KR20150141062A - Session management method and system for controlling data of multi-channel - Google Patents

Abstract

Disclosed are a session management method for controlling data of a plurality of channels, and a system thereof. To this end, each session transmitting data of each channel, is grouped, and a control session transceiving a data control command representing the grouped session, is set. Also, data, which is transmitted through each session in the session group, is disposed in a particular order to transmit the same to a client through one single session, thereby minimizing a time delay generated when the data of each channel is controlled at a time, and managing a bandwidth only through one single session.

Description

[0001] Session management method and system for controlling data of a plurality of channels [0002]

More particularly, the present invention relates to a method and system for controlling and managing a plurality of sessions created between a server for transmitting and receiving data of a plurality of channels through a plurality of sessions and a client .

Streaming refers to a technique of playing back files in real time while downloading, out of the conventional method in which files such as video, sound, and animation are downloaded from the Internet to a storage device such as a hard disk drive and played back.

Especially, in a security device or a surveillance device, a single client can receive images of a plurality of channels in real time from one server.

FIG. 1 is a schematic view illustrating a DVR (Digital Video Recorder) device for storing and transmitting images of 16 channels, in which images of 16 channels are output on one screen of a client.

At this time, if the video provided by the DVR server is being recorded in real time by an external camera device or the like, the client can use the FREEZE function to stop the video or use two video stream controls that can continuously receive the video, If the image provided by the server is an image stored in the server, various playback control commands such as playback, stop, forward, backward, forward or backward by one frame, or fast playback or slow playback can be issued from the client.

That is, the real time in the streaming technique does not mean that the transmitted data is recorded in real time, but it means that it is possible for the client to reproduce and control it only with a part of the transmitted data.

In order to transfer data of one channel between a server and a client, a session must be created as a logical connection between the server and the client. Conventionally, in order to facilitate management for each channel, In order to maximize the efficiency of security devices and surveillance devices, when the images of multiple channels are to be played back in one client, the number of sessions and the number of channels do not match, When data of a plurality of channels is transmitted and received between a server and a client through a plurality of sessions, a method for efficiently controlling and managing sessions is required.

(Patent Document 0001) Domestic Registration No. 0823904

SUMMARY OF THE INVENTION The present invention is directed to a system and method for transmitting and receiving data of a plurality of channels, And a method and system for managing a plurality of sessions between a server and a client.

According to a first aspect of the present invention, there is provided a method of managing a plurality of sessions between a server and a client, The method comprising the steps of: receiving a session group command including identification information of a control session and identification information of at least one normal session from the client, A session control step of setting a session corresponding to identification information of the control session among a plurality of included sessions as a control session and grouping the control session and the normal session into a session group; And receiving a data control command from the client through the control session and transmitting a response to the data control command via the control session, And a data control step of transmitting the data of the channel to the client.

According to a second aspect of the present invention, there is provided a method of managing a plurality of sessions between a server and a client, A session management system for controlling data of a plurality of channels, the system comprising: a receiving unit for receiving a session group command including identification information of a control session and identification information of at least one normal session from the client, A session control unit setting a session corresponding to identification information of the control session among a plurality of included sessions as a control session and grouping the control session and the normal session into a session group; And receiving a data control command from the client through the control session and transmitting a response to the data control command via the control session, And a data control unit for transmitting the data of the channel to the client.

According to the session management method of the present invention, all or a part of a plurality of sessions formed between a server and a client are grouped, and any one of the grouped sessions is set as a control session, By controlling data to be transmitted and received, it is possible to prevent a time delay caused by repeated command transmission per session.

In addition, by consolidating a plurality of sessions in a session group into one session, bandwidth management can be handled in one session.

FIG. 1 is a schematic view illustrating a DVR (Digital Video Recorder) device for storing and transmitting images of 16 channels, in which images of 16 channels are output on one screen of a client.
FIG. 2 is a schematic view illustrating a process of transmitting and controlling data between a server and a client using RTSP / RTP, which is one embodiment of the present invention.
FIG. 3A is a block diagram illustrating a plurality of servers and a client for transmitting and receiving data according to the present invention.
FIG. 3B is a block diagram illustrating one network video recorder (NVR) server and one network client for transmitting and receiving data according to an exemplary embodiment of the present invention.
4A, 4B, and 4C schematically illustrate a method of transmitting media data using a conventional RTSP standard protocol.
FIG. 5 schematically illustrates a change in session state between a server and a client according to a Session Group command, which is one embodiment of the present invention.
FIG. 6 shows a plurality of session groups generated between a server and a client when data of a plurality of channels (Multi Channels) is transmitted and received.
FIG. 7 schematically illustrates a change in session state between a server and a client in accordance with one of the embodiments of the present invention, a session merge command.
8A schematically shows the state of a session in which a session group command is applied to four sessions between a server and a client.
FIG. 8B schematically shows that, in the session state of FIG. 8A, a session merge command configured with an RTSP instruction is applied to integrate four sessions in a session group into one session.
FIG. 9 is a flowchart showing the order in which a session group command, a session D group command, a session merge command, and a session dimmer command are issued.
10 is a schematic block diagram of a session management system for controlling data of a plurality of channels as one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the same components of the drawings are denoted by the same reference numerals and signs as possible even if they are shown on different drawings.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

On the other hand, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

Among the concepts to be described later, data refers to a concept of collecting objects transmitted between a server and a client, and media data is a sub-concept defining video or audio data among various data. In addition, the media streaming data is a sub-concept of limiting the media data, which is reproducible for a part of the received data even before completion of reception at the client side receiving the media streaming data (Media Streaming Data).

