HRP20020227A2 - Message chaining transmission process and system for data bases - Google Patents

Abstract

The invention concerns a method and a system for transmitting a chain of messages for updating a database between a management centre and a plurality of geographically distributed subscriber databases. Each message comprises a chain identifier (FM) and a chain index (FI) for identifying the message in the chain. If a message is not received following a disturbance in the connection, the processing of the next messages can block the databases. In order to remedy that inconvenience, the solution consists in assigning to each message a block status (CD) which determines whether said message is to be processed without referring to the members of the chain and what are the conditions concerning the prior processing of members of the chain.

Description

The subject invention relates to a procedure and a system for updating (harmonizing with the latest version) a database, especially during the transmission of a chain of messages.

In a system that includes a control center and a large number of subscribers in a wide area, it is known to send information to update the database of those subscribers by telephone or Hertz. These messages are addressed either to all subscribers, or to one specific subscriber, that means they contain the address of the subscriber module.

These messages serve to manage the system and are superimposed with useful information such as video, audio or data. It is understandable that the place used for this information is limited. Another limitation applies to the length of the message, which is limited by the fact that the useful data cannot be interrupted, except for a moment. So, it is clear that in the example of audio/video transmission, the broadcasting channel can be interrupted only for a short moment, in order not to notice the visual effect.

Therefore, in order to transfer a large amount of information, this information should be divided into a large number of messages.

These messages are sent in a certain order to the network, in logical order, that means one after the other, separated by a short interval, for example a second.

Due to the fact that some systems of this type do not use a return path to the control center, such as a modem connection, the control center can hardly know whether the sent information has arrived correctly. For this reason, these messages should be repeated periodically, in order to statistically ensure that each message has reached its destination.

The subscriber module schematically implies a digital receiver, or an audio or video or data receiver, and as much as possible a combination of these three types, a decoding device that needs to separate management messages, and that they are directed to the security module containing the subscriber database. This security module can be placed directly in the subscriber module, where for reasons of security and costs it can be presented in the form of a separate module such as a smart card or chip card.

Messages that arrive at the security module are processed by the control command reader. It may happen that the messages do not arrive in the order of transmission due to transmission interference, or simply due to the fact that the subscriber's unit was not connected during the previous message. It should be specified that before processing, each message should be deciphered and its authenticity checked. A message that does not meet the control criteria is discarded. According to this assumption, the security module will receive, for example, a message marked with 3 before the messages marked with 1 and 2. The execution or enforcement of message 3 without first having

executed two previous messages, may lead to database blocking or any other error.

The first solution consists in memorizing all the messages that form the chain, and when the message is complete, processing should be started. This solution hardly defines the maximum length of the chain as a function of the available memory.

The memory capacity of a detachable smart card is limited, which means that the card must process each message as it arrives.

The problem whose solution is proposed by the present invention is to cancel the negative effects on the subscriber database of the necessity of executing messages in an order different from the originally intended order.

This goal is fully achieved by the process of transferring the control message chain of the subscriber database, which process consists in optionally adding a conditional block, which determines whether the message should be processed regardless of all or part of the other elements of the chain or the conditions related to pre-processing of all or part of other elements of the chain.

In fact, thanks to this new conditional block included in each element in the message chain, it is possible to determine whether that message can be processed separately or should satisfy the processing condition of messages considered to have been received first. It is obvious that this test allows to determine whether the message during evaluation has already been processed.

In order to achieve this goal, the security module has a memory organized in the form of a table that shows for each chain which parts of messages from that chain have already been processed. After processing all elements of a chain, the table of that chain is saved to avoid returning the same chain from restarting its execution. It can be deleted at the request of the control center or after some predetermined time.

A conditional block contained in a message contains not only a simple indication that links the processing of the message in progress with the condition to execute the previous message, but also includes much more complex functions, such as conditions for each element of the message chain. It is possible, for example, that element 4 of the chain undergoes processing provided that either element 1 or 2 is processed, and that element 3 is imperatively processed. We will have a function:

F(4) = (1 or 2) and 3.

