KR20120087574A - System and method of packet transmission for subscriber in digital cable braodcasting environment - Google Patents

Abstract

PURPOSE: A packet transmitting system for a subscriber terminal in a digital cable broadcast environment and a method thereof are provided to configure broadcast data inputted to a CMTS and data of an MPEG section format in a table and transmit the table to the subscriber terminal, thereby reducing table configuration time of the subscriber terminal. CONSTITUTION: A demultiplexer(100) receives an MPEG(Moving Picture Expert Group) section type packet based on header information among a packet transmitted to a CMTS(Cable Modem Termination System)(10) based on OpenCable standards. A database unit(200) receives the MPEG section type packet and configures the MPEG section type packet in an MPEG table wherein the version of the MPEG section type packet is the same as the version of the header information. A streaming unit(300) receives the MPEG table, streams the MPEG table by an IP(Internet Protocol) packet, allocates the MPEG table to a set multicast address and bandwidth, and transmits the MPEG table to a subscriber terminal.

Description

System and method of packet transmission for subscriber station in digital cable broadcasting environment {system and method of packet transmission for subscriber in digital cable braodcasting environment}

The present invention relates to a packet transmission system and method for a subscriber station in a digital cable broadcasting environment, and more specifically, to a subscriber station having only an Ethernet port terminal. A packet transmission system and method for a subscriber station in a digital cable broadcasting environment for retransmission with an input bandwidth.

Digital cable broadcasting can provide multimedia services including video and audio broadcasting signals as well as interactive services such as VOD (Video On Demand) and data broadcasting through HFC (Hybrid Fiber Cable) transmission network. It is a structure that can be combined with a telephone to accommodate various converged services.

In recent years, cable broadcasting has been standardized and commercialized at the same time. For example, DOCSIS is applied to provide high-speed cable Internet service to subscribers, and in the case of digital cable broadcasting, OpenCable standards and OCAP (OpenCable Application Platform) are currently applied.

As the standard described above is applied, an Entitlement Management Message for managing SI information and viewing authority for easy and quick access to channels, video on demand (VOD), and other broadcasting products that viewers want in a digital cable broadcasting environment. Various types of information are transmitted to a subscriber station through a Cable Modem Termination System (CMTS) through DOCSIS TUNNEL.

Here, the SI (Service Information) is a broadcast that provides convenience to the user such as a channel name, a broadcast schedule, and a detailed description of a program, unlike Program Specific Information (PSI), which is broadcast reception information for receiving an actual broadcast or providing information directly related to the broadcast. Additional information.

On the other hand, in order to manage the viewing rights, a CAS (Conditional Access System) is applied to the CMTS and the subscriber terminal, the CAS finds a control word (CW), which is the password of the encrypted stream, and the set-top box included in the subscriber terminal ( In the main chip of STB), the CW can reproduce the stream transmitted from the CMTS.

In order to support such a CAS operation, an EMM and an Entitlement Contents Message (ECM) are transmitted from the CMTS to the subscriber terminal, and the EMM is data used to determine a user's authority. Encrypted and transmitted, the subscriber station obtains an intermediate key by decrypting the EMM according to whether or not it matches a previously stored unique number.

In addition, the ECM includes the encrypted CW, and the subscriber station receives the ECM from the CMTS, decrypts the ECM using an intermediate key obtained from the EMM, obtains the CW, and uses the CW. The scrambled bit stream can be descrambled through the CMTS, converted into a normal bit stream form, and received.

Meanwhile, DOSIS TUNNEL, which is a data transmission protocol in an HFC network, is applied between the CMTS and the subscriber station, and CMTS, which has recently applied the channel bonding technology of DOCSIS 3.0, is commercialized, and the subscriber station combines each channel based on an extended bandwidth. You can use multiple channels at the same time.

Based on the environment as described above, the general subscriber station may be composed of a STB or Cable Ready TV, and a CM (Cable Modem) for receiving a packet transmitted through the DOCSIS TUNNEL connected to the STB or Cable Ready TV.

1, the CM may transmit a packet received through the DOCSIS interface to the STB directly through the internal interface of the STB when the CM is configured in the STB as shown in FIG. 1.

However, in the case of a Cable Ready TV having only an Ethernet port terminal as shown in FIG. 2, the CM is configured in an external form, and the CMTS converts into a multicast address and retransmits the packets to the Cable Ready TV. The CM receives IP packets received by DOCSIS TUNNEL and transmits them to the Ethernet terminal of the Cable Ready TV. The Cable Ready TV is a non-contiguous or MPEG section (TABLE) that constitutes an MPEG table among the received IP packets. After the process of configuring and analyzing a separate MPEG table for the packet of the form, it is necessary to perform the initial operation (user authentication, EPG initialization, terminal initialization, firmware update, etc.) for watching digital cable broadcasting.

