KR102135737B1 - Peer and method for starting point adaptation - Google Patents

Abstract

A method of adjusting a peer's starting point is disclosed. In one embodiment, a start point (SP) value and a download point (DP) value of a counterpart peer are received from the counterpart peer, and based on the received SP value and the received DP value, Determine the initial SP value, and when the determined initial SP value is less than the received SP value, the ratio between the average move rate of the play point of the peer and the average fragment reception rate of the peer Then, a margin is calculated based on the calculated ratio, and an SP value of the peer is determined using any one of the received SP value and the received DP value and the calculated margin.

Description

Peer and peer start point coordination method {PEER AND METHOD FOR STARTING POINT ADAPTATION}

The following embodiments are directed to a peer and a method of adjusting the starting point of the peer.

In the case of mesh-based peer-to-peer (P2P) streaming, the buffer maps of each peer (or each terminal) are different due to the characteristics of P2P.

Since the peer does not receive the buffer map from the tracker server, but fetches it from another peer, a new peer who participates in the network sets the starting point based on the buffer map of the counterpart peer that first connected. When a peer connects to the peer, it requests a chunk corresponding to the size of the buffer map based on the starting point set by the peer.

If the peer sets the starting point of the buffer map to a value that is too old, there may be a situation in which a new chunk is not received because a desired chunk is not found in the buffer map of the peer. In addition, when the bitrate of an image is high, the generation speed of chunks increases, and thus the sliding speed of the buffer map increases.

If the peer's buffer map does not move according to the actual video speed, the peer becomes orphan in the overlay network from a certain point in time, and new data may no longer be received from other peers. In addition, a peer that has become an orphan can become an orphan to a corresponding peer by transmitting an incorrect starting point to one or more peers that first access it.

A method for adjusting a start point of a peer according to one side includes: receiving a start point (SP) value and a download point (DP) value of the counterpart peer from the counterpart peer; Determining an initial SP value of a peer based on the received SP value and the received DP value; If the determined initial SP value is less than the received SP value, calculating a ratio between an average move rate of a play point of the peer and an average fragment reception speed of the peer; Calculating a margin based on the calculated ratio; And determining the SP value of the peer using one of the received SP value and the received DP value and the calculated margin.

The determining of the initial SP value may include calculating a difference value between the received DP value and the received SP value, and multiplying a second constant value by a larger value among the calculated difference value and a first constant value. ; And rounding the multiplication result and determining a difference value between the received DP value and the rounding result as the initial SP value.

The first constant value may be 1, and the second constant value may be 0.5.

The calculating of the margin may include calculating a difference value between the received DP value and the received SP value, and multiplying the calculated difference value by the calculated ratio; Rounding the larger of the multiplication result and a third constant value; And determining the rounding result as the margin.

The third constant value may be 1.

The determining of the SP value may include determining the SP value to be close to the received DP value among the received SP value and the received DP value when the average fragment reception speed is greater than a threshold value. have.

The difference between the determined SP value and the received DP value may correspond to the calculated margin.

The determining of the SP value may include determining the SP value to be close to the received SP value among the received SP value and the received DP value when the average fragment reception speed is less than or equal to a threshold value. .

The difference between the determined SP value and the received SP value may correspond to the calculated margin.

The determining of the SP value may include determining a result of subtracting the calculated margin from the received DP value as the SP value when the average fragment reception speed is greater than a threshold value; And determining a result of adding the calculated margin to the received SP value as the SP value when the average fragment reception speed is less than or equal to a threshold value.

The average moving speed of the reproducing point may be related to the generation speed of the fragment.

The peer according to one side comprises a communication interface; And receiving a start point (SP) value and a download point (DP) value of the counterpart peer from the counterpart peer through the communication interface, and based on the received SP value and the received DP value. Determines the initial SP value of the peer, and when the determined initial SP value is less than the received SP value, between the average move rate of the play point of the peer and the average fragment reception rate of the peer Calculate a ratio of, calculate a margin based on the calculated ratio, and determine the SP value of the peer using any one of the received SP value and the received DP value and the calculated margin It includes a processor that does.

The processor calculates a difference value between the received DP value and the received SP value, multiplies a larger value of the calculated difference value and a first constant value by a second constant value, and rounds the multiplication result. The difference between the received DP value and the rounding result may be determined as the initial SP value.

