Abstract:
A user through a mobile or fixed terminal ( 5 ) informs an agent ( 33 ) hosted by an operator server ( 13 ) of subjects in respect of which content is requested. The agent ( 33 ) searches the internet for relevant content, and determines from a set of user preferences, relating to cost and timing of delivery preferences, a network for use in delivering the content to the terminal. Delivery may be made by a free network, e.g. a WLAN or Bluetooth network, if one is available, or over an expensive network such as a 3G, GSM or GPRS network if the content is requited quickly. If delivery is to be made over a broadcast network ( 11 ), such as a DVB-T network ( 11 ), a signal is sent to the terminal over a mobile telephone network ( 7 ) giving the time of broadcast, in response to which the terminal ( 5 ) enables its broadcast receiver at the appropriate time. Also, the agent ( 33 ) periodically reviews the content on a data carousel ( 45 ) which is awaiting broadcast, and informs the terminal ( 5 ) of any forthcoming content which is relevant to the user request.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a hybrid network. The invention relates also to a content delivery method, to an agent connectable to a network and to a content delivery system.  
       BACKGROUND OF THE INVENTION  
       [0002]     As a result of the perceived needs of the consumer, it is considered that the opportunities so offered by digital technology will result in a convergence of product features and capabilities. Such a convergence is already evident today in the provision of add-on and even integrated cellular telephony capabilities to the so-call personal data assistant (PDA) product category. Such convergence will undoubtedly bring advantages to the consumer in that she will no longer need to transport a range of devices with her.  
         [0003]     However, from the perspective of the manufacturer and/or service provider, the convergence of products brings particular challis. In the case of the manufacturer, such challenges include the need to integrate the functionality of what previously were devices having different operating systems, power requirements and such like, and typically all within a smaller, more compact form factor. For the service provider, the challenge is to provide existing and new services in a form which complements the synergies brought to the user by the convergence of functionality in the product.  
       SUMMARY OF THE INVENTION  
       [0004]     According to a first aspect of the invention, there is provided a content delivery method comprising establishing a set of user preferences related to delivery of content, sourcing content in response to a request received from a terminal connected to a network and selecting based on said set of user preferences a network over which to deliver said content to said terminal.  
         [0005]     This method can allow content to be delivered over a network which is most suitable to the user, providing flexibility of service. Allowing user preferences to be settable and to be acted on can allow a user to feel in control of content delivery services, which might cause the user to demand more content tin otherwise. Content delivery services using the method could be considered as customisable, and thus user-considerate. Also, if the user preferences are changeable, in response to changed service conditions or otherwise, the invention may allow a user confidence to subscribe to or merely request content which otherwise would have been missed, enriching user experience. The user preferences might relate to cost and/or delivery timing preferences.  
         [0006]     The method preferably comprises maintaining in an agent a log of sourced content relating to the request, which could include an indication of the delivery status of the content. Such could allow a network straightforward management of content relating to the user, and avoid the user or the user&#39;s terminal having to ensure that all requested content has been delivered, and delivered fully and correctly.  
         [0007]     Preferably, the method includes acknowledging receipt of the content over a or the duplex network which allows the preferred feature of updating the delivery status of the log on receiving an acknowledgement receipt.  
         [0008]     In a preferred example, the method comprises notifying over a duplex network the terminal prior to the delivery of content over a simplex network. This is particularly advantageous since the enabling of a receiver for reception of content over a simplex network can consume power at relatively high rates, especially where the simplex network is a DVB network or similar. Power consumption minimisation is particularly important in mobile terminals.  
         [0009]     The content may be selected by reviewing content items on a data carousel and determining from the reviewing step if any forthcoming content matches the user request or by conducting a search for content relating to the request, preferably using the internet. Searching for content on the internet is expected to be particularly prevalent in years to come. Using the invention, it may be possible to provide content relating to any given subject through regular searches, without the user having to instruct the search on each occasion.  
         [0010]     To aid searching, the method may include comprising storing in an agent information relating to the last update of content relating to the request, and/or information relating to the user&#39;s time and/or frequency of updating preferences, and/or information relating to domains to which searching relating to the content request is limited.  
         [0011]     According to a second aspect of the invention, there is provided an agent connectable to a network, the agent being operable to establish a set of user preferences relating to delivery of content to a user terminal, to source content in response to a user request, and to deliver said content to a user terminal over a network selected in dependence on said set of user preferences.  