In other words, as described above, a subscriber station having an Ethernet terminal requires a separate MPEG table configuration time, which causes a delay. As a result, broadcast viewing time is delayed, thereby preventing a subscriber from providing a smooth viewing environment.

In addition, re-transmitting all packets flowing into the CMTS for the subscriber terminal having only such an Ethernet port terminal as the original bandwidth with different addresses may result in inefficient operation of the limited network bandwidth. A solution is required.

The present invention provides an efficient digital cable broadcasting reception environment by reducing the time required to construct a table in a subscriber station having only an Ethernet terminal for packets that form a non-continuous or MPEG table flowing into a CMTS in a digital cable broadcasting environment. The purpose is.

In addition, the present invention provides a system and method for efficiently operating a limited bandwidth, such as reducing the transmission bandwidth of data that is not used or low frequency of use in cable broadcasting, and increasing the transmission bandwidth of data that is specialized or high frequency of use for subscriber stations. The purpose is.

A packet transmission system for a subscriber station in a digital cable broadcasting environment according to the present invention for achieving the above object, in the form of MPEG section based on the header information of the packets transmitted to the CMTS (Cable Modem Termination System) according to the OpenCable standard A database configured to receive a packet and a MPEG section packet from the demux unit, and to form an MPEG table of the MPEG section type packet having the same version based on a version included in the header information. And a streaming unit for receiving the MPEG table from the database unit and streaming the received IP table in an IP packet, and allocating the MPEG table to a subscriber station by allocating a predetermined multicast address and bandwidth.

In this case, the streaming unit may multicast the subscriber station including the Ethernet terminal as a group address, and may set the bandwidth differently according to the version of the MPEG table.

Also, a packet transmission system for a subscriber station in a digital cable broadcasting environment according to an embodiment of the present invention includes a demux unit for receiving a packet in the form of a MEPG section based on header information among packets transmitted to a CMTS according to the OpenCable standard. Receiving an MPEG section packet from the demux unit, and configuring the MPEG section type packet having the same version as an MPEG table based on the version included in the header information, and caching the MPEG table in the memory. A database section for updating the memory to configure the MPEG section format packets for the different versions into an MPEG table and caching them in a memory when the MPEG section format packets are received from the MPEG section; Receives the table and streams it as an IP packet. Assigning a width and comprising a stream to be transmitted to the subscriber station.

Meanwhile, a packet transmission method for retransmitting a packet having an MPEG section form among packets received by a cable modem termination system (CMTS) according to the OpenCable standard to a subscriber station including an Ethernet terminal for achieving the above object includes a demux unit. A first step of receiving an MPEG section type packet based on header information among the packets received by the CMTS, and the database unit receives the MPEG section type packet from the demux, based on the version included in the header information A second step of configuring the MPEG section type packet having a version into an MPEG table, and a streaming unit receives the MPEG table from the database unit and transmits the MPEG table to an IP packet, and allocates the subscriber to a predetermined multicast address and bandwidth. The third step of transmitting to the terminal.

In this case, the third step may be characterized in that the streaming unit multicasts the subscriber station including the Ethernet terminal as a group address, and sets the bandwidth differently according to the version of the MPEG table.

In addition, a packet transmission method for retransmitting a packet having an MPEG section form among packets received by a cable modem termination system (CMTS) according to the OpenCable standard to a subscriber station including an Ethernet terminal according to another embodiment of the present invention is a demux. The first step of receiving the MPEG section of the packet based on the header information of the packet received by the CMTS, the database unit receives the MPEG section of the packet from the demux, based on the version included in the header information The MPEG section type packet having the same version is configured as an MPEG table and cached in a memory. When the MPEG section type packet of a different version is received from the demux unit, the memory is updated to update the memory for the different version. A second step of caching the MPEG section type packet into an MPEG table and caching it in a memory; But the streaming transfer to receive the MPEG table from the database unit to the IP packet, by assigning a multicast address and a predetermined bandwidth and a third step of transmitting to the subscriber station.

According to the present invention, the subscriber terminal is configured by transmitting data in the form of MPEG section, which is additional data associated with broadcast data flowing into the CMTS in a digital cable broadcasting environment, to a subscriber terminal having an Ethernet terminal at a multicast address in advance. Efficient broadcasting viewing is achieved by reducing the table configuration time.

