RU203223U1 - DEVICE FOR CALCULATING THE OPTIMAL PACKET SIZE BY CRITERION OF MINIMUM DELAY AND MESSAGE TRANSMISSION TIME DIFFERENCE - Google Patents

Abstract

The utility model relates to the field of communication technology. The technical result is to create a device for calculating the optimal packet size for various parameters of the used communication channel and transmitted traffic according to the criterion of the minimum difference between the delay and transmission time of a message of a given size. This device is due to the use of an input block for the value of the packet data transmission rate, an input block for the value of the output stream rate, an input block for the size of the service part of the packet, an input block for the size of the transmitted message, two division blocks, three multiplication blocks, a block for increasing by one, two blocks multiplication by two, a multiplication unit by four, three subtraction units, a squaring unit, a square root calculation unit, an addition unit, a result display unit and the organization of connections between them allows you to implement a method for calculating the optimal packet size according to the criterion of the minimum delay and message transmission time difference ... 2 ill.

Description

The utility model relates to the field of communication technology and can be used to calculate the optimal packet size according to the criterion of the minimum difference between the delay and the transmission time of a message (file) in communication systems with constant transmission rates.

In its explicit form, this device has few analogs and in most cases is included in larger technical solutions in the form of a separate unit, which is often called a packager or packet generator, and the order of packet formation is not disclosed.

Known devices [1, 2], containing elements similar in purpose to the proposed device. The elements included in the devices [1, 2] as separate blocks are mainly aimed at optimizing the parameters of the communication network by changing the route or throughput.

Known device [1], which implements the method of bandwidth control based on the use of traffic shaping at the device level located between the server adaptive streaming and client devices adaptive streaming. In this device, bandwidth management allows you to choose the optimal ratio between the number of possible parallel services and the perceived QoF of each service.

The disadvantage of this device is the inability to control the size of the packet when transmitting data within the established connection of streaming multimedia traffic and select its optimal value to ensure that the difference in delay and message transmission time is minimized.

In the device [2], the transport communication network is optimized by using a module for collecting / outputting parameters, made with the ability to obtain information from the operator's network, at least the average delay time and availability factors of communication lines, information from the access network, at least the average size of the protocol data blocks and the rate of receipt of protocol data blocks, requirements for the quality of service, information about the network elements of the transport communication network, transmission of switching tables, topology and resource management to network elements, a module for finding connected structures, made with the ability to find connected structures of a transport communication network according to the criterion of minimum the average delay time for the corresponding connected structures and according to the criterion of the maximum availability factor for the corresponding connected structures, the structural optimization module, made with the possibility of calculating the optimal logical structure of the transport communication network, with is using information from the operator's network, at least the average delay time and availability factors of communication lines, information about the network elements of the transport communication network, information about the found connected structures according to the criterion of the minimum average delay time for the corresponding connected structures, a parametric optimization module made with the ability to calculate optimal distribution of the bandwidth of the logical channels of the transport communication network, using information from the access network, at least the average size of the protocol data blocks and the intensity of the arrival of the protocol data blocks, the requirements for the quality of service, the content module made with the ability to fill the switching tables, topology and resource management transport communication network and transfer of table data to the module for collecting / outputting parameters, and the first output of the module for collecting / outputting parameters is connected to the first input of the module for finding communication structures, the second output of the module is faulty pa / parameter output is connected to the first input of the structural optimization module, the third output of the parameter acquisition / output module is connected to the first input of the parametric optimization module, the first output of the module for finding connected structures is connected to the second input of the structural optimization module, the second output of the module for finding connected structures is connected to the second the input of the parametric optimization module, the third output of the module for finding connected structures is connected to the third input of the content module, the first output of the structural optimization module is connected to the second input of the module for finding connected structures, the second output of the structural optimization module is connected to the first input of the content module, the third output of the structural optimization module is connected with the third input of the parametric optimization unit, the first output of the parametric optimization unit is connected to the second input of the content unit, the first output of the content unit is connected to the first input of the parameter output unit.

This device-analogue solves the problem of structural and parametric optimization of the transport communication network, which makes it possible to increase the utilization rate of the total channel resource of the transport communication network and the availability of the transport communication network, by changing the route and allocating bandwidth, but the packet size is not optimized during packaging ...

