Abstract:
A method of transmitting a web object over a broadcast standard channel to a remote mobile device, the method comprising the steps of accessing one or more web objects from a web server, wherein each web object has an address, determining a hierarchy and an address linkage pattern for the one or more web objects, identifying a closed web site from the one or more web objects, translating the address of one of the web objects in the closed web site to an indicator which is based on the hierarchy and address linkage pattern of the web objects; storing the closed web site such that the web object is stored with its associated indicator, and transmitting a required web object from the stored closed web site at a frequency and a repetition rate which is determined from the indicator.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is related to U.S. Patent application Ser. No. ______ (Attorney Docket No. FR920060019US1) entitled “METHOD AND APPARATUS FOR CACHING BROADCASTING INFORMATION”, filed on ______, and hereby incorporated by reference. 
     
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a method and apparatus for broadcasting information particularly but not exclusively to information presented in the form of web information to be sent to a mobile device. 
       BACKGROUND OF THE INVENTION 
       [0003]    In the environment of mobile television (e.g. hand held television) there are several broadcasting techniques. Mobile TV technology offers consumers the chance to enjoy high quality terrestrial digital broadcasts along with voice telephony and Internet access all in a single wireless device. The digital video broadcast for hand-held (DVB-H) broadcasts Internet Protocol (IP) data-casts is an end-to-end broadcast system for the delivery of any type of digital content and services using IP based mechanisms that are optimised for devices with limitations on computational and battery resources. 
         [0004]    An inherent part of IP data-cast (IPDC) is that it comprises a unidirectional DVD broadcast path that may be combined with a bidirectional mobile cellular interactive part. IPDC is a valuable platform for enabling the convergence of services from broadcast media and telecommunications demand. 
         [0005]    The file delivery method used in the IPDC is based on the File Delivery Over Unidirectional Transport (FLUTE) protocol. FLUTE delivers contents in files, which may include any type of data (e.g. audio, video, binary, still images, texts, ESG meta-data etc.). 
         [0006]    It is possible to access a web server using mobile equipment, for example using WIFI. However, WIFI coverage tends to be very limited and is generally only used in private areas or airports and the like. Although it is possible to connect to a web server using 2.5G or 3G communication means such as GPRS, EDGE or UMTS, it is also necessary to have a subscription which can be expensive and tends to be used by professionals and is not always attractive to the public. New standards are emerging to broadcast TV on mobile equipment (e.g. DVB-H). Some of these standards define means for object transmission. 
         [0007]      FIG. 1  depicts a known mobile internet infrastructure  100  and a separated Digital Video Broadcast infrastructure  102 . A mobile user may access both TV channels and an internet site using a mobile device  104 . TV channels may be broadcast using, for example, DVB-H in Europe. A video source  106  may broadcast using a DVB-H Broadcast Head-End  108  which may include a DVB-H Encapsulation module  110 , a DVB-H Streamer or Modulator  112  and an Amplifier  114 . A VHF/UHF signal  116  can be emitted by the DVB-H Head-End  108  and received by the mobile device  104 . Mobile device  104  may be a GSM phone or a PDA enabled to process DVB-H. In a parallel mode, mobile device  104  may support conventional Web browser capabilities and can receive signals  118  from an access point  120  belonging to a GPRS/UMTS network  122  for example. The GPRS/UMTS network may access the internet  124  by means of a Telco gateway  126 . The internet may access a Web server  128  to obtain content for transmission to the user. Web server  128  may also be accessed by means of a non-mobile device, for example a computer  130 , which may be connected via a wired line such as PSTN, ADSL, etc. 
         [0008]    There are some problems that are encountered with the known systems and methods. Firstly there is a requirement for expensive subscriptions and wireless equipment able to support a communication stack capable of reaching the internet and a separate communication stack capable of receiving broadcast television. A further problem exists in that coverage for internet and TV broadcast are not necessarily equivalent in certain areas, some areas may have coverage of one, some may have coverage of another, and some may have coverage of both or neither. 
         [0009]    One object of the present invention is to overcome at least some of the problems associated with known methods and systems using new broadcast transmission mean (Eg: DVB-H) to transmit web objects included in a closed web site and to allow a user to navigate this web site in a broadcast environment without requiring return channel means as well as video services and associated data such as an Electronic Service Guide (ESG). 