         [0012]     The agent preferably is arranged to maintain a log of sourced content relating to the request, which preferably includes an indication of the delivery status of the content. Advantageously, the agent is arranged to update the delivery status of the log on receiving an acknowledgement receipt.  
         [0013]     The user preferences could relate to cost and/or delivery timing preferences.  
         [0014]     The agent may comprise means for reviewing content items on a data carousel, and means for determining from the reviewing step if any forthcoming content matches the user request.  
         [0015]     If the agent includes means for searching for content relating to the request, it also preferably includes means for storing information relating to the last update of content relating to the request, and/or means for storing information relating to the user&#39;s time and/or frequency of updating preferences, and/or means for storing information relating to domains to which searching relating to the content request is limited.  
         [0016]     In accordance with a third aspect of the invention, there is provided a content delivery system comprising a first duplex network, a second network and a user terminal connectable to said first and second network, wherein the system further comprises an agent connectable to said first and second networks, the agent being operable to source content in response to a user request received from said user terminal via said first network, and to deliver said content to said terminal over a network selected in accordance with a set of user preferences.  
         [0017]     User preferences could be established by the agent, or be generated by the terminal.  
         [0018]     The second network could be a simplex network, such as a broadcast network, for example a DVB network. In such a case, it is particularly advantageous for the system to include means for notifying over the first network the terminal prior to the deliver of content over the second network. Instead of a simplex network, though, the second network could be a duplex network such as a Bluetooth network, or a network operating to any of the GPRS, GSK 3G or WLAN standards.  
         [0019]     The agent might be arranged to maintain a log of sourced content relating to the request, and to maintain in the log an indication of the delivery status of the content.  
         [0020]     If the terminal is arranged to acknowledge receipt of the content over the duplex network or one of the duplex networks, the agent preferably is arranged to update the delivery status in the log on receiving an acknowledgement receipt.  
         [0021]     The user preferences could relate to cost and/or delivery timing preferences.  
         [0022]     The system may comprise means for reviewing content items on a data carousel, and means for determining from the reviewing step if any forthcoming content matches the user request. Alternatively or in addition, the system could comprise means for conducting a search for content relating to the request, preferably using the internet. In either case, the agent preferably is arranged to store information relating to the last update of content relating to the request, and/or information relating to the user&#39;s time and/or frequency of updating preferences, and/or information relating to domains to which searing relating to the content request is limited.  
         [0023]     Embodiments of the invention win be described, by way of example only, with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]     In the drawings:  
         [0025]      FIGS. 1   a ,  1   b  and  7  are diagrams illustrative of hybrid systems in accordance with one aspect of the present invention and including agents according to another aspect of the invention;  
         [0026]      FIG. 2  is a schematic diagram of a mobile telephone and its user interface components;  
         [0027]      FIG. 3  is a schematic diagram illustrating operation of the  FIG. 2  telephone;  
         [0028]      FIG. 4  is a schematic diagram of an agent according to one aspect of the invention and included in another aspect of the invention;  
         [0029]      FIGS. 5   a ,  5   b  and  6  are flowcharts illustrating operation of the  FIGS. 1   a  and  1   b  systems; and  
         [0030]      FIG. 8  is a schematic diagram of a preferred form of agent. 
     
    
       [0031]     In the Figures, like reference numerals are used to refer to like elements throughout.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]     With reference to  FIGS. 1   a  and  1   b , there is shown a hybrid network  1  connectable to a source of content  3  on an intranet and/or the Internet. The hybrid network  1  includes a plurality of user-operated terminals  5 , both mobile and fixed, a first duplex communication network  7 , and in the case of  FIG. 1   a  a second simplex broadband network  9  and in the case of  FIG. 1   b , a so-called ‘hot-spot’  11  providing an access point to the source of content  3  using a wireless local area network including, but not limited to, a low power radio frequency network. Clearly, the hybrid network  1  can also comprise a combination of the above two examples in which both the second simplex broadband network  9  and at least one hot-spot  11  are available in conjunction with the first duplex network  7 .  
