APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING ELECTRONIC SERVICE GUIDE IN DIGITAL VIDEO BROADCASTING

SYSTEM

[Detailed Description of the Invention]

[Technical Field]

The present invention generally relates to a digital video broadcasting system. More particularly, the present invention relates to an apparatus and method for transmitting/receiving an Electronic Service Guide (ESG) on a communication channel.

[Background Art]

Digital Video Broadcasting (DVB), which is a digital broadcasting technology developed in Europe, is a transmission standard for supporting digital multimedia service in a mobile/portable manner as well as conventional digital broadcasting.

The DVB system can transmit an IP-based data stream simultaneously with multiplexing MPEG2 TS-based broadcasting data. Also, the DVB system can multiplex a plurality of services to one IP stream and transmit it. A terminal receives the data of the transmitted on IP stream, demultiplexes them into the individual services, demodulates the services, and outputs the demodulated services on a screen.

Information about the types and contents of the various services that the DVB system needs to be notified to users. To provide the users with the service information, an ESG is used. The ESG contains time information for particular services, associated contents, information required for receiving the contents, and information required for purchasing the contents.

For efficient transmission of the ESG, the DVB system configures an ESG data model and determines ESG information to be transmitted according to the ESG data module. An example of the ESG data model is illustrated in FIG. 1. The contents and formats of the ESG information comply with DVB-CBMS

Phase 1 ESG Specification (ETSI TS 102 471).

Referring to FIG. 1, blocks represent ESG fragments. The ESG data model includes a service fragment 101 with a description of overall services, a schedule event fragment 103 for providing information about the services according to time, a content fragment 105, an acquisition fragment 107 with information required for receiving actual data, a service bundle fragment 109 with information about a service bundle when a plurality of services are bound into a bundle, a purchase fragment 111 for providing information about a price of the service bundle, and a purchase channel fragment 113 for providing information about a system to be used in order to acquire a right to the purchase.

In the data model, each fragment can refer to another fragment. The reference means that information about a current fragment can be delivered on another fragment.

For example, when one service is comprised of a plurality of contents, the service fragment 101 may simply provide an overall description of a service, inclusive of the name and language of the service, without descriptions of contents in the service. Instead, the content fragment 105 associated with the contents is referred to for a description of the contents of the service.

A terminal can acquire information required to receive the service, that I, session information used in a transmitted protocol by receiving the acquisition fragment 107 that the service fragment 101 refers to and demodulating the acquisition fragment 107.

The fragments that refer to one another should have the IPs of fragments that they refer to. For instance, when the service fragment 101 refers to particular contents, it clarifies the ID of the content fragment 105 that it refers to.

The ESG is transmitted to the terminal in a different IP stream at a different time from those of a data stream for a real service. Therefore, a service provider can transmit information that users should know preliminarily to receive

the data stream of the real service, according to the above-described ESG data model. Aside from guidance to programs, the ESG can serve for other various usages.

For ESG transmission, a minimum transmission unit called container is used. A plurality of divided fragments forming the ESG are in one or more containers. Table 1 and Table 2 below list the syntaxes of an ESG container and the meaning of each field as defined in DVB-CBMS Phase 1 ESG Specification (ETSI TS 102 471).

Table 1

Table 3 below describes the meanings of values of structure type defined in Table 1. structure type is a field indicating whether the contents of a structure included in the container are fragment management information, ESG data repository, or others.

Table 3

In Table 3, Fragment management information provides the version and ID of a fragment in the ESG, Data Repository indicates that general data is transmitted, Index list, Index, and multi field sub index indicate that the structure transmits information about containers carrying each fragment of the ESG

collectively, ESG data Repository indicates that an actual ESG fragment is included, ESG session partition declaration provides information as to how the ESG is divided into a plurality of IP flows, and ESG init message indicates that the structure contains initialization information for decoding the ESG.

Meanwhile, the ESG can be provided to the terminal on an interactive channel as well as on a broadcasting channel. In this case, there is a need for a technique for, when a specific fragment is added to or removed from the ESG or an update such as contents change occurs after the terminal receives the ESG, delivering the updated fragment to the terminal efficiently. Basically, the ESG transmission unit is a container in the broadcasting channel and thus a minimum unit from which an update is known is also a container. However, when a fragment within one container is updated, retransmission of the whole container on the communication channel is very inefficient, considering that the communication channel is expensive.