We will show an example of the arrival of a message element of family 5 in the security module, where this message is element 4 of that family. The first operation will be to determine whether the processing is subject to other conditions. If this is not the case, it can be processed immediately. It should be emphasized that the fact that the messages are chained does not mean that processing must be done in the order specified in the chain. One can imagine a case where an important program package is loaded and for this reason it is shared for transmission in a message chain. Each of these messages contains a download address and corresponding data. Because of this, the chain element can be processed in any order. On the other hand, the last element of the chain that starts that new program contains a condition that determines that all the elements of the chain must be executed (implemented), so that it too could be executed. When that condition is met, the table corresponding to that family states that all messages have been executed.

According to one variant of the invention, the conditional block is divided into two parts, one called "operation" to describe the type of logical function, and the other "element of interest" to describe on which other elements to perform the operation. The format of the "element of interest" part corresponds to the format used in the table stored in the database, which indicates the processing state of the elements of the chain. In this way, logical comparison is much easier.

According to other embodiments, the conditional block does not apply to all other elements of the chain, but only to some. It is possible, for example, that it refers to the three preceding elements and not to all elements. This allows reducing the length of the conditional block and taking into account the fact that the mismatch (mess) rarely exceeds the time of three messages. According to another example, a chain structure could be defined where only the last element contains a conditional block.

This structure allows, contrary to solutions from the prior art, to discard only the minimum message. In fact, when a message is missing from the chain (dropped), all subsequent messages are discarded until the missing message is passed again. Execution of the chain thus depended on the constant receipt of elements of the chain, with each missing element resulting in discarding messages with an index higher than the missing message.

According to one embodiment of this invention, the subscriber module, in parallel with sending messages to the security module, has a memory to memorize them as soon as they arrive.

It can therefore happen that the absence of one message that contains the condition for the previous message leads to the rejection of all subsequent messages. When that expected message arrives, it is of course processed with the authorization of the processing of other messages. It can happen, on the other hand, that a long time passes before they are present in the transmission, with the risk that some are dropped, for example due to the poor quality of the connection between the control center and the subscriber.

In order to minimize the number of repeated messages needed to complete the chain, the security module can access the memory, located in the subscriber module, because it contains all messages in order of arrival. Thus, immediately upon the arrival of the missing message and upon completion of its processing, the security module will request a memory readout in order to process all messages that were rejected due to the conditions on the missing message.

An important aspect of the subject invention is the fact that each message is presented to the security module in parallel with the saving in the memory of the subscriber module. This principle may contain exceptions in case some messages are not intended for the security module, but only for the subscriber module. If some messages are rejected by the security module because the conditions are not met, it knows that the message is in the memory of the subscriber module and can, after the condition is met, access the memory to process those messages, instead of waiting for a new pass of the following messages.

In one embodiment, the memory of the subscriber module is organized as a set of memory locations with serial inputs, and each new input causes the previous input to shift.

Reading using the security module can be done in different ways. It can ask for the exact memory address to be transferred. In any case, an important aspect of security in this type of application is based on the confidentiality of the information organization. Therefore, instead of requesting the transfer of one specific address, the security module requests the subscriber module to deliver all or part of the messages contained in its memory. The security module should perform a selection of messages that have been implemented or should be implemented.

The invention will be better understood from the detailed description that follows and refers to the attached drawings, which are given by way of non-limiting example and in which:

- Fig. 1 shows a message as it is sent in systems according to the current state of the art;

- Fig. 2 represents a message such as that sent in accordance with the subject invention;

- Fig. 3 gives an example of updating (updating) the cache of the subscriber module.

On Fig. 1 schematically shows the different blocks of one message that participate in the chaining function. The first leading block HD describes the type of message and contains information that this message is part of a chain. In order to form a chain, the second block of the FM family indicates which family the message belongs to. In fact, it is possible for multiple chains to be transmitted at the same time, and family identification is necessary. When a family is defined, the following FI block is used to identify each family member and its place in the chain. Thus, using these two pieces of information, each family member can be placed side by side with other members of the same family, if necessary. It is known that the maximum number of family members should be indicated in one or another FI or FM control block. This function can be obtained by special labeling of the last member of the family.

On the example from Fig. 2, message from Fig. 1, by including two blocks FM and FI, one can see the binding of an additional block CD which determines the condition for carrying out that message. According to the first embodiment of the subject invention, that block is composed of one bit that indicates whether or not the previous message should be executed. If this condition is required, the translation program in charge of database operations checks whether the previous message was executed correctly and executes the new message.

