Patent Publication Number: US-2004059824-A1

Title: Transmitter, receiver, transmitter/receiver, transmitting method and receiving method

Description:
TECHNICAL FIELD  
       [0001] The present invention relates to a transmitting apparatus, a receiving apparatus, a transmitting and receiving apparatus, a transmitting method, and a receiving method used in the art of for example a technology for distributing data to many and unspecified people and for effectively updating and managing distributed data.  
       BACKGROUND ART  
       [0002] So far, many methods for data distribution systems have been proposed. For example, in the present, on the Internet, data described in the HTML (Hyper Markup Language) using the WWW (World Wide Web) corresponding to the HTTP (Hyper Text Transfer Protocol) is distributed. In the HTML, a multimedia content is described using tags that are presentation elements as functions such as presentation attributes and link attributes. The HTML is a logical structure descriptive language based on the SGML (Standard Generalized Markup Language), which is an international standard of the ISO (International Organization for Standardization).  
       [0003] There is a possibility of which distributed data contains data that is partly changed time by time. For example, weather forecasts and news topics are frequently changed partly, not entirely. In a conventional data distribution system using the WWW, even if a part of a web page is changed, the entire document is retransmitted.  
       [0004] In contrast, in a difference update protocol that has been proposed by the applicant of the present invention as Japanese Patent Laid-Open Publication No. 10-303983 and a protocol format described in Japanese Patent Laid-Open Publication No. 11-306068, update notification information that represents that the content has been changed and update information that represents the contents of the update are transmitted so that information of the content has been partly changed. As a result, data can be effectively updated.  
       [0005] Therefore, an object of the present invention is to provide a transmitting apparatus, a receiving apparatus, a transmitting and receiving apparatus, a transmitting method, and a receiving method that allow the efficiency of a process performed by the receiving apparatus for the protocol format disclosed in Japanese Patent Laid-Open Publication No. 11-306086 to be further improved. In particular, the present invention is adapted to update a content using a predetermined document format used to describe content data, for example difference update notification information and update information described in a format similar to the XML format. According to the present invention, the function of the difference updating process performed on the receiving apparatus side can be accomplished in the same manner as the process for content data. As a result, the efficiency of the process performed on the receiving apparatus is improved. In addition, the process for creating update notification information performed by the transmitting apparatus side can be effectively performed.  
       DISCLOSURE OF THE INVENTION  
       [0006] To solve the forgoing problem, claim  1  of the present invention is a transmitting apparatus for transmitting data for a content to be provided, the transmitting apparatus comprising:  
       [0007] content storing means for storing content data to be transmitted;  
       [0008] content operating means for inputting data to the content storing means or updating data stored in the content storing means;  
       [0009] update notification information creating means for detecting that data has been updated by the content operating means and creating update notification information which notifies a receiving side that the data has been updated;  
       [0010] update information creating means for creating update information which represents contents of an update of a content; and  
       [0011] transmitting means for transmitting a content stored in the content storing means, the update notification information, and the update information,  
       [0012] wherein a content stored in the content storing means has been described in a predetermined document format, and  
       [0013] wherein the update notification information creating means creates update notification information which has been described in the predetermined document format.  
       [0014] Claim  4  of the present invention is a receiving apparatus for receiving data for a content which has been provided, the receiving apparatus comprising:  
       [0015] receiving means for receiving data;  
       [0016] content storing means for storing content information received by the receiving means;  
       [0017] update notification information processing means for processing update notification information received by the receiving means;  
       [0018] updating processing means for processing update information received by the receiving means; and  
       [0019] analyzing means for analyzing the content, the update notification information, and the update information,  
       [0020] wherein a content stored in the content storing means has been described in a predetermined document format, and  
       [0021] wherein the update notification information has been described in the predetermined document format.  
       [0022] Claim  8  of the present invention is a transmitting and receiving apparatus having a transmitting apparatus for transmitting data for a content to be provided and a receiving apparatus for receiving data for a content which has been provided, the transmitting apparatus comprising:  
       [0023] content storing means for storing content data to be transmitted;  
       [0024] content operating means for inputting data to the content storing means or updating data stored in the content storing means;  
       [0025] update notification information creating means for detecting that data has been updated by the content operating means and creating update notification information which notifies a receiving side that the data has been updated;  
       [0026] update information creating means for creating update information which represents contents of an update of a content; and  
       [0027] transmitting means for transmitting a content stored in the content storing means, the update notification information, and the update information,  
       [0028] wherein a content stored in the content storing means has been described in a predetermined document format, and  
       [0029] wherein the update notification information creating means creates update notification information which has been described in the predetermined document format,  
       [0030] the receiving apparatus comprising:  
       [0031] receiving means for receiving data;  
       [0032] content storing means for storing content information received by the receiving means;  
       [0033] update notification information processing means for processing update notification information received by the receiving means;  
       [0034] updating processing means for processing update information received by the receiving means; and  
       [0035] analyzing means for analyzing the content, the update notification information, and the update information,  
       [0036] wherein a content stored in the content storing means has been described in a predetermined document format, and  
       [0037] wherein the update notification information has been described in the predetermined document format.  