         [0033]      FIG. 2  illustrates the main components relied upon by a user in interacting with a terminal  5 . Thus, the terminal  5  includes a keypad  15 , a microphone  17 , a loudspeaker  19  and a display  21 . The operation of these components is under the control of a controller  23  shown in more detail in  FIG. 3 . The controller  23  performs not only the tasks necessary to provide interaction with the user via the above described elements, but also ensures that the terminal  5  operates correctly within the hybrid network  7 . Thus, the controller  23  is connected to a memory  25  for storage of instructions relevant to the operation of the terminal. User data is stored on long teem storage  27  such as flash media and the like, again the task of providing access to such data is carried by the controller  23 . A transceiver section  29  connected to a bus  31  serving the controller  23  interprets radio frequency and/or infrared signals arriving at the terminal  5  and similarly converts output from the controller  23  into the appropriate radio frequency and/or infrared signals. The particular format of the signals received and transmitted by the terminal  5  is determined by the network portion  7 ,  11 ,  9  of the hybrid network with which the terminal is communicating. Thus, where the terminal  5  is in communication with the first duplex network  7 , then the appropriate configuration of the transceiver section  29  is selected by the controller  23 . Similarly, the transceiver section  29  is configured to match the requirements of the simplex network  9  or hot-spot  11  as appropriate.  
         [0034]     Turning now to  FIG. 4 , there is shown an agent  33  resident on a network element, which in this case is a server  13  (see  FIG. 1   a  and  FIG. 1   b ) under the control of the operator. The agent  33  can be a software application running on the server  13 , although the agent may alternatively be provided in hardware or as a combination of software and hardware. Furthermore, the agent  33  may comprise a number of processes hereinafter referred to as modules each resident on one or more different distributed network elements.  
         [0035]     The agent  33  has a communication module  35  which facilitates communication with external processes linked to it via a network connection  37  through the transmission and reception of data packets corresponding to a particular IP protocol, such as IPv6. The communication module  35  is arranged to determine those packets which are intended for delivery to the agent  33 , and these packets are passed to a control module  39 .  
         [0036]     The control module  39  carries out the core processes of the agent  33  and as such has access to a log module  41  which module retains details of terminal  5  sessions, namely a list of activity which has taken place with respect to a particular terminal  5 . The log module  41  further provides the controller with a mechanism for maintaining an indication of currently active sessions that are taking place with terminals. As terminals  5  enter into communication with the agent  33 , respective entries are made in the log module  41  in accordance with instructions received from the control module  39 . As has been mentioned, the log module  41  records any activity that takes place during a terminal session.  
         [0037]     The control module  39  is further provided with access to a user preference module  43 . This module  43  may be located on the server  13  in the sense that communication with the module  43  takes place directly between the control module  39  and the user preference module  43  or it may be distributed in the sense that communication with the user preference module  43  is made via the communication module  35  and network connection  37 . Indeed, it may be that the log module is also distributed over the network. The user preference module  43  comprises a store of information relating to the individual preferences of a particular terminal, or a group of terminals such as those belonging to a particular entity (a company or an individual. The preferences provided by a user may include a definition of the cost and delivery timescale the user attaches to the receipt of particular content. As is described in more detail below, the agent  33  is provided with details of the particular content or service (these terms being used interchangeably throughout the specification) to be delivered to the user through a request generated either at the terminal or through a separate web-based interface, for example. The request may be generated in real-time in the sense that the agent  33  responds to the request during an interactive session exhibiting a low level of latency, or the request may be generated and then acted upon by the agent  33  at a later time, such as where resolution of the request is contingent upon a factor such a particular delivery method being available.  
         [0038]     In the present embodiment, the communication between the terminal  5 , the agent  33  and content provider is carried out utilising the IPv6 protocol, although this should not be understood to Emit the invention to use of this particular protocol since any suitable protocol, such as IPv4 for example, could be used.  
         [0039]     Referring again to  Figure 1   a  and  FIG. 1   b , the first duplex communication network  7  is a cellular telephony network operating in accordance with one of many well-understood standards such as GSK GPRS, CDMA, WCDMA and the like. All such cellular telephony networks share the characteristic of serving a plurality of mobile terminals from a fixed network of base stations operated by a telecommunication network operator, hereinafter termed a network operator. The network operator may also provide services as a service provider, although the provision of services to terminal users may be carried out by service providers who need not themselves be responsible for provision of the network services. A further characteristic shared by such networks is that each utilises a specific air interface and transmission technique. Thus, the transceiver section  29  of the terminal  5  is adapted to suit a particular air interface and transmission technique. In some terminals, there nay exist the capability to have a plurality of transceiver configurations within one transceiver, rather than a plurality of transceivers within the transceiver section  29 , such as is found in so-called software radios.  
