KR20080018626A - Receiver of digital cable broadcast and method for remote controlling - Google Patents

Abstract

A digital cable broadcast receiver and a remote control method are provided to control an STB(Set Top Box) remotely by mapping all the keys of a remote controller to nodes(agents) of a private MIB(Management Information Basement). An open cable STB establishes an SNMP(Simple Network Management Protocol) network to an Internet connection via a DOCSIS(Data Over Cable Service Interface Specification) channel(S500). A set-request message is transmitted from an SNMP manager to an SNMP agent mounted in each agent of the open cable STB(S510). A remote control key mapped to a private MIB of the SNMP agent is extracted from the set-request message to change a status of each agent(S520). Particular event occurrence signals from each agent are discriminated(S530). When an agent event occurs, the SNMP transmits an SNMP Trap message to the SNMP manager(S540). Upon receiving the SNMP trap message, the SNMP manager controls a state of the SNMP agent of the STB(S550).

Description

Receiver of digital cable broadcast and method for remote controlling}

1A is a block diagram showing a TCP / IP network management system according to the present invention.

Figure 1b is a block diagram showing an open cable SNMP network management connection according to an embodiment of the present invention.

Figure 2 is a schematic block diagram of an open cable STB according to an embodiment of the present invention.

3 is a remote control signal flow diagram using SNMP of the open cable STB according to the present invention.

Figure 4 (a, b) is an exemplary diagram showing an SNMP message protocol format for remote control of a digital cable broadcast receiver according to the present invention.

5 is a flow chart showing a remote control method of the open cable STB according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings

100. Bureau 200.CMTS

300. Open cable STB 310. Tuner (FAT channel)

311. Demodulator (QAM) 320. Tuner (FDC channel)

321. Demodulator (QPSK) 330. Transmitter

331. Modulator (QPSK) 332. Modulator (DOCSIS)

340. DOCSIS channel 341. Demodulator (QAM)

342. Bridging / filtering section 350. Cable card

351. CAC 352. OOB processing unit

360. Demux / Decode Division 370. Multimedia Processing Division

380. Host CPU

The present invention relates to a broadcast receiver, and more particularly, to a remote control method using an SNMP protocol in an open cable STB (Settop Box).

Cable set-top box (STB) is a STB for digital cable TV. It is a decoder that restores digital signals transmitted from cable stations to homes, and various applications that work with cable TVs and remote controllers. And it is a device that enables pay-TV by mounting a reception restriction system (CAS).

In the case of the open cable STB, not only MPEG stream playback but also DSG (Docsis Settop Gateway) method, EPG (Electric Program) can be downloaded and received from the headend (station) and application through a separate cable modem. It is a system developed to transmit and use more information such as guide, video on demand (VOD), pay per view (PPV), and data broadcasting.

These applications are possible because the cable modem is built into the STB as a separate module. The cable modem is a system that can be networked using shared media with a well-known wired cable. The cable modem built into Open Cable has all the same features as a standard cable modem except for allocating about 10% (1 to 2 MBytes) of downlink bandwidth to receive the SI, applications, and upgrades mentioned above.

Naturally, since a cable modem is a network device, it also has an SNMP agent that can be controlled remotely. This indicates that a module that can handle the SNMP protocol is mounted.

The present invention relates to a remote control method using a network module of an open cable set-top box (STB), in particular, to control the set-top remotely with a simple network management protocol (SNMP) through a cable modem in the STB.

In addition, an object of the present invention is to map all the keys of the remote control to the node of the private MIB to control the set-top remotely.

In order to achieve the above object, the digital cable broadcast receiver of the present invention comprises a cable modem connected to an SNMP manager via a cable channel to receive an SNMP agent management request message from the SNMP manager; And an SNMP agent extracting a management information object mapped with a remote control command from the received SNMP agent management request message to change the state of each host and each node.

The SNMP manager may be at least one of a PC connected to the digital cable broadcast receiver and a remote control terminal.

The SNMP agent may be software installed in a host and each node device in the digital cable broadcast receiver.