       [0038] Claim  9  of the present invention is a transmitting method for transmitting data for a content to be provided, the transmitting method comprising the steps of:  
       [0039] updating data of a content stored in storing means;  
       [0040] detecting that data has been updated at the content operating step and creating update notification information which notifies a receiving side that the data has been updated;  
       [0041] creating update information which represents an update process for a content; and  
       [0042] transmitting the content, the update notification information, and the update information,  
       [0043] wherein a content stored in the content storing means has been described in a predetermined document format, and  
       [0044] wherein the update notification information creating step is performed by creating update notification information which has been described in the predetermined document format.  
       [0045] Claim  12  of the present invention is a receiving method for receiving data for a content which has been provided, the receiving method comprising the steps of:  
       [0046] receiving data;  
       [0047] storing content information out of the data received at the receiving step;  
       [0048] processing update notification information received at the receiving step;  
       [0049] processing update information received at the receiving step; and  
       [0050] analyzing the content, the update notification information, and the update information,  
       [0051] wherein a content stored at the content storing step has been described in a predetermined document format, and  
       [0052] wherein the update notification information has been described in the predetermined document format.  
       [0053] According to the present invention, a document described in a predetermined document format for example the XML format is updated using update notification information and update information that are described in a document format similar thereto for example the XML format. As a result, the efficiency of the process performed by the receiving apparatus can be improved. In addition, a process for a document described in a predetermined document format and a process for update notification described in a document format similar thereto can be shared by the transmitting apparatus and the receiving apparatus. As a result, the cost and load for the processes can be reduced. 
     
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
     [0054]FIG. 1 is a block diagram showing the structure of a content providing system according to an embodiment of the present invention;  
     [0055]FIG. 2 is a block diagram showing an example of the structure of a broadcasting station according to an embodiment of the present invention;  
     [0056]FIG. 3 is a block diagram showing an example of the structure of a receiving terminal apparatus according to an embodiment of the present invention;  
     [0057]FIG. 4 is a schematic diagram showing an example of a data format of content information of a weather forecast, the content information having been described in the XML;  
     [0058]FIG. 5 is a schematic diagram showing an example of a data format of update notification information described in the XML;  
     [0059]FIG. 6 is a schematic diagram showing an example of a data format of update information described in the XML;  
     [0060]FIG. 7 is a flow chart showing an updating process for a content by the receiving terminal apparatus; and  
     [0061]FIG. 8 is a flow chart showing a displaying process for a content by the receiving terminal apparatus. 
    
    
     BEST MODES FOR CARRYING OUT THE INVENTION  
     [0062] Next, a content providing system according to an embodiment of the present invention will be described. FIG. 1 shows an example of the system according to the embodiment. The system is composed of information providing apparatuses designated by reference numeral  101   1  and  101   2 , a broadcasting station designated by reference numeral  102 , receiving terminal apparatuses designated by reference numerals  103   1  and  103   2 , a multi-cast network designated by reference numeral  104 , and a bi-directional network designated by reference numeral  105 .  
     [0063] The information providing apparatuses  101   1  and  101   2  have respective server units that store data of contents (also called objects) to be provided to the receiving terminal apparatuses. An example of content data is an WWW page described in the XML. The information providing apparatuses  101   1  and  101   2  are connected to the broadcasting station  102  and the receiving terminal apparatuses  103   3  and  103   2  through the bi-directional network  105 .  
     [0064] Likewise, the broadcasting station  102  has a database that stores content data to be provided to the receiving terminal apparatuses. The broadcasting station  102  is connected to the receiving terminal apparatuses  103   1  and  103   2  through the multi-cast network  104 . The broadcasting station  102  can provide content data to the receiving terminal apparatuses  103   1  and  103   2 . In addition, the broadcasting station  102  can receive content data from the information providing apparatuses  101   1  and  101   2  through the bi-directional network  105  or a dedicated line and provide content data to the receiving terminal apparatuses  103   1  and  103   2  through the multi-cast network  104 . A real example of the multi-cast network is a broadcast (a digital broadcast such as a satellite broadcast or a ground wave broadcast).  