The first constant value may be 1, and the second constant value may be 0.5.

The processor calculates a difference value between the received DP value and the received SP value, multiplies the calculated difference value by the calculated ratio, and rounds the larger of the multiplication result and a third constant value, and , The rounding result may be determined as the margin.

The third constant value may be 1.

When the average fragment reception speed is greater than a threshold value, the processor may determine the SP value to be close to the received DP value among the received SP value and the received DP value.

The difference between the determined SP value and the received DP value may correspond to the calculated margin.

When the average fragment reception rate is less than or equal to a threshold value, the processor may determine the SP value to be close to the received SP value among the received SP value and the received DP value.

The difference between the determined SP value and the received SP value may correspond to the calculated margin.

When the average fragment reception speed is greater than a threshold value, the processor determines a result of subtracting the calculated margin from the received DP value as the SP value, and when the average fragment reception speed is less than a threshold value, the reception The result of adding the calculated margin to the generated SP value may be determined as the SP value.

The average moving speed of the reproducing point may be related to the generation speed of the fragment.

According to an embodiment, the peer may readjust the starting point when it is determined that its starting value is lagging in the process of negotiating a buffer map with the counterpart peer. Due to this, the risk of the peer becoming an orphan in the network may be lowered. In addition, through this readjustment function, the playback times of each of several peer terminals can be synchronized.

1 is a diagram for describing a starting point of a peer.
2 to 3 are diagrams for explaining adjustment of a starting point of a peer according to an embodiment.
4 is a flowchart illustrating a method of adjusting a starting point of a peer according to an embodiment.
5 is a block diagram illustrating a peer according to an embodiment.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. However, since various changes may be made to the embodiments, the scope of the rights of the patent application is not limited or limited by these embodiments. It should be understood that all changes, equivalents, or substitutes to the embodiments are included in the scope of the rights.

The terms used in the examples are used for illustrative purposes only and should not be interpreted as limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiment belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this application. Does not.

In addition, in the description with reference to the accompanying drawings, the same reference numerals are assigned to the same components regardless of the reference numerals, and redundant descriptions thereof will be omitted. In describing the embodiments, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the embodiments, the detailed description thereof will be omitted.

Prior to the detailed description, a buffer map will be described. The buffer map consists of a Completed section, a Downloading section, and an Empty section.

A complete section represents a section that a peer possesses fragments continuously.

The downloading section represents a section that a peer does not possess fragments continuously.

The empty section represents a section that will be used for buffering to prevent from overriding SP by DP to prevent overriding SP by DP.

And, the buffermap has the following attributes that point specific fragment identifier.

-CP (Completed Point): CP indicates the end of the completed section in the buffer map (This value points to the end of the completed section in the buffermap). In other words, CP corresponds to the end of the complete section.

-DP (Downloading Point): DP indicates the end of the downloading section in the buffer map (This value points to the end of the downloading section in the buffermap). In other words, DP corresponds to the end of the downloading section.

-SP (Starting Point): SP represents the identifier at the beginning of the buffer map (This value points to the identifier at the beginning of the buffermap). In other words, SP represents the beginning of the buffer map.

-PP (Play Point): PP represents the identifier passed to the player in the buffer map (This value points to the identifier that is passed to the player in the buffermap). PP is used for flow control (This value is used for flow control with other peers).

-EP (End Point): EP indicates the end of the empty section.

1 is a diagram for describing a starting point of a peer.

1, the buffer map of the peer P2 120 may precede the buffer map of the peer P1 110. In other words, the start point (SP) of the peer P1 110 may be older than the SP of the peer P2 120. In this case, even if the peer P1 110 accesses the peer P2 120 and requests a chunk corresponding to the size of the buffer map of the peer P1 110 from the peer P2 120 based on its SP The desired chunk may not be found in the buffer map of the peer P2 120. In addition, peer P1 110 may not be able to receive a newly created chunk from P2 120.

In addition, the buffer map of the peer P2 (120) is moved in accordance with the video speed in a situation in which the buffer map of the peer P1 (110) is ahead of the buffer map of the peer P1 (110) (in other words, sliding) ), from a specific point in time, the peer P1 110 may become an orphan in an overlay network. In this case, peer P1 110 may no longer receive data from peer P2 120 as well as other peers. In addition, the peer P1 110, which has become an orphan, can propagate an incorrect starting point to one or more third peers that have accessed it, so that the corresponding third peers can become orphans in the overlay network.

