WO1999017564A1

WO1999017564A1 - Method and apparatus for providing subscriber identification protection to a receiver

Info

Publication number: WO1999017564A1
Application number: PCT/US1998/019258
Authority: WO
Inventors: Robert Nathan Nelms
Original assignee: Motorola Inc.
Priority date: 1997-09-29
Filing date: 1998-09-17
Publication date: 1999-04-08
Also published as: AU9486998A

Abstract

A communication receiver such as a pager (50) includes a SIM card reader for receiving a SIM card (72). The SIM card (72) needs to be installed in pager (50) in order for received messages to be presented to the user. If the SIM card (72) is removed from the pager (50), incoming messages are received and stored, but not allowed to be presented to the user either via the display (68) or in some cases, via the audible alert circuit (58). The use of the SIM card (72) prevents the unauthorized cloning of pagers and also allows for one particular user to own several different types of pagers without the paging service provider having to worry about illegal use of the pagers.

Description

METHOD AND APPARATUS FOR PROVIDING SUBSCRIBER IDENTIFICATION PROTECTION TO A RECEIVER

Field of the Invention

This invention relates in general to communication devices, and more specifically to a method and apparatus for providing subscriber identification protection to a communication receiver.

Background of the Invention

Paging system operators lose revenues due to the illegal cloning of pagers onto their paging systems. Such cloning (sometimes referred to in the industry as pager "party lines") allows for a plurality of individuals to use the same pager address and pay for just a single paging system subscription fee. Typically, after a pager's information (e.g., capped address, etc.) is cloned onto several other pagers, the users of such pagers use special codes (e.g., append a particular prefix code to a message) to identify for which cloned pager the message is actually intended.

Another major problem experienced by the paging industry, is that there is currently no simple way to allow for one individual paging subscriber to buy different types of pagers (e.g., voice, alphanumeric, etc.) for use on different occasions, all of which use the same pager address, and hence get billed to the same subscriber account. A pager which would allow for such flexibility, while protecting the paging service provider against pager "party lines", would allow a paging subscriber to own different types of pagers for different applications at a reduced service cost. For example, during working hours, a paging subscriber could use a full featured alphanumeric pager, while during recreational periods, the subscriber could use a smaller numeric pager. Such pager flexibility would give the paging industry the opportunity to target sales of different types of pagers to existing pager users. A need exists in the art for a method and apparatus which can provide solutions to the above mentioned problems. Brief Description of the Drawings

FIG. 1 is a block diagram of a communication receiver in accordance with the preferred embodiment of the present invention. FIG. 2 shows a more detailed block diagram of the decoder/ controller in accordance with the preferred embodiment.

FIG. 3 shows a flowchart highlighting the operation of a receiver in accordance with the preferred embodiment.

Description of the Preferred Embodiment

Referring now to the drawings and in particular to FIG. 1, an electrical block diagram of a communication receiver such as a selective call receiver (e.g., a pager, etc.) in accordance with the preferred embodiment of the present invention is shown. The selective call receiver 50 comprises an antenna 52 for intercepting transmitted radio frequency (R.F.) signals which are coupled to the input of a receiver section 54. The R.F. signals are preferably selective call (paging) message signals which provide a receiver address and an associated message, such as numeric or alphanumeric message. However, it will be appreciated that other well known paging signaling formats, such as tone only signaling or tone and voice signaling, would be suitable for use as well. The receiver 54 processes the R.F. signal and produces at the output a data stream representative of a demodulated address and message information. The demodulated address and message information are coupled into the input of a decoder /controller 56 which processes the information in a manner well known in the art. A power switch 70, coupled to the decoder /controller 56, is used to control the supply of power to the receiver 54, thereby providing a battery saving function as is well known in the art for use with selective call receivers.

For purposes of this illustration, it will be assumed that the POCSAG signaling format is utilized which is well known in the art, although other signaling formats could be utilized as well (e.g., FLEX™ a trademark of Motorola, Inc., other newer paging protocols which utilize sub-address(es) and/or topics, etc.). When the address is received by the decoder/controller 56, the received address information is compared with one or more addresses stored in a code plug (or code memory) 64, and when a match is detected the message is stored in memory. Optionally, an alert signal is generated to alert a user that a selective call message, or page, has been received. The alert signal is directed to an audible alerting device 58 for generating an audible alert or to a tactile alerting device 60 for generating a silent vibrating alert. Switches 62 allow the user of the selective call receiver to select between the audible alert 58 and the tactile alert 60 in a manner well known in the art.