         [0040]     With respect to  FIG. 1   a , as has been mentioned above, the second simplex network  11  is provided by a simplex or unidirectional broadband network such as a terrestrial Digital Video Broadcast DVB-T network. The second simplex network  11  includes a data carousel  45  which is operated by a service provider who may also be the network operator. The data carousel  45  is a form of repository into which services are placed and from which these services are selected for delivery over the second network  11  to one or more terminals  5 . In other words, the data carousel  45  comprises a number of files each corresponding to a service and these files are broadcast on a cyclical basis. The data carousel  45  has sufficient capacity to store a large number of services. Typically, the services will include content obtained from a content source  3 .  
         [0041]     In addition to the second network,  FIG. 1   a  also shows the operator server  13  which forms part of the first duplex network  7 . The operator server  13  also hosts the agent  33  and the agent  33  is capable of connecting via the communication module  35  to service providers via the Internet and also to the data carousel  45 .  
         [0042]     With respect to  FIG. 1   b , the second network is, as has already been indicated, a wireless LAN or LPRF hot-spot  9 . As in the case of  FIG. 1   a , the operator server  13  forms part of the first duplex network  7 . The operator server  13  also hosts the agent  33 . The agent  33  is capable of connecting via the communication module  35  to service providers via the Internet and to the hot-spot  11 .  
         [0043]     To understand the invention more completely, reference is made to the flowcharts of  FIG. 5  and  FIG. 6 , in relation to the examples shown in  FIGS. 1   a  and  1   b  respectively.  
         [0044]     Firstly with reference to  FIG. 5 , in which a user enters a subscription for a particular service such as a top ten MP3 download list, which is updated on a once-per-week basis.  
         [0045]     Initially, the user enters a subscription request at step  100  via a keyboard  15  input, the controller  39  interprets the input and the request is appropriately formatted before being delivered via the first duplex network  7  to the user preference module  43  where the subscription request is held at step  101 . The subscription request may additionally incorporate delivery parameters which the agent  33  should comply with when meeting the subscription request, the parameters being such as cost, time of delivery and the like.  
         [0046]     Subsequently, at step  102 , the control module  39  instructs the communication module  35  to select and then deliver packets of data identifying the forthcoming content of the data carousel  45  of the second simplex network  9  to the control module  39  for analysis. This is carried out on a periodic basis. On receipt of such packets, the control module  39  checks the preference module  43  to determine what subscription requests have been received. If the control module  39  determines at step  103  that a user subscription request held by the user preference module  43  identifies content forthcoming on the data carousel  45 , the control module  39  proceeds at  104  to the next step  105 , otherwise the control module  39  continues the process  102  of analysing packets of data identifying the forthcoming content of the data carousel  45 .  
         [0047]     Where content has been identified as forthcoming and of interest to a user, the control module  39  proceeds as follows. The control module  39  raises a query at step  105  with the log module  41  in order to determine the status of content delivery made to a terminal  5  of the user. In particular, the control module  39  attempts to determine form the log module  41  whether the specific content forthcoming on the data carousel  45  has previously been successfully delivered to the terminal  5 . If the result of the query is negative in the sense that there is no log entry indicative of the content having been delivered, the control module  39  proceeds at  106  to step  107 . Then, the control module  39  extracts, from the data identifying the forthcoming content, details of the transmission time and channel. These details are then passed to the communication channel in the form of a request  107  which is then delivered over the first duplex network  7  to the terminal  5  of the user.  
         [0048]     The request is received by the transceiver section  29  of the terminal  5  and passed to the controller  23  where it is analysed such that the controller  23  recognises that a delivery of content over the second simplex network  9  is imminent. Consequently, the controller  23  ensures that the transceiver section  29  is reconfigured to receive the content over the second simplex network  9  at the previously informed delivery time. As a result, the terminal  5  is able to receive the desired content via the appropriately configured transceiver section  29  into storage  25  whereupon it may be consumed by the user in accordance with the distribution policies of the content provider. As a final step, once delivery of the content has occurred, the controller  23  sends a delivery acknowledgement message via the appropriately configured transceiver section  29  over the first duplex network  7 , which message is addressed to the agent  33 .  