     [0065] The receiving terminal apparatuses  103   1  and  103   2  receive and store contents and provide them to the users. Information of contents is transmitted through the multi-cast network  104  and stored in the receiving terminal apparatuses  103   1  and  103   2 . Alternatively, information of contents is obtained on demand through the bi-directional network  105 .  
     [0066]FIG. 2 shows an example of the structure of the broadcasting station  102 . A content storing portion designated by reference numeral  201  stores data of contents to be provided to the receiving terminal apparatuses  103   1  and  103   2 . In this example, the receiving terminal apparatuses  103   1  and  103   2  store contents described in a predetermined document format, for example the XLM, which is a content descriptive language. In other words, the content storing portion  201  stores files encoded corresponding to the XML.  
     [0067] Contents are input to the content storing portion  201  and contents stored therein are updated by a content operating portion  202 . When the content operating portion  202  updates a content stored in the content storing portion  201 , an update notification information creating portion  203  creates update notification information that represents that the content has been updated. In addition, when the content operating portion  202  updates a content stored in the content storing portion  201 , an update information creating portion  204  creates update information. The created update information is a script that causes a pre-updated content to be updated.  
     [0068] A content stored in the content storing portion  201 , update notification information created by the update notification information creating portion  203 , and update information created by the update information creating portion  204  are supplied to an encoding portion  207 . The encoding portion  207  converts a content, update notification information, and update information into a predetermined transmission format. The transmission format that is used should comply with the network through which a content, update notification information, and update information are transmitted.  
     [0069] Output information of the encoding portion  207  is transmitted from a transmitting portion  205  to the receiving terminal apparatuses  103   1  and  103   2  through the multi-cast network  104 . Output information of the encoding portion  207  can be transmitted from the transmitting portion  205  to the receiving terminal apparatus  103   1  and  103   2  through the bi-directional network  105  corresponding to requests issued from the receiving terminal apparatuses  103   1  and  103   2 . The information providing apparatus  101   1  and  101   2  each have the same structure as the forgoing broadcasting station  102 . However, normally, the information providing apparatuses  101   1  and  101   2  do not have the transmitting portion  205  shown in FIG. 2.  
     [0070]FIG. 3 shows an example of the structure of the receiving terminal apparatus  103   1 . The other receiving terminal apparatus  103   2  has the same structure as the receiving terminal apparatus  103   1 . Reference numeral  301  represents a receiving portion. The receiving portion  301  receives content data, update notification information, and update information from the broadcasting station  102  through the multi-cast network  104 . A communication controlling portion  308  performs a communication control so as to receive content data, update notification information, and update information from the broadcasting station  102  and the information providing apparatus  101   1  or  101   2  through the bi-directional network  105 .  
     [0071] The received information is supplied to a decoding portion  302 . The decoding portion  302  decodes the transmission format of the received content, update notification information, and update information. The decoded content is stored in a content storing portion  306 . A analyzing portion  303  analyzes the decoded data. The analyzing portion  303  performs processes for the content, update notification information, and update information. In other words, the analyzing portion  303  interprets a content described in the XML, update notification information described in the XML, and update information described in the XML and hands the results to respective processing portions. For example, the content described in the XML is interpreted by the analyzing portion  303  and displayed on a content displaying portion  307 .  
     [0072] As processing portions, besides the content displaying portion  307 , an update notification information processing portion  304  and an updating processing portion  305  are disposed. The received update notification information is processed by the update notification information processing portion  304 . The update notification information contains information representing an occurrence of an update and location information of update information. As a real update content, update information should be received. Thus, the location information is supplied to the receiving portion  301  or the communication controlling portion  308 . Update information to be received is obtained through the receiving portion  301  or the communication controlling portion  308 .  
     [0073] After the update information is analyzed by the analyzing portion  303 , the analyzed result is processed by the updating processing portion  305 . The updating processing portion  305  updates a content stored in the content storing portion  306  corresponding to update information received from the analyzing portion  303 . A received content is stored in the content storing portion  306 . Corresponding to a request issued by the user, the analyzing portion  303  analyzes the content. The content displaying portion  307  displays the analyzed content. The analyzing portion  303  performs an analyzing process for the XML format that is in common with a content, update notification information, and update information.  
     [0074] Next, with reference to FIG. 4, an example of a data format of content information described in the XML will be described. In this example, a content of a weather forecast is described. The content of the weather forecast is assigned an identifier ID that is a URI. A content, update information, and update notification information are correlated by the ID of the content. Reference numeral  400  represents a document format and version information. In the example shown in FIG. 4, the document format is the XML. The version information represents the lateness of the content. Whenever the content is updated, the version information is incremented.  