The server described later can be replaced with a server or a base station in a DVR, an NVR, or an IP camera system as a device capable of storing and transmitting various media data including video and audio, and a client can store various media data including video and audio And can be replaced with a DVR, a NVR, a client or a terminal in the IP Camera system.

RTSP (Real Time Streaming Protocol) is a protocol relating to data transmitted and received in real time, and provides a method for controlling data such as playback, pause, fast forward, rewind, and playback position change command.

The RTP (Real Time Transport Protocol) is a protocol for transmitting and receiving real-time data, and is a protocol for transmitting media data (hereinafter, referred to as media data) including video or audio data.

The RTCP (Real Time Transport Control Protocol) is a protocol for monitoring the RTP data transmission state and transmitting session related information. The RTCP is a protocol for periodically transmitting control packets to all receivers in a session, And calculates the transmission rate at the receiving end, and is used for flow control for RTP.

As the data transmission standard of RTSP and RTP, either Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) can be used, which will be described later with reference to FIG. 4A. RTSP / RTP / TCP, RTSP / RTP / UDP, and the former are TCP data transmission standards, the data control protocol is RTSP, and the data transmission protocol is RTP in order to minimize duplication in the specification. The latter uses UDP as the data transmission standard, and the remainder is the former. Since RTCP follows RTP as it is, it is regarded as the same condition as RTP unless otherwise explained.

FIG. 2 is a schematic view illustrating a process of transmitting and controlling media data between a server and a client using RTSP / RTP, which is one embodiment of the present invention.

In each step, except for the data transmission state monitoring step (S205), if the client issues a command to the server first, the server responds to the command.

First, an instruction acquisition step (S201) is performed in which the client issues a command to the server to acquire the command provided by the server and the server responds to the command. As an example of the command that the client sends to the server, the OPTION command of RTSP may be used.

Next, a data information acquisition step (S202) is performed in which the client issues a command to the server to acquire data information held by the server and the server responds thereto. Examples of the data information that the server has include resolution of a media file, codec, frame rate, bit rate, audio information, and the like. As an example of an instruction to obtain data information, the DESCRIBE command of RTSP may be used.

Thereafter, the client transmits a command for creating a session between the server transmitting the data and the client to be received to the server, and a session creation step (S203) is performed in which the server accepts the command and creates a session. As an example of a command that a client sends to a server that sends data to create a session, the SETUP command of RTSP may be used.

After receiving the data transmission command from the client after the session is created, a data transmission request step (S204) is performed in which the server approves the data transmission command, which corresponds to the PLAY command of the RTSP. When the server approves the data transmission request of the client and then transmits the data to the client according to the RTP, the server side calculates the transmission rate of the client side and monitors the quality of service (QoS) And a data transmission state monitoring step (S205) for receiving feedback data.

A transmission stop request step (S206) and a session end request step (S207) in which the server responds can be performed, and a request to stop the data transmission from the client As an example of the case, the TEARDOWN command of the RTSP may be used as an example in which the PAUSE command of the RTSP receives an instruction to terminate the session from the client.

FIG. 3A is a block diagram illustrating a plurality of servers and a client for transmitting and receiving data according to the present invention.

3A, the first server 310a includes a recorder 315a, a data storage 320a, a network client management unit 325a, an RTSP transmission / reception unit 330a, and an RTP transmission / reception unit 335a. (350a) includes a channel control management unit 355a, and two RTSP / RTP data transmission / reception units (360a and 365a from the top).

The recorder 315a receives data from a camera (not shown) connected to the server through a wired or wireless connection, and transmits the data to the data storage device 320a for storage.

The data storage device 320a stores data inputted from a camera in real time in the form of an image file, or receives and stores data from an external storage device.

The network client management unit 325a adjusts the bandwidth of a session created between the server and the client in a manner to prevent transmission of unnecessary data frames or prevent duplication of the same data.

The RTSP transmitting / receiving unit 330a receives and processes the RTSP command from the client, and the RTP transmitting / receiving unit 335a processes the RTP data to be transmitted / received to / from the client.

In addition, the number of servers from the second server 3101a to the n-th (310na) server may be plural, and each server includes the same configuration as the first server 310a.

The channel control management unit 355a manages data of each channel received from the server 310a in cooperation with the network client management unit 325a.

The RTSP / RTP data transmission / reception units 360a and 365a are connected to the RTSP transmission / reception unit 330a and the RTP transmission / reception unit 335a to transmit and receive RTSP commands and RTP data. The number of RTSP / RTP transmission / reception units is indicated by two for convenience of explanation, and may be changed according to the number of channels transmitted from the server.

FIG. 3B is a block diagram illustrating one network video recorder (NVR) server and one network client for transmitting and receiving data according to an exemplary embodiment of the present invention.