Accordingly, there exists a need for a mechanism to transmit only an updated part when an ESG is transmitted on an interactive channel.

[Disclosure of the Invention]

[Problems to be Solved]

To overcome at least the problems, an object of the present invention is to provide a method and apparatus for efficiently transmitting ESG data on a communication channel in a DVB system.

Another object of the present invention is to provide a method and apparatus for transmitting on an updated part of an ESG when the ESG is transmitted on an interactive channel.

[Means to Solve the Problems]

According to one aspect of the present invention, there is provided a method for transmitting an ESG to a terminal in a server in a Digital DVB system is provided, in which a new ESG container is formed by collecting only data of updated ESG fragments from among data of ESG fragments, upon receipt of an

ESG transmission request from the terminal, and transmitted to the terminal.

According to another aspect of the present invention, there is provided a method for receiving an ESG from a server in a terminal in a DVB system, in which necessary ESG data is requested to the server, an ESG container is received from the server, a structure type indicating that the ESG container is a new ESG container including only data of updated ESG fragments is checked in the received ESG container, and only the data of the updated fragments is received.

According to a further aspect of the present invention, there is provided an apparatus for transmitting an ESG to a terminal in a server in a DVB system, in which a receiver receives an ESG transmission request from the terminal, an ESG database stores data of ESG fragments, an ESG processing controller forms a new ESG container by collecting only data of updated ESG fragments detected from among the data of the ESG fragments in the ESG database, and a transmitter transmits the new ESG container to the terminal.

According to still another aspect of the present invention, there is provided an apparatus for receiving an ESG from a server in a terminal in a DVB system, in which a transmitter transmits a message requesting ESG data to the server, and an ESG processing controller receives an ESG container from the server, checks a structure type indicating that the ESG container is a new ESG container including only data of updated ESG fragments, and receives only the data of the updated fragments.

[Effects]

When an ESG is transmitted on an interactive channel, ESG data extracted from one or more ESGs can be transmitted and ESG data requested by a terminal can be transmitted not in a container being a conventional basic transmission unit but at a fragment level. Therefore, communication network bandwidth can be saved.

[Brief Description of the Drawings]

FIG. 1 is a schematic view of a typical ESG data model;

FIG. 2 is a flowchart illustrating an operation for transmitting ESG data in a server according to a preferred embodiment of the present invention;

FIG. 3 is a flowchart illustrating an operation for receiving ESG data in a terminal according to a preferred embodiment of the present invention;

FIG. 4 is a block diagram of a transmitter according to a preferred embodiment of the present invention; and

FIG. 5 is a block diagram of a receiver according to a preferred embodiment of the present invention.

[Best Mode for Carrying Out the Invention]

The matters defined in the description such as a detailed construction and elements are provided to assist in a comprehensive understanding of exemplary embodiments of the invention. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

The present invention proposes a method for, when only part of the fragments contained in an ESG container are updated, generating a novel container containing only the updated fragments in a DVB system.

The novel container is not an existing container within the ESG but a new one generated at an update or generation time. Therefore, a new ID should be allocated to the novel container.

Also, a terminal should be notified that the novel container contains only the updated fragments. For this purpose, the present invention adds structure type called 'deltalist' to the ESG container. Table 4 illustrates the added deltalist being a new structure type within the proposed ESG container.

Table 4

Table 5 illustrates the configuration of the deltalist structure according to the present invention.

Table 5

Referring to Table 5, updated fragments are defined in one structure. When the fragments are included in a plurality of ESGs, ESG entry num indicates the number of ESG entries. For each ESG entry, ESG identification information is provided, such as ESG providerID and ESG URI, followed by the fragments of the ESGs in the structure. Fragment_reference() provides reference information about encapsulate ESG fragments, fragment version indicates the version of each fragment, and fragmented provides the ID of each fragment. When esg fragment type is OxOO, the fragment is an encapsulated ESG XML fragment. If esg fragment type is OxO 1 , the fragment is encapsulated ESG Aux. data and if esg fragment type is 0x02, the fragment is encapsulated private aux. data.

That is, the proposed structure type includes information for identifying fragments included in a plurality of ESGs. This structure type has information for identifying each ESG, information about fragments contained in each ESG, and the actual fragments. The fields listed in Table 5 are a mere exemplary application of the present invention and thus they can be changed or modified to other fields as far as they include the above-described information.

