Abstract:
A method of providing a terminal connected to at least two communication networks with information regarding services provided in said networks comprises the following steps: providing a database server with a database; collecting information regarding services provided in said at least two communication networks in said database server; storing said collected information in the database as service information in a uniform format; and transferring said uniform service information to the terminal. With the method, an overview of services provided by different digital networks is obtained. A system, a terminal and a computer program product are also provided.

Description:
FIELD OF INVENTION  
         [0001]    The present invention relates generally to a method and a system for providing terminals in a communication system with information. More specifically, it concerns a method and a system for providing a digital receiver with information regarding services provided in communication networks adapted to for example the DVB standard. The invention also concerns a terminal and a computer program porduct adapted for use with such system.  
         BACKGROUND  
         [0002]    A system adapted to the Digital Video Broadcasting (DVB) standard comprises several independent networks, such as terrestrial, satellite or cable networks. In such a system with more than one distribution network, network dependent information is usually distributed separately in each network. Information about provided services, such as Service Information (SI) and Program Specific Information (PSI), relevant for a first network is distributed in that first network, information relevant for a second network is distributed in that second network etc. In the above mentioned example with a service conforming to the DVB standard, information is set according to the particular standard used, such as DVB-S (satellite), DVB-C (cable) or DVB-T (terrestrial). For more information regarding the DVB standard, reference is made to the publication “Digital Television MPEG 1 MPEG 2 And principles of the DVB System”, H Benoit, ISBN 0-471-23810-4, or to the DVB Home Page on the Internet: http://www.dvb.org.  
           [0003]    However, a problem associated with information distributed over several networks is that the information seldom is completely according to a standard. There are often application specific standards adding or changing information elements compared with the agreed standard. This could for example result in that, during channel search performed by a digital receiver, many channels are found but the associated parameters sent with the channel do not match or are missing.  
           [0004]    Another problem is the difficulty to schedule service information. One common DVB application is television broadcasting. Today, the supply of services in that field is immense and still increasing. Thus, it is almost impossible to get an overview of what is on TV that day or the next week. The only way to find out is to read a large number of newspapers or magazines or to check TV guide web sites on the Internet. Alternatively, a user can tune into all available networks and download guide information, if a guide mode is at all available in the user equipment. This equipment is normally a so-called Integrated Receiver Decoder (IRD), e.g., a Set Top Box (STB) etc. In the case of the satellite version of the DVB standard, DVB-S, if the user has a motor driven antenna or a DiSEqC-controlled switch with which several satellites can be tuned into, it is even more difficult to get an overview of the services available.  
           [0005]    Yet another problem is that non-DVB transmitted channels are hard to find with a standard channel search.  
           [0006]    The transmitted parameters may not match the actual parameters used by the receiver system.  
           [0007]    Still yet another problem is that the amount of information that requires transmission is rather large. Thus, it is difficult and expensive to transmit all information available for all provided services to the user. In addition, especially for low-end receivers, where the memory budget is very tight, a large amount of information poses problems.  
         OBJECTS OF THE INVENTION  
         [0008]    An object of the present invention is to provide a method and a system for providing a digital receiver connected to several communication networks with information regarding services provided in the networks wherein at least some of the above mentioned problems associated with prior art are overcome.  
           [0009]    Another object is to provide a digital receiver terminal and a computer programme adapted for receiving such information.  
         SUMMARY OF THE INVENTION  
         [0010]    The invention is based on the realisation, that information regarding services of different networks can be collected centrally in a common database in a standardised format.  
           [0011]    According to one aspect of the invention there is provided a method as defined in claim  1 . According to other aspects of the invention there are also provided a communication system as defined in claim  13 , a terminal for use in such a system as defined in claim  25  and a computer program product as defined in claim  27 .  
           [0012]    With the method and the system according to the invention, the problems of providing a digital receiver connected to several communication networks with service information are eliminated or at least mitigated. Thus, with the present invention, a user is provided only with service information quickly and efficiently and in a standardised way for all networks. Furthermore, bandwidth can be utilised more efficiently as service information transmissions can take place more seldom and during low traffic. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0013]    The invention is now described, by way of example, with reference to the accompanying drawings, in which:  
         [0014]    [0014]FIG. 1 is an overview of a communication system according to the invention,  
         [0015]    [0015]FIG. 2 is a block diagram of a service information server according to the invention,  
         [0016]    [0016]FIG. 3 is a flow chart illustrating the major steps when providing a terminal in the communication system of FIG. 1 with service information, and  
         [0017]    [0017]FIG. 4 shows the mapping of information in the service information server of FIG. 2. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]    In the following, a detailed description of a communication system according to the invention will be described. When the term client terminal or simply terminal is used in this document, it is to be interpreted as all kinds of user terminals capable of communicating the relevant kind of information, such Set Top Boxes (STBs) or personal computer equipped with Digital Television (DTV) receiver cards.  
         [0019]    In FIG. 1, an overview of a digital communication system is shown. The system is preferably adapted to an MPEG 2  based standard, such as the DVB standard, or ATSC and cablelabs systems wherein data in the system is used to provide information on how to tune to services and to display the information. The system is built around several networks, one of which is a data network, generally designated  10 , such as the Internet. Different service providers, such as TV companies, are connected to this network through respective service provider equipment, one of which  20  is shown in FIG. 1. Users subscribing to the services are also connected to the network  10  through respective user equipment or client terminal, one of which  30  is shown in FIG. 1. The terminal  30  can be any of a personal computer with an associated modem, a separate display unit, an integrated receiver decoder (IRD) in the form of a monitor accompanying a so-called Set Top Box (STB) etc.  