According to an embodiment, the peer P1 110 may solve the above-described problem by adjusting its SP. Hereinafter, the SP adjustment of the peer P1 110 will be described with reference to FIGS. 2 to 3.

2 to 3 are diagrams for explaining adjustment of a starting point of a peer according to an embodiment.

Referring to FIG. 2, peer P1 110 performs buffer map negotiation with peer P2 120 (210). At this time, the peer P1 (110) may receive the SP value and the DP (download point) value of the peer P2 (120) from the peer P2 (120), and the SP value of the peer P1 (110) is peer P2 (120). If it is less than the SP value of ), the new SP value, that is, the SP' value is determined.

If the peer P1 110 is executed for the first time and the SP value is not set and there is no buffermap time table (BTT) information, the peer P1 110 is the SP value of the peer P2 120 and the peer P2 The peer P1 110 may determine its own initial SP value based on the DP value of 120. For example, the peer P1 110 may determine its initial SP value according to Equation 1 below.

[Equation 1]

mySP_ini = peerDP-ROUND[ ½ × max{(peerDP-peerSP), 1}]

In Equation 1 above, mySP_ini represents the initial SP value of peer P1 (110), peerDP represents the DP value of peer 2 (120), and peerSP represents the SP value of peer 2 (120). In addition, in Equation 1 above, max denotes an operator for selecting a larger value of 1 and a difference value between peerDP and peerSP, and ROUND denotes a rounding operator. For example, if 1 of 1 and the difference value between peerDP and peerSP is larger, mySP_ini may be determined as the difference value between peerDP and ROUND[½×1], that is, peerDP-1.

If the initial SP value is smaller than the SP value of the peer P2 120, the peer P1 110 newly determines the SP' value without using the initial SP value.

Hereinafter, how the peer P1 110 determines the SP' value will be described.

Let the SP value of peer P1(110) be mySP.

Peer P1 (110) determines the value of SP' according to Equation 2 below when mySP is smaller than peerSP.

[Equation 2]

R= APMrate/ADrate; /* (0 <R <1) */

N=ROUND[max{(peerDP-peerSP) x R, 1}];

if (ADrate> Limit) mySP = peerDP-N;

else mySP = peerSP + N;

In Equation 2 above, APMrate is an abbreviation of average play point move rate and represents the average move rate of the play point of peer P1 (110), and AD rate is the abbreviation of average download rate, peer P1 Represents an average piece reception rate of 110. Since the APMrate is almost similar to the generation speed of a fragment, the peer P1 110 can estimate the APMrate through the generation speed of the fragment.

When peer P1 110 calculates the ratio R between the APMrate and the ADrate, it determines the margin R. Referring to Equation 2 above, the peer P1 110 may determine the margin R by rounding the larger value of the result of multiplying (peerDP-peerSP) by the margin R and 1.

When the margin R is determined, the peer P1 110 may compare the ADrate and the threshold limit. The threshold value Limit may be calculated based on, for example, an average consumption rate (APrate).

As a result of the comparison, if the ADrate is greater than the Limit, the peer P1 110 may determine peerDP-N as an SP' value. In other words, when the AD rate is greater than the limit, the peer P1 110 may determine the SP' value as a value of a point close to the peerDP. At this time, the difference between the value of the point close to peerDP and peerDP corresponds to the margin R.

A case in which the AD rate is greater than the Limit is shown in FIG. 3. Referring to FIG. 3, peer P1 110 may determine peerDP-N as an SP' value. If the value of SP' becomes too close to peerDP, peer P1 110 may not be able to hold the corresponding piece at the time when the piece is to be played back. To prevent this problem from occurring or to minimize this problem, the peer P1 110 may determine the difference value between peerDP and the properly calculated buffer interval N as the value SP'.

As a result of the comparison, if the AD rate is less than or equal to the Limit, the peer P1 110 may determine peerSP + N as an SP' value. In other words, when the AD rate is less than or equal to the Limit, the peer P1 110 may determine the SP' value as a value of a point close to the peerSP. At this time, the difference between the value of the point close to the peerSP and the peerSP corresponds to the margin R.

