Title of Invention	METHOD OF PROCESSING AUTHORIZATION MESSAGES BY A MOBILE RECEIVER LINKED TO A MANAGEMENT CENTRE AND A METHOD OF TRANSMITTING SUCH MESSAGES TO A PLURALITY OF DESTINED MOBILE RECEIVERS
Abstract	The present invention relates to a method of transmitting authorization messages destined for a plurality of mobile receivers, comprising the following steps: definition of at least one set of authorization messages, a first part of which, forming a first message category, is intended for a first group of mobile receivers and a second part of which, forming a second message category, is intended for a second group of mobile receivers; - creation of a first packet of authorization messages containing at least the said first part of the set of authorization messages; - creation of a second packet of authorization messages containing at least the said second part of the set of authorization messages; transmission of the said first packet of authorization messages over a first service, without previously sending information indicating the multimedia unit which message packets concern it; - transmission of the said second packet of authorization messages over a second service distinct from the said first service without previously sending information telling the multimedia unit which message packets relate to it.

Title of Invention

METHOD OF PROCESSING AUTHORIZATION MESSAGES BY A MOBILE RECEIVER LINKED TO A MANAGEMENT CENTRE AND A METHOD OF TRANSMITTING SUCH MESSAGES TO A PLURALITY OF DESTINED MOBILE RECEIVERS

Abstract

The present invention relates to a method of transmitting authorization messages destined for a plurality of mobile receivers, comprising the following steps: definition of at least one set of authorization messages, a first part of which, forming a first message category, is intended for a first group of mobile receivers and a second part of which, forming a second message category, is intended for a second group of mobile receivers; - creation of a first packet of authorization messages containing at least the said first part of the set of authorization messages; - creation of a second packet of authorization messages containing at least the said second part of the set of authorization messages; transmission of the said first packet of authorization messages over a first service, without previously sending information indicating the multimedia unit which message packets concern it; - transmission of the said second packet of authorization messages over a second service distinct from the said first service without previously sending information telling the multimedia unit which message packets relate to it.