3B, the NVR server 310b includes a recorder 315b, a data storage device 320b, a client bandwidth manager 325b, and an RTSP / RTP manager 330b. The network client 350b includes a channel Control management unit 355b and a plurality of RTSP / RTP transceivers. The description of the configuration described in FIG. 3A is omitted for the sake of simplification of the description.

The client bandwidth management unit 325b is connected to the channel control management unit 355b through a network, receives information on a session created between the server and the client, and manages the bandwidth.

The RTSP / RTP management unit 330b receives data from the data storage device, classifies channels indicating the types of data to be transmitted to the network client 350b, creates a session mapped to each channel, and transmits RTSP / RTP And transmits and receives data according to the received data.

The number of RTSP / RTP transmission / reception units of the network client may be changed according to the channel control management unit 355b, and the number thereof is determined by the number of channels transmitted from the RTSP / RTP management unit 330b. The RTSP / RTP transceiver unit finally transmits data from the NVR server to an output unit (not shown) capable of reproducing or outputting the data.

The client and network client of FIG. 3A and FIG. 3B have information of a session mapped to a channel received from each server. As described above with reference to FIG. 2, when the session is created between the server and the client in the session creation step (S203) during the RTSP connection process, the session information is determined and stored in the server and the client, respectively. It can also be referred to as session identification information.

4A, 4B, and 4C schematically show a method of transmitting data using a conventional RTSP standard protocol.

As shown in FIG. 4A, when UDP is used as the data transmission standard of RTSP and RTP, according to RTSP for transmitting / receiving a control command due to the unidirectional nature of not receiving a process of confirming whether data is received by a receiving end after UDP transmits data A command session 420a and a data session 425a according to RTP to send and receive data, respectively. The command according to the RTCP is transmitted and received between the server 410a and the client 415a through a session such as RTP.

4B shows that the server 410b and the client 415b use TCP as the data transmission standard for RTSP and RTP, and that the command session according to the RTSP and the data session according to the RTP are the same. In other words, it is possible to transmit and receive data of RTSP and RTP in one session. Since commands according to the RTCP are transmitted and received using the same session as the RTP, in this case, commands and data according to the RTSP RTP and the RTCP are all transmitted and received through one session 420b.

FIG. 4C is a view between the server and the client when data of a plurality of channels (Multi Channels) is transmitted / received through each session mapped to each channel in FIG. 4B.

In FIG. 4C, four sessions are created between the server 410c and the client 415c. For example, suppose that the numbers of the four sessions 420c, 425c, 430c, and 435c are 4711234, 2345611, 2341566 and 8721345, respectively. The server of FIG. 4c is a server of a specific broadcasting station, F channel, and Z channel, and that the identification information of each channel is allocated in order of 0, 2, 6, and 12, respectively.

First, since the number of the session numbered as 4711234, 2345611, 2341566, and 8721345 is information for identifying each session, session identification information

ion Information). In the same way, 0, 2, 6, and 12 are channel identification information. Each piece of identification information is not limited to a number but can be a character. The session identification information is generated in a session creation step (S203) in which the server sends a response to the command after receiving an instruction to create a session from the client. The generation of the channel identification information will be described later with reference to Table 10.

Tables 1 and 2 are one embodiment of the present invention, each showing a session creation command including session identification information and a response thereof. Letters C and S represent clients and servers, respectively.

C-> S: SETUP rtsp: //example.com/foo/bar/baz.rm RTSP / 1.0
CSeq: 302
Transport: RTP / AVP; unicast; client_port = 4588-4589

Table 1 shows that the client makes a session creation request to the server.

As an example of a session creation step (S203) for creating a session described above with reference to FIG. 2, the client transmits a SETUP command to the server.

S-> C: RTSP / 1.0 200 OK
CSeq: 302
Date: 23 Jan 1997 15:35:06 GMT
Session: 4711234
Transport: RTP / AVP; unicast;
client_port = 4588-4589; server_port = 6256-6257

Table 2 shows that the server responds to the client after receiving the session creation request from the client.

If the client's session creation request is valid, the server creates a session with the identification information 4711234, and sends a response including the session identification information and the port number to the client, thereby creating a session in the RTSP connection step S203 ) Is terminated.

A session having the identification information 2345611, 2341566, and 8721345 is also generated through the same process as above, and the channel identification information and session identification information are 1: 1 mapped. For example, a channel having channel identification information of 6 is mapped to a session having session identification information of 4711234, and a channel having channel identification information of 12 is mapped to a session having identification information of 2341566. After the mapping between the session and the channel is completed, the data of each channel is transmitted from the server to the client through the session mapped to each channel. Using the above example, F-channel data having channel identification information 6 is transmitted through a session corresponding to the session identification information 4711234, and a Z channel having channel identification information 12 through a session corresponding to the session identification information 2341566 Is transmitted.

Referring to FIG. 4C, a data control command according to the RTSP is expressed through each session, which individually controls the transmission operation of data of different channels transmitted through each session. For example, when a data control command according to RTSP to stop data transmission through a session having identification information 4711234 and a data control command according to RTSP to speed up data transmission through a session having identification information 2341566 are transmitted, The transmission of data to be transmitted to the client through the session with the identification information 4711234 is stopped and the transmission rate of data transmitted to the client through the session with the identification information 2341566 is increased.