         [0020]    In addition to the data network  10 , there is a satellite network, generally designated  40 , a cable channel network  50  and a terrestrial network  60 . Thus, the services provided by the service providers  20  can be delivered in many different ways. As an example, a digital television channel can be transmitted to a user by satellite, by a cable channel network or even by a broadcasting network or a data network, such as the Internet.  
         [0021]    Shown in FIG. 1 is also a database or Service Information (SI) Server  70 , also connected to the data network  10 . In the following, the function of the SI Server  70  will be explained in more detail, partly with reference to FIG. 2. Reference is also made to FIG. 3, which outlines the major steps of the method used in connection with a preferred embodiment of the invention.  
         [0022]    The SI server  70  can be any common computer equipment capable of creating and maintaining a database, step  81  in FIG. 3. Thus, the server  70  comprises a display  71  and a keyboard  72 . It also comprises a hard disk  73  or equivalent storage medium for the storage of the database information and other data in digital form. A central processing unit  79  processes all operations in the server and is connected to the different parts of the server, as is usual.  
         [0023]    Further, the server comprises a working storage or memory  74  for running software applications. An example of that is an information collection software application  75 . The function of the information collection application is to gather information regarding the different services provided in the communication networks, step  82  in FIG. 3. This can be accomplished in several ways. The simplest way is to tune into the different networks and perform an automatic channel search, thus collecting information of the respective networks  10 ,  40 ,  50 , and  60 . This is done by means of an integrated receiver  76  provided in the SI Server and connected to the networks through one or more suitable interfaces  77   a ,  77   b  etc. The SI server  70  is thus capable of receiving information from the different networks, see FIG. 1.  
         [0024]    There are alternative ways to input information. Information to be input can be collected from any source, such as newspapers, TV magazines, TV guides on the Internet etc. and input through a user interface, such as the keyboard  72 . Use of Internet search engines and automated collection from other sources are also possible.  
         [0025]    A problem mentioned above in connection with the description of prior art is that some of the transmitted channels are difficult to acquire with a standard channel search. The transmitted parameters associated with the channels do not match the actual parameters needed by a client terminal. However, in the SI Server  70 , this problem can be solved by using a specialised software application  78  having knowledge of the nonstandard features of the different services provided. By means of this specialised application  78 , the parameters provided with the service are analysed and converted into standard parameters useable by the client terminals  30 , step  83  in FIG. 3. These standard parameters are then stored in the database  73  for later use, step  84 .  
         [0026]    It is very important that the information in the SI Server database always is up to date. To that end, the information collection application  75  has a schedule for collecting information. As an example thereof, the integrated receiver  76  is instructed at predetermined intervals to make the above mentioned channel search and supply the information to the SI database, which is then updated if the information received during the channel search differs from that previously stored in the database.  
         [0027]    In the following, several alternative ways of using the information stored in the SI database  73  will be described. As already mentioned, the SI Server  70  is connected to a data network  10 , such as the Internet. This means that client terminals  30  can access the SI database  73  over the network  10  and collect information stored therein. In a preferred embodiment, the client terminal  30  logs into the server  70  by giving a username and password, as is usual. Associated with each username there is a user profile stored in the server. This user profile contains information regarding what kind of receiver is used by the user client terminal  30 , to which networks the terminal is connected, access rights, user preferences, such as fields of interest regarding TV programmes etc. This means that when a client terminal is logged into the SI Server  70 , only information elements relevant to that specific client terminal  30  have to be retrieved.  
         [0028]    This solution with user profile has several advantages. When downloading the service information from the SI Server  70  to the client terminal  30 , step  85  in FIG. 3, the transfer time will be kept to a minimum, thus saving costs and frustration associated with a delay. In addition, it is easier for a user using the downloaded information to get an overview thereof when only relevant information is available to him/her.  
         [0029]    In an alternative solution, the obtained information is filtered in the client terminal  30 . This has the advantage that the preferences can be changed more dynamicaly. In addition, in case there are several users of a specific client terminal  30 , as is often the case, the different users can have different preferences, thus facilitating the use of the service information.  
         [0030]    A combination of the two suggested solutions can also be used, i.e., the information is filtered partly on the SI Server side and partly on the client terminal side. The solution selected largely depends on the performance distribution in the system.  
         [0031]    The information can also be pushed by the SI Server in accordance with any of the standards available, such as ATVEF standard (ATVEF—Advanced Television Enhancement Forum). The advantage of this solution is that the SI server  70  knows when service information relevant for a particular user is updated and therefore can push this information without unnecessary delay.  
         [0032]    The timing of the information transfer is usually not critical. The service information can cover several days and channel parameters seldom change. Thus, as an alternative to sending the information to the client terminal  30  with a PPP connection, it can be broadcasted during e.g. night-time when bandwidth is cheaper. Information can be transferred to the terminal in any IP channel, PPP, ADSL, cable modem etc.  
         [0033]    In FIG. 4, there is shown a preferred way of storing information regarding the different services. In the present example, the services  73   a  are termed “Channel 1”, “Channel 2” etc. However, this is just an example. Associated with each service is a set of parameters  73   b  comprising information, such as frequency, forward error correction (FEC), symbol rate, packet identifier (PID) for audio, video and data etc.  
         [0034]    Preferred embodiments of the invention have been described. It is realised that these can be varied within the scope of the appended claims. Thus, DVB compatible receivers have been shown. However, the invention is applicable to any digital communication system wherein different services are provided.  
         [0035]    Only one network of each kind, i.e., data, satellite, cable and terrestrial, is shown in FIG. 1. There may of course be provided more than one network of each kind. As already mentioned, a terminal can receive information from several satellite networks, for example, possibly by means of a motor driven antenna.