CN1228861A - Method for controlling the use of pagers, pagers operated by the method and chip cards for conditional access pagers - Google Patents

Abstract

The pager (1) whose use is to be controlled is associated with a chip (25) card (21). When a message is delivered, units are deducted in a memory (26) of the chip card prepaid units to ensure that the messaging service provided is proportional to the use. In an alternative embodiment, the chip card has an authentication circuit (PIN, 27) for verifying that if the card bearer is authorized to receive all or part of the messages contained in the pager.

Description

Method of controlling the use of pagers, pagers operated by this method and chip cards for conditional access pagers

It is an object of the present invention to provide a method of controlling the use of pagers (commonly referred to as "Pagers" or "Pageurs"). The purpose of the present invention is to rationally use this device. It also relates to a pager operating according to this Act and a chip card suitable for accessing (entering) the pager.

A pager is a device for receiving and forwarding any number of times, and the user generally relies on it to receive the forecast sent by the person with the communication link and start to understand the information processing. Typically, transmissions between the message sender and the pager are via the Hertz (radio wave) method. Yet can realize this transmission by wired method or other methods fully in fact, for example: adopt the pager that connects to disperse in the vicinity of the whole effective geographical range regularly and receive and store the waiting and the message that is assigned to the user regularly.

Personal mobile communications using radio receivers have become widespread in recent years, especially radio receivers for receiving messages recorded on liquid crystal screens. Among these personal mobile communication devices or desktop devices we can also cite cellular telephones.

The object of the invention is to adapt a chip card to an already available receiver. The use of control cards has also become customary for different kinds of devices, for example for card-based public telephones. Credit cards are also contemplated by the present invention.

In the case of information transmission via radio links, the information is transmitted by the operator by means of a frequency-modulated carrier code. The transmitter periodically sends the different interlocutors concerned in order to make sure that they are received satisfactorily. A pager contains a radio wave receiver with a personal identification number. The receiver has the ability to detect the transmitted information and to select among the transmitted information which is reserved for it. At the instant the message is received, the pager generates an announcement signal, sounds, vibrates, or lights up a display. Usually on the selected pager display, the caller's number can also be read out, or the caller's information can be read out directly. In some systems callers can be notified of incoming messages by virtue of their pagers. Calls are made to the interlocutor who is trying to reach him, generally by means of the nearest telephone.

Until now such a service remained of a specialized nature. But people have recently found that with the appearance of low-cost pagers, it is developing towards the direction of popular application. On the other hand, the change of customers has caused the emergence of new service businesses.

Wireless paging systems today communicate with callees through the caller's telephone call, operated by the sending operator with subscription payment. A disadvantage of current operator pays systems is that the callee can call back using another network than the operator. It even sometimes avoids calling without calling back when the information is quite important.

Although such a system is a particularly effective means for simplifying telephone network billing procedures and/or reducing the number of connections in a dwelling, it has the disadvantage of being more expensive to purchase and/or requiring a deposit. In some cases, some users do not pay the subscription fee until the communication service is used.

Furthermore, at the moment of sending a message to a destination using such a system it is desirable to ensure that the pager bearer is exactly the one to whom the message is intended and not an outsider or perhaps a fraudster. This may be hampered if the outsider obtains the content of the message that was not intended for him. Preferably we try to solve both problems at the same time. The object of the present invention is to allow equipment, especially subscribers, to subscribe and ensure that they receive those communication services that are intended for them.

