Abstract:
A communication system  10  includes a head end  12.  The head end communicates with a system gateway  26.  A plurality of user devices  28  is coupled to the gateway  26.  The gateway receives the plurality of first encrypted signals, decrypts the plurality of first encrypted signals to form unencrypted signals and encrypts the unencrypted signals with a second encryption to form a plurality of second encrypted signals and communicates the second encrypted signals to the plurality of user devices. The signals may also be super-encrypted signals. That is, rather than un-encrypting at the gateway, the first encrypted signals may be again encrypted.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. application Serial No. [Attorney Docket No. 205077], filed simultaneously herewith. The disclosure of the above application is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to a content delivery system and, more specifically, to a system that redistributes content to various devices within a building such as a multiple dwelling unit from a gateway on or within the building using encryption. 
       BACKGROUND 
       [0003]    The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
         [0004]    Satellite television has become increasingly popular due to the wide variety of content and the quality of content available. A satellite television system typically includes a set top box that is used to receive the satellite signals and decode the satellite signals for use on a television. The set top box typically has a memory associated therewith. The memory may include a digital video recorder or the like as well as the operating code for the set top box. 
         [0005]    Satellite television systems typically broadcast content to a number of users simultaneously in a system. Satellite television systems also offer subscription or pay-per-view access to the broadcast content. Access is provided using signals broadcast over the satellite. Once access is provided the user can access the particular content. 
         [0006]    It may be desirable to provide satellite television to various users in a building such as a multiple dwelling unit (MDU) such as an apartment building, office building, hotel or hospital. However providing antennas and the associated hardware for each unit on an individual basis is not cost effective and may consume a large portion of the building. This may not be aesthetically pleasing as well. 
         [0007]    Providing content to a large number of consumers in a particular building must be done in a secure manner. Authorized users may share a communal subscription, or may be offered individual subscriptions or pay-per-view. 
       SUMMARY 
       [0008]    The present invention allows content to be distributed throughout a building using a gateway. Authorizations may be obtained through many types of communication means including through a satellite. 
         [0009]    In one aspect of the disclosure, a method of operating a communication system includes encrypting a plurality of signals with a first encryption to form a plurality of first encrypted signals, communicating the plurality of first encrypted signals to a system gateway, decrypting the plurality of first encrypted signals at the gateway to form unencrypted signals, encrypting the unencrypted signals at the gateway with a second encryption to form a plurality of second encrypted signals, communicating the second encrypted signals to a plurality of user devices from the gateway. 
         [0010]    In another aspect of the disclosure, a method of operating a communication system includes encrypting a plurality of signals with a first encryption to form a plurality of first encrypted signals, communicating the plurality of first encrypted signals to a system gateway, encrypting the first encrypted signals at the gateway with a second encryption to form a plurality of super-encrypted signals, communicating a decryption key to the plurality of user devices and communicating the super-encrypted signals to a plurality of user devices from the gateway. 
         [0011]    In yet another aspect of the disclosure, a communication system includes a head end encrypting a plurality of signals with a first encryption to form a plurality of first encrypted signals and a plurality of user devices. The system also includes a system gateway in communication with the head end and the plurality of user devices. The gateway receives the plurality of first encrypted signals, decrypts the plurality of first encrypted signals to form unencrypted signals and encrypts the unencrypted signals with a second encryption to form a plurality of second encrypted signals and communicates the second encrypted signals to the plurality of user devices. 
         [0012]    In still a further aspect of this disclosure, a communication system includes a head end encrypting a plurality of signals with a first encryption to form a plurality of first encrypted signals, a plurality of user devices and a system gateway in communication with the head end and the plurality of user devices. The gateway receives the plurality of first encrypted signals, encrypts the first encrypted signals with a second encryption to form a plurality of super-encrypted signals, communicates a decryption key to the plurality of user devices and communicates the super-encrypted signals to the plurality of user devices from the gateway. 
         [0013]    To enhance security in the system, some embodiments may include a satellite connection conveying the conditional access packets, encryption information and lists. 
         [0014]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0015]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
           [0016]      FIG. 1  is a block diagrammatic illustration of a content delivery system according to the disclosure. 
           [0017]      FIG. 2  is a flowchart of a first example for a method of operating the present disclosure. 
           [0018]      FIG. 3  is a flowchart of a second example for a method of operating the present disclosure. 
           [0019]      FIG. 4  is a flowchart of a third example for a method of operating the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure. 