Since the session identification information generated in the RTSP connection process has a unique value, two or more different sessions can not have the same session identification information, and the given session identification information is retained until a corresponding connection is terminated by a teardown command or the like do.

FIG. 5 schematically illustrates a change in session state between a server and a client according to a Session Group command, which is one embodiment of the present invention.

When the user issues a session group command through the client 415c in the session state of FIG. 4c, the command is transmitted to the server 410c and changes the session state according to the information included in the command, as shown in FIG. The session group command that the user makes via the client 415c includes identification information of the control session and identification information of at least one normal session.

The control session 550 means a session designated by at least one of a plurality of sessions created between the server 510 and the client 520 by a session group command. The session corresponding to the identification information of the control session included in the session group command becomes the control session 550 and the transmission operation of the data transmitted through all the sessions in the session group is controlled (550). ≪ / RTI >

For example, each session identification information in FIG. 4C is assigned 4711234, 2345611, 2341566 and 8721345 from the top, identification information of the control session included in the session group command is 4711234, identification of the normal session included in the session group command The information is assumed to be 2345611, 2341566, 8721345. In this case, the session forming the session group is four sessions corresponding to the session identification information 4711234, 2345611, 2341566, and 8721345, and the control session becomes the session with the session identification information 4711234.

5, when a user issues a data control command to increase the transmission rate of all data transmitted from the server to the client through the session group through the client, the command issued by the user is transmitted to the control session 550 ) To the server. Then, the server transmits the data transmission speeds of all the data transmitted through the sessions 550, 560, 570 and 580 in the session group to the client faster than before the data control command is received. At this time, the response of the server to the data control command is transmitted through the control session 550.

For example, if the user has been receiving an image, the command to prompt the user to play back the image coming through the client and the server's response to the command are sent and received via the control session 550, Through the session, the data of the image that the user was receiving is transmitted from the server to the client faster than before the user receives the command.

Since the data control command issued from the client uses TCP as a transmission standard, acknowledgment is required when a specific command is transmitted. When there are a plurality of sessions and data to be transmitted through each session is to be controlled at the same time, if a data control command is issued for each session, 1) data control command is transmitted through each session, 2) And 3) a time delay occurs between each session in a process in which the command is applied to the transmission state of data transmitted through all sessions. According to the session group command according to an embodiment of the present invention, a control session for exclusive transmission / reception of a data control command is transmitted, and data is transmitted from the server to the client through all sessions in the session group according to the data control command received through the control session Data can be controlled, so that it is possible to minimize the time delay between each image when it is necessary to receive and control several images on one screen at a time.

FIG. 6 shows two session groups created between a server and a client when data of a plurality of channels (Multi Channels) are transmitted and received.

In the first session group, the second session (625) was designated as the control session, and in the second session group, the sixth session (665) was designated as the control session. The data of the plurality of channels transmitted through the four sessions of the first session group is controlled by the data control command transmitted through the control session 625 of the first session group and is transmitted through the six sessions of the second session group The media data of the plurality of transmitted channels is controlled by a data control command transmitted through the control session 665 of the second session group. The remaining five sessions 670 to 690 do not form a separate session group, and data control commands according to RTSP and data according to RTP are transmitted / received through each individual session in the same manner as a normal session.

If the session group command is applied to a plurality of specific sessions between the server and the client and there is no need to control data of a plurality of channels received from the server at a time through the same control command, Degroup) command to release the grouped session, and change the control session already set to the normal session. That is, the session de-grouping command includes identification information of all the sessions belonging to the session group to be ungrouped. If there are a plurality of session groups, it is possible to ungroup only some of the session groups.

As shown in FIG. 5, if a user drops a session de-group command through a client in a session state between a server and a client to which a session group command is applied, the session state is changed as shown in FIG. A plurality of sessions in which the session group is released after the session D group command is applied to the specific session group between the server and the client are separately issued for each session as before the session group command is applied and the data according to the RTP .

The data control command transmitted through the control session in the session group is effectively handled until the user releases the session group command through the client and the existing session group is released. Therefore, the data control command It has no effect on the transmission operation of data transmitted and received through all the sessions in the session group.

FIG. 7 schematically illustrates a change in session state between a server and a client according to a session merge command, which is one embodiment of the present invention.

In case of RTSP / RTP / TCP, since media data of multiple channels can be transmitted through an interleaved transmission method, when a plurality of sessions are managed as one group, an interleaved transmission method is applied, The data of all the channels transmitted through one session can be transmitted through one session. FIG. 7 shows a session state between a server and a client after receiving a session merge command in the session state between the server and the client in FIG. 5, and further description of the changed session state will be described with reference to Table 9 and Table 10.

In the conventional RTSP / RTP / TCP, the interleaved transmission method is applied between the server and the client after the following communication process between the server and the client.

C-> S: SETUP rtsp: //foo.com/bar.file RTSP / 1.0
CSeq: 2
Trasport: RTP / AVP / TCP; interleaved = 0-1

S-> C: RTSP / 1.0 200 OK
CSeq: 2
Date: 05 Jun 1997 18:57:17 GMT
Trasport: RTP / AVP / TCP; interleaved = 0-1

Table 3 shows that in the RTSP connection process, the client makes an interleaved transmission request to the server.

The number after interleaved in the interleaved instruction syntax means the identification information of the channel identification information and the data of the RTCP.