The message information which is subsequently received is stored in memory (not shown) and can be accessed by the user for display using one or more of the switches 62 which provide such additional functions as reset, read, delete, etc. Specifically, by the use of appropriate functions provided by the switches 62, the stored message is recovered from memory and processed by the decoder /controller 56 for displaying by a display 68 which enables the user to view the message. A real time clock circuit 74 provides conventional timing features such as the information required to display time of day information on display 68.

In accordance with the present invention, pager 50 includes a subscriber identification module (SIM) card reader which accepts a SIM card 72 or other well known information bearing memory card. Discussion of a SIM card reader can be found in U.S. Pat. No. 5,257,414, entitled "Apparatus For Accepting And Retaining A Memory Card", which is assigned to the present assignee and which is hereby incorporated by reference. The SIM card 72 is inserted into the card reader for providing subscriber identification and other information regarding the operation of pager 50 (e.g., message decryption algorithms, pager personality information, etc.). In accordance with the present invention, SIM card 72 will contain address and/or sub-address(es) and other user information (e.g., identification number, secure keys, etc.) which is /are required to be read and matched by controller 56 in order to allow the pager 50 to present received messages to the user.

Furthermore, SIM card 72 will contain any encryption /decryption protocols (e.g., Exclusive-OR scrambling, or other well known encryption/ decryption protocol) needed to decrypted any incoming message addressed to the pager which is encrypted. The controller/decoder 56 of FIG. 1 can be constructed utilizing a microcomputer as shown in FIG. 2, although other hardware arrangements as known in the art can also be used. FIG. 2 is an electrical block diagram of a microcomputer based decoder /controller suitable for use in the selective call receiver of FIG. 1. As shown, the microcomputer 56 can preferably comprise a MC68HC05 (or MC68HC11) microcomputer manufactured by Motorola, Inc. which preferably includes an on-board display driver 114. The microcomputer 56 includes an oscillator 100 which generates the timing signals utilized in the operation of the microcomputer 56. A crystal, or crystal oscillator (not shown) is coupled to the inputs of the oscillator 100 to provide a reference signal for establishing the microcomputer timing. A timer/counter 102 couples to the oscillator 100 and provides programmable timing functions which are utilized in controlling the operation of the receiver. A RAM (random access memory) 104 is utilized to store variables derived during processing, as well as to provide storage of message information which are received during operation as a selective call receiver as previously discussed. A ROM (read only memory) 106 stores the subroutines which control the operation of the receiver as well as the routines required to perform the present invention.

It will be appreciated that in many microcomputer implementations, the programmable-ROM (PROM) memory area can be provided by, or further include, an EEPROM (electrically erasable programmable read only memory). The oscillator 100, timer/counter 102, RAM 104, and ROM 106 couple through an address /data /control bus 108 to a central processing unit (CPU) 110 which performs the instructions and controls the operations of the microcomputer 56. The demodulated data generated by the receiver is coupled into the microcomputer 56 through an input/output (I/O) port 112A. The demodulated data is processed by the CPU 110, and when the received address information is the same as the code-plug memory which couples into the microcomputer through an I/O port 112B, the message, if any, is received and stored in RAM 104. Recovery of the stored message, and selection of the predetermined destination address, is provided by the switches which are coupled to the I/O port 112A. In accordance with the invention, if the pager user wants to read a message which has been received be it a numeric alphanumeric, voice or other type of message, the microcomputer first verifies the information stored in SIM card 72 via I/O port 112B. Once the information located in SIM card 72 has been verified as matching information stored in pager 50 (e.g., address information match or a special ID stored in both the SIM card and pager match, etc.), the microcomputer recovers the stored message from memory, and directs the information over the data bus 108 to the display driver 114 which processes the information and formats the information for presentation by a display such as an LCD (liquid crystal display). In one embodiment of the invention, at the time a message is received, an alert signal is generated which can be routed through the data bus 108 to an alert tone generator 116 that generates the alert signal which is coupled to the audible alert device 58 that was described above. Alternatively, when the vibrator alert is selected as described above, the microcomputer generates an alert enable signal which is coupled through data bus 108 to the I/O port 112B to enable generation of a vibratory, or silent alert. In a second embodiment, if a proper SIM card 72 is not connected to the pager 50 or the information in the SIM card 72 is not correct, no audible alert tone or vibratory alert is provided to the user. The choice of whether to allow or not allow an audible alert tone upon the receipt of a message if the SIM card 72 is not attached to the pager 50 can be software programmable and set, during manufacturing, by the paging service provider, or by the user himself, depending on the design of the pager 50. The audible alert tone feature must not be confused with a voice page. In the case of a voice page being received and stored, the voice page, it being the message itself, is not enunciated to the pager user until a proper SIM card 72 is coupled to the pager 50.