These problems are solved with the pager of the present invention which allows it to be supplied to or sold to subscribers. The operator is compensated for the investment and/or services provided by the user, preferably in a coercive, non-fraudulent or getaway manner, each time the message is delivered to him. For this purpose we equip each pager with, for example, a portable electronic carrier; actually a chip card. The pager then contains a chip card reader and is only permitted to operate when a valid chip card has been inserted into the pager. In this case, the chip card will be of the prepaid unit type, so that as the information is received it will deduct the relevant portion from the chip card and, if the discretionary portion is sufficient, authorize their transfer to Pager carrier. In this case, it is easier to resolve that the bearer of the pager coincides with the recipient of the message by identifying and/or authenticating the bias of the chip card inserted into the pager. In this way we can also provide receivers that receive and store messages (reserved for multiple receivers) and only allow the receiver's messages to be transmitted if the receiver inserts its appropriate chip card into the pager. A sub-addressing can then be implemented which functions as an address contained in the pager and as a sub-address contained in the card. Because of this multi-user capability, the cost of pager purchases can be distributed among multiple individuals. In this case, the pager may be able to operate from a fixed location accessible to each user. In another example, the pager will perform all these functions without adding chips.

In the case of multiple users, the identification of the receiver is achieved by means of a so-called PIN-coded offset introduced by a keypad prepared for this purpose by each receiver on the pager. The means allowing to realize the above-mentioned (multi-user) functions are of known type.

The present invention cooperates the controlled chip card or smart card with the message radio receiver displayed on the liquid crystal screen, and then the pager and the card realize multiple functions in the following manner.

Once started, the personal receiver is in the state of waiting to receive messages; for each message, a signal appears on the screen (on the LCD screen);

- When the receiver user receives the signal, then insert the chip card to get every message on the screen.

- The card is preferably a prepaid card which only enables the receiver to operate if there is sufficient credit to reproduce the message; Chip card inserted.

- Furthermore, it is conceivable that the chip card is used to realize the decoding of each message that should be reproduced, since the function of the chip card is to decode the message, which means that by encoding, the card translates the signal into a text in a known language, each A message represents a charge which is deducted from the value of the card.

Thus, in a first implementation, the chip card that constitutes the object of the invention makes it possible to adjust the prepayment of the messages displayed on the liquid crystal screen, which controls a certain number of messages and the size of the message volume.

In a second implementation, the chip card which constitutes the object of the invention comprises, in addition to the functions described above, the decoding of each message by means of a coded translation into a text in a known language.

Since the invention must be considered in a broad and non-limiting sense, the invention may be embodied in many ways without thereby being beyond its scope.

Therefore content of the present invention is about the use of control pager, and it comprises following several steps:

- the pager receives the message sent by the transmitter,

- check if the messages are for the pager, if yes, store them in the pager,

- then transmit them to the pager bearer,

characterized by the fact that before transmitting them,

- Check to see if the pager carrier has permission to know about the transmission.

The subject of the invention also relates to a pager comprising a circuit for receiving messages and a circuit for transmitting received messages, characterized in that it comprises a chip support, i.e. a reading device for a chip card, the chip support being inserted into the reading device , the circuitry that allows the transmission of received messages when the correct chip carrier is inserted into the reader.

The invention also relates to the content of the chip card of a radio receiver for displaying messages on a liquid crystal screen, characterized in that the receiver is equipped with elements to receive the card, only if the balance is sufficient for reproducing the message (i.e. the card's function is access to the message on the screen), the card will control the credits that make the receiver work, which means: the message is subject to the insertion of the card.

To this end, the present invention relates to a pager whose functions and/or messaging are preferably subordinated to the payment of a prepaid portion stored in a memory.

According to a first embodiment, the part of the prepaid unit is the stored information in the memory of the chip card with which the pager cooperates in order to credit the said payment part.

According to a second embodiment, the payment unit is stored information in the memory of the pager, which works in an automatic manner to credit said payment unit.

There are two possible solutions in both cases:

- non-refillable (chargeable) units (pagers or cards are disposable);

- Refillable (rechargeable) (chargeable) units, preferably by various charging means, especially remote (e.g. radio, no contact with chip card or by use of the pager itself, e.g. infrared, electro-acoustic) is rechargeable.

In this case, the advantage is the re-use of the memory and the avoidance of removal for the chip card.

Finally, the subject of the invention concerns a chip card for radio reception to display information on a liquid crystal screen, characterized in that it implements a decoding function that allows each information to be reproduced, i.e. it translates the signal into a known language The encoding of the text decodes the message.