Full Text	FORM 2 THE PATENTS ACT, 1970 (39 OF 1970) As amended by the Patents (Amendment) Act, 2005 & The Patents Rules, 2003 As amended by the Patents (Amendment) Rules, 2006 COMPLETE SPECIFICATION (See section 10 and rule 13) TITLE OF THE INVENTION Method of processing authorization messages destined for a plurality of mobile receivers and method of transmitting such messages APPLICANTS Name : Nagra France SAS Address : Rue du Colonel Pierre Avia 28, F-75015 Paris, France Nationality : a French Company INVENTOR Name Address Nationality ZHAO Yishan Avenue de la Division Leclerc 122, F-92160 Antony, France a French National PREAMBLE TO THE DESCRIPTION The following specification particularly describes the nature of this invention and the manner in which it is to be performed : 1 0 0 5\|-tSLS? I2008 Technical field The present invention is generally related to the transmission of contents to mobile receivers. These contents can, in particular, but not exclusively, be pay-television events, audio contents, games, software or information such as weather forecasts, stock exchange information or other similar information. This invention also concerns the processing of these messages. The concerned receivers can in particular be mobile phones, personal digital assistants (PDA), portable computers (laptops), receivers destined for being placed in vehicles or any mobile receiver developed for an application that uses the above-indicated contents. More in detail, the invention refers to a method for transmitting authorization messages intended for a plurality of mobile receivers, as well as to a method for processing transmitted messages according to this method. Background art In the field of the broadcasting of contents as defined above and in particular of television contents with conditional access destined to mobile receivers, known with the acronym DVB-H (Digital Video Broadcast - Handheld), the contents are sent in a cyclic way in the form of packets (known as Time Slices). The packets correspond to services. A service can be defined as one or more digital streams forming a subset of the global digital stream. This subset shares a common identifier so as to be able to create an event starting from this identifier. The rights and other controls are sent in the form of authorization messages also in the form of packets. These packets of authorization messages are considered as a specific service and are therefore sent in the form of service data. In a diffusion environment, each authorization message is repetitively broadcast in order to be able to effectively reach its receiver. When the number of subscribers or users is high, the number of messages to be broadcast is likewise. The packet of each cycle containing these messages can occupy a considerable broadband. In practice, the number of authorization messages intended for each receiver is relatively low. 2 Nonetheless, all the receivers receive the packet containing the authorization messages and process them in order to establish if these messages relate to them or not. When using mobile receivers working with batteries, the energy consumption problem is particularly important. Actually, in order to ensure the receiver's maximum autonomy, it is useful to try to reduce the energy consumption to a minimum. For this reason, it is therefore essential to process as little useless information as possible. In the prior art systems, the authorization messages, containing in particular access rights to events or keys which allow for the decryption of encrypted information, are sent to all the receivers which have access to the concerned services. Among this set of receivers, each authorization message is actually intended for a low number of receivers. These must however process these authorization messages, in particular they must receive and decrypt them if necessary, before being able to establish whether the receivers are really concerned or not. This implies that the receiver must be in active mode at the moment of the reception of the packet of authorization messages and that it must consume energy for receiving and processing messages that maybe do not concern it. Energy is therefore often wasted, which can considerably reduce the autonomy of the mobile receiver. The application EP 0 975 109 describes a method for broadcasting digital content to receivers, in which these receivers are started only when a content is intended for them. To realize this, the method involves the preliminary sending of information tables to each receiver. These information tables involve an indication of a type of transmitted information, an identifier of the receivers to which the information is intended for as well as a time interval during which the information will be broadcast. At the reception of an information table, the receiver determines which group it belongs to and memorizes the time ranges corresponding to the broadcasting of information related to it. Then it sets itself up in standby mode and sets itself up in receiving mode only a short time before informationjelating to it is broadcast. 3 The concerned receivers are in inactive state and set themselves up in receiving state some seconds before the information intended for them is sent. This information is sent for each group of receiver for about ten minutes. In a system using portable decoders, a duration of some seconds corresponds to a complete cycle of messages being sent. Consequently, by using the system described in the EP 0 975 109, no energy saving is possible. This method is therefore not compatible with the broadcasting on mobile receivers. Moreover, in order for a receiver to be able to have access to the authorization messages relating to it, it is necessary for it to receive the corresponding table. In an application using in particular mobile receivers, this means that this table must be sent very frequently so that a user starting its unit in a certain moment would not have to wait for a long time before being able to receive the corresponding messages. It so follows that the receiver must be started up to obtain the table concerning it, which is in contradiction with the aim of the invention, that is, to reduce energy consumption. Description of the invention The present invention is intended to avoid the drawbacks of the prior art methods by providing a method in which the energy is used in an optimal way, that is, a minimum quantity of energy is consumed to process the messages not concerning the receiver receiving these messages or in other words, that a maximum amount of messages processed by a receiver really concern this receiver. According to this invention, there is no preliminary sending of indications of the time at which messages will be sent. In this way, it is not necessary to use energy for the reception of such indications. The aim of the invention is achieved by a method of processing authorization messages by a mobile receiver, characterised in that these authorization messages are transmitted in a cyclic way by message packets, these message packets including a subset of authorization messages, at least one of the packets of authorization messages being intended for said mobile receiver and at least another one of the packets being not intended for the mobile receiver, said method comprising the following steps: reception of all the packets of authorization messages by said mobile receiver during the duration of at least one cycle; 4 determination of at least one group of receivers to which said mobile receiver belongs; among the packets of authorization messages received during a cycle, determination of all the packets of authorization messages intended for the said group of receivers to which said mobile receiver belongs; - reception of at least one packet of authorization messages intended for the group of receivers to which said receiver belongs and absence of reception of at least one packet of authorization messages intended for a group of receivers to which said mobile receiver does not belong; - processing by the mobile receiver, of said messages received in the packets. The aim of the invention is likewise achieved by a method of transmitting authorization messages destined for a plurality of mobile receivers, comprising the following steps: definition of at least one set of authorization messages, a first part of which, forming a first message category, is intended for a first group of mobile receivers and a second part of which, forming a second message category, is intended for a second group of mobile receivers; creation of a first packet of authorization messages containing at least the said first part of the set of authorization messages; creation of a second packet of authorization messages containing at least the said second part of the set of authorization messages; transmission of the said first packet of authorization messages over a first service, without previously sending information indicating the multimedia unit which message packets concern it; - transmission of the said second packet of authorization messages over a second service distinct from the said first service without previously sending information telling the multimedia unit which message packets relate to it. The solution proposed by the present invention consists in segmenting the set of authorization messages in groups of messages of smaller size according to different criteria. A first type of criteria concerns the authorization messages and a second type of criteria concerns the receivers. 