         [0010]    Another object of the invention is to calculate an object weight to order the frequency and delay with which a web object can be transmitted over the broadcast means. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention is directed to the method and system as defined in the independent claims. 
         [0012]    According to one aspect of the invention there is provided a method of transmitting at least one web object over a broadcast standard channel to a remote mobile device, the method comprising the steps of accessing the at least one web object from a web server, wherein the at least one web object has an address, determining a hierarchy and an address linkage pattern for the at least one web object, identifying a closed web site from the at least one web object, translating the address of the at least one web object in the closed web site to an indicator which is based on the hierarchy and address linkage pattern of the at least one web object, storing the closed web site such that the at least one web object is stored with its associated indicator, and transmitting the at least one web object from the stored closed web site at a frequency and a repetition rate which is determined from the indicator. 
         [0013]    According to another aspect of the invention there is provided an apparatus for transmitting at least one web object over a broadcast standard channel to a remote mobile device, the apparatus comprising a web server including at least one web object, wherein the at least one web object has an address, a hierarchy and an address linkage pattern for the at least one web object, a closed web site from the at least one web object, and an indicator which is based on the hierarchy and address linkage pattern of the at least one web object for translating the address of the at least one web object in the closed web site. 
         [0014]    According to yet another aspect of the invention there is provided a system of transmitting at least one web object over a broadcast standard channel to a remote mobile device, the system comprising means for accessing the at least one web object from a web server, wherein the at least one web object has an address, means for determining a hierarchy and an address linkage pattern for the at least one web object, means for identifying a closed web site from the at least one web object, means for translating the address of the at least one web object in the closed web site to an indicator which is based on the hierarchy and address linkage pattern of the at least one web object, means for storing the closed web site such that the at least one web object is stored with its associated indicator, and means for transmitting the at least one web object from the stored closed web site at a frequency and a repetition rate which is determined from the indicator. 
         [0015]    According to still yet another aspect of the invention there is provided a Web Broadcast gateway device comprising a Web site pump for exploring a closed web site to identify each web object in the site, a web page translator, and a Carousel scheduler. 
         [0016]    Further embodiments of the invention are provided in the appended dependent claims. 
         [0017]    The advantages of the present invention are that all media (both web objects and video for example) are broadcast using only the broadcast side of access to the mobile device. Whilst network subscription e.g. UMTS/3G can be maintained if required they are not necessary using the present invention to navigate in a closed web site and to access web objects therein. In addition, the fact that there are reduced costs in terms of subscription is likely to result in increased adoption of mobile devices adapted to operate in accordance with the present invention. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    Reference will now be made by way of example, to the accompanying drawings, in which: 
           [0019]      FIG. 1  is a block diagram of a known mobile internet infrastructure system and a separated Digital Video Broadcast infrastructure. 
           [0020]      FIG. 2  is a block diagram of a Web Cast and Digital Video Broadcast infrastructure according to the present invention. 
           [0021]      FIG. 3  is a block diagram showing the relationship between different Web objects according to the present invention. 
           [0022]      FIG. 4  is a URL Mapping Table which shows the URL mapping of the web objects according to the present invention. 
           [0023]      FIG. 5  shows an HTML page translation according to the present invention. 
           [0024]      FIG. 6  is a diagram showing the object transport format of a data system according to the present invention. 
           [0025]      FIG. 7  is a block diagram showing the structure of an embodiment of a Web client according to the present invention. 
           [0026]      FIG. 8  is a flow chart showing the method steps carried out at the transmission end of the data system in accordance with the present invention. 
           [0027]      FIG. 9  is a flow chart showing the method steps carried out at the reception end of the data system in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0028]    The  FIG. 2  shows a web cast and digital video broadcast infrastructure/system, which includes a Web Broadcast gateway  200  in accordance with the present invention. Web Broadcast gateway  200  is a link between a WEB server  202  and the digital video broadcast environment. Web Broadcast gateway  200  allows a mobile user having only broadcast TV capabilities, to access a web site and to access web objects such as music, Video, images, etc. The term web objects used herein is intended to include all types of information found on the web. Web Broadcast gateway  200  is used to broadcast objects forming a so-called closed web site or closed web object set. The term closed web site defines a web site in which links found on a web page of the site, refer to an object of this web site. In other words, no reference to an “external site” may be found in a web page of a closed web site. This will be described in greater detail below. The closed web site is generated in any appropriate manner by the service provider (ISP). Once the closed site is formed it is broadcast from the transmitter as will be described hereinbelow. 