According to another feature of the invention, the pager implements a security function for charging the unit. The security is implemented either in the pager, preferably by means of a suitable security module, or in the card of the microprocessor. A suitable security module is inaccessible and inviolable due to the physical protection of the element, which may be passive or active. Such modules typically use a search protocol and a validation protocol, the types of which are well known in the chip art.

The recharging phase is as follows: The user walks up to the distributor in order to recharge his pager or card. Give the pager or card identification number and the money corresponding to the purchased unit. The distributor calls a center attendant who sends a representative coded recharging signal containing a previously transmitted identification number or possibly a secret code. The microprocessor performs a comparison test between message encoding and content within the appropriate security module (or in the card) before increasing the known number of units of unit memory.

The order to charge and pay for the unit can be alternately executed through the communication system.

For practical reasons of simplification, the recharge signal is preferably transmitted in the same manner as the message.

For safety reasons, the recharging signal can be transmitted on certain terminals in order to centralize charging and avoid another pager being able to hog the recharging signal. Binding posts can be stored in cubicles or post offices, telephone booths, eg (or) infrared connectors.

In the case of a booth or a telephone booth, the user can notify the above-mentioned data to the center attendant through the telephone line and receive charging through the telephone line. Some means of receiving audio signals, especially of the DTMF type, can be provided in the pager.

In order to avoid general fraud, especially the shunting of the output signal of the receiving antenna, the message can be hidden in the transmitted message and then stored in memory, either pager or card, before sending out. It is then sent after decryption implemented by an appropriate security module. A suitable security module in this case contains at least a microprocessor and a decryption algorithm. Messages can also be stored directly in the storage area of a suitable security module. The management function of the pager and the microcomputer management function of the card can be realized by a suitable unique microcomputer contained in the security module.

A suitable security module is preferably included in the pager. In the solution of the first embodiment, a suitable security module may be included in the card, so that it itself realizes all or part of the decryption function.

In the case of the first embodiment, in order to avoid fraud with a fake card, the pager can implement card authentication technology. People can have the so-called first-generation telephone card type low-level storage card of the simple realization unit storage function identification function and passive identification function (no microcomputer) in use. But rather a second generation card (never without a microprocessor) that allows active authentication of the card, perhaps of the pager, is used.

The pager thus operates with a reasonable level of security using inexpensive standard calling cards (which are purchased through pre-profiling groups of people).

Pagers are capable of implementing receiver authentication and/or identification techniques. Authentication is achieved by, for example, introducing a secret code in the desired pager. This secret coding can also be used for lending to bank card type cards.

In the case of a multi-user pager, identification of the receiver can be achieved by means of an identification code contained in the card. The last two functions concerning identification and authentication can be taken into account.

The security module is advantageously used for the multifunctionality of the pager, in particular for the acceptance of all or part of the circuit allowing the transmission of received messages, but also for the acceptance of all or part of the decryption algorithm, and/or the ability to reset the memory of the prepaid unit. Full or partial charging of the circuit.

The invention will be better understood upon reading the following description and examining the accompanying drawings. These are given only on the title of the present invention and without limitation.

- Figure 1 shows a pager according to the invention;

- Fig. 2 represents the main process according to the control pager using method of the present invention;

- Fig. 3 represents the typical structure of sending a message by the transmitter of the pager of the present invention;

- Figure 4 represents a typical message structure registered in the memory of the pager and capable of being sent by the pager;

- Figure 5 represents a radio receiver controlled by a smart card according to the invention, a model of a deck;

- Figure 6 shows the same portable receiver.