5 The authorization messages can be first segmented in a classic way into global, shared and individual authorization messages. The mobile receivers are organized in several groups or categories. These categories are defined on the basis of criteria like for example the type of receiver (mobile phone, PDA, car receiver,...), the identification number, a category of access rights, a mobile receiver version or the type of configuration of said receiver, etc. The authorization messages are grouped in order to form different packets for each type of message and/or category of receivers. At the reception, the receivers filter the services in order to process only the categories of messages that may concern them. The messages of the different groups are sent on different services, in a way similar to the different services used to transmit audio/video contents. The management of the reception of the services does not require any preliminary sending of tables, but is carried out in a similar way to the sending of the audio/video content. This presents the advantage that the method of the invention is compatible with the short time cycles required in the applications using mobile receivers. Moreover, no energy is consumed for receiving and processing information related to the sending of subsequent messages. Brief description of the drawings The present invention and its advantages will be better understood with reference to the enclosed drawings and to the detailed description of particular embodiments, in which: Figure 1 illustrates the emission of data by a content supplier; Figure 2 illustrates the reception of data by a mobile receiver, these data being emitted as shown by Figure 1; - Figure 3 represents a first embodiment of the segmentation of data in categories according to the invention; Figure 4 represents a second embodiment of the segmentation of data in categories, similar to the one of figure 3; Figure 5 schematically represents the reception of data on the basis of the categories illustrated by means of figure 3; and 6 - Figure 6 represents the reception of data on the basis of the categories illustrated by means of figure 4. Ways to carry out the invention Figure 1 illustrates the method of the invention, seen from the side of the emission of content. In the context of the invention, some contents as pay-television events, audio contents, games, softwares or information such as weather forecasts, stock exchange information or other such information are broadcast by content suppliers. In the invention, these contents are intended for mobile receivers such as mobile phones, personal digital assistants (PDA), portable computers (laptops), receivers destined for being placed in vehicles or any mobile receiver developed for an application that uses the above-indicated contents. These mobile receivers are linked to a management centre that has in particular the function of managing the access rights, subscriptions, content encryption keys, etc. The content suppliers and the management centre may be linked to a same entity or may be different entities. It is well known that the contents broadcast to mobile receivers are generally not continuously broadcast, as in the case of fixed receivers, but are broadcast in the form of data packets. These packets are distributed in different services, marked with SI, ... S10 on figure 1. Each packet corresponds to a channel or a service. The packets are broadcast in a cyclic way according to a cycle time generally between 2 and 5 seconds in practice. Each packet contains the amount of information corresponding to the chosen cycle time. By way of example, in the case of the broadcasting of a pay-television event, let us consider that the cycle time ct is 2 seconds. The first packet marked with S1 on figure 1 contains data corresponding to 2 seconds when they are displayed on the mobile receiver. After this time cycle, a second cycle re-starts by broadcasting the content linked to the service 1, and likewise containing the equivalent of 2 seconds of visualization. The transmission duration of a packet can range between about 0.1 and 0.5 seconds in practice. The cycle time and effective transmission time of each service is statically and/or dynamically settable. Figure 2 illustrates the reception of content by a mobile receiver. Let us consider that the receiver is fixed on the service SI. It then receives each packet linked to this service. It does not receive the other packets linked to the content of other services, so 7. that it can be put in standby mode during the transmission of packets linked to the other services S2, ... S10. According to a practical embodiment, this embodiment allows an energy saving of up to 90%. In figure 1, in addition to the packets linked to the content, some packets linked to the authorization messages are likewise represented. These packets are marked with EMM CT1, EMM CT2 and EMM CT3. Each of these packets corresponds to a particular category of authorization message, as explained hereinafter, with reference to figures 3 and 4. Generally, the authorization messages can contain access rights to one or more particular contents, keys allowing for the contents' decryption or access means to a certain content, controls, for instance destined for the receiver, or in a broader sense, any message other than the content in the strict sense of the word. In the method of the invention, the set of authorization messages is separated into several categories, at least two. In the embodiments illustrated with figures 3 and 4, six categories are illustrated. In the example represented, the set of authorization messages is segmented into global, shared and individual messages. The global messages contain the messages that are destined for all the users connected to a management centre. These global messages are marked with EMM-G in the figure. The shared messages are messages destined for a group of receivers, this group being a subset of all of the mobile receivers connected to the management centre. These messages are marked with EMM-S in the figures. The individual messages are destined for a particular receiver. They are marked with EMM-U. The set of global authorization messages is not segmented. The shared authorization messages are segmented into two parts in figures 3 and 4. A first segmenting is made depending on the type of concerned mobile receiver. Among the receivers, mobile phones, receivers destined for being placed in a car or other vehicle, personal assistant type receivers or receivers specially conceived for the selected application may in particular be used. The first subset of authorization messages, marked with EMM-S Type 1 in figures 3 and 4 could for instance contain the shared authorization messages intended for 8 mobile phones, while the subset EMM-S Type 2 could contain the shared authorization messages intended for other receivers. The individual authorization messages are likewise divided into several categories, marked with EMM-U Type i and EMM-U Type ii. According to a concrete example, this segmenting can likewise be made on the basis of the type of mobile receiver for which the messages is intended. By way of example, let us assume that the messages of the category EMM-U Type i are destined for mobile phones and the messages of the category marked with EMM-U Type ii are those destined for the receivers which are different from mobile phones. The subset marked with EMM-U Type ii, whose messages are destined for receivers which are different from mobile phones, is divided in two parts. This separation is based on a parameter of the concerned mobile receiver. By way of example, one of the parts could contain all the messages destined for receivers having an even identification number, this group being marked with "0" in the figures 3 and 4, and the other part could contain the messages destined for receivers having an odd identification number, this group being marked with " 1" on these figures. This has the advantage of separating the group into two parts, which allows for a better processing, as explained hereinafter. Six categories are thus defined according to authorization messages types and receivers parameters. According to the method of the invention, packets of authorization messages are afterwards defined on the basis of previously realised segmentations. In the embodiment disclosed with Figure 3, each segment corresponds to a specific packet, marked with CAT1, CAT2,..., CAT6. In the embodiment disclosed with Figure 4, several categories are grouped to form a packet. By way of example, the first packet marked with EMM CT1 is formed by categories including the global authorization messages EMM-G and the shared authorization messages intended for mobile phones. The second packet, marked with EMM CT2 includes the global authorization messages EMM-G, the shared authorization messages intended for mobile receivers 9 which are different from mobile phones and the individual authorization messages for the mobile receivers which are different from mobile phones having an even identification number. Finally, the third packet, marked with EMM CT3 includes the global authorization messages EMM-G, the shared authorization messages intended for mobile receivers which are different from mobile phones and the individual authorization messages intended for the mobile receivers which are different from mobile phones having an odd identification number. It should be noticed that one of the above-defined segmentations, corresponding to the individual authorization messages intended for mobile phones, is not introduced in any packet, for a reason to be explained afterwards. The particular embodiment disclosed with Figure 4 corresponds to data sent according to the embodiment of Figure 1. As one can see on this Figure, the categories EMM CTl, EMM CT2 and EMM CT3 previously defined are broadcast in the form of packets, as are the services. They are considered by the receiver as service data. Each authorization message packet is sent as a distinct service. Referring to figure 