A case in which AD rate is less than or equal to Limit is shown in FIG. 4. Referring to FIG. 4, peer P1 110 may determine peerSP + N as an SP' value. If the peer P1 110 uses the SP value of the peer P2 120 as it is, the SP of P2 may move while the buffer map adaptation is in progress. In this case, even though the peer P2 120 requests a piece that matches the SP' of the peer P1 110, the peer P2 120 may not be able to transmit the corresponding piece to the peer P1 110. To prevent this problem from occurring or to minimize this problem, the peer P1 110 may set the sum of the peerSP and the appropriately calculated margin N to the value SP'.

When the SP' value is determined, the peer P1 110 requests a fragment or a chunk from the peer P2 120 based on the SP' value (220).

Peer P1 110 receives a fragment or chunk from peer P2 120 (230).

Accordingly, the peer P1 110 can play the video at an appropriate time point during streaming.

5 is a flowchart illustrating a method of adjusting a starting point of a peer according to an embodiment. The peer described with reference to FIG. 5 represents the peer P1 110 described above, and the peer peer represents the peer P2 120 described above.

Referring to FIG. 5, the peer receives the SP value and the DP value of the counterpart peer from the counterpart peer (510). The peer may receive an SP value and a DP value of the counterpart peer from the counterpart peer in the process of performing buffer map negotiation with the counterpart peer.

The peer determines an initial SP value of the peer based on the received SP value and the received DP value (520). Step 520 may correspond to a process in which the peer P1 110 calculates mySP_ini.

When the determined initial SP value is less than the received SP value, the peer calculates a ratio between the average move rate of the peer's play point and the average fragment reception rate of the peer (530). The ratio calculated in step 530 may correspond to the above-described R.

The peer calculates a margin based on the calculated ratio (540). The margin calculated in step 540 may correspond to the aforementioned N.

The peer determines the SP value of the peer using one of the received SP value and the received DP value and the calculated margin (550). For example, if the average fragment reception rate is greater than the threshold limit, the peer may determine the value obtained by subtracting the margin from the received DP value as the peer's SP value. If the average fragment reception rate is less than the threshold limit, the received SP The value plus the margin can be determined as the peer's SP value. The SP value determined in step 550 may correspond to the above-described SP' value.

The matters described through FIGS. 1 to 4 may be applied to the matters described through FIG. 5, and thus detailed descriptions are omitted.

6 is a block diagram illustrating a peer according to an embodiment.

Referring to FIG. 6, the peer 600 includes a communication interface 610 and a processor 620. The peer 600 described through FIG. 6 represents the peer P1 110, and the peer peer represents the peer P2 120.

The processor 620 receives the SP value and the DP value of the counterpart peer from the counterpart peer through the communication interface 610.

The processor 620 determines an initial SP value of the peer 600 based on the received SP value and the received DP value.

When the determined initial SP value is less than the received SP value, the processor 620 calculates a ratio between the average moving speed of the playback point of the peer 600 and the average fragment receiving speed of the peer 600.

The processor 620 calculates a margin based on the calculated ratio.

The processor 620 determines the SP value of the peer using one of the received SP value and the received DP value and the calculated margin.

The matters described through FIGS. 1 to 5 may be applied to the matters described through FIG. 6, so a detailed description thereof will be omitted.

According to an embodiment, if the peer P1 110 determines that the buffer map of the peer P2 120 is ahead of its own buffer map in the process of a buffer map negotiation with the peer P2 120, the SP value To the value of SP'. Accordingly, the buffer map of the peer P1 110 is also moved.

When real-time is important such as live broadcasting, the peer P1 110 may determine the SP' value or adjust the SP value so as to match the possible new generation interval. When providing a smooth service is more important than real-time, the peer P1 110 may determine the SP' value or adjust the SP value to match the section in which sufficient fragments are secured.

Due to the nature of streaming, the buffer map keeps moving over time. That is, the buffer map of peer P2 120 is moved. For this reason, if the peer P1 110 uses the SP of the peer P2 120 as it is in the process of adjusting the SP, it may not receive a desired fragment from the peer P2 120 (CASE 1).

Alternatively, if the peer P1 110 determines the SP' value too close to the DP of the peer P2 120, a problem may occur in that the fragment cannot be secured at a necessary point in time (CASE 2).

Therefore, there must be some margin in setting the SP' value.