A closer analogue is the device [3], in which the MPEG transport stream is converted into IP packets for broadcasting in WLAN, and this device contains a packeter, but the composition of the packetizer is not disclosed, but it is only stipulated that the formation of packets is carried out in compliance with some internet protocols and program-specific information. Thus, the formation of packets does not allow minimizing the difference between the delay and the transmission time of a message (file).

The closest in technical essence and selected as a prototype is the device [4], which implements the approach of variable packet lengths for transmissions with a high packet data rate.

An apparatus [4] for transmitting data packets in an access network (AN), comprises a data rate control (DRC) node for receiving data rate requests from access terminals, each data rate request indicating at least one transmission rate, which the access terminal requests from the access network device to transmit data to the access terminal; a physical layer (PL) packet generation unit, configured to receive data rate requests from a DRC node based on transmission rate requests, select at least two access terminals to receive data from a multiuser PL packet, select a length from a set of lengths for the multi-user PL packet, selecting a transmission rate from a set of transmission rates for transmitting the multi-user PL packet, and generating a multi-user PL packet of the selected length; and a transmitter for transmitting the multi-user PL packet to the access terminals.

The disadvantage of this technical solution is the choice of the packet size based on the requested transmission rate, and the set of possible packet sizes corresponding to a specific transmission rate is predetermined.

This does not allow optimal (by the criterion of the minimum difference between the delay and the message transmission time) to use this device in systems with constant input / output flow rates.

The device [4] has the following main disadvantages:

1. Do not optimize the packet size for various connection and traffic parameters based on the criterion of the minimum difference between the delay and the transmission time of the message (file).

2. Do not take into account the size of the transmitted message (file) when choosing the packet size.

In the proposed utility model, the noted disadvantages are eliminated.

The purpose (technical result) of the utility model is to create a device for calculating the optimal packet size for various parameters of the used communication channel and transmitted traffic according to the criterion of the minimum difference between the delay and transmission time of a message (file) of a given size.

The stated goal is achieved by the fact that this device is achieved through the use of an input unit for the packet data rate, an input unit for the output stream rate, an input unit for the size of the service part of the packet, an input unit for the size of the transmitted message, two division blocks, three multiplication blocks, a block increase by one, two blocks for multiplying by two, block for multiplying by four, three blocks for subtraction, block for squaring, block for calculating the square root, block for addition, block for displaying the result, and the output of block 1 for inputting the packet data rate value is connected to input 1 block 5 dividing, the output of block 2 for inputting the value of the input flow rate is connected to input 2 of block 5 for dividing, the output of block 3 for inputting the size of the service part of the packet is connected to input 2 of block 7 of multiplication, with input 2 of block 6 of multiplication and input 2 of block 10 of subtraction, the output of block 4 of input of the value of the size of the transmitted message is connected to input 2 of the block ka 11 subtraction, the output 1 of the block 5 division is connected to the input 1 of the block 8 of increasing by one and to the input 1 of the block 6 of multiplication, the output 1 of the block 6 of multiplication is connected to the input 1 of the block 9 of multiplication by two, the output 2 of the block 6 of multiplication is connected to the input 1 block 7 of multiplication, output 1 of block 7 of multiplication is connected to input 1 of block 12 of multiplication, output 1 of block 8 of multiplication by one is connected to input 2 of block 12 of multiplication and input 1 of block 13 of multiplication by two, output 1 of block 9 of multiplication by two is connected to input 1 of the subtraction unit 10, the output 1 of the subtraction unit 10 is connected to the input 1 of the subtraction unit 11, the output 1 of the subtraction unit 11 is connected to the input 1 of the squaring unit 14 and the input 2 of the addition unit 18, the output 1 of the multiplication unit 12 is connected to the input 1 of the unit 15 multiply by four, the output 1 of the block 13 of multiplication by 2 is connected to the input 2 of the division 19, the output 1 of the squaring block 14 is connected to the input 1 of the subtraction block 16, the output 1 of the multiplication by four block 15 is connected to the input 2 of the subtraction block 16, the output 1 block 1 6 subtraction is connected to the input 1 of the unit 17 for calculating the square root, the output 1 of the unit 17 for calculating the square root is connected to the input 1 of the addition unit 18, the output 1 of the addition unit 18 is connected to the input 1 of the division unit 19, the output 1 of the division unit 19 is connected to the input of the unit 20 displaying the result.