2, which is set from the receiving side, the concerned mobile receiver is involved only with the authorization messages packet of the first category EMM CTl. It is only switched on for the reception of this packet. When the other packets are broadcast, it is in standby mode and therefore it does not receive them, which allows for substantial energy saving, as previously indicated. When the categories are defined as explained referring to Figure 3, the reception and processing of information is disclosed by Figure 5. Let us consider the case in which the considered mobile receiver is a mobile phone. In this case, it will receive first of all the global authorization messages that are destined to all of the receivers as per definition. This corresponds to the first category CAT1. It will likewise receive the shared authorization messages destined to the mobile phones, which corresponds to the second category marked with CAT2. The individual authorization messages destined to the mobile phones correspond to the fourth previously defined category, whose messages are not part of the stream in the chosen example. Each of these messages being destined to a particular receiver, they are supposed to be sent in the 10 form of individual messages with well-known means (SMS, TEXTO) and each mobile phone receives only the individual messages that are destined for it. The message packets are sent by category according to a clearly defined frequency and cycle. This allows the receiver to scan only the message packets that are likely to concern it. The packets that the receiver must receive can be automatically determined by the receiver or can be memorized in the receiver at the moment of the personalization of apparatus or by sending an updating message for example. A way to automatically establish which packets may concern a particular mobile receiver, consists in the scanning of all of the services during an initializing phase. Starting from the information contained in these services, the receiver memorizes which service it must receive for the future and which services it must not receive. The receivers can also automatically or manually connect to the management centre servers to recover their reception configuration during the initializing phase. In this way, it is not necessary for the receivers to remain in reception mode until they have received the information related to the groups concerning them. In the embodiment disclosed by Figure 4, the message categories are grouped in order to form specific packets. These packets are sent as disclosed by Figure 1 and processed as indicated by Figure 6. Resuming the hypothesis that the receiver is a mobile phone, this receiver will have to receive, as before, the global authorization messages intended for all of the receivers as well as the authorization messages intended for the mobile phones. These messages are grouped in the first category marked with EMM CT1. The receiver belonging to this category and having access to the service S1 will only be active when data relative to this service S1 are broadcast and when messages of the category EMM CT1 are broadcast. This corresponds to the case disclosed by Figure 2. Out of these periods, the receiver can be set in standby mode. The present invention is interesting because, rather than receiving all the authorization messages, the majority of which do not concern the receiver, they are segmented into categories susceptible to regard the receivers receiving the messages. Thus, significant energy saving can be achieved for the receiver that is active only during the periods in which it can be useful. 11 The indicated segmentations have been given by way of example. It is clear that other categories could be used for the segmentation. Instead of grouping all of the mobile receivers except mobile phones in a single category, it is, of course, possible to form categories for different kinds of existing mobile receivers. Concerning the identification number, this number being possibly that of a physical component, of a software component or of a receiver certificate, the segmentation is based on the parity of the number in the described example. It is clear that other separations could be made, for example by modulo function, by contiguous ranges of identification numbers. In the last case, ranges are defined in such a way that there are not "too many" different categories and that each interval does not contain "too many" receivers. Another possible segmentation concerns the categories of access rights. Actually, it is possible to separate the authorization messages according to the type of subscription, to the specific authorized channels or to other similar criteria. Another segmentation can be made on the basis of a mobile receiver version, of a security module configuration associated to the mobile receiver or of a software version used by the receiver in particular. 12 We claim : 1. Method of processing authorization messages by a mobile receiver, characterised in that these authorization messages are transmitted in a cyclic way by message packets, these message packets including a subset of authorization messages, at least one of the packets of authorization messages being intended for said mobile receiver and at least another one of the packets being not intended for the mobile receiver, said method comprising the following steps: - reception of all the packets of authorization messages by said mobile receiver during the duration of at least one cycle; determination of at least one group of receivers to which said mobile receiver belongs; among the packets of authorization messages received during a cycle, determination of all the packets of authorization messages intended for the said group of receivers to which said mobile receiver belongs; - reception of at least one packet of authorization messages intended for the group of receivers to which said receiver belongs and absence of reception of at least one packet of authorization messages intended for a group of receivers to which said mobile receiver does not belong; - processing by the mobile receiver, of said messages received in the packets. 2. Method of processing authorization messages according to claim 1, characterised in that said mobile receiver receives only one packet of authorization messages per cycle and in that only this packet is processed during each cycle. 3. Method of processing authorization messages according to claim 1, characterised in that said mobile receiver is set in standby mode when the packets of sent authorization messages are not part of packets of authorization messages intended for said mobile receiver. 4. Method of processing authorization messages according to claim 3, characterised in that the standby mode setting is made on the basis of a time cycle and of an instant within the cycle, as of which the packet of authorization messages concerning said mobile receiver is sent. 13 5. Method of transmitting authorization messages destined for a plurality of mobile receivers, comprising the following steps: definition of at least one set of authorization messages, a first part of which, forming a first message category, is intended for a first group of mobile receivers and a second part of which, forming a second message category, is intended for a second group of mobile receivers; - creation of a first packet of authorization messages containing at least the said first part of the set of authorization messages; - creation of a second packet of authorization messages containing at least the said second part of the set of authorization messages; - transmission of the said first packet of authorization messages over a first service, without previously sending information indicating the multimedia unit which message packets concern it; - transmission of the said second packet of authorization messages over a second service distinct from the said first service without previously sending information telling the multimedia unit which message packets relate to it. 6. Method of transmitting authorization messages according to claim 5, characterised in that the authorization messages are divided into several sets each of them defining at least one category of authorization messages. 7. Method of transmitting authorization messages according to claim 6, characterised in that all or a part of the remaining authorization messages of the set are transmitted on at least a third service different from the first and the second service. 8. Method of transmitting authorization messages according to claim 6, characterised in that the categories of authorization messages are defined on the basis of criteria linked with at least one parameter of the concerned mobile receivers. 9. Method of transmitting authorization messages according to claim 8, characterised in that the parameter of the mobile receivers is chosen among the type of mobile receiver, an identification number, a category of access rights or a mobile receiver or configuration version of said mobile receiver. 10. Method of transmitting authorization messages according to claims 6 and 8, characterised in that the categories of authorization messages are defined on the basis 14 of criteria linked simultaneously to the authorization message type and to the parameter linked to the concerned mobile receivers. 11. Method of transmitting authorization messages according to claim 5, characterised in that the authorization messages packets comprise a single category of authorization messages. 12. Method of transmitting authorization messages according to claim 5, characterised in that at least one of the authorization message packets comprise several categories of authorization messages. Dated this 15th day of May 2008 (Prita Madan) ofKhaitan&Co Agent for the Applicants 15