According to the present invention, it is possible to efficiently operate bandwidth resources by rebalancing various additional data transmitted through DOCSIS TUNNEL in a digital cable broadcasting environment according to the frequency and importance of use within a limited multicast network bandwidth. .

1 illustrates an STB connected via a CMTS and DOCSIS protocols.
2 illustrates a Cable Ready TV connected via CMTS and DOCSIS protocols.
3 is a block diagram of a packet transmission system for a subscriber station in a digital cable broadcasting environment according to the present invention.
4 is a flowchart illustrating a packet transmission method for a subscriber station in a digital cable broadcasting environment according to the present invention.

In the digital cable broadcasting environment, packets flowing into the CMTS are not stream data but non-continuous data in the MPEG section, or when one MPEG table is composed of multiple MPEG sections. Has a continuous character. Therefore, when retransmitting by simply changing the packet with only the incoming packet, there is a problem that the time for configuring the entire intact MPEG table can be increased rather than improved from the viewpoint of the actual receiving terminal.

In order to solve this problem, the present invention receives and analyzes the MPEG section packet flowing into the CMTS, completely reconstructs the MPEG table which is divided into multiple sections, and caches the memory in the memory. And a function of sequentially retransmitting a plurality of MPEG sections constituting one MPEG table by changing a bandwidth.

3 is a diagram illustrating a configuration of a packet transmission system for a subscriber station in a digital cable broadcasting environment according to the present invention, and may include a demux unit 100, a database unit 200, and a streaming unit 300.

The demux unit 100 receives a packet for an MPEG section, not a packet for data in a bit stream form, from among data transmitted through the multiple channels to the CMTS 10 and transmits the packet to the database unit 200. .

As data composed of packets for the MPEG section, various additional information for watching digital broadcasting may be included, and may include PSIP, EMMG, CVT, EIT, ETT, and Private SI as shown.

At this time, the PSIP (Program and System Information Protocol) is a table in accordance with the DVS097 (ATSC A / 65) standard in the Advanced Television Systems Committee (ATSC), and not only the position of the audio / video for viewing the DTV (Digital Television) screen, but also the program. Contains organizational information.

In addition, the EMMG (Entiltlement Management Message Generator) is for the EMM applied to the CAS, the Code Version Table (CVT) is a service provider that provides the version information and the firmware for the firmware received from the subscriber station receiving the cable broadcast Contains identification information.

In addition, the EIT (Event Informaiton Table) is for a table for providing EPG (Eltectronic Program Guide) information in the DVB SI specification, and more specifically, a table for providing the temporal order and details of individual broadcasts. In addition, the extended text table (ETT) includes title and content information of a program for each serviced channel. That is, the ETT and the EIT are filled with entities of a broadcast including a broadcast ID, a broadcast time, a broadcast name, and the like.

In addition, the Private SI is a table defined for service information and includes a Program Association Table (PAT) and a Program Map Table (PMT).

As described above, the demux unit 100 may monitor the version by analyzing the header portion of the MPEG section packet transmitted with the digital broadcast data, so that the demux unit 100 Version monitoring allows the discontinuity data of an MPEG section or a single MPEG table to receive packets consisting of a plurality of MPEG sections. In this case, the demux unit 100 may analyze the PID information of the header, and thereby may perform version monitoring on the MPEG section type packet.

Meanwhile, the demux unit 100 transmits the received packet to the database unit 200, and the database unit 200 receives the MPEG section type packet to configure the MPEG table which is a superset of sections. Done.

At this time, the database unit 200 may receive a packet constituting the same version based on the PID information of the header when configuring the table to configure a single complete MPEG table, by using the section number information included in each packet When the reception is completed until the last section, one MPEG table configuration is finished.

When the table configuration is finished, the database unit 200 transmits the MPEG table to the streaming unit 300, the streaming unit 300 transmits the IP packet as continuous data in the form of a stream, Through this, the subscriber station having an Ethernet terminal can configure a table without delay by continuously receiving only IP packets of the MPEG section.

Meanwhile, the streaming unit 300 may set a group address for a plurality of subscriber stations having Ethernet terminals, support multicast transmission, and recognize the version of the table to stream according to a preset bandwidth according to the version. .

For example, the streaming unit 300 may reduce the transmission bandwidth for the MPEG table that is not used or low in the subscriber terminal with a limited bandwidth, and data that is specialized or frequently used in the subscriber terminal may be allocated by increasing the transmission bandwidth. have.