The management information object may be a private management information base (MIB) having an identifier of a specific node.

The cable channel is characterized in that the DSG (Docsis Settop Gateway) channel method.

The network connection may be an internet network connection between the SNMP manager and the SNMP agent.

The state change of the host and each node is defined in system-related information (system name, OS, version, company name, etc.), network-related information (IP address, route table, outgoing packet number, etc.) and MIB (Management Information Basement). It is characterized by changing the information.

In addition, the present invention provides a remote control method for a digital cable broadcast receiver, comprising: connecting a network with an SNMP manager via a cable channel; Receiving an SNMP agent management request message from the SNMP manager; Extracting a management information object mapped with a remote control command from the SNMP agent management request message; And changing the state of the host and each node based on the extracted management information object mapped to the remote command.

In another aspect, the present invention provides a remote control method of a digital cable broadcast receiver, comprising: connecting a network with an SNMP manager via a cable channel; Receiving an SNMP agent management request message from the SNMP manager; And sending a SNMP Trap message to the SNMP manager when a response to the SNMP agent management request message is delayed or when a specific event occurs in the SNMP agent.

The objects, features and advantages of the present invention will be more readily understood by reference to the accompanying drawings and the following detailed description. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the description thereof will be omitted.

1A is a block diagram showing a TCP / IP network management system according to the present invention.

Simple Network Management Protocol (SNMP) is a network management protocol in the Transmission Control Protocol / Internet Protocol (TCP / IP) environment.It is equipped with SNMP agent software on devices (network elements) that require continuous management, such as hubs. Remote managers can monitor port-specific operations.

SNMP, a type of network management protocol, is designed to manage TCP / IP networks and can be routed using standard IP routers, making it suitable for environments such as networks connected by bridges and routers. The SNMP management system provides the network management station 100 which is an SNMP manager to check all network conditions, and builds a database that performs management data analysis and fault management. The SNMP agent is installed in network equipment such as STB 300, PC, host, router, bridge, and hub, which are managed target devices, and transmits management information or performs action requests of the management system according to the management system's request. It automatically notifies the management system of the failure situation when a problem occurs.

1B is a block diagram illustrating an open cable SNMP network management connection according to an embodiment of the present invention.

The management station 100 supporting SNMP network management, the CMTS 200 supporting the TCP / IP protocol, and the open cable STB 300 supporting SNMP network management are connected. The management station 100 which is an SNMP manager transmits a signal for requesting specific management information for SNMP network management and a signal for requesting a state change for the specific management information to the open cable STB, an SNMP agent. In response, the SNMP agent transmits a response signal for specific management information requested by the SNMP manager. In particular, if a problem occurs in the SNMP agent, a warning message is sent to the SNMP manager.

Cable Modem Termination System (CMTS) is a cable modem head-end, and is a device that converts cable modem data into Internet data packets. CMTS provides several features, including routing to hold local data within the cable system, filtering to protect cable operators from unwanted hacking, and traffic shaping to ensure the quality of service to subscribers.

2 is a schematic block diagram of an open cable STB 300 according to an embodiment of the present invention.

Simple Network Management Protocol (SNMP) is a simple protocol for managing networks. The open cable STB 300 according to the present invention is composed of a manager and an agent, and an agent is mounted and driven in all nodes supporting SNMP. An SNMP agent is an SNMP module (or application) installed on a system to be managed to collect necessary information (network or system), and an SNMP manager is an SNMP module that requests information required on a system on which an SNMP agent is installed. SNMP manages node information and status using MIB (Management Information Basement). The MIB represents a collection of specific objects, such as information and resources, to be managed in the network that sends and receives specific information between the manager and the agent.

The tuner (FAT channel) 310 outputs to the QAM demodulator 311 by tuning only a specific channel frequency of the cable A / V broadcast transmitted in the in-band via the cable. At this time, the QAM demodulator 311 demodulates the cable A / V broadcast signal by the QAM method. The CA system 351 is a system for broadcasting (communication) service providers to manage users who use a paid service and charge a fee for use. The CA system 351 generates and descrambles the same key value used in the transmitter. Therefore, normal decoding is performed on the received pay service signal.