Full Text

FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
Method of processing authorization messages destined for a
plurality of mobile receivers and method of transmitting such messages
APPLICANTS
Name : Nagra France SAS
Address : Rue du Colonel Pierre Avia 28, F-75015 Paris, France
Nationality : a French Company INVENTOR

Name
Address
Nationality

ZHAO Yishan
Avenue de la Division Leclerc 122, F-92160 Antony, France
a French National

PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed :

1 0 0 5|-tSLS? I2008

Technical field
The present invention is generally related to the transmission of contents to mobile receivers. These contents can, in particular, but not exclusively, be pay-television events, audio contents, games, software or information such as weather forecasts, stock exchange information or other similar information. This invention also concerns the processing of these messages.
The concerned receivers can in particular be mobile phones, personal digital assistants (PDA), portable computers (laptops), receivers destined for being placed in vehicles or any mobile receiver developed for an application that uses the above-indicated contents.
More in detail, the invention refers to a method for transmitting authorization messages intended for a plurality of mobile receivers, as well as to a method for processing transmitted messages according to this method.
Background art
In the field of the broadcasting of contents as defined above and in particular of television contents with conditional access destined to mobile receivers, known with the acronym DVB-H (Digital Video Broadcast - Handheld), the contents are sent in a cyclic way in the form of packets (known as Time Slices). The packets correspond to services. A service can be defined as one or more digital streams forming a subset of the global digital stream. This subset shares a common identifier so as to be able to create an event starting from this identifier.
The rights and other controls are sent in the form of authorization messages also in the form of packets. These packets of authorization messages are considered as a specific service and are therefore sent in the form of service data.
In a diffusion environment, each authorization message is repetitively broadcast in order to be able to effectively reach its receiver. When the number of subscribers or users is high, the number of messages to be broadcast is likewise. The packet of each cycle containing these messages can occupy a considerable broadband. In practice, the number of authorization messages intended for each receiver is relatively low.
2

Nonetheless, all the receivers receive the packet containing the authorization messages and process them in order to establish if these messages relate to them or not.
When using mobile receivers working with batteries, the energy consumption problem is particularly important. Actually, in order to ensure the receiver's maximum autonomy, it is useful to try to reduce the energy consumption to a minimum. For this reason, it is therefore essential to process as little useless information as possible.
In the prior art systems, the authorization messages, containing in particular access rights to events or keys which allow for the decryption of encrypted information, are sent to all the receivers which have access to the concerned services. Among this set of receivers, each authorization message is actually intended for a low number of receivers. These must however process these authorization messages, in particular they must receive and decrypt them if necessary, before being able to establish whether the receivers are really concerned or not.
This implies that the receiver must be in active mode at the moment of the reception of the packet of authorization messages and that it must consume energy for receiving and processing messages that maybe do not concern it. Energy is therefore often wasted, which can considerably reduce the autonomy of the mobile receiver.
The application EP 0 975 109 describes a method for broadcasting digital content to receivers, in which these receivers are started only when a content is intended for them. To realize this, the method involves the preliminary sending of information tables to each receiver. These information tables involve an indication of a type of transmitted information, an identifier of the receivers to which the information is intended for as well as a time interval during which the information will be broadcast.
At the reception of an information table, the receiver determines which group it belongs to and memorizes the time ranges corresponding to the broadcasting of information related to it. Then it sets itself up in standby mode and sets itself up in receiving mode only a short time before informationjelating to it is broadcast.
3

The concerned receivers are in inactive state and set themselves up in receiving state some seconds before the information intended for them is sent. This information is sent for each group of receiver for about ten minutes.
In a system using portable decoders, a duration of some seconds corresponds to a complete cycle of messages being sent. Consequently, by using the system described in the EP 0 975 109, no energy saving is possible. This method is therefore not compatible with the broadcasting on mobile receivers.
Moreover, in order for a receiver to be able to have access to the authorization messages relating to it, it is necessary for it to receive the corresponding table. In an application using in particular mobile receivers, this means that this table must be sent very frequently so that a user starting its unit in a certain moment would not have to wait for a long time before being able to receive the corresponding messages. It so follows that the receiver must be started up to obtain the table concerning it, which is in contradiction with the aim of the invention, that is, to reduce energy consumption.
Description of the invention
The present invention is intended to avoid the drawbacks of the prior art methods by providing a method in which the energy is used in an optimal way, that is, a minimum quantity of energy is consumed to process the messages not concerning the receiver receiving these messages or in other words, that a maximum amount of messages processed by a receiver really concern this receiver. According to this invention, there is no preliminary sending of indications of the time at which messages will be sent. In this way, it is not necessary to use energy for the reception of such indications.
The aim of the invention is achieved by a method of processing authorization messages by a mobile receiver, characterised in that these authorization messages are transmitted in a cyclic way by message packets, these message packets including a subset of authorization messages, at least one of the packets of authorization messages being intended for said mobile receiver and at least another one of the packets being not intended for the mobile receiver, said method comprising the following steps:
reception of all the packets of authorization messages by said mobile receiver
during the duration of at least one cycle;
4