Figure 1 shows a pager that can use the control method of the present invention. The pager comprises a box 1 equipped with a receiving circuit 2 for receiving messages transmitted by a transmitter 3 . In the example shown, the transmitter 3 is a radio transmitter, but it is after all a database of connected (permitted) terminals in case a connection to the transmitter 1 is required. In one example, the receiving circuit 2 comprises a radio frequency coil 4 connected to the electronic circuit of the radio frequency interface 5 . Especially in the case of radio frequency transmission, the receiving circuit 2 ensures the reception and detection of the information as well as the amplification of the radio frequency signal received during the initial phases 6 and 7 of the method ( FIG. 2 ). In the case of radio frequency transmission, interface 3 also demodulates the signal received in phase 8. The demodulation work will naturally include a digitization stage so that all subsequent processing of the received message can be performed in binary. If the transmission is not radio frequency, stages 6 to 8 can be absent.

According to the present state of the art, the pager includes either a cable circuit or a microprocessor 9 which performs all of its operations. Microprocessor 9 communicates with program memory 10 , data memories 11 and 12 and pointer 13 via data bus 23 , addresses and commands. The indicator 13 is a liquid crystal screen in this example. When receiving, the microprocessor 9 checks whether the message received in the pager is sufficient for the pager. For this purpose, the message (FIG. 3) comprises two main components, the address 14 of the pager on the one hand and the message content 15 on the other. The microprocessor 9 retrieves information about the address of the pager in the parameter memory 11 of the pager.

In the present invention the message is kept secret and can be protected, for example, within a secure memory block. This security measure is preferably used in particular to ensure that the prepaid unit is replenished (charged) in the memory of the pager and/or the card.

During the operation 16 of checking the destination, the microprocessor 9 checks whether the address in the memory 11 is the same as the address in the message part 14, and in case of a successful operation 17, the microprocessor 9 causes the received message to Recorded in memory 12. Furthermore, the memories 10 , 11 , 12 can be combined into one component, a single component containing the respective areas. The non-volatile memories 10 and 11 are preferably non-erasable, and the non-volatile memory 12 is preferably erasable and programmable.

In a conventional manner, the use of the microprocessor 9 containing subroutines received in the memory 10 will, when stored, cause the transmission of successive or simultaneous forecast signals. The microprocessor 9 can also display a menu 19 all the time or after the forecast signal, inviting the pager carrier to specifically display its message. For this purpose, pagers according to the state of the art also contain a control panel 20 in relation to the microprocessor 9, in order to enable the bearer to control the pager and to send messages. Phases 18 and 19 can be absent and the carrier regularly checks its messages to know if they are received.

In order to solve the above-mentioned problems in the present invention, it is contemplated in one embodiment that the pager 1 is associated with a chip holder, preferably a chip card 21 . For this purpose, the pager comprises an interface 22 connected to a bus 23 for address data and control of the pager 1 . in one instance. The interface 22 includes a connector for contact with the connection contacts 24 of the chip 25 of the carrier 21 . In the case of a contactless chip card, the operative coupling of the chip carrier to the pager 1 can also be of the Hertz (radio) type. According to the invention, chip 25 will contain at least one of the following two memories: prepaid unit memory 26, parameter memory 27. Preferably it contains both memories. Preferably it will also contain a microprocessor 28. If microprocessor 9 is allowed to be associated with memories 26 and 27 for a given mode of operation, microprocessor 28 is not required. This is generally the case for standard phone chips.

In one example, the insertion of the chip carrier 21 in the interface 22 can be detected, for example, by means of moving end-of-stroke contacts 29 mounted in the press opening 22 . This detection can send a command through the bus 23 of the microprocessor 9 so that it starts a program SECUR to check whether the pager carrier is authorized to know and should be sent. Therefore, after the operation 30 of checking the existence of the support plate, the microprocessor 9, in cooperation with the microprocessor 28 if necessary, checks on the one hand whether the inserted chip card can be operated with the pager 1 and/or prepaid by the card 25 in it. The program DEBIT contained in a sufficient portion of the memory 26 which is also freely available operates in order to authorize the transmission of received and stored information. When microprocessor 28 is active, microprocessor 9 is preferred because card 25 contains a program memory (not shown) connected to microprocessor 28, just as memory 10 is connected to microprocessor 9.

The two stages of authentication of the chip card and debiting of the unit can be used irrespective of the order according to the predetermined checking mode.