         [0049]     The acknowledgement message is accepted by the communication module  35  and passed to the control module  39  of the agent  33 . The control module  39  ensures that the log module  41  is updated with a flag indicating successful delivery of the particular content.  
         [0050]     In another example based on the same user preferences, the user enters a subscription request at step  200  via a keyboard  15  input, input is interpreted by the controller  23  and the request is appropriately formatted before being delivered via the first duplex network to the agent  33  and finally to the user preference module  43  where the subscription request is held. The subscription request may additionally incorporate delivery parameters which the agent  33  should comply with when meeting the subscription request such as cost, time of delivery and the like.  
         [0051]     With reference both to  FIG. 1   b  and  FIG. 5   b , the terminal is subsequently carried by the user into a hot-spot  11  provided by a Wireless Local Area Network WLAN, although similar functionality could be provided by a Low Power Radio Frequency hot-spot such as one provided by a Bluetooth transceiver. On entry to the hot-spot  11  at step S 201 , the terminal controller  23  is notified by the transceiver section  29  that the terminal  5  is now within the hot-spot  11 . The controller  23  thereupon generates a notification announcement for delivery at step S 202  to the agent  33 . The notification announcement contains data indicative of the presence of the terminal  5  in the particular hot-sot  11 . The announcement is sent via the appropriately configured transceiver section  29  over the second duplex network provided by the hot-spot  11  and ultimately is detected by the communication module  35  of the agent  33  and passed to the control module  39 . The control module  39  thereupon determines that a user subscription request is being held by the user preference module  43  which request identifies specific content. The control module  39  then at step S 203  raises a query with the log module  41  in order to determine the status of content delivery made to a terminal of the user. In particular, the control module  39  attempts to determine from the log module  41  whether the specific content has previously been successfully delivered to the terminal  5 . If the result of the query is negative in the sense that there is no log entry indicative of the content having been delivered, the control module  39  proceeds to attempt to source the content from a content provider. Thus, the control module  39  either generates a search query using an appropriate search engine, which may be restricted to collections of content held by a particular content provider, to obtain a link to the content, or the source of the content is predefined in the sense that the user preferences provide an explicit link to the desired content. In either case, the control module  39  then downloads the content from the particular location  3  and forwards the content over the second duplex network or hot-spot  11  to the terminal  5  whereupon it may be consumed by the user in a manner appropriate to the distribution conditions imposed by the content provider. As a final step, once delivery of the content has occurred, the controller  23  sends at step S 204  a delivery acknowledgement message via the appropriately configured transceiver section  29  over the second duplex network  11 , which message is addressed to the agent  33 .  
         [0052]     The acknowledgement message is accepted by the communication module  35  and it is passed to the control module  39  of the agent  33 . The control module  39  ensures at step  206  that the log module  41  is updated with a flag indicating successful delivery of the particular content.  
         [0053]     In still another example, the user generates, using her terminal  5 , an immediate request  300  for content in accordance with a possibly predefined set of preferences which include setting a maximum transport cost for the desired content of          n and a best efforts for minimum delivery latency subject to the overriding transport cost constraint. As described above, the user will have previously entered her subscription preferences request via a keyboard  15  input in which the controller  23  interprets the input and the request is appropriately formatted before being delivered via the first duplex network  7  to the user preference module  43  where the subscription request is held. The subscription request incorporates the aforementioned delivery parameters which the agent  33  must comply with when meeting the subscription request.  