determination of at least one group of receivers to which said mobile receiver
belongs;
among the packets of authorization messages received during a cycle,
determination of all the packets of authorization messages intended for the said
group of receivers to which said mobile receiver belongs;
- reception of at least one packet of authorization messages intended for the group of receivers to which said receiver belongs and absence of reception of at least one packet of authorization messages intended for a group of receivers to which said mobile receiver does not belong;
- processing by the mobile receiver, of said messages received in the packets.
The aim of the invention is likewise achieved by a method of transmitting authorization messages destined for a plurality of mobile receivers, comprising the following steps:
definition of at least one set of authorization messages, a first part of which,
forming a first message category, is intended for a first group of mobile receivers
and a second part of which, forming a second message category, is intended for a
second group of mobile receivers;
creation of a first packet of authorization messages containing at least the said first
part of the set of authorization messages;
creation of a second packet of authorization messages containing at least the said
second part of the set of authorization messages;
transmission of the said first packet of authorization messages over a first service,
without previously sending information indicating the multimedia unit which
message packets concern it;
- transmission of the said second packet of authorization messages over a second
service distinct from the said first service without previously sending information
telling the multimedia unit which message packets relate to it.
The solution proposed by the present invention consists in segmenting the set of authorization messages in groups of messages of smaller size according to different criteria. A first type of criteria concerns the authorization messages and a second type of criteria concerns the receivers.
5