So if limited to checking by a personal identification number (PIN) that allows pager carriers and chip cards to be used, this will re-schedule persistent type appointments. Rather only check the part of the carrier code (PIN), in situ, during the card authentication operation, it is possible to check that the valid date 27 stored in the memory 27 is stored in the supplementary part 34 of message signaling after the date 33 . In this case we implement limited time appointments.

The pager may be equipped with a suitable security module 50 . This module is also connected to the bus 23 . For the pager 1 in particular a pager carrier authentication protocol can be used. In this case they can be operated without a chip card, the functionality of which is fully ensured by this module of the pager.

In another case, during operation 35, the contents of the discretionary units within the memory 26 are checked and can be eliminated, which is necessary in order to allow the sending of the message. The deduction of these discretionary parts can be arbitrary, for example a part is deducted by the message; this may be linked to the length of the message part 15 (ie content). The number of these parts can also be enforced via the consumption index 350 present in the message field 34 . Through this index, the communication operator managing the transmitter 3 can equalize the cost of sending a message, here also according to the length of a message, or according to the moment of sending a message - low peak time, peak time or even by the same message The national or international characters transmitted by the transmitter 3, this is to allow for the pager bearer to be constantly in one or more regions of the world. It is also possible to link the distribution of the user, since certain messages (eg category packets) are subject to the presence of distributions contained in the card. The total amount paid may be related to this distribution.

The authentication operations used by microprocessor 9 and microprocessor 28 are of conventional type. It contains a comparison of the codes typed with the keyboard 20 by the bearer of the pager and chip card with the codes (secret or not) recorded in the memory 27 . Furthermore, in order to prevent the coded PIN stored in the support plate 21 from being exposed for a long time, these checking operations can be performed in a known manner deciphered into cryptographic operations.

The operation of the unit partial deduction is also traditional. For example memory 26 is a memory comprising some memory cells of the non-volatile, only programmable type, since their transition from a pure state or an erasable state to a programmable state is equivalent to a consumption of the cells. Units can also be constructed by the presence of sequentially failing fuses. Perhaps the memory 26 is of the erasable and programmable type. In this case, a strut 21 is added as before for replenishment next to the operator's aid for managing the transmitter 3 , without payment of course. The date recorded in the memory 27 is also programmable, taking into account the reserved format, so that at least this part of the memory is erasable and programmable. Preferably the memory is comprised in the case of EEPROM type memory cells.

The pager's memory 12 contains a number of message records received and stored in 17 stages. Each record within this memory 12 contains a series of instructions 36, perhaps including a brief description 37, allowing the pager carrier to understand the contents of the record. Each record also contains an area 38 for the exact narrated message and an area 39 for use in the event that units must be deducted for sending a message. Area 39 itself contains two sub-areas, a first sub-area 40, which is optionally debited, indicates the number of units which must be paid in order to be able to see the message, and an area 41, which indicates the amount paid for sending the message number of units. Field 41 contains only a single bit (indicated according to its status), whereas card 21 has either been debited in its field 26 or not.

At the moment of operation of debiting, in the case of consumption not singular but a function of message content or index 350, the units in memory 26 are extracted in order to debit them in zone 41 up to the value indicated in zone 40 total. Therefore, in the case that the original content is not enough, we can easily supplement the extracted unit in the card 21 by the unit extracted with the card as described below. The debited DEBIT recorded in the program memory 10 of the pager 1 operates by reading the contents of area 40 (if there is only one of them), and reading the contents of area 41, and extracting both on behalf of the location in memory 26. content differences. In this way, the only instruction type DEBIT can be unambiguously represented.