The demux / decoder unit 360 separates the multiplexed transmitted video signal and the audio signal, restores the compressed A / V signal to the original signal through the video decoding algorithm and the audio algorithm, respectively, and then executes the multimedia processing unit 370. After display.

The QPSK tuner (FDC channel) 320 tunes a specific channel frequency among data broadcasts transmitted to an out-of-band band (OOB) through a cable and outputs it to the OOB QPSK demodulator 321. The OOB QPSK demodulator 321 demodulates the received data by a quadrature phase shift (QPSK) method and outputs the demodulated data to the OOB processing unit 352 in the cable card 350. That is, while the matching of the OOB processing unit 352 and the host CPU 380 operates in the OOB mode, the cable card 350 transmits an FDC channel request message to the host CPU 380.

When bidirectional communication is possible between the cable broadcasting station and the cable broadcasting receiver, information transmitted from the cable broadcasting receiver to the cable broadcasting station (for example, a paid program request, diagnostic information of the host, etc.) is transmitted in an OOB or DSG method. In the OOB method, user information or system diagnostic information is output to the OOB QPSK modulator 331 through the OOB processing unit 352 in the cable card 350, QPSK modulated by the OOB QPSK modulator 331, and then through a cable station. Is sent to. In addition, in the DSG method, the host CPU 380 and the DOCSIS MAC data bridging / filtering 342 are output to the DOCSIS modulator 332 and the Docsis The QAM-16 is modulated by the DOCSIS modulator 332 and transmitted to the SNMP manager connected to the SNMP network through a transmitter (Return channel) 330.

A tuner (DOCSIS channel) 340 tunes a specific channel frequency among data channels transmitted through a cable for connecting an SNMP network according to the present invention to a QAM demodulator 341 using a DSG (DOCSIS Set-Top Gateway) method. The QAM demodulator 341 demodulates a DSG type SNMP agent management request message and transmits the same to a host CPU 380 including a MIB mapped to a remote control control command through DOCSIS MAC bridging / filtering 342. do.

In addition, the communication device defined in the above specification can perform an existing function by downloading the software CAS provided by the operator to the subscriber set-top box or integrated TV without separately placing the existing hardware CAS module in the subscriber set-top box or integrated TV. have. As an example of the method of downloading the software CAS module, when a security processor pre-embedded in the set-top is connected to a network, the CA may automatically download a conditional access (CA) image from the head-end.

3 is a flowchart of a remote control signal using SNMP of the open cable STB according to the present invention.

The SNMP manager (a) checks the status of each SNMP agent (b). Here, status means various information about each node, for example, system related information (system name, OS, version, company name, etc.), network related information (IP address, route table, outgoing packet number, etc.), etc. Information defined in various MIBs (Management Information Basement). SNMP manages node information and status using MIB (Management Information Basement). Network management is based on the exchange of specific information between a system acting as a manager and a system acting as an agent. At this time, specific information and resources are called objects. The collection of these objects is called a Management Information Base (MIB). In the method of remotely controlling a network according to the present invention, a manager reads a specific value among MIBs provided by agents managed by the manager to determine the state of the agent or change the value. Therefore, the state of the corresponding agent can be changed by changing the string or numerical value of the MIB as well as the value, and instructs or executes a predetermined operation to the agent. MIB can be divided into Standard MIB and Private MIB. The Standard MIB provides the standard functionality that network equipment must implement by default. Private MIB implements and provides unique functions for each company and equipment.

According to the present invention, the SNMP manager (a) can remotely change the IP address, change the routing table, and change node states such as system names. However, the node must allow these changes and be implemented. In other words, the SNMP agent (b) must be implemented in the STB.

When the SNMP packet transmitted from the SNMP manager through the Internet network is received by the SNMP gateway agent, the SNMP gateway agent extracts and identifies an object identification (OID) from the received SNMP packet.