The authorization messages can be first segmented in a classic way into global, shared and individual authorization messages.
The mobile receivers are organized in several groups or categories. These categories are defined on the basis of criteria like for example the type of receiver (mobile phone, PDA, car receiver,...), the identification number, a category of access rights, a mobile receiver version or the type of configuration of said receiver, etc.
The authorization messages are grouped in order to form different packets for each type of message and/or category of receivers. At the reception, the receivers filter the services in order to process only the categories of messages that may concern them.
The messages of the different groups are sent on different services, in a way similar to the different services used to transmit audio/video contents.
The management of the reception of the services does not require any preliminary sending of tables, but is carried out in a similar way to the sending of the audio/video content. This presents the advantage that the method of the invention is compatible with the short time cycles required in the applications using mobile receivers. Moreover, no energy is consumed for receiving and processing information related to the sending of subsequent messages.
Brief description of the drawings
The present invention and its advantages will be better understood with reference to the enclosed drawings and to the detailed description of particular embodiments, in which:
Figure 1 illustrates the emission of data by a content supplier;
Figure 2 illustrates the reception of data by a mobile receiver, these data being
emitted as shown by Figure 1; - Figure 3 represents a first embodiment of the segmentation of data in categories
according to the invention;
Figure 4 represents a second embodiment of the segmentation of data in
categories, similar to the one of figure 3;
Figure 5 schematically represents the reception of data on the basis of the
categories illustrated by means of figure 3; and
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- Figure 6 represents the reception of data on the basis of the categories illustrated by means of figure 4.
Ways to carry out the invention
Figure 1 illustrates the method of the invention, seen from the side of the emission of content. In the context of the invention, some contents as pay-television events, audio contents, games, softwares or information such as weather forecasts, stock exchange information or other such information are broadcast by content suppliers. In the invention, these contents are intended for mobile receivers such as mobile phones, personal digital assistants (PDA), portable computers (laptops), receivers destined for being placed in vehicles or any mobile receiver developed for an application that uses the above-indicated contents. These mobile receivers are linked to a management centre that has in particular the function of managing the access rights, subscriptions, content encryption keys, etc. The content suppliers and the management centre may be linked to a same entity or may be different entities.
It is well known that the contents broadcast to mobile receivers are generally not continuously broadcast, as in the case of fixed receivers, but are broadcast in the form of data packets. These packets are distributed in different services, marked with SI, ... S10 on figure 1. Each packet corresponds to a channel or a service. The packets are broadcast in a cyclic way according to a cycle time generally between 2 and 5 seconds in practice. Each packet contains the amount of information corresponding to the chosen cycle time. By way of example, in the case of the broadcasting of a pay-television event, let us consider that the cycle time ct is 2 seconds. The first packet marked with S1 on figure 1 contains data corresponding to 2 seconds when they are displayed on the mobile receiver. After this time cycle, a second cycle re-starts by broadcasting the content linked to the service 1, and likewise containing the equivalent of 2 seconds of visualization. The transmission duration of a packet can range between about 0.1 and 0.5 seconds in practice. The cycle time and effective transmission time of each service is statically and/or dynamically settable.
Figure 2 illustrates the reception of content by a mobile receiver. Let us consider that the receiver is fixed on the service SI. It then receives each packet linked to this service. It does not receive the other packets linked to the content of other services, so
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that it can be put in standby mode during the transmission of packets linked to the other services S2, ... S10. According to a practical embodiment, this embodiment allows an energy saving of up to 90%.
In figure 1, in addition to the packets linked to the content, some packets linked to the authorization messages are likewise represented. These packets are marked with EMM CT1, EMM CT2 and EMM CT3. Each of these packets corresponds to a particular category of authorization message, as explained hereinafter, with reference to figures 3 and 4.
Generally, the authorization messages can contain access rights to one or more particular contents, keys allowing for the contents' decryption or access means to a certain content, controls, for instance destined for the receiver, or in a broader sense, any message other than the content in the strict sense of the word.
In the method of the invention, the set of authorization messages is separated into several categories, at least two. In the embodiments illustrated with figures 3 and 4, six categories are illustrated. In the example represented, the set of authorization messages is segmented into global, shared and individual messages. The global messages contain the messages that are destined for all the users connected to a management centre. These global messages are marked with EMM-G in the figure. The shared messages are messages destined for a group of receivers, this group being a subset of all of the mobile receivers connected to the management centre. These messages are marked with EMM-S in the figures. The individual messages are destined for a particular receiver. They are marked with EMM-U.
The set of global authorization messages is not segmented. The shared authorization messages are segmented into two parts in figures 3 and 4. A first segmenting is made depending on the type of concerned mobile receiver. Among the receivers, mobile phones, receivers destined for being placed in a car or other vehicle, personal assistant type receivers or receivers specially conceived for the selected application may in particular be used.
The first subset of authorization messages, marked with EMM-S Type 1 in figures 3 and 4 could for instance contain the shared authorization messages intended for
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mobile phones, while the subset EMM-S Type 2 could contain the shared authorization messages intended for other receivers.
The individual authorization messages are likewise divided into several categories, marked with EMM-U Type i and EMM-U Type ii. According to a concrete example, this segmenting can likewise be made on the basis of the type of mobile receiver for which the messages is intended. By way of example, let us assume that the messages of the category EMM-U Type i are destined for mobile phones and the messages of the category marked with EMM-U Type ii are those destined for the receivers which are different from mobile phones.
The subset marked with EMM-U Type ii, whose messages are destined for receivers which are different from mobile phones, is divided in two parts. This separation is based on a parameter of the concerned mobile receiver. By way of example, one of the parts could contain all the messages destined for receivers having an even identification number, this group being marked with "0" in the figures 3 and 4, and the other part could contain the messages destined for receivers having an odd identification number, this group being marked with " 1" on these figures. This has the advantage of separating the group into two parts, which allows for a better processing, as explained hereinafter.
Six categories are thus defined according to authorization messages types and receivers parameters.
According to the method of the invention, packets of authorization messages are afterwards defined on the basis of previously realised segmentations. In the embodiment disclosed with Figure 3, each segment corresponds to a specific packet, marked with CAT1, CAT2,..., CAT6.
In the embodiment disclosed with Figure 4, several categories are grouped to form a packet. By way of example, the first packet marked with EMM CT1 is formed by categories including the global authorization messages EMM-G and the shared authorization messages intended for mobile phones.
The second packet, marked with EMM CT2 includes the global authorization messages EMM-G, the shared authorization messages intended for mobile receivers
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which are different from mobile phones and the individual authorization messages for the mobile receivers which are different from mobile phones having an even identification number.
Finally, the third packet, marked with EMM CT3 includes the global authorization messages EMM-G, the shared authorization messages intended for mobile receivers which are different from mobile phones and the individual authorization messages intended for the mobile receivers which are different from mobile phones having an odd identification number.
It should be noticed that one of the above-defined segmentations, corresponding to the individual authorization messages intended for mobile phones, is not introduced in any packet, for a reason to be explained afterwards.
The particular embodiment disclosed with Figure 4 corresponds to data sent according to the embodiment of Figure 1. As one can see on this Figure, the categories EMM CTl, EMM CT2 and EMM CT3 previously defined are broadcast in the form of packets, as are the services. They are considered by the receiver as service data. Each authorization message packet is sent as a distinct service.
Referring to figure 2, which is set from the receiving side, the concerned mobile receiver is involved only with the authorization messages packet of the first category EMM CTl. It is only switched on for the reception of this packet. When the other packets are broadcast, it is in standby mode and therefore it does not receive them, which allows for substantial energy saving, as previously indicated.
When the categories are defined as explained referring to Figure 3, the reception and processing of information is disclosed by Figure 5. Let us consider the case in which the considered mobile receiver is a mobile phone. In this case, it will receive first of all the global authorization messages that are destined to all of the receivers as per definition. This corresponds to the first category CAT1. It will likewise receive the shared authorization messages destined to the mobile phones, which corresponds to the second category marked with CAT2. The individual authorization messages destined to the mobile phones correspond to the fourth previously defined category, whose messages are not part of the stream in the chosen example. Each of these messages being destined to a particular receiver, they are supposed to be sent in the
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form of individual messages with well-known means (SMS, TEXTO) and each mobile phone receives only the individual messages that are destined for it.
The message packets are sent by category according to a clearly defined frequency and cycle. This allows the receiver to scan only the message packets that are likely to concern it. The packets that the receiver must receive can be automatically determined by the receiver or can be memorized in the receiver at the moment of the personalization of apparatus or by sending an updating message for example. A way to automatically establish which packets may concern a particular mobile receiver, consists in the scanning of all of the services during an initializing phase. Starting from the information contained in these services, the receiver memorizes which service it must receive for the future and which services it must not receive. The receivers can also automatically or manually connect to the management centre servers to recover their reception configuration during the initializing phase. In this way, it is not necessary for the receivers to remain in reception mode until they have received the information related to the groups concerning them.
In the embodiment disclosed by Figure 4, the message categories are grouped in order to form specific packets. These packets are sent as disclosed by Figure 1 and processed as indicated by Figure 6.
Resuming the hypothesis that the receiver is a mobile phone, this receiver will have to receive, as before, the global authorization messages intended for all of the receivers as well as the authorization messages intended for the mobile phones. These messages are grouped in the first category marked with EMM CT1.
The receiver belonging to this category and having access to the service S1 will only be active when data relative to this service S1 are broadcast and when messages of the category EMM CT1 are broadcast. This corresponds to the case disclosed by Figure 2. Out of these periods, the receiver can be set in standby mode.
The present invention is interesting because, rather than receiving all the authorization messages, the majority of which do not concern the receiver, they are segmented into categories susceptible to regard the receivers receiving the messages. Thus, significant energy saving can be achieved for the receiver that is active only during the periods in which it can be useful.
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The indicated segmentations have been given by way of example. It is clear that other categories could be used for the segmentation. Instead of grouping all of the mobile receivers except mobile phones in a single category, it is, of course, possible to form categories for different kinds of existing mobile receivers.
Concerning the identification number, this number being possibly that of a physical component, of a software component or of a receiver certificate, the segmentation is based on the parity of the number in the described example. It is clear that other separations could be made, for example by modulo function, by contiguous ranges of identification numbers. In the last case, ranges are defined in such a way that there are not "too many" different categories and that each interval does not contain "too many" receivers.
Another possible segmentation concerns the categories of access rights. Actually, it is possible to separate the authorization messages according to the type of subscription, to the specific authorized channels or to other similar criteria. Another segmentation can be made on the basis of a mobile receiver version, of a security module configuration associated to the mobile receiver or of a software version used by the receiver in particular.
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We claim :
1. Method of processing authorization messages by a mobile receiver, characterised in
that these authorization messages are transmitted in a cyclic way by message packets,
these message packets including a subset of authorization messages, at least one of the
packets of authorization messages being intended for said mobile receiver and at least
another one of the packets being not intended for the mobile receiver, said method
comprising the following steps:
- reception of all the packets of authorization messages by said mobile receiver
during the duration of at least one cycle;
determination of at least one group of receivers to which said mobile receiver
belongs;
among the packets of authorization messages received during a cycle,
determination of all the packets of authorization messages intended for the said
group of receivers to which said mobile receiver belongs;
- reception of at least one packet of authorization messages intended for the group of receivers to which said receiver belongs and absence of reception of at least one packet of authorization messages intended for a group of receivers to which said mobile receiver does not belong;
- processing by the mobile receiver, of said messages received in the packets.