In another embodiment, that conditional block CD is composed of fields divided into groups, one group for each member of the chain. Each group contains one condition for one element of the chain and can have multiple meanings, for example the condition "should have been executed", "can be executed" or "must not be executed". This last condition largely corresponds to the first.

Let's take the example of a chain of 6 elements, where element 3 must necessarily be executed before element 5. In that case, it should be specified in message 3 that it should not be executed if message 5 has been executed. This condition can lead to blocking, if not specified reverse the condition in message 5. In this case, message 5 will contain the "should have executed" condition on message 3, so that if message 5 arrives before message 3, it will not be processed.

On Fig. 3 shows the application of the M memory module of the subscriber and the connection with the security module. The input stream is first filtered through the SEL module, which should separate control messages from other data. These messages are then sent to the selection module SW, which has the task of sending them to different modules, that is, to the security module SM, to the processing center CTR of the subscriber module STB and to the memory of the subscriber module M. Placing these messages in the memory leads to an increase in the number of incoming messages. , so that no message can be lost, and the oldest message is eliminated from memory. In parallel, these messages are transmitted to the security module, which is shown here as a smart card (chip card) SM. That SM card contains the first memory management module GM and the control translator INT to manage the database control BD. That GM memory management module can communicate with the CTR processing center via an I/O connection (input/output) and thus influence the connections in the optional SW module. Dashed line shown in Fig. 3 represents the STB subscriber module. All administrative messages addressed to the security module SM are routed by the optional module SW to the security module, especially the memory management element GM, and are then transferred to the translation element if the execution conditions are met. The GM memory management module updates the implemented message table to perform the necessary comparisons as soon as a new message arrives. The connection with the smart card SM is of the input/output type and in this way information and commands can be sent to the destination of the subscriber module, where this connection is represented by the line I/O. As already explained before, the memory M is physically located in the STB subscriber unit. For this reason, the SM card can request the disposal of a part of the memory via the I/O line in order to be able to save the messages of one chain. In our example, the maximum number of elements in the chain must not exceed 16. Thus, upon the arrival of the first member of the chain, the SM card, via the I/O line, requests the reservation of at least 16 memory locations. If, during the transfer of that first chain, another chain is announced, the card will request the reservation of 16 new seats, in order to ensure the storage of the maximum number of chain members according to the conditions of admission.

In order to be able to read information stored in memory M, for example location M3, the SM card can order, through the SW menu, the address multiplexer AMUX to return the contents of that memory location to it. In order to direct data to the card, the DMUX data multiplexer has the function of reading the requested memory location and transferring it to the card. These different transmissions are controlled by the optional SW element.

When the execution of the chain is interrupted, for example due to an error on one message, the other messages continue to be stored in the memory of the subscriber module. When the control center resends the missing message and it executes correctly, the GM memory control element will call all other chain messages to join the subscriber module memory. In this case, the input of the intelligent card is no longer performed upon the arrival of a message, but according to the contents of memory M. This access to memory M can be carried out either by direct access by specifying the memory address, or by sequential access by reading the messages according to the order in which they arrived.

In one embodiment, the memory M is organized as a temporary memory of constant length according to the availability of free memory of the subscriber module. This memory includes an input number that is incremented with each message entered into the memory and an output number that is incremented with each read by the GM memory manager.

The ability to communicate between the SM card and the STB subscriber module, more precisely the CTR center, authorizes more complex functions. One of the frequent problems encountered when changing one or another system element or card or subscriber module is ensuring the compatibility of functions with equipment of older generations. That is why it is interesting to establish an inter-room dialogue of different elements, in order to obtain the functions that would be available in each of them; it is the purpose of the I/O line that allows instructions to be sent from the card to the subscriber module. Those instructions may, for example, require the subscriber module to be related to audio/video functions or data, module generation or software package version. In order to respond to this request, the STB module has the means to compose control messages and to transfer them either to the memory M for subsequent reading from the card, or directly to the card, as shown in Fig. 3.

According to another form of the invention, the STB module has a connection to the control center via a modem. In this case, the STB module can announce the source (resource) to the control center via modem, and at the request of the SM security module.