[RFC2326] Real Time Streaming Protocol RTSP RTSP End Mark Block Mark (1 byte) Ch.identifier (1 byte) Length (2 bytes) Command CRLF $ 0 MM

Table 4 shows the RTSP commands defined on RFC2326.

In the RTSP connection according to Table 4, the identification number of the channel to be interleaved starts from 0, and the symbol $ is used as an identifier before each identification number.

8A schematically shows the state of a session in which a session group command is applied to four sessions between a server and a client.

Since the control session is the first session from the top of the four generated sessions between the server and the client, the command according to the RTSP is delivered through the corresponding control session, and data corresponding to the RTP through the three sessions in the remaining session group , A data transmission status monitoring command according to the RTCP is transmitted. The left part refers to one unit packet transmitted through each session based on the dotted line, and the data according to RTP and the data transmission status monitoring command according to RTCP are transmitted together at a ratio of 1: 1. Herein, not only the commands according to the RTSP but also the data according to the RTP and the data transmission status monitoring commands according to the RTCP are transmitted and received through the control session with reference to FIG. 4B.

FIG. 8B schematically shows that, in the session state of FIG. 8A, a session merge command composed of RTSP instructions is applied to integrate four sessions in a session group into one session.

For convenience of explanation, it is assumed that the session merge command includes an instruction to designate the first session from the top of the four sessions between the server and the client as a single session in FIG. 8A. 8A, video data of channel A and channel C are transmitted through the first and third sessions, respectively. Audio data of the B radio channel and D radio channel are transmitted through the second and fourth sessions, And the interleaved sequence is assumed to be from the first session to the fourth session from the top. That is, the A channel is mapped in the first session, the B radio channel is mapped in the second session, and the relationship between the remaining sessions and the channel is the same.

Upon receiving the session merge command in the state of FIG. 8A, the identification information 0 is assigned to the channel mapped to the first session by the RTSP command. For example, since the channel mapped to the first session is the A channel, which is a video channel transmitted according to the RTP, 'RTP video $ 0' (see Table 4) can be obtained by roughly expressing the final identification information of the data packet of the corresponding channel. . In addition, the value obtained by adding 1 to the identification information of the channel is automatically the final identification information of the command packet of the RTCP. Therefore, it can be expressed as 'RTCP video $ 1' (see Table 4). The allocation of the channel identification information will be described later in more detail with reference to Table 5 and Table 6.

FIG. 8B also applies the above scheme to channels mapped to different sessions, and indicates that each data packet and command packet are transmitted through the single session described above. More specifically, it shows the process of making the data of each channel in the session group into one integrated data according to the channel identification information and the RTCP identification information included in the session merge command, and transmitting it to the client through a single session. The process of generating integrated data according to the channel identification information and the RTCP identification information will be described later with reference to Tables 9 and 10 as one embodiment of the present invention.

When blocks in a single session shown in FIG. 8B are referred to only as an identifier and identification information for ease of explanation, the inclusion of $ 0 and $ 1 means that video data of channel A transmitted through the first session before receiving the session merge command And $ 2 and $ 3 are the audio data and the audio data monitoring command of the B radio channel transmitted through the second session, You can distinguish between commands.

Referring to FIG. 4C and FIG. 5, the transmission of data according to RTP / RTCP is dependent on the command of RTSP. For example, if the RTSP command is the PLAY command, the server will send RTP / RTCP data to the client. If the RTSP command is PAUSE, the server sends RTP / RTCP data to the client. It will temporarily stop until an instruction is given.

Since the RTSP command is one embodiment of the data control command issued from the client and is not intended to be limited to only the RTSP command in the command related to the data transmission, Even if data is controlled, it does not fall outside the scope of the present invention, and this is also true for commands according to RTP and RTCP.

If the user no longer needs to use a single session, a single session can be divided into a plurality of sessions through a session demerge command through the client, Session Degroup) command until it receives the command.

When the session merge command is executed, the session for transmitting the control command according to the existing RTSP is maintained, and the session for transmitting data according to the RTP / RTCP is changed to one session. This allows the RTP / RTCP data to be transmitted immediately to the command session in which a control command according to the existing RTSP is transmitted, even if the user subsequently issues a session de-merge command through the client and thus the unified session is divided into a plurality of sessions .

As one embodiment of the present invention, a session group command is implemented using a Setparameter command provided in a standard protocol of RTSP.

C-> S: SET_PARAMETER rtsp: //example.com/media.mp4 RTSP / 1.0
CSeq: 10
Content-length: 86
Content-type: text / parameters

COMMAND: SESSION GROUP
CONTROL SESSION: 4711234
GROUP: 2345611, 2341566, 8721345

Table 5 shows that the client issues a session group command to the server.

This session group command includes a control session (identification information 4711234) for sending and receiving a data control command in a session group and three sessions (identification information 2345611, 2341566, 8721345).

S-> C: RTSP / 1.0 451 Invalid Parameter
CSeq: 10
Content-length: 10
Content-type: text / parameters

S-> C: RTSP / 1.0 200 SET_PARAMETER
CSeq: 10
Content-length: 10
Content-type: text / parameters

COMMAND: SESSION GROUP OK
CONTROL SESSION: 4711234
GROUP: 2345611, 2341566, 8721345

Table 6 shows the responses that the server receives and receives for the session group command from the client.

