Abstract:
A predefined advertising service identifier, or trigger code, is broadcast along with the digital media in a media distribution system, to give explicit insert triggers to re-distributors in a multi-tiered distribution system. These service identifiers are encrypted so that other parties without access to the triggers that are receiving the broadcast cannot identify ad insert time slots and therefore cannot insert ads without prior agreement. In one embodiment, the triggers are contained within pre-existing conditional access control word packets.

Description:
TECHNICAL FIELD 
     The present invention relates generally to a system and method for inserting media advertisements in a media distribution system and more particularly to a system and method for inserting media advertisements in a media distribution system having multiple tiers. 
     BACKGROUND OF THE INVENTION 
     In the cable and broadcast television industries a major source of revenue is the sale of advertising time or “ad spots”. Spots are sold at both national and local levels. In the cable industry, a major programmer, such as CNN and ESPN, includes ads in the signal it distributes to its cable service providers. The signal includes tone cues, or digital signal identifiers, to the provider&#39;s equipment and by business agreement, the cable providers can insert ad spots after the tone cues. 
     A direct broadcast distribution company, or satellite television provider, typically has the right to use the “ad spots”, which are reserved for the local cable company spot insert opportunities, for their own inserts. Many ad inserts are intended for viewing by a typical consumer, i.e. pay-per-view events being advertised to a viewer at home. However, there are many instances where the direct broadcast distributor has a specialized distribution agreement which cause the signals to be received and re-distributed by other entities such as restaurants, hotels, office buildings, commercial aircraft, passenger ships, multiple dwelling units, etc. 
     These specialized redistribution systems are directed to someone other than a typical residential consumer. And therefore, advertisements for an intended audience, such as pay-per-view events, are not accessible to the audience of the re-distribution system and the valuable ad spot is essentially going to waste. For example, a hotel guest, or a passenger on a cruise ship cannot actually purchase an impulse pay-per-view event advertised by the distributor, rendering the ad spot useless. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to permit a tiered system of commercial inserts. It is a further object of the present invention to broadcast unique trigger identifiers that, in association with special hardware, can be used to access and insert ad spots in a multi-tier system. 
     According to the present invention, a predefined, unique service identifier is broadcast along with a service identifier in a conditional access system, to give explicit insert triggers to re-distributors in a multi-tiered distribution system. The service identifiers are encrypted in a control word packet (CWP) so that other parties without access to the triggers that are receiving the broadcast cannot insert ads. The present invention uses a small portion of pre-existing conditional access CWP&#39;s routinely used for protection and authorization of the digital media itself. A hardware interface is used to identify the encrypted cues that are hidden in the CWP&#39;s appearing throughout the transmit bit streams. 
     Other objects and advantages of the present invention will become apparent upon reading the following detailed description and appended claims, and upon reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of this invention, reference should now be had to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples of the invention. In the drawings: 
         FIG. 1  is a block diagram illustrating an overview of a prior art video distribution system; 
         FIG. 2  is an overall system diagram of potential recipients of the distribution of media inserts according to the present invention; 
         FIG. 3  is a block diagram of a two-tier distribution system according to the present invention; and 
         FIG. 4  is a block diagram of the specialized receiver required at the receiving tier according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1  is a diagram illustrating an overview of a multi-channel video distribution system  100 . The video distribution system  100  comprises an uplink center  104 , a satellite  108 , a terrestrial receiver  112  and a subscriber  110 . 
     The uplink center  104  receives program material from external sources  102  via a communications link  114 , and using an uplink antenna  106 , transmits the program material and program control information to the satellite  108  via uplink  116 . The satellite receives and transmits the video programs and control information to the subscriber via downlink transmission signal  118 . The subscriber  110  receives this information using the terrestrial receiver  112 . 
       FIG. 2  is an overall system diagram of a direct broadcast satellite (DBS)  1  and potential business entities that may be inclined to take advantage of the advertising time slots when the broadcast ad spots are not applicable to the businesses&#39; customers. It should be noted that the entities shown in  FIG. 2  are for example purposes only and are not intended to limit the application of the present invention. The first tier is the DBS broadcaster  1 , which broadcasts a signal to either a private or public redistribution system. For example, a private redistribution system may be a commercial airline  2 , a passenger ship  3 , commercial users  5  such as hotels, restaurants, doctor&#39;s offices, etc., multiple dwelling units  6  such as apartments and condominium complexes, private residences  7 , and a subdivision, planned community development  8 , or resort complex  9 . A public redistribution system  4  may be a cable television system or a satellite digital radio audio system. 
     The number of tiers is not limited to two. In the case of a resort complex  9  or a planned community development  8 , there is the possibility of expanding the tiers beyond the two-tier system described above. For example, a resort may have several hotels within the complex. While the overall resort  9  will have general advertisements to insert over the available ad-spots, one hotel  9   a  within the complex may have the opportunity to insert its own advertisements directed to their target subscribers that may be different from another hotel  9   b  within the complex. 
     Similarly, in the case of a planned community development, there may be an individual developer  8   a  within the community that will have target subscribers that are different from another developer  8   b  with its own target subscriber. The possibilities for additional tiers are endless and while the detailed description is focusing on two and three tiers, it is possible to apply the present invention beyond three tiers without departing from the scope of the present invention. 
