Abstract:
Enforcing a global access policy, comprising a global access rule for a user&#39;s devices, for consumption of a content item. The user&#39;s devices advantageously comprise a set-top box, a tablet and a gateway. The gateway is configured to split the global access rule into local access rules for the set-top box and the tablet so that independent consumption of the content item by the set-top box and the tablet according to the respective local access rules does not violate the global access rule; and to send the local access rules to a first and a second enforcement point, which are configured to receive a request to access the content item from a user device; and allow or inhibit access to the content item depending on whether or not access to the content item is authorized by the local access rule for the user device from which the request was received.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates generally to digital content delivery, and in particular to controlling access to digital content. 
       BACKGROUND 
       [0002]    This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention that are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
         [0003]    In today&#39;s digital multimedia distribution networks, content providers may distribute free content or sell valuable (often similar) content such as Pay TV to e.g. broadband customers and Internet customers. In the former case, the content is available through a broadband connection; in the latter case, the content is accessible over the Internet, typically from a public portal. The two possibilities usually are not linked together. For this reason, an end-user having already subscribed to broadband content access at home must also subscribe to (possibly a different content provider) to Internet content access in order to obtain the same (or often similar) content. 
         [0004]    Technically speaking, broadband access and Internet access are implemented using separated, independent enforcement points. One enforcement point allows local access to a content using the broadband network while another enforcement point allows (possibly remote) Internet access. There is no communication or synchronization between the enforcement points. 
         [0005]    WO 2009/106818 teaches a solution in which a content provider distributes content to, for example, a set-top box to be shown on a home display or to a mobile phone. When the mobile user wishes to consume the content, it connects to and authenticates with a server. The server then streams the content to the mobile phone and also sends a disable signal to the set-top box, thereby making sure that the content is only consumed by one device. While this solution enables access through different channels, a drawback is that the server must be accessible from both networks, which means that the solution does not work in case the different networks are distinct or local. 
         [0006]    Slingbox is a device that connects to the audio and/or video output of a consumer electronics device in a user&#39;s home. The Slingbox receives the content and redirects it to the user&#39;s remote device or other device chosen by the user. This solution has the drawbacks that the quality of the redirected content may be inferior since the redirected content is taken from the output of another device. In addition, it is a drawback to the content provider that the redirection of the content may not be controlled. 
         [0007]    HbbTV® (http://www.hbbtv.org/) and Project Canvas (http://www. projectcanvas.co.uk) frameworks combine broadcast and broadband Internet links for a compliant home device. The main goal is to make cost effective the content repurposing from Internet to broadcast TV receiver for improving the end-user experience. 
         [0008]    It will thus be appreciated that there is a need for a solution that is able to able to identify current access to a content (e.g. from broadband or the Internet), and allow new access or remove an existing access according to a global access policy and a given access request. The solution should not rely on a central and always available policy server. 
         [0009]    The problem may thus be stated as how to make a plurality of enforcements points cooperate to ensure that distributed access to a given content conforms with the global policy of the content provider. The present invention provides such a solution. 
       SUMMARY OF INVENTION 
       [0010]    In a first aspect, the invention is directed to a system for enforcing a policy restricting access to consumption of a content item on a plurality of user devices associated with a user, the policy comprising a first access rule for all of the plurality of user devices, the plurality of user devices comprising a first device, a second device and a third device. The third device is configured to: split the first access rule into a first subordinate access rule for the first device and a second subordinate access rule for the second device, each subordinate access rule comprising a subset of the first access rule so that independent consumption of the content item by the first device and the second device respectively according to the first subordinate access rule and the second subordinate access rule respects the first access rule; and send the first subordinate access rule to a first enforcement point and the second subordinate access rule to the second enforcement point. The first enforcement point and the second enforcement point are configured to: receive a request to access the content item from a user device; and allow or inhibit access to the content item depending on whether or not access to the content item is authorized by the subordinate access rule for the user device from which the request was received. 
         [0011]    In a first preferred embodiment, the third device is a gateway in a home network. It is advantageous that the first enforcement point is implemented in a network termination element connected to the gateway and the second enforcement point is implemented in a content server contactable by the second device via a network distinct from the home network. 
         [0012]    In a second preferred embodiment, the first enforcement point is implemented by the first device and the second enforcement point is implemented by the second device. 
         [0013]    In a third preferred embodiment, the policy further comprises a second access rule for all of the plurality of user devices and the first enforcement point and the second enforcement point are further configured to exchange information about access states and current access requests for the content, and to allow or inhibit access to the content item also depending on whether or not access to the content item is authorized by the second access rule for the user device from which the request was received. 