Thanks to the new set of features due to the additional introduction of two division blocks, three multiplication blocks, an increase by one, two multiplication blocks by two, a multiplication by four, three subtraction blocks, a squaring block, a square root calculation block, an addition and organization block the connections between them, the optimal value of the packet size is calculated, at which the minimum difference between the delay and the transmission time of a message (file) of a fixed size is provided.

The utility model can be widely used in communication systems using synchronization mechanisms for encryption or error-correcting coding, as well as in organizing data streaming using smoothing buffers in cases where it is necessary to provide a balanced combination of delay and transmission time of a file message.

The use of the proposed device makes it possible to calculate such an optimal packet size, which provides the minimum difference between the delay and the transmission time of the message (file).

The device implements the following theoretical provisions.

Modern communication systems generally use standard packet sizes for all types of traffic and message lengths. However, such unification deprives the overload control algorithms of the necessary degrees of freedom. In addition, a fixed packet size is an additional intelligence feature that allows you to determine the type of transmitted stream. However, the TCP / IP or UDP / IP protocol stack allows the programmer to control the packet size, naturally within acceptable limits. And in view of the fact that these protocols, in fact, are the basis of all modern communication systems, there is objectively a scientific task of choosing the optimal packet size.

As you know, each packet consists of a header and a payload. When transmitting streaming video, audio, it is necessary that the packet size guarantees the minimum delay. The delay in this case arises due to the need to wait some time before receiving sufficient data to fill the entire useful part of the packet.

It is intuitively clear that the minimum delay in this case will be at the minimum packet size, but the total transmission time will tend to infinity. Finding the optimal value will make it possible to use the resources of the communication system in a balanced way.

The problem of optimizing the packet size exists when dealing with bit errors arising from transmission over a noisy channel. In this case, the choice of the optimal packet size will ensure the balanced functioning of the system for duplicating the lost parts of the message.

Let us introduce the following notation:

- размер передаваемого сообщения (общий размер полезной части), байт;

- the size of the transmitted message (total size of the useful part), bytes;

- размер сообщения после пакетирования с учетом служебных данных, байт;

- message size after batching including service data, bytes;

- размер служебной части сообщения после пакетирования, байт;

- the size of the service part of the message after packaging, bytes;

- размер пакета, байт;

- packet size, bytes;

- размер служебной части пакета, байт;

- the size of the service part of the packet, bytes;

- размер полезной части пакета, байт;

- the size of the useful part of the packet, bytes;

- скорость поступления потока, байт/с;

- flow rate, bytes / s;

- скорость передачи пакетированных данных, байт/с;

- packet data transfer rate, bytes / s;

- время передачи сообщения с учетом полезной и служебной части, с;

- time of message transmission, taking into account the useful and service parts, s;

- количество пакетов сообщения, шт.;

- number of message packets, pcs;

- задержка формирования пакета, с;

- packet formation delay, s;

- задержка передачи пакета, с;

- packet transmission delay, s;

- общая задержка передачи пакета, с.

- total packet transmission delay, sec.

, который бы обеспечивал минимум задержки

при минимуме времени

на передачу всего сообщения (файла) или другими словами минимум разности задержки и времени передачи сообщения (файла).It is necessary to determine such a packet size

that would provide a minimum of latency

with a minimum of time

to transfer the entire message (file), or in other words, the minimum difference between the delay and transmission time of the message (file).

после пакетирования в соответствии с выражениемDetermine the number of packets that the original message will consist of

after packaging according to the expression

In this case, the resulting value is not necessarily an integer, but when used in real communication systems, it should be rounded up.

As a result of batching, the volume of message data will increase by the amount of the total service part

The amount of data after packaging, taking into account the service part, can be defined as

The total transmission delay in this case includes the delay in collecting data for filling the packet and the actual transmission of the packet and can be represented as

The delay in the transmission of one packet can be found from the expression

Substituting (1) and (3) in (5) as a result, we obtain

The delay in the formation of the packet can be found based on the expression

Substituting (6) and (7) into (4) and performing elementary transformations, we obtain

Now let's find the total time of message transmission

Substituting (3) into (9), we obtain

и

представлены на фигуре 1.Function graphs

and

are presented in figure 1.

.Figure 1 clearly shows two solutions, one of which can be excluded based on the physical meaning of the problem. The packet size cannot be less than the size of the service part, and the transmission time must satisfy the condition

...