At the moment of the debiting operation of the execution unit, the memory 12 has to be read out again immediately during the operation 42 . This operation 41 carried out by the microprocessor 9 is of course only activated within the scope of the complete success of the processable operations 30, 31 and 35 (that is: according to a predetermined mode of operation, all operations or only a single operation is completely successful). ). The content of the message recorded in field 38 at the moment of interpretation may be a cryptographic message. In this case, we can use the microprocessor 9 and possibly also the microprocessor 28 to cause the decoding 43 of the message by means of the message identifier in the area 44 of the memory 27 . At the end of the computation, at step 45, a message is transmitted. The simplest transmission consists in displaying the message on the screen 13 . However, stored messages can be transmitted orally if the pager 1 includes a tweeter and circuitry to convert written messages to spoken messages.

Through the selection of the menu 19, any pre-recorded message will be able to be selected in the present invention, and this message can be transmitted many times, the number of times is equal to the number of times that is conditionally desired, perhaps if authentication is required, then the chip card 21 for authentication is inserted In the pager 1, an indication or a display of the unit deduction may be written in the area 41, or both conditions may be combined at the same time. Preferably, the decoding of the messages is always performed last, so that only the encoded information in the area 38 is stored. In this case, the presence of the card will be necessary in order to extract the key 44 therefrom.

When the pager can be a pager corresponding to several receivers, it can then be used as a supplementary part (complement code) of the information address stored in the memory 27 of the chip card, (for example its serial number 46 or even address 47). In this case, the pager address contained within the message field 14 is longer than the effective address (which can identify various pagers). It contains the complement of address 48.

In this case, pager 1 receives messages destined for several receivers. The address complement 48 is then compared with the serial number 46 or address 47 of the card 21 and the microprocessor 9 only authorizes the transmission of a message to the user if these serial numbers correspond to the address complement 48.

Authorization according to the invention is granted only upon excellent completion of one or more of the tests described below. - Presence of card - Authenticated card - Confirmation of carrier - Validity of date - Sufficient number of prepaid units - Address complement. The identification according to the invention is also only made after the relevant combination of these tests has been performed satisfactorily. Combinations of all these tests are possible.

In a pager-chip card relationship, it is possible for the microprocessor of the card to replace the microprocessor of the pager. As long as the microprocessor of the card is not used then the microprocessor of the pager (eg removed or at least) cannot function. In contrast, in the case of a pager without a card, the pager circuitry will contain some of the circuitry depicted for the card as required.

Authorization may affect the operation of the pager at all stages from message launch to delivery.

Thus, for example, reception or storage or decryption may be prohibited (via functions specified for this purpose) without authorization.

In another situation, the pager may actually be incapacitated: for example, when the pager's microprocessor is only the contents of the card, the pager will only work if the card is inserted into the pager and/or it has sufficient balance .

According to an advantageous solution, the pager can receive the message but the user is notified of receipt only when the card is inserted and has sufficient credit. This avoids the minimal use of pagers that only receive notification signals. Notifications will take various forms such as sounding; lighting etc.

Cards can be plugged in frequently, and for this purpose cards can be of a more discreet size, such as a "plug-in" type.

In the event that the subscription is not renewed by the user, the transmitter may transmit an instruction to disable the operation of the pager in question. This can be performed in different ways as described below.

The message slot 34 within the index 350 can contain a data, preferably encrypted, which means that the user is not authorized. Introducing a consumption index 350, exceeding the total balance value present, is sufficient to prohibit the sending of the message if the message is dependent on credit.

According to another embodiment, the message can contain a slot reserved for authorization data (an authorization data is transmitted for each message by the transmitter system used by the control service). In this case authorization can be checked by systematically comparing the received data with secret and protected data stored in a security module of the pager, for example a suitable security module (SAM).

According to another approach, calls to the user's receiver that are not on the day of the appointment are redirected or blocked by the transmitter (operator). This means that the check is performed before the message is sent by the transmitter.

To this end, the control/verification method can include a comparison phase, comparing all addresses of the pager contained in the waiting message transmitted by the operator with the address list corresponding to the non-compliant user (non-same-day appointment), and if the addresses match then prevent launch. To this end, storage means for this list should be provided, corresponding to information comparison means at transmitter level, such as a microdata processor, and means for selecting messages by address 14 combined with it.

