8 inverts the pulse at the second input of the second element AND 9. If the message code passes without distortion through the switch 3, a pulse appears at the second output of the decoder 7 and at the output of the second element And 10, indicating that the message is addressed to the second subscriber At the outputs of the other elements And 10 and at the outputs of all elements And 9 in this case there are no pulses. From the output of the second element And 10 pulse

arrives at the input of the element OR 18, first sets the register 16 to the zero state, and after some time the delay arrives at the second input of the element OR 20 and then to the input of the generator start 5 pulse 0 messages, i.e. the device returns to its original state and is ready to transmit a new message to a new subscriber.

If the message addressed to the second subscriber passes through the switch

5 3 with distortions, it is received by another subscriber. Suppose that the message was received by the first subscriber, i.e. a pulse appears at the first output of the decoder 7, In this case, at the outputs of all elements AND

0 10 pulses are absent (at the output of the first element AND 10 a pulse is also absent, because a low potential is at its other input), and at the output of the first element I 9 a pulse appears, because at its other input

5, there is a high potential from the first element HE 8. There are no pulses at the outputs of the other elements AND 9, since they have low potentials at the first inputs. The presence of pulses at the second output of the de0 encoder 6 and at the output of the first element I 9 (at the first output of the decoder 7) indicates that the message addressed to the second subscriber was mistakenly received by the first subscriber. From the output of the first element AND 9, a pulse arrives at the input of the element OR 17 and then to the input Read register 16, and the message code addressed to the second subscriber, previously recorded in the register, is read

0 to the input of the decoder 6, and through the switch 3 to the input of the decoder 7.

If the message passes through the switch 3 with distortions again and is received by, say, the fifth subscriber, then the pulse 5 appears on the fifth output of the decoder 7, i.e. at the output of the fifth element of AND 9 (at the outputs of all the elements of And 10 and at all other outputs of the elements of And 9 there are no pulses). From the output of the fifth element AND 9 through the element OR 17 the pulse is again fed to the input Read register 16 and the message for the second subscriber is transmitted again. The center will repeat the message until it is correct.

5 received by the second subscriber. If the message is correctly received, the second subscriber at the second output of the decoder 7 appears a pulse that passes through the second element AND 10, and through the element OR 18 this pulse sets the register

16 to the zero state, and then, passage through the delay element 21 and the OR element 20, is fed to the start input of the generator 5 message pulses. After this triggering pulse arrives, the device starts sending a new message to the new subscriber. If the entire message code through switch 3 does not pass, the pulse is present only at the corresponding output of the decoder 6, and there are no pulses at the outputs of all elements And 9 and 10, This indicates a complete malfunction of the data transmission channel (the channel is not valid) and emergency stop of the device.

Statistical characteristics can be obtained on the basis of meter readings connected to the corresponding elements and outputs of the device.

Claims (1)

The invention The device for modeling data transmission systems by author. No. 1451718, characterized in that, in order to expand the functionality of the device by simulating multicast data transmission systems with address re-request of messages, it further comprises a third switch, a memory register, three OR elements and a delay element, the outputs of the random number sensor are connected respectively to the information inputs of the third switch whose control input is connected to the output of the message pulse generator, and the outputs to the corresponding information inputs of the memory register, the outputs of the AND elements of the first group connected respectively to the inputs of the first element OR, the output of which is connected to the read input of the memory register, the outputs of the elements AND of the second group are connected respectively to the inputs of the second the OR element, whose output is connected to the memory register reset input and the delay element input, the output of which is connected to the first input of the third OR element, the second input of which is the device start input, and the output of the third OR element connected to the start input of the message pulse generator, the output of which is connected to the input of the register of the memory register, the outputs of the bits of which are connected respectively to the information inputs of the second switch and the first decoder