         [0029]    In a preferred embodiment of this invention Web Broadcast gateway  200  includes three main elements. The first element is a WEB site pump  210 , which periodically explores the closed web site to identify each object belonging to the site. For each object found, a unique reference, unique object identifier (OID) is determined and a record is added or updated in a table which contains all the objects constituting the closed web site. The table is formed during an interrogation phase in which the extent and content of the closed web site is determined. The table may be marked as complete once the interrogation phase is finished. 
         [0030]    The second element of Web Broadcast gateway  200  is a HyperText Language Translator  220  which replaces the URL found in the web page (HTML, WML, etc.) to a new URL which comprises the OID and optionally meta-data relating to the web page or object. This will be described in greater detail below. 
         [0031]    The third element of Web Broadcast gateway  200  is a Carousel scheduler  230 . Scheduler  230  may utilize the table built by WEB site pump  210 . Scheduler  230  includes a weighting associated with each object. The weighting is based on the number of references to this object in the other closed web site pages or objects, the number of “hops” to reach this object from the root page and the size of the object. Using the weighting, the Carousel is populated. 
         [0032]    The web objects which are identified, stored, and broadcast are then delivered at the user end using the FLUTE protocol as will be described in greater detail below. 
         [0033]    The weighting depends on a number of parameters or criteria and will determine the frequency and regularity with which objects are broadcast. For example, the root object will be stored in most slots of the carousel and be broadcast at those slots. Objects further down the web tree may be stored less often and broadcast less often. The objects at the bottom of the tree will be the least frequent. The frequency and weighting of the objects will also depend on the relative sizes of the objects and Carousel and also the frequency of transmission for slot to slot. 
         [0034]    Web objects are downloaded from WEB Server  202  prior to being processed and stored by Web Broadcast gateway  200 . The mobile internet structure described in  FIG. 1  is still maintained, i.e. Telco Gateway  126 , GPRS/UMTS  122  and the GSM access point. However the structure as shown in  FIG. 1  is not used to download web objects. Instead the output from Web Broadcast gateway  200  (from Carousel scheduler  230 ) is combined with the video source output in DVB-H encapsulation module  110  as will be described in more detail below. 
         [0035]    Mobile device  104  thus only receives transmissions from the DVB-H Broadcast Head_End. The connections may be still available for other technologies for example GPRS or UMTS via link  118 . However for the purposes of this invention these types of connections will not be described further. 
         [0036]    The closed web site will now be described in more detail with reference to  FIG. 3 .  FIG. 3  shows web objects with their relationships within a closed web site  300 . Closed web site  300  is a site where there is no reference to an external web site having references to other sites. In other words, the number of hops starting from the root page to reach the farthest web object in the site is limited to a predefined value. This can vary depending on the storage capacity, the nature of the tree (i.e. how many pages at each hop) and the individual page sizes etc. If there are external references (i.e. outside the closed web site) these can be ignored and/or generate an appropriate message for the user to indicate that the external reference is not available. In closed web site  300  a root page  310  (Index.htm) has four links. Three links are on other web pages, link  320  on a first page page1.htm  350 , link  330  on a second page page2.htm and link  340  on a third page page3.htm. The fourth link refers to an image Bkgrnd.gif  380 . In turn each of the pages on the second level (page one, page two and page three) have links to pages at a third level which are two hops from root page  310 . Page2.htm is referenced two times in root page  310  and in page1.htm  350  and can be reached from different routes. 
         [0037]    The third level of pages (pages 11, 12, 21, 22, 31, 32) is the final level in this example. In other situations the tree could include more or less than three levels of pages. A file (or object) VIDEO1.mpg can be accessed in a number of different locations (e.g. page 1, page 21, page 22 and page 31). Similarly audio1.mp3 can be accessed on pages 2, 11 and 21. Flexibility to the user in accessing web objects or files and in minimizing delays in the user viewing specific pages is enhanced. With knowledge of the web object tree and the various jumps, hops or steps between respective pages a table can be created which will be described with reference to  FIG. 4 . This enables the system of the present invention to operate hypertext language translations and to optimize storage. 