         [0014]    In a fourth preferred embodiment, the first enforcement point is implemented on the third device. 
         [0015]    In a second aspect, the invention is directed to a method for enforcing a policy restricting access to consumption of a content item on a plurality of user devices associated with a user, the policy comprising a first access rule for all of the plurality of user devices, the plurality of user devices comprising a first device, a second device and a third device. The third device receives the first access rule; splits the first access rule into a first subordinate access rule for the first device and a second subordinate access rule for the second device, each subordinate access rule comprising a subset of the first access rule so that independent consumption of the content item by the first device and the second device respectively according to the first subordinate access rule and the second subordinate access rule respects the first access rule; and sends the first subordinate access rule to a first enforcement point and the second subordinate access rule to the second enforcement point. The first enforcement point receives from the first device a request to access the content item; and allows or inhibits access to the content item depending on whether or not access to the content item is authorized by the first subordinate access rule for the first device. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0016]    Preferred features of the present invention will now be described, by way of non-limiting example, with reference to the accompanying drawings, in which 
           [0017]      FIG. 1  illustrates an exemplary network in which a preferred embodiment of the present invention is used; 
           [0018]      FIG. 2  illustrates a synchronization method according to a preferred embodiment of the present invention; and 
           [0019]      FIG. 3  illustrates a network according to an alternate embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0020]      FIG. 1  illustrates an exemplary network in which a preferred embodiment of the present invention is used. The network  100  comprises a home network  110 , a content provider  120 , the Internet (or other suitable network)  130 , and a tablet  140 . 
         [0021]    The home network  110  comprises a gateway  111  connected to a set-top box (STB)  112 ; naturally, there may be more devices in the home network  110 . The gateway  111  is configured to receive content from a broadband content server  121  (or other kind of suitable content server) at the content provider  120 —in either pull or push mode—and to forward the content to the STB  112 . The broadband content server  121  is preferably connected to a content database. 
         [0022]    The user of the home network  110  also has a tablet  140 , e.g. an iPad (or other kind of mobile content rendering device, such as a mobile phone). The tablet  140  may be used as part of the home network  110 , in which case it receives content from the gateway. The tablet  140  may also be used outside the home network  140 , in which case it advantageously communicates, via the Internet  130 , with an internet content server  122  at the content provider  120  so as to order and receive content. 
         [0023]    It will be noted that in WO 2009/106818, the content provider  120  also enforces consumption rules, such as who gets precedence in case of “conflicting access”, i.e. when devices desire access to content that may not be granted to all of the devices. This may be the case if the devices simultaneously want to consume access that may not be consumed by more than one device at a time. 
         [0024]    In contrast to this prior art solution, possibly conflicting access is resolved by distributed enforcement points according to a global access policy, i.e. a policy that applies to all of the user&#39;s devices. These enforcement points are advantageously located in content consuming devices or in network termination devices.  FIG. 1  illustrates the former case: a first enforcement point  1121  resides within the STB  112  and a second enforcement point  141  within the tablet  140 . 
         [0025]    The skilled person will appreciate that enforcement points, all of the user device&#39;s—i.e. the gateway  111 , the STB  112  and the tablet  140 —and the content provider&#39;s servers  121 ,  122  are implemented using the necessary hardware such as processors, memory, interfaces etc., but this will not be described further since this is beyond the scope of the present invention. In addition, it is possible to share hardware; e.g. the tablet  140  and the second enforcement point  141  advantageously, but not necessarily, share some hardware, for instance a processor. The same holds true for the system in  FIG. 3  hereinafter. 
         [0026]    It will also be appreciated that the enforcement points are preferably implemented at a ‘network level’, which is to say that they are not bound to a particular application for rendering the content. As such it is preferred to implement the enforcement points in a device&#39;s firewall, in a proxy, in an application enforcing MAC-based address control or in a Web Application Firewall (WAF). 
         [0027]    While the distribution of the global policy is out of the scope of the present invention, it may be performed as described in this paragraph. The global policy is preferably set by the content provider  120  and may comprise a plurality of access policy rules. Different items of content from a provider may be subject to different policies. Global policies are defined centrally and then—possibly after having been adapted—pushed onto the distributed enforcement points. It is preferred that the content provider  120  attaches the global policy for a given content to the content itself. It is also preferred that the global policy is sent to the gateway  111 . 