         [0054]     With particular reference again to  FIG. 1   b  and  FIG. 6 , having received the immediate request for content the controller  23  determines at step  301  whether the terminal  5  is presently located in a hot-spot  11 . If this is the case, the request is sent at step  302  via the appropriately configured transceiver section  29  over the second duplex network provided by the hot-spot  11  and ultimately is detected by the communication module  35  of the agent  33  and passed to the control module. The control module  39  thereupon determines that a user subscription request is being held by the user preference module  43 , which request identifies specific content. Assuming the cost constraint is not broken by the intended delivery using the second duplex network  11 , the control module  39  then proceeds to the next step in the process which is to attempt to source the content from a content provider. Thus, the control module  39  either generates a search query using an appropriate search engine which may be restricted to collections of content held by a particular content provider, in order to obtain a link to the content, or the source of the content is predefined in the sense that the user preferences provide an explicit link to the desired content. In either case, the control module  39  then downloads the content  13  from the particular location and forwards the content over the second duplex network  11  to the terminal  5  whereupon it may be consumed by the user in a manner appropriate to the distribution conditions imposed by the content provider. As a final step, once delivery of the content  3  has occurred, the controller  23  sends a delivery acknowledgement message via the appropriately configured transceiver section  29  over the second duplex network  11 , which message is addressed to the agent  33 .  
         [0055]     However, where the terminal  5  is not located within a hot-spot  11  or the cost of delivery via the second hot-spot duplex network  11  exceeds          n, the controller  23  sends at  303  the request via the first duplex network  7  utilising the appropriately configured transceiver section  29 . The request is received in the communications module  35  and passed to the control module  39  where the agent  33  seeks a delivery cost estimate from the first duplex network  7 . Where the cost does not exceed in then the control module  39  proceeds by attempting to source the content from a content provider. Thus, the control module  39  either generates a search query using an appropriate search engine, which may be restricted to collections of content held by a particular content provider, in order to obtain a link to the content, or the source of the content is predefined in the sense that the user preferences provide an explicit link to the desired content. In either case, the control module  39  then downloads the content  3  from the particular location and forwards  304  the content  3  over the first duplex network  7  to the terminal  5  whereupon it may be consumed by the user in a manner appropriate to the distribution conditions imposed by the content provider. As a final step, once delivery of the content  3  has occurred, the controller  23  sends a delivery acknowledgement message via the appropriately configured transceiver section  29  over the first duplex network  7 , which message is addressed to the agent  33 .  
         [0056]     In the event that immediate delivery is not possible over the first duplex network  7  because of the cost constraint, then the control module  29  generates a confirmation request for delivery  305  to the terminal  5  which when received over the first duplex network  7  by the transceiver section  29  is passed to the controller  23  and suitably formatted for presentation on the display  21  of the terminal  5 , whereupon the user can elect whether to override the cost constant and request immediate delivery  306  or alternatively to confirm that the cost constraint should not be broken  307 . In the former case  306 , delivery  308  proceeds at a cost exceeding the constraint in the manner mentioned above, namely the control module  39  proceeds by attempting to source the content from a content provider. Thus, the control module  39  either generates a search query using an appropriate search engine, which may be restricted to collections of content held by a particular content provider, in order to obtain a link to the content, or the source of the content is predefined in the sense that the user preferences provide an explicit link to the desired content. In either case, the control module  39  then downloads the content  3  from the particular location and forwards the content over the first duplex network  7  to the terminal  5  whereupon it may be consumed by the user in a manner appropriate to the distribution conditions imposed by the content provider. As a final step, once delivery of the content  3  has occurred, the controller  23  sends a delivery acknowledgement message via the appropriately configured transceiver section  29  over the first duplex network  7 , which message is addressed to the agent  33 .  
         [0057]     In the case where confirmation  307  is received from the terminal  5  that the delivery cost construct is not to be exceeded, the control module  39  proceeds by attempting to source the content from a content provider. Thus, the control module either generates a search query using an appropriate search engine, which may be restricted to collections of content held by a particular content provider, in order to obtain a link to the content, or the source of the content is predefined in the sense that the user preferences provide an explicit link to the desired content  3 . This link to the desired content  3  is then logged  309  in the log module  41  and flagged as being an outstanding request to deliver content  3  to the terminal  5 . Subsequently, when the terminal  5  enters a hot-spot  11  a notification announcement is generated at step  310  by the terminal  5 . As previously described, the announcement is sent via the appropriately configured transceiver section  29  over the second duplex network provided by the hot-spot  11  and ultimately is detected by the communication module  35  of the agent  33  and passed to the control module  39 . The control module  39  then raises a query with the log module  41  in order to determine the status of content delivery made to a terminal  5  of the user. In particular, the control module  39  attempts to determine from the log module  41  whether the specific content has previously been successfully delivered to the terminal  5 . In this case, the control module  39  also determines that there is an outstanding delivery request for the specific content  3  and using the link provided by the log module  41 , the agent  33  downloads the specific content  3  and forwards  311  the content  3  over the first duplex network  7  to the terminal whereupon it may be consumed by the user in a manner appropriate to the distribution conditions imposed by the content provider. As a final step, once delivery of the content  3  has occurred, the controller  23  sends a delivery acknowledgement message via the appropriately configured transceiver section  29  over the first duplex network  7 , which message is addressed to the agent  33 . On receipt of the acknowledgement message, the control module  39  is able to instruct the log module  41  to update  312  the log and to change the flag state to indicate successful delivery of the content  3 .  