         [0021]    While the following disclosure is made with respect to example DIRECTV® broadcast services and systems, it should be understood that many other delivery systems are readily applicable to disclosed systems and methods. Such systems include wireless terrestrial distribution systems, wired or cable distribution systems, cable television distribution systems, Ultra High Frequency (UHF)/Very High Frequency (VHF) radio frequency systems or other terrestrial broadcast systems (e.g., Multi-channel Multi-point Distribution System (MMDS), Local Multi-point Distribution System (LMDS), etc.), Internet-based distribution systems, cellular distribution systems, power-line broadcast systems, any point-to-point and/or multicast Internet Protocol (IP) delivery network, and fiber optic networks. Further, the different functions collectively allocated among a head end (HE) and integrated receiver/decoders (IRDs) as described below can be reallocated as desired without departing from the intended scope of the present patent. 
         [0022]    Further, while the following disclosure is made with respect to the delivery of content (e.g., television (TV), movies, music videos, etc.), it should be understood that the systems and methods disclosed herein could also be used for delivery of any media content type, for example, audio, music, data files, web pages, games, etc. Additionally, throughout this disclosure reference is made to data, information, programs, movies, assets, video data, etc., however, it will be readily apparent to persons of ordinary skill in the art that these terms are substantially equivalent in reference to the example systems and/or methods disclosed herein. As used herein, the term title will be used to refer to, for example, a movie itself and not the name of the movie. 
         [0023]    As illustrated in  FIG. 1 , a communication system  10  includes a head end  12  that is coupled to an uplink antenna  14 . The head end  12  may be used for many things, including multiplexing, modulating and uplinking signals  16  to satellite  18 . It should be noted that satellite  18  may comprise a number of satellites operating in a system. The satellite  18  is used to generate downlink signals  20  to a multiple dwelling unit (MDU) delivery system  22 , and, more specifically, to an antenna  24  of the multiple dwelling unit (MDU) delivery system  22 . The multiple dwelling unit (MDU) delivery system  22  may include a gateway  26  that is used to receive signals from the satellite and distribute the signals to various client or user devices  28  that also constitute part of the MDU delivery system  22 . Multiple dwelling unit (MDU) delivery system  22  may also be used to process the received satellite signals. The user devices  28  may be referred to as a set top box, a satellite set top box, or an integrated receiver decoder. The wireless communications between the head end  12  and the multiple dwelling unit (MDU) delivery system  22  may take place at any suitable frequency such as Ka band and/or Ku band frequencies. Information signals may also be communicated from the multiple dwelling unit (MDU) delivery system  22  to the head end  12  through the satellite  18 . The delivery system  22  may use Internet protocol to delivery the content therein. Each user device and the gateway may have an IP address assigned thereto and use the respective IP addresses to communicate. 
         [0024]    The multiple dwelling unit delivery system  22  communicates signals within a multiple dwelling unit  30 . The multiple dwelling unit  30  may comprise various types of buildings in which multiple user devices are coupled to a gateway. Examples of such buildings include, but are not limited to, an apartment building, condominium, office building, hotel or hospital. The service gateway  26  is associated with the particular MDU  30 . One or more gateways  26  may be provided. The gateway or at least the antenna  24  may be mounted to an outer roof structure or wall. The various modules of the gateway  26  may be disposed within the MDU  30 . The gateway  26  may be wired or wirelessly connected to the user devices  28 . 
         [0025]    Various types of content and security information signals including but not limited to security information, encryption-decryption information, digital rights management information, purchase information packets (PIPs), conditional access packets (CAPs), channel or content access lists or rights may be communicated through the communication system  10 . It should also be noted that various content may be encrypted based upon a control word (CW) known to the head end  12  and known to the various user devices and/or to the MDU gateway  26  and/or multiple dwelling unit (MDU) delivery system  22  authorized to view and/or play back the content. The control word packets (CWPs) may include, among other things, a time stamp, authorization requirements and an input value for generating the control word. Control word packets may from time to time be transmitted to the satellite to the MDU gateway  26 . 
         [0026]    The multiple dwelling unit (MDU) delivery system  22  may also communicate to the head end  12  through a communication network  50 . The communication network  50  may include various types of communication, including but not limited to a telephone-type communication link, an Internet-type communication link, a fiber optic communication link, a wired terrestrial communication link, a terrestrial wireless or cellular link. The communications through the communication network  50  may include content signals into the MDU delivery system  22 . The communication network  50  may replace the satellite  18 . The MDU delivery system  22  may also transmit call back information such as program and pay-per-view requests and reportback, interactive television signals and gaming signals. 
         [0027]    A conditional access system  40  may be coupled to or be part of the head end  12 . The conditional access system  40  includes a permission packet generator such as a conditional access packet generator  44  and a local key generator module  46 . A MDU client list generator module  48  may also be included within the conditional access system  40 . The MDU client list generator module  48  may generate a user list in response to information from a subscriber information module  52 . The signals from the conditional access system  40  are communicated to the head end  12  where the signals are broadcast to the (MDU) delivery system  22 . 