To better deter fraud, the card preferably has a certain lifespan, and the card is either rechargeable or non-rechargeable. At the end of the lifetime, the new card can re-use the new security algorithm.

In order to use the lifetime functionality, the card can contain a limited date stored in memory and a subroutine provided for this. According to this subroutine, we can compare the effective date to the message launch date contained in each message. If there is a match, the pager refuses to operate, eg refuses to send a signal and/or message.

Claims (21)

1. The method that control pager (1) uses, it comprises the following several steps: - the pager receives (2) the message sent by the transmitter, - Check (16) whether the received message is intended for a pager, if yes, it is stored (17) in the pager. - subsequently send (45) to the pager carrier, characterized in that before sending them, - Check (30,31,35) whether the bearer of the pager is authorized to know about this transmission. 2. A method according to claim 1, characterized in that in order to check whether the carrier is authorized to know about the emission, it is carried out, - Check the identification number (PIN) of the aircraft holder. 3. A method according to any one of claims 1 to 2, characterized in that in order to check whether the carrier is authorized to know about the emission, a - check that the pager contains a discretionary prepaid portion in the memory (26) and - To obtain permission to send a message, one or several parts in the memory are deducted. 4. The method according to claim 3, characterized in that: - Deduct the relevant part according to the transmitted message (15,33,35). 5. The method according to any one of claims 3 to 4, characterized in that: - Deduct the relevant part according to the consumption index (350) contained in the message. 6. The method according to any one of claims 1 to 5, characterized in that: - make the portable stand fit the pager (22,24), - Check with Portable (30,31,35) if the carrier is allowed to know about the send. 7. The method according to claim 6, characterized in that: the pager is qualified to receive messages for at least one user, - Checking whether the received message is intended for at least one portable strut bearer by comparing the strut address information (46,47) with the complement of the message address. 8. A method according to any one of claims 1 to 7, characterized in that the message is encrypted, - The message is decrypted (43) before transmission. 9. The method according to any one of claims 1 to 8, characterized in that: - Indexing (41) the approved messages in memory so that they can be retransmitted. 10. The method according to any one of claims 1 to 9, characterized in that: - send a forecast message before sending the message, 11. The method according to any one of claims 1 to 10, characterized in that: - Receive (2) radio messages - demodulation (8) (ie detection) of received radio messages within the pager, 12. A pager (1), which includes a message receiving circuit (2) and a circuit (9, 10-13) for retransmitting received messages, is characterized by: - It contains a circuit (9, 28) for the authorization of the transmission of received messages. 13. A pager as claimed in claim 12, characterized in that the circuit for obtaining authorization comprises a circuit (26) for debiting the prepaid portion contained in the memory (26). 14. 13. A pager as claimed in claim 12 or 13, characterized in that the circuit for authorization comprises a circuit (27) for identifying the bearer of the pager. 15. 14. A pager as claimed in any one of claims 12 to 14, characterized in that it comprises a security module (50) containing all or part of the circuitry for obtaining authorization to transmit received information. 16. A pager according to claim 15, characterized in that the security module contains all or part of the decryption algorithm. 17. 16. A pager as claimed in any one of claims 15 to 16, characterized in that the security module contains all or part of a circuit capable of implementing prepaid unit memory replenishment. 18. 17. A pager as claimed in one of claims 12 to 17, characterized in that it comprises chip card reading means. 19. 18. A pager as claimed in any one of claims 12 to 18, characterized in that it comprises means capable of identifying and/or authenticating a plurality of users. 20. Chip card, radio receiver for displaying messages in text on an LCD screen, characterized in that the receiver is equipped with elements for receiving a card that will control a credit that will allow the receiver to reproduce the message only if the balance is sufficient It only works when the card is used, that is, the function of the card is to access the on-screen message, which means that the message is subject to the card insertion. twenty one. Chip card according to claim 20, a radio receiver for displaying messages in text on a liquid crystal screen, characterized in that it implements a decoding function capable of reproducing each message, i.e. by translating the signal into a known The encoding of the text of the language that decodes the message.

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