In the MIB process, the SNMP gateway agent searches the OID agent address mapping table to determine whether there is an OID corresponding to the OID. If there is a corresponding OID, the corresponding SNMP agent is processed by using the address of the corresponding SNMP agent as a destination address, generating an SNMP packet according to another network protocol, and then transmitting the generated SNMP packet to another network interface. The remote control command transmitted from the SNMP manager is performed by the destination OID agent based on the private MIB mapped with the remote control command key according to the present invention.

In the method of remotely controlling a network according to the present invention, a manager reads a specific value among MIBs provided by agents managed by the manager to determine the state of the agent or change the value. Therefore, the state of the corresponding agent is changed by changing the string or numerical value of the private MIB as well as the value, and instructs or performs a predetermined operation to the agent.

When a predetermined SNMP packet is transmitted from the SNMP agent to the SNMP gateway agent, the SNMP gateway agent receives the transmitted SNMP packet and converts it to TCP / IP, and converts the converted SNMP packet of the TCP / IP SNMP manager through the Internet. To send.

SNMP is a network management protocol in the TCP / IP environment. SNMP agent software is installed in devices (network elements) requiring continuous management, such as hubs, so that remote managers can monitor port-specific operations.

SNMP is a connection-less service, which uses a control command PDU (Product Data Unit), which is transmitted through an authentication service. In this case, the transmitted message is transmitted using UDP (User Datagram Protocol). SNMP uses five control command (PDU) messages to manage the network by default: Get-request, Get-next-request, Set-request, Get-response, and Trap.

Get-request is a control command for getting the value of a specific managed object (MO) in the SNMP agent (b) from the SNMP manager (a). Get-next-request is a control command to get the next object value of the object value specified in the SNMP manager (a) or the next index value when the specified object is a table. Get-response is a control command to return the object value from the agent according to the request of the SNMP manager (a). Set-request is a command for the SNMP manager (a) to change the value of the object in the SNMP agent (b). Control command. Trap is a control command for notifying the SNMP manager (a) that a specific failure situation (trap) has occurred in the SNMP agent (b) or for sending a response when a response time for a request is long. In SNMP, SNMP trap is responsible for notifying the SNMP manager (a) when a specific event occurs from the SNMP agent (b). In other words, if one port of the device fails, the SNMP manager (a) is notified via SNMP Trap.

4 (a, b) is an exemplary diagram showing an SNMP message protocol format for remote control of a digital cable broadcast receiver according to the present invention.

In the total IP datagram shown in FIG. 4A, 20 bytes are included as the IP header part of the network layer, and 8 bytes are represented as the UDP header part of the transport layer in the UDP datagram. SNMP message protocol format includes Version, Community, and PDU type in common SNMP header, and request ID, error status (0 ~) in get / set header when PDU type (0 ~ 3). 5) and the error index. Variables transmitted in a get / set message include variable bindings and a plurality of object values (object value 1 to object value N). For the PDU type (4), the Trap header contains the enterprise, agent addr, trap type (0-6), specific code, time stamp, and indicates the relevant variable part.

4B illustrates an SNMP message format according to SNMP PDU types (0 to 4).

(1) From a SNMP message containing a Version, Community, and SNMP PDU, if the PDU type is a Get-request PDU, Get-Next-Request PDU, and Set-request PDU (2), the PDU Type is Get In the case of -response PDU (3), the PDU type may be Trap PDU (4).

SNMP basically manages the network using five control commands (PDUs): Get-Request, Get-Next-Request, Set-Request, Get-Response, and Trap.

The Get-Request is a control command for the SNMP manager to get a value of a specific Managed Object (MO) in the SNMP agent in the STB, and the Get-Next-Request is a next object value or a value specified by the manager. Control command to get the next index value when the object is a table. Get-Response is a control command for the SNMP agent to return the object value according to the manager's request, and Set-Request is a control command for the manager to change the object value in the SNMP agent. Trap is a control command that informs the SNMP manager that a specific failure situation (trap) has occurred in the STB, or sends a response when the response time is long.