In order to solve the above-described CASEs 1 and 2, an initial SP value and an SP' value may be determined based on activity information of the peer P1 110. In other words, it is possible to flexibly deduce the SP' value in consideration of the moving speed (APMrate) of the PP and the average fragment reception speed (ADrate).

This is possible by inferring the video playback bitrate through the fragment generation speed, and the APMrate of the PP is almost the same as the fragment creation speed. Peer device capabilities can be inferred.

That is, through a combination of these two values, an optimum value that is most suitable for multimedia characteristics of a session, that is, SP', may be determined in consideration of network conditions and performance of peer equipment.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -A hardware device specially configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of the program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operation of the embodiment, and vice versa.

The software may include a computer program, code, instructions, or a combination of one or more of these, configuring the processing unit to behave as desired or processed independently or collectively. You can command the device. Software and/or data may be interpreted by a processing device or to provide instructions or data to a processing device, of any type of machine, component, physical device, virtual equipment, computer storage medium or device. , Or may be permanently or temporarily embodyed in a transmitted signal wave. The software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

As described above, although the embodiments have been described by the limited drawings, a person of ordinary skill in the art can apply various technical modifications and variations based on the above. For example, the described techniques are performed in a different order from the described method, and/or components such as a system, structure, device, circuit, etc. described are combined or combined in a form different from the described method, or other components Alternatively, even if substituted or substituted by an equivalent, an appropriate result can be achieved.

Therefore, other implementations, other embodiments and claims and equivalents fall within the scope of the following claims.

Claims (18)

Acquiring a start point value and a download point value of the counterpart peer;
Calculating a ratio between an average move rate of a peer's play point and an average piece reception speed of the peer;
Determining a margin based on the calculated ratio;
If the average fragment reception speed is greater than a predetermined limit, determining a starting point value of the peer based on the download point value of the counterpart peer and the determined margin; And
If the average fragment reception speed is less than the predetermined limit, determining a starting point value of the peer based on the starting point value of the counterpart peer and the determined margin
Containing,
How to adjust the peer's starting point.
delete delete The method of claim 1,
The step of determining the margin,
Calculating a difference value between the download point value of the counterpart peer and the start point value of the counterpart peer, and multiplying the calculated difference value by the calculated ratio;
Rounding off the larger of the multiplication result and the constant value; And
Determining the rounding result as the margin
Including,
The constant value is 1,
How to adjust the peer's starting point.
delete The method of claim 1,
The step of determining a starting point value of the peer based on the download point value of the counterpart peer and the determined margin,
Determining a difference between the download point value of the counterpart peer and the determined margin as the start point value of the peer
Containing,
How to adjust the peer's starting point.
The method of claim 1,
The step of determining the start point value of the peer based on the start point value of the counterpart peer and the determined margin,
Determining the sum of the starting point value of the counterpart peer and the determined margin as the starting point value of the peer
Containing,
How to adjust the peer's starting point.
delete The method of claim 1,
The average moving speed of the reproduction point is related to the generation speed of a fragment,
How to adjust the peer's starting point.
Acquire a start point value and a download point value of the peer peer, and determine the ratio between the average move rate of the peer's play point and the average fragment reception speed of the peer. Calculate, determine an interval based on the calculated ratio, and if the average fragment reception speed is greater than a predetermined limit, the peer's download point value and the determined margin A processor that determines a start point value, and if the average fragment reception speed is less than the predetermined limit, determines a start point value of the peer based on the start point value of the counterpart peer and the determined margin
Containing,
Peer.
delete delete The method of claim 10,
The processor,
Calculate a difference value between the download point value of the counterpart peer and the start point value of the counterpart peer, multiply the calculated difference value by the calculated ratio, and round the larger of the multiplication result and the constant value, Determine the rounding result as the margin,
The constant value is 1,
Peer.
delete The method of claim 10,
If the average fragment reception speed is greater than the predetermined limit, the processor determines a difference between the download point value of the counterpart peer and the determined margin as the start point value of the peer,
Peer.
The method of claim 10,
If the average fragment reception speed is less than the predetermined limit, the processor determines the sum of the starting point value of the counterpart peer and the determined margin as the starting point value of the peer,
Peer.
delete The method of claim 10,
The average moving speed of the reproduction point is related to the generation speed of a fragment,
Peer.

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