     [0075] Reference numeral  401  represents that the identifier ID, which identifies a weather forecast area, of the content of the weather forecast is “Tokyo.” Reference numeral  402  represents that the city name is “Tokyo.” Reference numeral  403  represents that the today&#39;s weather is “fine.” Reference numeral  404  represents that the tomorrow&#39;s weather is “cloudy.” Reference numeral  405  represents that the area ID is “Osaka.” Likewise, reference numeral  406  represents a city name. Reference numeral  407  represents the today&#39;s weather. Reference numeral  408  represents the tomorrow&#39;s weather.  
     [0076]FIG. 5 shows an example of a data format of update notification information described in the XML. Update notification information contains information that represents an occurrence of an update and location information necessary for obtaining update information. Reference numeral  500  represents a document format and version information. Reference numeral  501  represents that the sequence number of an event (representing update notification information) is “123.” Reference numeral  502  represents the ID of the content to be updated, namely, it represents that URI is “http://www/weather.xml.” Reference numeral  503  represents that the update type is “modification.” Reference numeral  504  represents that the date and time of the update is “2000-7-7 10:12.” Reference numeral  505  represents that the validation period of the event is six days.  
     [0077] In addition, update notification information contains information necessary for obtaining update information (subject). In the example shown in FIG. 5, three kinds of obtaining methods are shown. Reference numeral  506  represents a URI with which update information is obtained from the bi-directional network. Reference numeral  507  represents information for obtaining update information from the multi-cast network, for example a digital broadcast. In the case of a digital broadcast, information that designates a packet of update information of a trans stream is contained. In the example shown in FIG. 5, the location of update information is described with information that designates a packet and broadcast time. Reference numeral  508  represents location information in the case that update information is broadcast on another broadcast date and time.  
     [0078]FIG. 6 shows an example of a data format of update information described in the XML. Reference numeral  600  represents a document format and version information. Update information contains an ID that identifies a content that has been updated, an update type, and the contents of the update. In FIG. 6, the ID of the content ID is a URI. The update type is “replace.” Reference numeral  601  represents that the tomorrow&#39;s weather forecast of Tokyo in the update information shown in FIG. 4 was changed from “cloudy” to “rainy.” Reference numeral  602  represents that the tomorrow&#39;s weather forecast of Osaka was changed from “rainy” to “fine.” 
     [0079] Next, with reference to a flow chart shown in FIG. 7, the content updating process will be described. At step S 1 , the receiving terminal apparatus receives update notification information through the receiving portion  301  or the communication controlling portion  308 . At step S 2 , the analyzing portion  303  analyzes the received update notification information. The update notification information has been described in the XML format as shown in FIG. 5. To extract the contents of the update notification information, it is analyzed by an XML interpreting program or the like.  
     [0080] At step S 3 , as the analyzed result, the update notification information processing portion  304  controls the receiving portion  301  or the communication controlling portion  308  so as to obtain update information corresponding to the update notification information. As a result, the update notification information processing portion  304  receives the update information. The received update information has been described in the XML format as shown in FIG. 6. At step S 4 , the analyzing portion  303  analyzes the update information so as to obtain the updated content. At step S 5 , the updating processing portion  305  updates the content stored in the storing portion  306  corresponding to the contents of the update.  
     [0081]FIG. 8 is a flow chart showing a content displaying process. At step S 11 , corresponding to a request issued by the user, a content to be displayed is retrieved from the content storing portion  306 . The content is described in the XML format as shown in FIG.  4 . At step S 12 , the analyzing portion  303  analyzes the contents. At step S 13 , the content displaying portion  307  displays the analyzed result.  
     [0082] Step S 2  (analyzing update notification information) and step S 4  (analyzing update information) shown in FIG. 7 and step S 12  (analyzing content) shown in FIG. 8 are performed for a process for analyzing the XML format. These steps are common in analyzing update notification information, update information, and a content.  
     [0083] It should be noted that the present invention is not limited to the forgoing embodiment. However, without departing from the sprit of the present invention, various modifications and ramifications thereof can be performed. For example, besides the XML, other document formats such as SGML and MHEG can be used. In addition, the content storing unit of the receiving apparatus is not limited to a hardware unit disposed therein. Alternatively, a storing unit that can be accessed through an intra network can be used.  
     [0084] According to the present invention, as update notification information that notifies the receiving side of an update event of a content, a predetermined document format, for example the XML format, is used. Thus, a process for a content described in the XML format and a process for an event message can be shared with the receiving side. As a result, the cost and load of the receiving apparatus can be reduced.  
     [0085] In addition, on the transmitting side, on the infrastructure of which a content is distributed in the XML format such as the WWW, update notification information that notifies the receiving side of an update event can be transmitted in the same XML format as a content. As a result, the cost and load of the transmitting apparatus can be reduced.