по выражению (10) и графику на фигуре 1 позволяет сделать вывод, что она терпит разрыв в точке

Function analysis

according to expression (10) and the graph in figure 1, it can be concluded that it suffers a break at the point

, найдем решением следующего уравненияThe point of intersection of the two dependencies will give the optimal ratio of delay and message transmission time. In this case, the minimum difference between the delay and the message transmission time will be ensured, and it is obviously equal to zero. Intersection point

, we find a solution to the following equation

, в результате выражение (11) примет вид:Multiply both sides by

, as a result, expression (11) will take the form:

, и выполним элементарные преобразованияMultiply both sides of (12) by

, and perform elementary transformations

Expand the brackets in (13)

We transform (14) to the quadratic equation

As a result, the solution will take the form

Given that one root of the equation can be eliminated, and this is the smaller root # 2, the solution is as follows

A device that implements these theoretical provisions is shown in figure 2.

The device for calculating the optimal packet size according to the criterion of the minimum difference between the delay and the transmission time of the message comprises: block 1 for inputting the value of the packet data transmission rate; block 2 for inputting the value of the input flow rate; block 3 for entering the value of the size of the service part of the packet; block 4 input the value of the size of the transmitted message; blocks 5, 19 divisions; blocks 6, 7, 12 multiplication; block 8 increase by one; block 9 multiply by two; subtraction blocks 10, 11, 16; block 13 multiply by two; block 14 squaring; block 15 multiplying by four; block 17 calculating the square root; block 18 addition; block 20 displaying the result.

The device operates as follows.

In block 1, the value of the packet data transmission rate is entered.

In block 2, enter the value of the input flow rate.

In block 3, the value of the size of the service part of the packet is entered.

In block 4, the value of the size of the transmitted message is entered.

и

соответственно, и на выходе 1 блока 5 деления формируется сигнал эквивалентный

.Signals equivalent to

and

respectively, and at the output 1 of the block 5 division, a signal is generated equivalent to

...

и

соответственно, и на выходах 1 и 2 блока 6 умножения формируются сигналы эквивалентные

.Signals equivalent to

and

respectively, and at the outputs 1 and 2 of the multiplication unit 6 signals are generated equivalent to

...

и

соответственно, и на выходе 1 блока 7 умножения формируется сигнал эквивалентный

.At the input 1 of the multiplication unit 7 from the output 2 of the multiplication unit 6 and at the input 2 of the multiplication unit 7 from the output of the input unit 3 of the value of the size of the service part of the packet, signals are received equivalent

and

respectively, and at the output 1 of the multiplication unit 7, a signal is formed equivalent to

...

, и на выходе 1 блока 8 увеличения на один формируются сигнал эквивалентный

.At the input 1 of block 8, increasing by one from the output 1 of block 5 of dividing, a signal is received equivalent to

, and at the output 1 of block 8, increasing by one, a signal is generated equivalent to

...

, и на выходе 1 блока 9 умножения на два формируется сигнал эквивалентный

.At the input 1 of block 9 of multiplication by two from the output 1 of block 6 of multiplication, a signal is received equivalent to

, and at the output 1 of block 9 for multiplying by two, a signal is generated equivalent to

...

и

соответственно, и на выходе 1 блока 10 вычитания формируется сигнал эквивалентный

.Signals equivalent to

and

respectively, and at the output 1 of the subtraction unit 10, a signal is generated equivalent to

...

и

соответственно, и на выходе 1 блока 11 вычитания формируется сигнал эквивалентный

.Signals equivalent to

and

respectively, and at the output 1 of the subtraction unit 11, a signal is generated equivalent to

...

и

соответственно, и на выходе 1 блока 11 вычитания формируется сигнал эквивалентный

.Signals equivalent

and

respectively, and at the output 1 of the subtraction unit 11, a signal is generated equivalent to

...

, и на выходе 1 блока 13 умножения на два формируется сигнал эквивалентный

.At the input 1 of the block 13 of multiplication by two from the output 1 of the block 8 of increasing by one, a signal is received equivalent

, and at the output 1 of block 13 for multiplying by two, a signal is generated equivalent to

...

, и на выходе 1 блока 14 возведения в квадрат формируется сигнал эквивалентный

.At the input 1 of the squaring unit 14 from the output 1 of the subtraction unit 11, a signal is received equivalent to

, and at the output 1 of the squaring unit 14, a signal is generated equivalent to

...