The server receives the session group command from the client and returns SESSION GROUP OK if it can operate according to the command, and returns the Invalid Parameter to the client when it can not operate according to the command. When the SESSION GROUP OK is returned, the RTSP command for the next session group is delivered through the control session, thereby controlling the data and data monitoring commands of the channel transmitted through all the sessions in the session group, It is possible to prevent the time delay caused by the difference in the RTSP command transmission time.

As one embodiment of the present invention, a session de-group command is implemented using a Setparameter command provided in a standard protocol of RTSP.

C-> S: SET_PARAMETER rtsp: //example.com/media.mp4 RTSP / 1.0
CSeq: 10
Content-length: 86
Content-type: text / parameters

COMMAND: SESSION DEGROUP
CONTROL SESSION: 4711234
DEGROUP: 2345611, 2341566, 8721345

Table 7 shows that the client issues a session de-group command to the server.

This session group command sends and receives a data control command in the current session group together with a COMMAND to ungroup the session, and three sessions other than the control session (identification information 4711234) and the control session constituting the session group (identification information 2345611 , 2341566, 8721345).

S-> C: RTSP / 1.0 451 Invalid Parameter
CSeq: 10
Content-length: 10
Content-type: text / parameters

S-> C: RTSP / 1.0 200 SET_PARAMETER
CSeq: 10
Content-length: 10
Content-type: text / parameters

COMMAND: SESSION DEGROUP OK
CONTROL SESSION: 4711234
DEGROUP: 2345611, 2341566, 8721345

Table 8 shows the responses that the server receives and sends to the client the session de-group command from the client.

The server receives the session group command from the client and returns SESSION DEGROUP OK if it can operate according to the command, and returns the Invalid Parameter to the client when it can not operate according to the command. When SESSION DEGROUP OK is returned, a session group consisting of a total of four sessions with the subsequent session identification information 4711234, 2345611, 2341566 and 8721345 is released and each operates as a normal session.

The session di group command is intended to separate some or all sessions from one session group. In order to completely release the session group, identification information of the control session or identification information of the entire session constituting the session group may be included as parameters of the session di group command. To separate only some sessions from the session group, It can be included in the parameters of the session D group command.

For example, although the identification information of the control session (4711234) is not included in the parameters of the session D group command in Table 8, three sessions (identification information 4711234, 2345611, 2341566 and 8721345) Is included in the parameters of the session D group command, the session group is released and the four sessions become a normal session following the RTSP command transmitted / received through each session. This is the same result as when the parameter of the session di group command is specified as the identification information of the control session, that is, 4711234 (all the session groups are released).

Assuming that only the session with the identification information 2341566, 8721345 is included in the parameter of the session di group command, only two sessions having the identification information 2341566 and 8721345 are separated from the session group and operate as a normal session, The session with the identification information of 4711234 and 2345611 still remains as the session constituting the session group.

As one embodiment of the present invention, a session merge command is implemented using a Setparameter command provided in the standard protocol of RTSP.

C-> S: SET_PARAMETER rtsp: //example.com/media.mp4 RTSP / 1.0
CSeq: 10
Content-length: 86
Content-type: text / parameters

COMMAND: SESSION MERGE
CONTROL SESSION: 4711234
MERGE: 4711234; interleaved = 0-1, 2345611; interleaved = 2-3,
2341566; interleaved = 4-5, 8721345; interleaved = 6-7

Table 9 shows that the client issues a session merge command to the server.

The session merge command includes an identification information (4711234) for a control session to be used as a single session, identification information of four sessions (identification information 4711234, 2345611, 2341566, 8721345) And information on the order of interleaving data according to RTP / RTCP in the session. The interleaved method has been described in FIGS. 8A and 8B.

S-> C: RTSP / 1.0 451 Invalid Parameter
CSeq: 10
Content-length: 10
Content-type: text / parameters

S-> C: RTSP / 1.0 200 SET_PARAMETER
CSeq: 10
Content-length: 10
Content-type: text / parameters

COMMAND: SESSION MERGE OK
CONTROL SESSION: 4711234
MERGE: 4711234; interleaved = 0-1, 2345611; interleaved = 2-3,
2341566; interleaved = 4-5, 8721345; interleaved = 6-7

Table 10 shows the responses that the server receives from the client and receives a session merge command.

The server receives the session merge command from the client and returns SESSION MERGE OK when it can operate according to the command, and returns the Invalid Parameter to the client when it can not operate according to the command. When SESSION MERGE OK is returned, the multiple sessions specified as parameters of the session merge command are merged into one session. Specifically, after designating one session of a plurality of sessions as a single session, data of all channels transmitted through a plurality of sessions between the server and the client are integrated in an interleaved manner and transmitted to the client through a single session.

Referring to Table 10, first, the four sessions corresponding to the identification information 4711234, 2345611, 2341566, and 8721345 are parameters of the session merge command. Since data of at least one channel is transmitted from the server to the client through each session, when the session identification information is given, the channel mapped to the session can be known.