         [0038]      FIG. 4  shows a URL Mapping Table  400  according to the present invention in which each entry represents an object of closed web site  300  shown in  FIG. 3 . The table includes a number of columns in which the headings are identified and described below. 
         [0039]    A page name  410  is shown in column  1  and is the name of the object as defined in the WEB server  202 . The name may be prefixed by a hierarchy of directories which are under the Web home directory, or in any other appropriate manner. 
         [0040]    A page type  430  is shown in column  2  and indicates the Web object type. Examples include “text” for html, wml pages; “image” for Jpeg, gif, tiff or any other image or photo files; “audio” for mp3, wma, avi or any other audio or music file formats; “video” for mpeg, avi, QuickTime movie or any other video file formats. 
         [0041]    An OID  440  is shown in the next column. The OID  440  is a unique reference number which identifies the web object in closed web site  300 . OID  440  will substitute the page name in the links found in all the pages forming closed web site  300  as will be described in greater detail below. 
         [0042]    A field indicating USAGE  450  is also identified and populated. Although all objects are broadcast, some objects may not be usable as they are received with control access protection. To make these objects usable, the user (consumer) may request a license. Usage “on demand” is associated with these protected objects, while usage “broadcast” is used for all other objects. 
         [0043]    A Root hop count  460  indicates the number of pages separating the object from the root page. This information will be used to compute the object weight for the carousel scheduling. 
         [0044]    A reference count (Ref cnt)  470  is the number of references pointing to an object in all the pages in closed web site  300 . This information is also used in the computation of the object weight for the carousel scheduling. 
         [0045]    A size indicator (Size)  480  of each object provides the size in Kbytes (Kb) and is also used in the computation of the object weight for the carousel scheduling as will be described below. 
         [0046]    The above-described table is used in a translator and also in the scheduler (or carousel) as will be described below. 
         [0047]    More detail of the translator is now described with reference to  FIG. 5 , which shows an example of an HTML page translation. An input page  500  (Index.htm) which is downloaded from the WEB server  202  is to be translated. The translation is carried out by an application  540  which parses the input and replaces all URL addresses in the link by a OID extracted from URL Mapping Table  400  which has been built by a web pump. The resulting translation gives a page  550  (100.htm) where input references  510 ,  520  and  530  are respectively replaced by OID references,  560 ,  570  and  580 . Moreover, the OID of the page itself is added in a header statement  590 . In the client web browser, the OID numbers in the translated pages are used to request from a client web proxy requested object among all broadcasted objects and to transmit these as soon as they have been received. In this way closed web site  300  may be updated. 
         [0048]      FIG. 6  depicts the format of a data system  600  used to transport the web object. OID  610  represents a unique object identification, while Size  630  indicates object size and Web object  640  is the web object itself. OID  610  and Size  630  are headers in this example and enable the contents of Web object  640  to be delivered to the user. The delivery of the converted files is effected as previously described with reference to  FIG. 2  by Carousel scheduler  230 . 
         [0049]    The receipt of the transmission is handled at the web client of the mobile device in accordance with the following.  FIG. 7  shows the structure of a Web client  700 . Web client  700  includes a Web Browser  720  communicating with Web server  202  through a Communication Stack  710  which may use one of the widely used protocol such as WIFI, 2.5 and 3G protocols (GPRS, EDGE, UMTS). Terminals supporting TV broadcast have new functions in accordance with the present invention, for example a Video Player  780  and a DVB-H Receiver  740 . 
         [0050]    DVBH Receiver  740  includes a number of different functions and layers, for example: a DVB-H Receiver  745 ; an IP module  750 ; a user datagram protocol (UDP) module  755  and two session layers  760  and  765  are provided for the data part FLUTE and for the video Real Time Protocol (RTP) respectively. 
         [0051]    The video processing elements also include a H.264 decoder  770  and a Video Streamer (IP Multicast)  775 . The output from Video Streamer  775  is sent to Video Player  780  for display to the user. 