         [0028]    According to the present invention, the global policy is advantageously split into a plurality of local policies, each of which is pushed to a different consuming device belonging to the user. The global policy is split so that when the consuming devices consume the same content item independently of one another, the global policy is not violated. In other words, the user receives a global policy that is then split among the user&#39;s devices. The expression ‘user’ may refer to a single person or other entity such as a company, but it may also refer to a group, such as the member of a family or of the household in which the home network is implemented. While it is preferred that the gateway  111  splits the global policy, it will be appreciated that this may also be performed by another device such as for example a computer (not shown) that belongs to the user and that is connected to the gateway  111  and even the STB  112  or the tablet  140 . In the latter two cases, the ‘splitter’ is located in the same device as an enforcement point. 
         [0029]    An example will make this clearer: if the gateway  111  receives a global policy for a content that comprises a global policy rule that limits the number of viewings on a tablet to  4  times, the gateway may split this global policy rule into two local policy rules. A first local policy rule is sent to a first tablet  140 , limiting the number of local viewings to  2 , while a second local policy rule is sent to a second tablet (not shown), also limiting the number of local viewings to 2. It will be appreciated that the global policy rule is respected by the two local policy rules. 
         [0030]    The global policy rule can concern all of the user&#39;s devices (no more than n viewing on all the devices), but the global policy rule may also be more fine-tuned (max m viewings on device type A and max n viewings on device type B). The number of viewings may be split in any possible way: for N devices and a maximum of M viewings, the number of ‘local’ viewings n i , may be set to 0≦n i ≦M, provided that Σ 1   N n i ≦M. 
         [0031]    The splitting of the global policy may also be combined with local enforcement of the global policy. Once the local policies have been pushed to the local enforcement points, the local enforcement points may communicate and synchronize to resolve potential conflicting accesses. An example of a global policy rule that could be enforced this way is a mutually exclusive access to the service, allowing local access or remote access but not at the same time, as in WO 2009/106818. Other examples are limitation to n simultaneous accesses to the content and granting access for a specified duration independently of whether the access is local or remote. The global policy may also depend on the type of the device or any software client used or a combination thereof. 
         [0032]      FIG. 2  illustrates a synchronization method according to a preferred embodiment of the present invention. 
         [0033]    A local enforcement point  1121 ,  141  identifies and authenticates S 21  an access request to a content from an end-user or a device (e.g. a Digital Video Recorder). 
         [0034]    Then a local enforcement point  1121 ,  141  (which may or may not be the same as the one in S 21 ) receives S 22  a further access request to the same content by a different end-user or device. 
         [0035]    The local enforcement points  1121 ,  141  then share and synchronize S 23  information about access states and current access requests, i.e. what is the current access state and what is the new access request. This is advantageously done via one or more secure channels. It will be noted that this step is preferably performed after step S 21  too, but it is not shown as there can be no conflicting access with only one access to the content. 
         [0036]    Each local enforcement point  1121 ,  141  then, preferably individually, resolves conflicting access requests S 24  by evaluating the global policy and taking a decision to grant or deny access for each device it enforces. The decision is based on at least the information received during the synchronization phase. 
         [0037]    Each local enforcement point  1121 ,  141  then locally enforces the access decision S 25  by granting or denying access to the content. 
         [0038]    It will be noted that the conflict resolution may intentionally create an interruption of content access for one or more devices at one or more enforcement points—cf. WO 2009/106818 where access for one device is interrupted by the central server. 
         [0039]    In a preferred embodiment, one enforcement point controls local access and at least one other enforcement point controls remote access. The enforcement point for local access may be implemented on the home residential gateway (as illustrated in  FIG. 1 ) or in the core network such as in a DSLAM (Digital Subscriber Line Access Multiplexer) or CMTS (Cable Modem Termination System). The enforcement point for remote access may be for instance implemented in the content provider&#39;s Web Portal or on mobile phones or tablets. 
         [0040]    The synchronization method may be implemented in the network illustrated in  FIG. 1 , in which the enforcement points reside on devices, exemplified by the STB  112  and the tablet  140 . The home gateway  111  advantageously comprises a hard drive (not shown) that can store blockbusters of the content provider&#39;s Video on Demand (VoD) catalogue that have been pushed onto the hard drive, while longtail (i.e. less popular) content is stored on the content provider&#39;s broadband content server  121 . Such systems are known to increase the performance of VoD systems. The content provider&#39;s entire VoD catalogue is also accessible via Internet on the Internet content server  122 . 