From the session identification information, the channel mapped to the session, and assigns the channel identification information to the data of the channel transmitted through the session. Referring to Table 10, channel identification information of 0 is assigned to the data of the channel transmitted through the session corresponding to the identification information 4711234, and channel identification information of the channel transmitted through the session corresponding to the identification information 2341566 is 4 . The fact that 0 or even numbers are assigned to the channel identification information in the data according to the RTP has already been described with reference to Table 4. [

Table 4 shows that a data transmission monitoring command according to the RTCP is also required for data transmission according to the RTP and identification information added with 1 to the channel identification information for the data transmission monitoring command according to the RTCP has already been described. For example, 1 and 5 are identification information (hereinafter referred to as RTCP identification information) for a data transmission supervision command of a channel having 0 and 4 as channel identification information, respectively.

After the identification information and the RTCP identification information of channels 0 to 7 are assigned to the four sessions in total, the data is integrated by a method of cross-disposition according to the order of identification information, and then the integrated data is transmitted through a single session (See FIG. 8B). A single session is the most preceding session in the parameter of the session merge command, and the control session is determined as a single session due to the fact that the RTSP command should be transmitted and received. Since the RTSP session is shared with the RTP session in the TCP data transmission standard, it is not necessary to specify the identification information separately in the syntax like RTP and RTCP, and the RTSP instruction is processed by a single unified session.

There may be a plurality of single sessions between the server and the client by a plurality of session merge commands, which is also one embodiment of the present invention.

In order to effectively manage the bandwidth, a bandwidth manager (see FIG. 3B) is separately provided in the server. However, when the number of sessions is large The bandwidth has to be managed on a session-by-session basis.

The bandwidth of the single session by the session merge command of the present invention is equal to the sum of the bandwidths of the individual sessions before receiving the session merge command but the number of sessions becomes one so that the bandwidth manager included in the server can not transmit unnecessary frames Or the bandwidth can be collectively and efficiently managed in such a manner as to prevent duplication of the same data.

As one embodiment of the present invention, a session demarcation instruction is implemented using a Setparameter command provided in a standard protocol of RTSP.

C-> S: SET_PARAMETER rtsp: //example.com/media.mp4 RTSP / 1.0
CSeq: 10
Content-length: 86
Content-type: text / parameters

COMMAND: SESSION DEMERGE
CONTROL SESSION: 4711234
MERGE: 4711234; interleaved = 0-1, 2345611; interleaved = 2-3,
2341566; interleaved = 4-5, 8721345; interleaved = 6-7

Table 11 shows the session demarcation commands that the client sends to the server.

The session demarcation command includes an identification of the single session (4711234) and identification of the four sessions (identification information 4711234, 2345611, 2341566, 8721345) constituting a single session and a single And information on the order of interleaving data according to RTP / RTCP in the session.

S-> C: RTSP / 1.0 451 Invalid Parameter
CSeq: 10
Content-length: 10
Content-type: text / parameters

S-> C: RTSP / 1.0 200 SET_PARAMETER
CSeq: 10
Content-length: 10
Content-type: text / parameters

COMMAND: SESSION DEMERGE OK
CONTROL SESSION: 4711234
MERGE: 4711234; interleaved = 0-1, 2345611; interleaved = 2-3,
2341566; interleaved = 4-5, 8721345; interleaved = 6-7

Table 12 shows the responses that the server receives from the client and receives a session merge command.

When receiving a session dimmer command from a client and sending a SESSION DEMERGE OK on the server side as a valid command, the server separates the unified single session into a plurality of sessions as before receiving the session merge command. Here, the separation of a single session into a plurality of sessions does not mean that a single session itself is divided into a plurality of sessions. More specifically, identification information of a channel for composing integrated data transmitted through a single session, It means to cancel the allocation of the identification information and change the data of each channel to be transmitted through each session mapped with it before receiving the session merge command.

For example, referring to the above command syntax, the channel identification information 2 allocated to the data of the channel transmitted through the session corresponding to the identification information 2345611 is canceled until the session merge command is received, and the single session 4711234 session The data transmitted through the 2345611 session will be transmitted through the session as it is. Since the command according to the RTCP is also the same, the RTCP identification information 3 is also canceled, and the data transmission status monitoring command according to the RTCP is also transmitted / received through the 2345611 session.

The plurality of separated sessions maintain the state of the session group until further receiving the session de-group command. When receiving a valid session de-group command from the client, the session de-group command corresponding to the identification information specified as the parameter of the session de- All sessions become regular sessions and send and receive data according to RTSP and RTP individually.

Since the number of single sessions generated by the session merge command is not limited, it is also possible to use multiple single session identification information as parameters of an instruction so that a single session integrated with the session merge command can be controlled by one RTSP instruction A session group command may be applied, which may also be one of the embodiments of the present invention.

FIG. 9 is a flowchart showing the order in which a session group command, a session D group command, a session merge command, and a session dimmer command are issued.

In step S910, the server receives a valid session group command from the client, sets all or a part of a plurality of sessions as a session group, and establishes a control session for each session group.

In step S920, the server determines whether a valid session merge command has been received and returns an invalid parameter to the client if not valid.

In step S930, the server responds to the client that it has received a valid session merge command, and merges all sessions in the session group having the session group identification information included in the session merge command into one single session using the interleaved method do.

In step S940, the server determines whether a valid session demarcation instruction has been received, and if not, returns an invalid parameter to the client.