As shown in Fig. 3, the STB module also receives administrative messages coming from the control center. Messages arriving at the CTR processing center may contain configuration request instructions. The answer can be given via modem or by transfer to the SM card. Some of these control messages are directed only to the STB module and will not be sent to the SM security module or to the M memory by the processing center CTR, which is responsible for controlling the STB module.

Claims (15)

1. The process of transferring a chain of management messages of the database between the management center and a number of subscriber databases, and each administrative message contains the leading element of the chain (HD), the identifier of the chain (FM), which allows the simultaneous transmission of several chains, indicated by the fact that consists in adding to each message a conditional block (CD) that determines whether this message should be processed without binding to all or part of the chain members or should be processed according to conditions related to the previous processing of all or part of the chain members. 2. The transmission method according to Patent Claim 1, characterized by the fact that it consists in determining according to the conditional block (CD), whether all or part of the members of the chain can, or must, or should not be previously processed. 3. The transmission procedure according to Patent Claim 1 or 2, characterized by the fact that it consists in managing a table in the heart of the subscriber database that contains information that represents the state of processing of each member of the chain, in updating the said table every time one member of the chain is processed, and in restarting the specified table or at the request of the control center, or after a predetermined time. 4. The transfer procedure according to Patent Claims 1 to 3, characterized in that the subscriber's database is connected to the subscriber's unit and that it consists in the fact that administrative messages are stored in the memory of the subscriber's unit and are made available to the database on request. 5. The transmission method according to Patent Claim 4, characterized by the fact that it consists in serial memorization of the input message, whereby each input message causes an increase in the indicator of incoming messages, and in enabling direct access to the messages requested by the database. 6. The transmission method according to Patent Claim 4, characterized in that it consists in using the memory of the subscriber unit, which functions as a serial temporary memory of constant length. 7. The transmission method according to Patent Claims 4 to 6, characterized in that it consists in receiving in the database an element of the chain message and in allocating in the subscriber unit the memory necessary to receive all elements of the chain. 8. The transfer procedure according to Patent Claims 4 to 7, characterized by the fact that, upon request, it consists in enabling the subscriber module to compose a control message describing its software and hardware, and characterized by the fact that the specified message is sent either to a database (SM), or to the control center. 9. The transmission method according to Patent Claim 8, characterized in that this request is sent either by the control center in the form of a control message, or by the database (SM) in the form of an instruction via the I/O line. 10. The database control message chain transmission system includes a control center and a number of subscriber units, each unit containing a database, and each message consisting of a message leader (HD), a chain identifier (FM) that allows simultaneous transmission of multiple chains , and the chain index (FI) that enables the recognition of the message in the chain, indicated by the fact that it contains a conditional block (CD) that determines whether the message should be processed without binding to all or part of the chain members, or whether it should be processed according to conditions related to the previous one processing of all or parts of the chain members. 11. Message chain transmission system according to Patent Claim 10, characterized in that the conditional block (CD) contains a condition that determines whether all or part of the chain members can, or must or must not be pre-processed. 12. Message chain transmission system according to Patent Claims 10 and 11, characterized in that the security module (SM) contains a message management circuit (GM) that can store in memory the state of processing of each message in the chain, and in that it includes means for comparing that state with the conditions mentioned in the conditional block (CD) of the message being processed. 13. Message chain transmission system according to Patent Claims 10 to 12, characterized in that the subscriber unit contains a memory (M) of messages, whereby each incoming message causes the movement of the previous message in the memory (M), and in that the security module (SM) includes elements for reading and processing these messages. 14. Message chain transmission system according to Patent Claims 10 to 13, characterized in that the subscriber unit (STB) contains a connection line (I/O) to the security module (SM) and includes elements for determining the size of the memory (M) according to the instructions received from the security module (SM), and to respond to the security module (SM) about composing and sending a control message. 15. Message chain transmission system according to Patent Claims 10 to 13, characterized in that the subscriber unit (STB) contains an optional module (SW) that enables the connection of a separate control message (SEL), a subscriber module processing center (CTR), a security module ( SM) and memory (M) and elements for recognizing control messages intended only for the processing center (CTR) and directing these messages by the optional module (SW) only to the processing center (CTR).