         [0028]    The subscriber information module  52  receives or collects information regarding the permissions of the various users. The information may take the form of a user list that includes channel or content permission authorizations for each of the various users. The users may be identified in various manners including using an IP address. The IP address may be specific to the MDU delivery system. That is, both the MDU delivery system  22  and/or the MDU gateway  26  and the user device  28  may be identified in the user list. Security information such as encryption or decryption information may also be in the user list. The security information may include but is not limited to local key information. 
         [0029]    A content source  54  may include a content delivery network, a content repository having contents received from a content provider or providers. The content may be various types of content including video, audio, games, data, or the like. A number of different content providers may be used to provide various types of content to the content source  54 . The content source  54  may be coupled to the head end  12  to provide conventional satellite television service. The contents of the content source  54  may be provided in various ways including through a fiber optic network, satellite, telephone line, tapes, or DVDs. 
         [0030]    Referring back to the multiple dwelling unit (MDU) delivery system  22 , the receiving antenna  24  receives signals that may include modulated multiplexed bit stream signals from the satellite  18  or communication network  50 . The receive antenna signals are coupled from a reflector and a feed to a low noise block (LNB)  60  which amplifies and frequency-down converts the receive signals. The output of the LNB  60  is provided to a receiver  62  that receives the signals and may include a tuner  64 , demodulator  66 , a depacketizer  68 , and a demultiplexer  70 . 
         [0031]    The gateway  26  may also include a decryption module  80  that is used for decrypting the incoming signals from the communication network  50  or the satellite  18 . As will be further described below, the decryption module  80  may provide conventional satellite broadcast decryption. The decryption module  80  is an optional module for the system. The decryption module  80  may not be required at the gateway  26  if the individual user devices  28  perform the satellite broadcast decryption. 
         [0032]    An access card or access cards  96  may also be included in the gateway  26 . The access cards  96  may be used to generate control words for decrypting the incoming signals. The control words provide access to authorized content and channels. The access cards  96  may also be referred to as smart cards. A number of access cards  96  may be used to generate control words and thereby provide access to various channels, groups of channels or various programs or content. The control words may also be encrypted by the access cards  96  to form encrypted control words. The control words or the encrypted control words may be provided to the decryption module  80  at the gateway or may be transmitted to the user devices  28  to perform decryption. Different combinations of decryption and encryption will be described below. 
         [0033]    An encryption module  82  may also be provided within the gateway  26 . The encryption module  82  may be used to re-encrypt or super-encrypt the signals received from the communication network  50  or the satellite  18 . Super-encryption is provided when encrypted signals are again encrypted with a local key. The encryption module  82 , whether re-encrypted or super-encrypted, may use a local key. The encryption module  82  is an optional module for the system. The encryption module  82  may not be required if re-encryption or super-encryption is not provided at the gateway  26 . 
         [0034]    An IP stream generator module  84  may be used to generate an IP stream of the various channels or content received from the communication network  50  or satellite  18 . The IP stream may broadcast signals to all user devices or target specific devices using the associated IP address. 
         [0035]    A comparison module  86  may be used to compare a received list that is generated at the client list generator module  48  of the conditional access system  40  with a request from a user device  28 . As will be mentioned below, the comparison module may provide access to a channel or content if the user device  28  is subscribed to the particular channel or content based upon the list. 
         [0036]    An interface module  88  may be used to interface to the communication network  50 . The interface module may transmit or receive information or signals from the communication network  50 . The interface module  88  may format or reformat the material so it is suitable for communication using the particular medium. 
         [0037]    An aggregator module  90  may also be included in the gateway  26 . The aggregator module  90  may receive signals from the various user devices  28 , collect them and form one consolidated communication signal through the communication network  50  or the satellite  18  to communicate the signals to the head end  12 . The gateway  26  may also include a controller  92  for controlling various operations within the gateway  26 . The controller  92  may be microprocessor-based. The various modules within the gateway  26  may also be incorporated in software within a controller  92 . 
         [0038]    The user devices  28  are in communication with the gateway  26 . The gateway  26  and the user devices  28  may form a network such as a wired network or a wireless network. The gateway  26  communicates various content or channels or security information signals to each user device through the network. Each user device  28  may include a decryption module  110 , an access card  112 , and an audio-visual card  114 . The audio-visual card  114  may include various functions including a tuner function, a demodulator function, a packetizer function, and a multiplexer function in much the same way as the receiver card  62  illustrated in the gateway  26 . The user device  28  may also be associated with or include a display  116 . The display  116  may include a television or other monitor-type device. 