         [0052]    The present invention implements a new component which may be launched as a service which intercepts all requests from the browser and acts as a Web Proxy  730 . This new component examines all files received on FLUTE  760  and delivers to the browser the requested file as soon as it has been received. This component does not need any modification by the client applications, just a configuration of the web browser to define local usage of the Web Proxy  730 . Web Proxy  730  caches the page and then passes it to the web browser. 
         [0053]    Web Proxy  730  connection to Communication Stack  710  can facilitate conventional connection to internet content if required. This facility is optional and may be switched on and off as required. 
         [0054]    With Web (and video) client  700  as described above the user may receive a broadcast stream of data including web objects and video without having to have two separate infrastructures for each. Any type of data can be broadcast to a user. The amount and speed of delivery being limited only as a function of the broadcast transmission capabilities and not as a function of the user&#39;s subscription, which might have limited availability and connectivity. 
         [0055]    The method steps carried out at both the transmission end of the system and the receiver end of the system will now be described with reference to  FIGS. 8 and 9  respectively. 
         [0056]    Firstly at a transmission end of the system as shown in  FIG. 8 , a broadcaster decides to transmit either web objects from a closed web site, a video source or a combination to mobile devices and commences the process at step  800 . The manner in which the the content is broadcast will depend on the nature of the mobile device and the broadcast reception available to the user. Prior to transmission, the video stream and web objects are processed differently. When a video stream is broadcast at step  802 , a video stream for the mobile device is formed at step  812  and transmitted at step  814 . 
         [0057]    For broadcasting web objects at step  804 , one or more web objects from closed web site  300  are downloaded from the web server. The web objects are formed into closed web site  300  as previously described at step  806 . The extent of closed web site  300  being determined by the size of the web pages, tree structure (i.e. hops from root pages) and the amount of links to the pages from other pages in closed web site  300 , as well as the capacity of the storage means at the transmitter and/or receiver ends of the system. 
         [0058]    The web objects in closed web site  300  are then translated so that the links between pages can be changed from HTML links to OID references (as described above) at step  808 . The translated objects are then loaded into the Carousel scheduler  230  at step  810  in a predetermined manner based on their weightings. 
         [0059]    The web objects are then formed into a package for broadcast at step  812  to the user. The package (and its contents) is broadcast to the mobile device of the user at step  814 . 
         [0060]    With reference to  FIG. 9 , the content from the transmission end of the system is received at the mobile device in bursts at regular time slots at step  900 . The different burst types are broadcast and received at different time slots. The time at which the bursts arrive is scheduled and known at step  902  and the type of burst is determined at step  904 . 
         [0061]    If the bursts are video  906 , the bursts are processed using for example, an RTP session at step  908 , a Decoding Stream step  910 , for example H. 264 decoding, and the content is steamed by a Video Streaming Process at step  912 . The video is then passed through a Video player at step  914  and displayed to the user at step  916 . 
         [0062]    If on the other hand, the bursts contain a Web object step  918  the contents are read and a FLUTE session is established at step  920 , which in turn facilitates file delivery at step  922  via the Web Proxy at step  924 . The Web Proxy passes the web object through the Web browser at step  926  and the content is displayed to the user at step  916 . 
         [0063]    The Web Proxy may also connect to the communications stack  710  at step  928  to enable further requests from the user to be communicated to the transmission end as is well known in the art. 
         [0064]    The mobile device may be of any type, including for example, pdas, mobile phones or any other type of which is mobile and can communicate remotely. 
         [0065]    The standards such as DVB-H, RTP, H.264 etc described herein are shown by way of example only and any other standards present or future may be equally applicable. 
         [0066]    There are many advantages of the present invention. A significant advantage being that all media (both web objects and video for example) are broadcast using only the broadcast side of access to the mobile device. Whilst network subscription eg. UMTS/GPRS can be maintained if required they are not necessary using the present invention for access to web objects. The fact that there are reduced costs in terms of subscription is likely to result in increased adoption of mobile devices adapted to operate in accordance with the present invention. 
         [0067]    The broadcaster may have influences on the closed web site to enable them to match the broadcast media, for example, tickets for the next match if a user is watching a certain game, appropriate advertising, etc. 
         [0068]    While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood that various changes in form and detail may be made therein without departing from the spirit, and scope of the invention.