         [0058]     A further embodiment of the invention is now described with reference to  FIGS. 7 and 8 . Referring firstly to  FIG. 7 , a system  50  is based on the system of  FIG. 1   a , the description of which is not reproduced here for the sake of conciseness. The main differences are in the provision of plural agents  3 ,  3   a ,  3   b , which are associated with the operator server  13  and the internet, and in the data carousel  45  being included within a broadcast operator server  51 . A content cache  52  is connected to the broadcast operator server  51  to allow communication therebetween. Content servers  53 ,  54  and  55  are connected for interaction with the internet.  
         [0059]     The agent  3  is shown in more detail in  FIG. 8 . The agent  3  includes a user preference database  60 , a last update database  61 , an update frequency database  62 , a content domain database  63  and an agent content cache  64 . The information shown in the databases  60  to  63  relate to a single user or group of users. Operation is as follows. A user of the terminal  5  decides on a subject on which information is required. The user then programs the terminal  5  with an identification of that subject, for example a sports team or a stock price, and frequency and optionally timing for which content relating to that subject is required. Optionally, the user specifies also the domains from which information is required to be sourced. The domains may be websites  53 ,  54 ,  55 , specified by way of their URLS. The information programmed into the terminal  5  is transmitted by way of the duplex network  7  and the mobile operator server  13  to the agent  3 , where the information is stored in the user preference database  60 , the update frequency database  62  and the content domain database  63  as appropriate. The information stored in these databases  60 ,  62 ,  63  is amendable by a user by the sending of appropriate amending information from the terminal  5 .  
         [0060]     When content relating to a chosen subject is due for updating, as indicated by the information stored in the update frequency database  62 , the agent  3  conducts a search though the internet for information relating to that subject. The search is limited to those domains  53 - 55  specified by the user, if there are any. If the agent  3  discovers any content which has been updated for the subject since its last search, the last update database  61  is marked with the time and date of the update, and the content is marked for delivery to the terminal  5 . Content which has been sent to the terminal  5  previously is disregarded. Content which is marked for delivery and which the mobile operator server  13  determines is best transmitted using the DVB network  9 , having regard to the user preferences, is sent to the broadcast operator  51  via the internet, where it is stored whilst awaiting a broadcast request. If the mobile operator server  13  and the broadcast operator server  51  are the same, which could occur if they are run by a single operator, the last step can be omitted. Once the content has been sent to the broadcast operator server  51 , the mobile operator server  13  signals to the terminal  5  that content is ready for broadcast, and includes a request for confirmation that the content is required. This step may include an indication of the content, such as a document or program title and optionally a summary of the information contained. Once the terminal  5  signals that the user wants to receive the content, the mobile operator server  13  sends to the broadcast operator server  51  a broadcast request, which identifies the content and includes location information relating to the terminal, such as the cell in which the terminal is located. In response, the broadcast operator server  51  loads the content from the cache  52  to the data carousel  45 , from where it is broadcasted to the terminal  5 .  
         [0061]     To minimise power consumption in the terminal  5 , it is provided with information identifying the broadcast time. This could be specified by the user or by the terminal  5 , and signalled to the broadcast operator server  51  via the mobile operator server  31 .  
         [0062]     Alternatively, it is to be specified by the mobile operator server  13 . Most likely, though, the broadcast time is specified by the broadcast operator server  51 , and the time information is signalled to the mobile operator server  51  for transmission to the terminal  5  over the duplex network  7 .  
         [0063]     The agent  3  may negotiate the transfer slot used to broadcast the content. For example, broadcasting content at night may be affordable to the user of the terminal  5  whereas broadcasting in the daytime might exceed the user&#39;s predefined cost limitations.  