         [0039]    The decryption module  110  may be used to decrypt the signals from the gateway  26 . Also, as mentioned above, the receive signals may not be encrypted at the gateway  26  and, thus, the decryption module may be used to decrypt the signals as they were transmitted from the satellite. Also, the decryption module  110  may provide double decryption to decrypt the super-encrypted signals. That is, the decryption module  110  may use a local key to, first, decrypt the signals to the condition the signals were received by the satellite. The signals may then use another decryption key for the communication system to decrypt the signals as they were transmitted through the satellite system. 
         [0040]    The access card  112  may be used to generate control words to perform the decryption. Typical satellite television systems include an access card or conditional access card. 
         [0041]    As mentioned above, a network may be formed between the user devices  28  and the gateway  26 . That is, the gateway  26  may include an Internet protocol address. Each user device  28  may also include an Internet protocol address. The Internet protocol address may be compared in the comparison module as an identifier for comparison with the channel authorizations provided in the list. This will be further described below. 
         [0042]    Referring now to  FIG. 2 , a first method for operating the system is illustrated. In step  200 , a list of authorized channels for each multi-dwelling unit may be compiled. The list may be compiled in a business center associated with the head end  12 . The list may also be compiled in a subscriber information module  52 . In step  202 , a list of authorized channels is communicated to the MDU gateway  26 . The list of authorized channels may include a list of channels authorized for each of the user devices associated with the multiple dwelling unit delivery system  22 . The list may identify the authorized user devices by way of a user identifier or device identifier or an Internet protocol address. The list may be communicated through a satellite  18  or through the communication network  50 . In step  204 , the list is stored in the gateway. In step  206 , a channel request is received from a user device within the multiple dwelling unit delivery system  22 . 
         [0043]    In step  208 , the list is compared to the user device. If the user device is authorized to receive the channel or content in step  208 , step  210  communicates the channel or content to the device  28 . In step  208 , if the user device  28  is not authorized to receive the channel or content, step  212  blocks the channel or content. 
         [0044]    Referring now to  FIG. 3 , in an alternative embodiment to that illustrated in  FIG. 2  or an additional embodiment to be used in conjunction with  FIG. 2 , step  250  generates a local key or group of local keys. That is, a local key may be generated at the gateway  26  or head end  12  for each channel. It should also be noted that a group of channels may include the same local key. For example, a subscription service may include a subscription to a number of channels and, thus, only one local key may be required for all of the channels in that group. 
         [0045]    In step  252 , the local keys are communicated to the MDU gateway  26  for each channel. This step is performed if the head end generates the local keys. This is an optional step since local keys may be generated at the gateway  26 . In step  254 , the received data stream, such as the channel, may be decrypted at the gateway  26 . This is an optional step since the data stream may be decrypted at the user device  28 . 
         [0046]    In step  256 , the data stream of content or a channel from the gateway  26  may be encrypted using a different encryption key for each channel or group of channels. This re-encryption or super-encryption may be performed using the local keys generated in step  250 . In step  258 , the decryption keys may be communicated to the user devices for channels authorized from the list. In step  260 , the channels are decrypted using the decryption key at the MDU user device. It should be noted that, in the case of super-encryption, a local key may be used to first decrypt these signals then a broadcast decryption key may be used to further decrypt the channel or content signals. In step  262 , the authorized channel or content may be viewed by the user device  28 . As is mentioned above, the steps of  FIG. 3  may be used together with the steps of  FIG. 2 . That is, encryption and decryption may also be performed when the channel is communicated to the user device in step  210  of  FIG. 2 . Also, the encryption information may be contained in the list or may be broadcast in a CAP or other communication packet from time to time. The encryption packet may itself be encrypted. 
         [0047]    Referring now to  FIG. 4 , another method for operating the communication system  10  is illustrated. In step  300 , the channels are transmitted to a gateway  26 . In step  302 , the received channels may be decrypted in bulk at the gateway  26 . Step  302  may also be skipped if the received channels are decrypted at the user device  28 . In step  304 , the channels or content may be locally encrypted. The local re-encryption or super-encryption may take place in the gateway  26  using local keys as described above. In step  306 , the local encryption key is communicated to the user devices  28 . In step  308 , the various channels or content may be communicated to the user devices. In step  310 , the content is decrypted or super-decrypted as mentioned above. 
         [0048]    In step  320 , call back signals may be generated from the plurality of user devices. Such call back may comprise program and pay-per-view requests and reportback, interactive television signals and gaming signals. In step  322 , the call back signals are communicated to the service gateway. In step  324 , the call back signals may be aggregated at the gateway. In step  326 , the aggregate signal is communicated to the head end. The aggregate signal may be communicated over the satellite or communicated over the communication network. 
         [0049]    Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.