         [0041]    Thus, the STB  112  and the tablet  140  (when in contact with the gateway  111 ) may consume blockbuster VoD content by accessing the VoD catalog on the local gateway  111 . The STB  112  may also consume longtail content by connecting to the broadband content server  121 . When roaming, the tablet  140  may connect to the Internet content server  121  to access VoD content. 
         [0042]    The VoD content stored by the gateway  111  preferably comprises the corresponding global access policies. The global access policies are transformed by the gateway  111  into local access policies that are pushed to the enforcement points  1121 ,  141 , i.e. onto the STB  112  and the tablet  140 . It will be appreciated that the local access policies may be generated and pushed anytime between the reception of the content and a request to access the content, but they may also be generated in response to a request to access the content; an advantage of the latter arrangement is that only the local access policies that are needed are generated. The local access policies may comprise at least one local access policy rule (e.g. the STB may display the content once and the tablet twice), at least one global access policy rule (e.g. no more than one simultaneous viewing of the content), or a combination thereof. 
         [0043]    It is preferred that a device that has been ‘absent’, for example switched off or not in connection with the gateway  111 , contacts the gateway when it is no longer absent so as to update its local access policies. A local access policy may comprise particular rules to use when a device is ‘isolated’, which may be the case if the tablet  140  is used without a network connection. 
         [0044]    Whenever the user accesses a particular content using the STB  112  or the tablet  140 , their enforcement points  1121 ,  141  synchronize their states in order to enforce the local access policies. If, for example, both devices try to watch the same content at the same time, access is denied to one of the two devices, depending on the policy, i.e. which device has the higher priority. The priority may also depend on the context: a device that is currently accessing the content may be prioritized to avoid service interruption. 
         [0045]    A particular case may occur: the tablet  140  may be used at home  110 , i.e normally connected to the gateway  111 . In this case, the global access policy is resolved locally between the STB  112  and the tablet  140 . Thus even if the Internet connection is broken, the user is capable of consuming blockbuster content on the STB  112  or the tablet  140  in accordance with the global access policy. 
         [0046]      FIG. 3  illustrates an alternate network in which the enforcement points reside in network termination elements. A network termination element  150  is a network element belonging to a provider that provides the last connectivity leg to an end-user to the home  110 . It could be a DSLAM (Digital Subscriber Line Access Multiplexer) for DSL or CMTS (Cable Modem Termination System) for Cable. For the remote access, the network termination element could be the Internet content server  122 . The network termination element  150 , located between the broadband content server  121  and the gateway  111 , comprises a first enforcement point  151  and the Internet content server  122  comprises a second enforcement point  123 . 
         [0047]    The alternate network essentially functions in the same way as the network illustrated in  FIG. 1 , i.e. the enforcement points communicate to enforce the global access policy, but there are some differences. As no enforcement points reside on the device—i.e. the STB  112  and the tablet  140 —the devices need a connection with a device with an enforcement point in order to ensure that the global access policy is respected. This connection is preferably, for the tablet  140 , a Secure Authenticated Channel. It is also advantageous have at least one an enforcement point enforce policies for a group of devices, such as for example all the devices connected to the gateway  112  in the home  110 . 
         [0048]    The configuration in  FIG. 3  may also be used, with some modifications, for virtual gateways. Each household has a thin gateway (i.e. one with low functionality) that is connected to an edge network element, for example located in a DSLAM. The edge network element then preferably provides an Ethernet connection to home devices, DHCP, a firewall and other services such as video access. As the edge network element serves a plurality of households, it also isolates the networks and rights of each household. 
         [0049]    The present invention can thus provide a solution in which the enforcement points are distributed, which means that there is no need for a central enforcement point that always must be available. The present invention can also make it possible for a plurality of distinct devices or networks to comply with a global security policy. 
         [0050]    From the content provider point of view, it can be possible to do without a specific infrastructure component to handle synchronization between devices accessing content with respect to a policy. 
         [0051]    It will be appreciated that while the description uses the expression content in the sense of multimedia data such as audio and video data either in the form of a stream (digital or analogue, broadcasted or VoD) or in the form of a file, but this is not to be interpreted in a limiting manner; it may e.g. include services as well. In addition, the examples given herein show a home network and a roaming device, but it is naturally also possible to have more elements, in particular a plurality of home networks, a plurality of roaming device, or combination thereof. 
         [0052]    Each feature disclosed in the description and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination. Features described as being implemented in hardware may also be implemented in software, and vice versa. Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.