While the structure is configured so that after an ESG is identified by use of ESG_prt[i] and then fragments of the ESG are located using a pointer in the structure in Table 5, it can be further contemplated that fragments are directly transmitted on an ESG basis in the structure, which is illustrated in FIG. 6.

Table 6

Referring to Table 6, ESG identification information and corresponding fragments are transmitted together in one ESG entry. In this case, ESG_ptr[i] is not needed, compared to Table 5.

If the structure is transmitted within one ESG range only, it can be configured such that ESG entry information is not provided. Such an example is given in Table 7.

Table 7

Now a description will be made of a method and apparatus for transmitting and receiving a container containing collected updated data of fragments of ESGs between a server and a terminal according to the present invention with reference to FIGs. 2 to 5. While the following description is made in the context of transmitting and receiving ESG data on an interactive channel in a DVB system, by way of example, it is made clear that the same thing applies to other channels configured to transmit updated ESG data.

FIG. 2 is a flowchart illustrating an operation for transmitting ESG data in a server according to a preferred embodiment of the present invention.

Referring to FIG. 2, the server configures ESG fragments by aggregating meta data to be included in an ESG data model in step 210.

Upon receipt of a request of specific ESG data transmission from a user or upon sensing update of particular fragments in step 220, the server detects the user-requested or updated ESG fragments in step 230. The server includes information about the detected ESG fragments in the afore-described ESG delta structure in step 240 and forms a new ESG container along with other structure information in step 250. The new ESG container is comprised of information about ESG fragments included in one or more ESGs and is allocated a new ID. In step 260, the server transmits the new ESG container to the MS.

FIG. 3 is a flowchart illustrating an operation for receiving ESG data in a receiver according to a preferred embodiment of the present invention.

Referring to FIG. 3, a terminal accesses an ESG bootstrapping session and acquires ESG provider information and information about ESGs provided by

ESG providers in step 310. In step 320, the terminal accesses an ESG announcement carousel and acquires basic information required to receive a particular ESG, that is, decoder initialization information, information about each IP flow in the case of ESG transmission in a plurality of IP flows, and index information indicating the mapping relationship between each container and fragments. Then the terminal requests necessary ESG data to the server in step 330. Upon receipt of an ESG container including the requested ESG data from the server in step 340, the terminal determines whether the ESG container includes delta structure information in step 350. If the container is of the delta structure, the terminal receives corresponding fragments in step 360.

The new structure proposed according to the present invention can be used when updated fragments are transmitted at a fragment level. Also, when a user requests information about a plurality of ESGs, the proposed structure can be used to collect the information and transmit it in one container. That is, when the user requests ESG information corresponding to a "soap opera" service among all available ESGs, the server can use the new structure because it should transmit fragments of the ESG information, with ESGs identified.

FIG. 4 is a block diagram of a transmitter of the server in the DVB system according to an embodiment of the present invention.

Referring to FIG. 4, the server of the DVB system includes a receiver 410 for receiving a request signal from an MS, an ESG DB 420 for storing ESG data and information about each container, i.e. ESG fragments, a transmitter 430 for transmitting a transmission message format processed from ESG information requested by the terminal to the MS, and an ESG processing controller 440 for controlling ESG data transmission.

The ESG processing controller 440 analyzes the request signal received from the receiver 410 and detects information corresponding to the analyzed information from the ESG DB 420. It assembles the detected information, i.e. user-requested ESG fragments to a message, and transmits the message to the terminal through the transmitter 430.

FIG. 5 is a block diagram of a receiver of the terminal according to an embodiment of the present invention.

The receiver is basically similar to the transmitter in configuration. The receiver of the terminal includes a transmitter for transmitting a message requesting ESG information to the server, a receiver 510 for receiving a response message for the ESG information request from the server, and outputting the response message after determining that it is ESG information, an ESG processor 520 for actually processing the ESG information received from the server, and an ESG processing controller 540 for controlling the ESG data reception.

The ESG processing controller 540 controls generation and' transmission of a message requesting necessary ESG data through the transmitter 540, extracts ESG fragment data requested by a received message from ESG data received from the receiver 510, and outputs the extracted ESG fragment data to the ESG processor 530.