         [0064]     The agent  3   a  may serve as a group of users, for example supporters of a certain sports team. In this case, the information contained in the databases  60 ,  62 ,  63  may be specified by a designated terminal. The agent  3   a , through the mobile  13 , arranges for plural members of the group to expect content delivery over the DVB network  9  at a time specified by the broadcast operator server  51 . The content remains in the data carousel  45  either until it has been successfully delivered to all members of the group, until the content is no longer relevant, for example because it has been updated, or until a timeout value has been exceeded.  
         [0065]     Alternatively, the agent  3   a  may store user preferences for each of the users in the group. The user preferences relate to cost and delivery timing preferences. A first user, for example, may request content update at two hourly intervals between 9 am and 11 pm, and require delivery over a pay-network only if the content cannot be delivered free within 30 minutes of the update time and if the cost of delivery for a two-hour period does not exceed one Euro. A second user may request content update daily at 8 pm, and not require delivery over a pay-network under any circumstances. Data indicative of these preferences is stored in the agent  3   a.    
         [0066]     The agent  3   a  also sources content relating to a subject in respect of which the users of the group are interested and to which the agent  3   a  is dedicated. Content is sourced from the Internet, by way of periodic searches.  
         [0067]     Periodically, for example every five minutes, the agent  3   a  determines which of the users an item of content is destined for delivery to. This decision is made on the basis of the user preferences as regards update time and frequency. If a suitably large number of users are deemed to require the content, then a slot for broadcast is negotiated with the DVB-T operator  51 . Once the broadcast details are known, the agent  3   a  informs each of the relevant users of the broadcast details in any suitable manner over the network  7 . Each of the users in the group which received the broadcast then sends a confirmation message to the agent  3   a , which updates its database. Some users will not receive the broadcast, for example because they do not have a DVB-T receiver, because their device was switched-off and so on. The users which did not receive the broadcast are identified and listed. Those users whose user preferences would be met if the content were not delivered until the next broadcast (where details of the broadcast are known) are identified, and removed from the list. In respect of each of the users remaining on the list, delivery is made, if possible, on a network selected according to the user&#39;s preferences and according to the networks to which the user has access or to which the user gains access. For those listed users which have repeatedly missed broadcasts and those for which it is known that reception from the DVB-T network  51  is not possible, special considerations are made. In particular, the users are continually monitored to determine whether they have entered a ‘hot-spot’ over which content can be delivered without charge to the operator. Monitoring may involve periodic poling of the users, or requesting the users to report to the agent  3   a  when access to a hot-spot is possible. In this way, content delivery can be made via the hot-spot if one becomes available. Once users are deemed to have received the content, the database is updated, and they are removed from the list. Delivery may be made via a GPPS or GSM network as the user preferences indicate that the end of an acceptable period for content delivery is imminent and if the user will tolerate the associated charges.  
         [0068]     As an enhancement, each user in the group may set a relevance level of required content. For example, a user requiring content at a high relevance level may be cause to receive only content which is deemed to be very relevant to the subject. A user not having a high relevance level setting may be caused to receive the content which is very relevant as well as content which is less relevant. Relevance may be determined on the basis of a computer classification, using a scheme similar to that used in Internet search engines for example.  
         [0069]     It is not necessary that the terminal  5  be provided with user interface output devices suitable for delivering the content. For example, in an unshown embodiment, a PC (personal computer) may be connected to a wireless terminal via an infra-red, Bluetooth™ or a USB (universal serial bus) connection. In this example, the PC may be used to control the terminal  5  to request information services, with broadcasts received by the terminal and forwarded to the PC for storage and/or immediate consumption. In this example, authentication of the mobile terminal on the duplex network  7  is required, which can be made by way of a SIM (subscriber identity module) or IMSI (international mobile subscriber identity).  
         [0070]     The above-described embodiments are illustrative only, and are not intended to be limiting on the scope of protection afforded. Any feature specified as being preferable or optional is not essential, but instead may be omitted entirely or alternatively replaced by another feature. Anything which is said ‘may’ be present or ‘may’ have some characteristic also is preferable, and could be omitted or instead replaced with another feature or characteristic. The scope of protection is to be limited only by the accompanying claims and their equivalents.