       FIG. 3  is a block diagram of a two-tier distribution system  10 . A DBS distributor collects an incoming television signal  12 , such as CNN at an antenna  14 . A receiver  16  receives the signal and a dual tone multi-frequency (DTMF) decoder  18  detects the tone, or trigger  22 , that is supplied by the television signal distributor. An automation system  24 . works in conjunction with a scheduling system  26  to insert advertisement material in the correct time slots. A media server  28  holds the material for the inserts and upon instruction by the automation system  24 , a router  20  routes the message to be broadcast during the correct time made available by the broadcaster of the incoming television signal  12 . 
     The automation system  24  provides an ad avails identifier, or trigger, to a conditional access system  32 . In addition, the conditional access system  32  creates a “tier two insert” service identifier and includes it within the outgoing control word packet. Bits within this service identifier may be used to indicate the duration or some other characteristic of the media insert. 
     In the DBS case, the signal is received in thousands of very small re-distribution locations. Therefore, the trigger should be hidden, or encrypted, so that it is not possible for an unethical proprietor to insert an ad over the DBS company&#39;s inserts without permission. The re-distribution location must have the necessary hardware and software interface to identify the trigger and overlay an advertisement. 
     An encoder  32  at the tier one distribution system is used to encrypt the control word packet, with the enclosed trigger, that is broadcast along with the advertisement in the ad spot. The encrypted trigger provides a control message to a second or higher tier that has the proper specialized hardware to identify the encrypted trigger. 
     Further, the encrypted trigger can be hidden within a periodic, or continuous, data stream. An occasional, isolated occurrence of an encrypted signal is easily identifiable, and even though the code itself may not be broken, just the occurrence of an isolated encrypted signal may be enough to allow an unauthorized user access to the ad spot. Therefore, hiding the trigger in a stream of encrypted data, may further prevent unauthorized use of the present invention. 
     The advertisement is then broadcast by the DBS distribution system by a satellite  30  to a second tier distributor, such as a resort complex television system. Beyond two tiers, in most cases, the receiving tier that is also distributing will have the same hardware as the second tier distributor shown in  FIG. 3 . Any recipient of the re-distribution must have the specialized receiver to detect the encrypted trigger and overlay an insert message. 
     In special applications, such as a resort having several hotels within the resort complex that are all owned by the same company, there may not be a need to encrypt and decode the trigger once it has passed the second tier. In the case of a planned community development, however, the need for encryption beyond the second tier may still be necessary to prevent unscrupulous developers from having access ad spots that they are not paying for. 
     The signal, containing the encrypted trigger is broadcast by the DBS satellite  30  to the second tier distributor, or re-distributor in the case of tiers beyond a second tier. The re-distributor has equipment similar to that of the DBS distributor and receives the signal at a receiver  34 . An additional receiver, a specialized receiver  36  at the re-distributor, also receives the signal and detects the encrypted trigger  38 . 
       FIG. 4  is a block diagram of the specialized receiver  36 . The incoming signal  50  is tuned, demodulated and decoded  52 . A microprocessor  54  causes a transport circuit  58  to route all control word packets (CWP) for the television signal to a conditional access module  56 . The conditional access module  56  is authorized to decrypt the control word packets with the trigger for the ad spot. The conditional access module  56  will send the decrypted control word packet back to the microprocessor, which sends the trigger information to the automation system (not shown in  FIG. 4 ). 
     Once the encrypted trigger is identified, the re-distributor overlays their media insert in the ad spot in a manner similar to the automation and scheduling system at the tier one distributor. Referring again to  FIG. 3 , the re-distributor has an automation system  40  that works in conjunction with a scheduling system  42  to take the appropriate material from a media server  44  and by way of a router  46 , overlays the targeted ad over the available spot. 
     A specific example will provide an overview of the present invention. The DBS system receives an incoming television signal from a cable television company, such as CNN. Through business agreements, certain ad spots are made available by CNN for the DBS company to overlay their own media inserts over the ad spots on CNN. The DBS system identifies the DTMF tone sent in the CNN television signal and inserts an advertisement for a pay-per-view sporting event in the identified ad time slot. 
     According to the present invention, the DBS system adds an encrypted trigger to the broadcast signal. The pay-per-view advertisement is then broadcast by the DBS satellite to multiple subscribers. One of the many subscribers that receive the signal is a resort complex whose guests cannot purchase pay-per-view events directly from the DBS company. The resort complex has a main distribution center having a specialized receiver that identifies the encrypted trigger sent with the pay-per-view advertisement and inserts their own advertisement in the spot. 
     As an example of a third tier, assume there are several hotels in the resort that receive the advertisement from the resort&#39;s main distribution center. In certain instances it may be desirable for a particular hotel to broadcast its own advertisements over the resort&#39;s overlay. In this case, encryption of the resort&#39;s trigger signal may not be necessary. However, in the case of hotels that are competing within the resort, it may be desirable to protect the trigger. This requires the resort main distribution center to encrypt the trigger and the hotel receiving the encrypted trigger must have a specialized IRD to detect and decrypt the trigger and overlay their targeted advertisement. 
     According to the present invention, the re-distributor, or tier-two distributor such as a hotel, that cannot provide its intended audience with access to the pay-per-view event and can then insert its own targeted advertisement. In this regard, the valuable ad spot is serving its intended purpose without being rendered useless by being broadcast to an uninterested audience. 
     It is to be understood that the preceding description of the preferred embodiment is merely illustrative of some of the many specific embodiments that represent applications of the principles of the present invention. For example, the present invention is not limited to a television signal and may be applied to a satellite digital audio radio system for example. The invention covers all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the appended claims.