According to an embodiment of the present invention, Set-request is used to replace the remote control function using SNMP. This replaces the input signal of a specific key with a remote controller connected to a node of a specific MIB. First, create a private MIB that maps to the remote control keys to control the STB. At this time, a MIB node of a remote control type used in the STB is created to map each node to a remote control key one by one.

5 is a flowchart illustrating a remote control method of the open cable STB according to an embodiment of the present invention.

The open cable set-top box (STB) establishes an SNMP network as an Internet connection through a DOCSIS channel (S500).

The set-request message is transmitted from the SNMP manager, which is a remote control terminal such as a PC, to an SNMP agent installed in each node of the open cable STB (S510).

At this time, the set-request extracts a remote control key mapped to a private MIB (Management Information Base) of each SNMP agent from the message and changes the state of each node (S520). In the STB, a MIB node of a remote control type used in advance is created, and one remote control key is mapped to each node.

A specific event occurrence signal is determined from each node (S530).

When a node (agent) event occurs, the SNMP agent transmits an SNMP Trap message to the SNMP manager (S540).

The SNMP manager receiving the SNMP Trap message remotely controls the status of the SNMP agent of the STB (S550).

On the other hand, the terms used in the present invention (terminology) are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the skilled person in the relevant field, the definitions of which are used throughout the present invention. Will have to be laid down as a foundation.

The present invention is not limited to the above-described embodiments and may be variously modified and changed by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

The present invention uses a simple network management protocol (SNMP) network module of an open cable set-top box (STB) to map all the keys of the remote control to the nodes of the private MIB to remotely troubleshoot or analyze the STB remotely. There is a controllable effect.

Claims (13)

A cable modem connected to the SNMP manager through a cable channel to receive an SNMP agent management request message from the SNMP manager; And And an SNMP agent extracting a management information object mapped with a remote control command from the received SNMP agent management request message to change a state of a host and each node. The method of claim 1, And the SNMP manager is at least one of a PC connected to the digital cable broadcast receiver and a remote control terminal. The method of claim 1, And the SNMP agent is software mounted on a host and each node device in the digital cable broadcast receiver. According to claim 1, And the management information object is a private management information base (MIB) having an identifier of a specific node. The method of claim 1, The cable channel is a digital cable broadcasting receiver, characterized in that the DSG channel method. The method of claim 1, And the network connection is an internet network connection between the SNMP manager and the SNMP agent. The method of claim 1, The state change of the host and each node is defined in system-related information (system name, OS, version, company name, etc.), network-related information (IP address, route table, outgoing packet number, etc.) and MIB (Management Information Basement). A digital cable broadcast receiver characterized by changing information. Connecting the network with the SNMP manager via a cable channel; Receiving an SNMP agent management request message from the SNMP manager; Extracting a management information object mapped with a remote control command from the SNMP agent management request message; And changing a state of a host and each node based on the extracted remote control command and the management information object mapped to the remote control command. The method of claim 8, The management information object is a remote control method of a digital cable broadcast receiver, characterized in that the private MIB (Management Information Basement) having an identifier of a specific node. The method of claim 8, The state change of the host and each node is defined in system-related information (system name, OS, version, company name, etc.), network-related information (IP address, route table, outgoing packet number, etc.) and MIB (Management Information Basement). A remote control method for a digital cable broadcast receiver, characterized by changing information. The method of claim 8, The SNMP manager is a remote control method of a digital cable broadcast receiver, characterized in that at least one of a PC, a networked remote control terminal connected to the digital cable broadcast receiver. The method of claim 8, The SNMP agent is a remote control method of the digital cable broadcast receiver, characterized in that the software mounted on the host and each node device in the digital cable broadcast receiver. Connecting the network with the SNMP manager via a cable channel; Receiving an SNMP agent management request message from the SNMP manager; And transmitting an SNMP Trap message to the SNMP manager when a response to the SNMP agent management request message is delayed or when a specific event occurs in the SNMP agent.

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