2. Method of processing authorization messages according to claim 1, characterised in that said mobile receiver receives only one packet of authorization messages per cycle and in that only this packet is processed during each cycle.
3. Method of processing authorization messages according to claim 1, characterised in that said mobile receiver is set in standby mode when the packets of sent authorization messages are not part of packets of authorization messages intended for said mobile receiver.
4. Method of processing authorization messages according to claim 3, characterised in that the standby mode setting is made on the basis of a time cycle and of an instant within the cycle, as of which the packet of authorization messages concerning said mobile receiver is sent.
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5. Method of transmitting authorization messages destined for a plurality of mobile
receivers, comprising the following steps:
definition of at least one set of authorization messages, a first part of which, forming a first message category, is intended for a first group of mobile receivers and a second part of which, forming a second message category, is intended for a second group of mobile receivers;
- creation of a first packet of authorization messages containing at least the said first part of the set of authorization messages;
- creation of a second packet of authorization messages containing at least the said second part of the set of authorization messages;
- transmission of the said first packet of authorization messages over a first service, without previously sending information indicating the multimedia unit which message packets concern it;
- transmission of the said second packet of authorization messages over a second service distinct from the said first service without previously sending information telling the multimedia unit which message packets relate to it.

6. Method of transmitting authorization messages according to claim 5, characterised in that the authorization messages are divided into several sets each of them defining at least one category of authorization messages.
7. Method of transmitting authorization messages according to claim 6, characterised in that all or a part of the remaining authorization messages of the set are transmitted on at least a third service different from the first and the second service.
8. Method of transmitting authorization messages according to claim 6, characterised in that the categories of authorization messages are defined on the basis of criteria linked with at least one parameter of the concerned mobile receivers.
9. Method of transmitting authorization messages according to claim 8, characterised in that the parameter of the mobile receivers is chosen among the type of mobile receiver, an identification number, a category of access rights or a mobile receiver or configuration version of said mobile receiver.
10. Method of transmitting authorization messages according to claims 6 and 8,
characterised in that the categories of authorization messages are defined on the basis
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of criteria linked simultaneously to the authorization message type and to the parameter linked to the concerned mobile receivers.
11. Method of transmitting authorization messages according to claim 5, characterised in that the authorization messages packets comprise a single category of authorization messages.
12. Method of transmitting authorization messages according to claim 5, characterised in that at least one of the authorization message packets comprise several categories of authorization messages.
Dated this 15th day of May 2008
(Prita Madan) ofKhaitan&Co Agent for the Applicants
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Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=UsLwUkfMjfCP0H8paPPqXQ==&loc=vsnutRQWHdTHa1EUofPtPQ==

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Patent Number

270181

Indian Patent Application Number

1005/MUMNP/2008

PG Journal Number

49/2015

Publication Date

04-Dec-2015

Grant Date

30-Nov-2015

Date of Filing

16-May-2008

Name of Patentee

NAGRA FRANCE SAS

Applicant Address

RUE DU COLONEL PIERRE AVIA 28, F-PARIS,

Inventors:

#	Inventor's Name	Inventor's Address
1	ZHAO YISHAN	AVENUE DE LA DIVISION LECLERC 122, F-92160 ANTONY,

PCT International Classification Number

H04N7/16

PCT International Application Number

PCT/EP2006/068974

PCT International Filing date

2006-11-28

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	05292545.0	2005-11-30	EUROPEAN UNION