Meanwhile, the database unit 200 caches an MPEG table in a memory to support streaming of the streaming unit 300, and the database unit 200 provides version information of a packet transmitted from the demux unit 100. If the version is changed by monitoring the cache, the cache may be updated to receive a packet for the changed version.

FIG. 4 is a flowchart illustrating a packet transmission method of a packet transmission system for a subscriber station in a digital cable broadcasting environment according to the present invention. As shown in FIG. 4, an MPEG section is based on header information of packets introduced into the CMTS. Receive a packet for, and transmit the packet to the database unit.

Thereafter, the database unit configures one intact MPEG table as an MPEG section type packet for the same version based on the header information of the packet, and transmission is completed up to the last section based on the section number information included in each packet. When the table configuration is finished.

In this case, the database unit may cache the memory at the same time as the MPEG table configuration and transmit the MPEG table to the streaming unit.

Thereafter, the streaming unit may stream the MPEG table received from the database unit to a predetermined multicast address and bandwidth to transmit the multicast to each subscriber station.

On the other hand, when the database unit receives a packet for a different version of the MPEG section from the demux unit, the database unit updates the memory, configures an MPEG table for the different version, and caches it in the memory, and stores the MPEG table for the different version. The above-described process may be repeated by transmitting to the streaming unit.

10: CMTS 100: Demux Division
200: database unit 300: streaming unit

Claims (6)

Demux unit for receiving the packet in the form of MPEG section based on the header information of the packet transmitted to the CMTS (Cable Modem Termination System) according to the OpenCable standard;
A database unit configured to receive an MPEG section type packet from the demux unit and to configure the MPEG section type packet having the same version as an MPEG table based on a version included in the header information; And
The streaming unit receives the MPEG table from the database unit and transmits the stream as an IP packet, and allocates it to a predetermined multicast address and bandwidth and transmits the same to the subscriber station.
Packet transmission system for a subscriber station in a digital cable broadcasting environment comprising a.
The method according to claim 1,
The streaming unit multicasts the subscriber station including the Ethernet terminal as a group address, and sets a different bandwidth according to the version of the MPEG table. .
Demux unit for receiving a packet of the MEPG section form based on the header information of the packet transmitted to the CMTS according to the OpenCable standard;
Receive MPEG section packet from the demux unit, and configure the MPEG section type packet having the same version based on the version included in the header information into an MPEG table and cache it in the memory. A database unit configured to update the memory when the packets of the MPEG section form of different versions are received, and to configure the MPEG section type packets for the different versions into an MPEG table and cache them in the memory; And
The streaming unit receives the MPEG table from the database unit and transmits the stream as an IP packet, and allocates it to a predetermined multicast address and bandwidth and transmits the same to the subscriber station.
Packet transmission system for a subscriber station in a digital cable broadcasting environment comprising a.
A packet transmission method for retransmitting a packet having an MPEG section form among packets received by a cable modem termination system (CMTS) according to the OpenCable standard for a subscriber station including an Ethernet terminal,
A first step of receiving, by a demux, a packet having an MPEG section form based on header information among packets received by the CMTS;
A second step of the database unit receiving the MPEG section type packet from the demux, and configuring the MPEG section type packet having the same version as an MPEG table based on the version included in the header information; And
A third step in which the streaming unit receives the MPEG table from the database unit and streams it as an IP packet, and allocates it to a predetermined multicast address and bandwidth to transmit it to the subscriber station;
Packet transmission method for a subscriber station in a digital cable broadcasting environment comprising a.
The method of claim 4,
The third step is
The streaming unit multicasts the subscriber station including the Ethernet terminal as a group address, and sets a different bandwidth according to the version of the MPEG table. .
A packet transmission method for retransmitting a packet having an MPEG section form among packets received by a cable modem termination system (CMTS) according to the OpenCable standard for a subscriber station including an Ethernet terminal,
A first step of receiving, by a demux, a packet having an MPEG section form based on header information among packets received by the CMTS;
The database unit receives the MPEG section type packet from the demux, configures the MPEG section type packet having the same version as an MPEG table, and caches it in a memory based on the version included in the header information. Updating the memory when different versions of the MPEG section type packets are received from the second memory module to configure the MPEG section type packets for the different versions into an MPEG table and cache them in the memory; And
A third step in which the streaming unit receives the MPEG table from the database unit and streams it as an IP packet, and allocates it to a predetermined multicast address and bandwidth to transmit it to the subscriber station;
Packet transmission method for a subscriber station in a digital cable broadcasting environment comprising a.

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