, и на выходе 1 блока 15 умножения на четыре формируется сигнал эквивалентный

.At the input 1 of the block 15 of multiplication by four from the output 1 of the block 12 of multiplication, a signal is received equivalent

, and at the output 1 of block 15 multiplying by four, a signal is generated equivalent to

...

и

соответственно, и на выходе 1 блока 16 вычитания формируется сигнал эквивалентный

.Signals equivalent to

and

respectively, and at the output 1 of the subtraction unit 16, a signal is generated equivalent to

...

, и на выходе 1 блока 17 вычисления квадратного корня формируется сигнал эквивалентный

.At the input 1 of the block 17 for calculating the square root from the output 1 of the block 16 of subtraction, a signal is received equivalent

, and at the output 1 of block 17 for calculating the square root, a signal is generated equivalent to

...

и

соответственно, и на выходе 1 блока 18 сложения формируется сигнал эквивалентный

.Signals equivalent to

and

respectively, and at the output 1 of the addition unit 18, a signal is generated equivalent to

...

и

соответственно, и на выходе 1 блока 19 деления формируется сигнал эквивалентный

.Signals equivalent to

and

respectively, and at the output 1 of the division unit 19, a signal is generated equivalent to

...

и производится его отображение на экране оператора.On the block 20 displaying the result from the output 1 of the block 19 addition is supplied with a signal equivalent to

and it is displayed on the operator's screen.

Thus, the use of the proposed device will make it possible to calculate such an optimal packet size, which provides a minimum difference between the delay and the transmission time of a message (file), taking into account the connection parameters and the size of the transmitted file, which allows a balance between the delay and the file transfer time. This can be useful both when designing new communication systems and when optimizing the operating parameters of existing ones.

SOURCES OF INFORMATION

1. RU 2604416, 2015.

2. RU 2680764, 2018.

3. RU 2370907, 2004.

4. RU 2341903, 2004.

Claims (1)

A device for calculating the optimal packet size according to the criterion of the minimum difference between the delay and the message transmission time, containing a block for inputting the value of the packet data transmission rate, an input block for the value of the output stream rate, an input block for the size of the service part of the packet, an input block for the size of the transmitted message, a block for displaying the result characterized in that, according to the utility model, it additionally contains two division units, three multiplication units, an increment unit by one, two multiplication units by two, a multiplication unit by four, three subtraction units, a squaring unit, a square root calculation unit, an addition unit, moreover, the output of block 1 for inputting the value of the packet data transmission rate is connected to the input 1 of block 5 of division, the output of block 2 for input of the value of the input stream rate is connected to input 2 of block 5 of division, the output of block 3 for input of the value of the size of the service part of the packet is connected to input 2 of block 7 of multiplication , with input 2 of multiplication unit 6 and input 2 of the subtraction unit 10, the output of the input unit 4 of the value of the size of the transmitted message is connected to the input 2 of the subtraction unit 11, the output 1 of the division unit 5 is connected to the input 1 of the block 8 of increasing by one and to the input 1 of the multiplication unit 6, the output 1 of the multiplication unit 6 is connected to input 1 of block 9 of multiplication by two, output 2 of block 6 of multiplication is connected to input 1 of block 7 of multiplication, output 1 of block 7 of multiplication is connected to input 1 of block 12 of multiplication, output 1 of block 8 of increasing by one is connected to input 2 of block 12 of multiplication and input 1 of the block 13 for multiplying by two, the output 1 of the block 9 for multiplying by two is connected to the input 1 of the subtraction unit 10, the output 1 of the subtraction unit 10 is connected to the input 1 of the subtraction unit 11, the output 1 of the subtraction unit 11 is connected to the input 1 of the squaring unit 14 and input 2 of addition block 18, output 1 of multiplication block 12 is connected to input 1 of block 15 of multiplication by four, output 1 of block 13 of multiplication by 2 is connected to input 2 of division 19, output 1 of squaring block 14 is connected to input 1 of block 16 subtraction, the output 1 of the unit 15 multiplying by four is connected to the input 2 of the subtraction unit 16, the output 1 of the subtraction unit 16 is connected to the input 1 of the unit 17 for calculating the square root, the output 1 of the unit 17 for calculating the square root is connected to the input 1 of the addition unit 18, the output 1 the addition unit 18 is connected to the input 1 of the dividing unit 19, the output 1 of the dividing unit 19 is connected to the input of the result display unit 20.

Images