In step S950, the server responds to the client that a valid session demarcation command has been received, and releases the single session having the identification information of the single session included in the session demarcation command into a session group including a plurality of sessions.

In step S960, the server determines whether a valid session de-group command has been received, and if not, returns an invalid parameter to the client.

In step S970, the server responds to the client that it has received a valid session de-grouping command, and separates the session group having the session group identification information included in the session de-group command into a plurality of normal sessions not belonging to the specific group.

10 is a schematic block diagram of a session management system for controlling data of a plurality of channels as one embodiment of the present invention.

Referring to FIG. 10, a session management system for controlling data of a plurality of channels according to an embodiment of the present invention is implemented according to a session management method for controlling data of a plurality of channels shown in FIGS. 5 to 8 . Therefore, the same contents as those of the session management method for controlling data of a plurality of channels shown in FIGS. 5 to 8 will be referred to, and a detailed description may be omitted below.

The session management system 1000 for controlling data of a plurality of channels includes a session control unit 1010 and a data control unit 1020.

The session control unit 1010 receives a session group command including identification information of a control session and identification information of at least one normal session from a client, identifies a control session among a plurality of sessions included in the session group, The session corresponding to the information is set as the control session, and the control session and the normal session are set as the session group.

As one embodiment of the present invention, the session control unit 1010 may include a merge command receiving unit (not shown) and a merge command applying unit (not shown).

A merge command receiver (not shown) receives a session merge command including identification information of all sessions belonging to a specific session group from a client, and receives a session merge command Specifies a single session.

The merge command application unit (not shown) allocates the channel identification information included in the session merge command to the data of each channel mapped to each session in the specific session group, and stores the data of each channel assigned channel identification information in a specific order And the integrated data is transmitted to the client through a single session.

The data control unit 1020 receives a data control command from a client through a control session and transmits a response to the data control command through the control session, To the client.

A session management method and system according to the present invention is a session management method and system for managing a session between a client and a server that transmits and receives data of a plurality of channels through a plurality of sessions, In addition, it is possible to integrate a plurality of sessions into a single session, thereby helping to manage the bandwidth. In particular, the session management when transmitting / receiving multi-channel streaming data using RTSP / RTP / TCP .

The present invention can also be embodied as computer-readable codes on a computer-readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers of the technical field to which the present invention belongs.

It is to be understood that the present invention is not limited to the above-described embodiments and the accompanying drawings, and that the scope of the present invention is defined by the appended claims, and that various changes, substitutions and alterations can be made hereto without departing from the spirit of the invention, It will be apparent to those skilled in the art that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention.

The present invention provides a function of controlling data of a different channel by a single command when transmitting data of a plurality of channels to a network in an apparatus for storing or transmitting various media data. The DVR, the NVR, the IP camera, and the Video Server Which is industrially applicable in the technical field of

Claims (6)

A session management method for controlling data of a plurality of channels between a server and a client in which a plurality of sessions are created between a server and a client and data of each channel mapped to each session is transmitted and received through each session,
Receiving a session group command including identification information of a control session and identification information of at least one or more normal sessions from the client, and receiving a session group command corresponding to identification information of the control session among a plurality of sessions included in the session group A session control step of setting a session to be a control session and grouping the control session and the normal session into a session group; And
Receiving a data control command from the client through the control session and transmitting a response to the data control command through the control session; To the client; The method of claim 1, 2. The method according to claim 1,
Receiving a session merge command including identification information of all sessions belonging to a specific session group from the client, and designating a single session of one of a plurality of sessions belonging to the specific session group according to the session merge command A merge command receiving step; And
Assigning channel identification information included in the session merge command to data of each channel mapped to each session in the specific session group and cross-arranging data of each channel allocated with the channel identification information in a specific order, And transmitting the merged data to a client through a single session; The method of claim 1, 3. The method according to claim 1 or 2,
The data of the channel is media streaming data including video and audio,
Wherein the session group command and the session merge command use a setparameter command of RTSP (Real Time Streaming Protocol). A session management system for controlling data of a plurality of channels between a server and a client in which a plurality of sessions are created between a server and a client and data of each channel mapped to each session is transmitted and received through each session,
Receiving a session group command including identification information of a control session and identification information of at least one or more normal sessions from the client, and receiving a session group command corresponding to identification information of the control session among a plurality of sessions included in the session group A session control unit configured to set a session as a control session, and to set the control session and the normal session as a session group; And
Receiving a data control command from the client through the control session and transmitting a response to the data control command through the control session; To the client; And a control unit for controlling the data of the plurality of channels. 5. The apparatus of claim 4,
Receiving a session merge command including identification information of all sessions belonging to a specific session group from the client and designating a single session of one of a plurality of sessions belonging to the specific session group according to the session merge command A merge command receiving unit; And
Assigning channel identification information included in the session merge command to data of each channel mapped to each session in the specific session group and cross-arranging data of each channel allocated with the channel identification information in a specific order, A merge command application unit for transmitting the merged data to the client through a single session; And a control unit for controlling the data of the plurality of channels. The method according to claim 4 or 5,
The data of the channel is media streaming data including video and audio,
Wherein the session group command and the session merge command use a setparameter command of an RTSP (Real Time Streaming Protocol).

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