The battery saver operation of pager 50 is control by the CPU 110 with battery saving signals which are directed over the data bus 108 to the I/O port 112A which couples to the power switch. Power is periodically supplied to the receiver to enable decoding of the received selective call receiver address signals and any message information which is directed to the receiver. Specifically according to the invention, FIG. 1 shows the SIM card 72 coupled to the decoder /controller 56 for establishing user identification, etc. The SIM card 72 is similar to a hardware key for a particular software program in which you may have many copies of a program, but you can only run the program if the hardware key is attached to the computer on which you wish to run the program.

In the case of a user who owns several pagers, the SIM card 72 will be programmed to allow the presentation of messages on all the pagers owned by the user. In this particular case, the SIM card may contain different keys, which may or not be encrypted, which will allow for the validation of the SIM card to each of the particular pagers. Also, the SIM card may contain certain pager personality information or pager feature activation codes or routines, which may be used by each of the pagers owned by the subscriber. These codes and/or may activate or provide different features to each of the pagers owned by the subscriber.

As well be explained in more detail below, in accordance with the preferred embodiment, if the proper SIM card 72 is not connected to pager 50, new messages received by the pager will be stored in memory, but will not allowed to be presented to the user. Without the proper SIM card 72 installed, the pager 50 will be placed in a freeze mode in which no information is presented to the user via the pager's message presentation devices (e.g., display 68, speaker 58, etc.). Messages received however will be stored for future retrieval by the user once the proper SIM card 72 is installed. This will prevent the cloning of pagers previously mentioned, since received messages can only be read by the user, if a SIM card is installed in the pager 50 and verified by the pager to be the proper SIM card 72. Preferably, pagers with features such as appointment book, phone lists, etc. will allow the user to use the feature(s), but any new information which may have been received by the pager will not be shown to the user via the feature until the SIM card 72 is inserted into the pager.

In FIG. 3, the steps taken once a message has been received by pager 50 in accordance with the preferred embodiment are shown. Once a message is received at step 302, in step 304 it is determined if the address (or sub-address) found on the message matches the address(es) stored in code plug 64. If the address found in the incoming message does not match the pager's address(es), the message is discarded in step 306. If the address of the incoming message does match the stored address, the routine moves to step 308. In step 308, it is determined if the received message is encrypted using one of a number of conventional encryption techniques. For example, using well known Exclusive-OR scrambling, or other encryption algorithms known in the art. If the received message is not encrypted, the message is stored in RAM 104 but not allowed to be displayed, or announced to the user in the case of voice pagers.

In step 316, it is determined if a proper SIM card 72 has been installed. The interrogation of SIM card 72 is performed by controller 56 comparing information stored in the SIM card 72 with information stored in the pager's EEPROM or Flash Ram (not shown), etc. using techniques which are known in the art. Information stored in SIM card 72 and pager 50 which can be used to verify that a proper SIM card has been inserted, can include, but is not limited to, address information, identification number information, etc. If it is determined that the proper SIM card 72 has been installed in step 316, the received messages are allowed to be displayed either automatically or upon the user activating one of the pager's switches 62 (e.g., read message switch). In this situation, an alert can be given to the user which would let him know that message(s) have been received during the time the SIM card 72 was not installed in the pager 50. In an alternate embodiment, if an improper SIM card is inserted into pager 50, all messages which have been previously received are purged from memory upon the insertion of an improper SIM card. Controller 56 determines that an improper SIM card has been attached by comparing the information stored in the pager with the identification information stored in the SIM card. If the information that is to be compared does not match, then the SIM card is determined to be an improper card. This embodiment can be useful for users who receive sensitive business information messages, etc. Since SIM card 72 includes memory space, important messages received by pager 50 can be retrieved from the pager's RAM 104 and stored in the SIM card 72. The pager 50 can be programmed to automatically transfer messages to SIM card 72 when the SIM card is installed in pager 50. These messages which are stored in pager 50 can then be retrieved and displayed at a later time, on the same pager which received the message, or another pager owned by the subscriber which is capable of presenting the stored message. Messages stored in SIM card 72 can be purged by the user activating a conventional message erase routine stored in the pager. If in step 308, it is determined that the received message was in fact encrypted, the message is saved as undecrypted (encrypted) data in step 310. In step 314, it is determined if the proper SIM card 72 has been installed in pager 50. If the proper SIM card 72 has been installed, the pager automatically, or upon the user wanting to read the message by activating a switch 62 (e.g., the "read" message switch), decrypts the message and stores the decrypted message in RAM 104 using the encryption /decryption algorithm stored in SIM card 72. In step 320, the decrypted message is then displayed or otherwise presented to the user once the user activates the proper user controls 62 found in the pager 50. Alternatively, the pager 50 can automatically show the received message or one of the received messages in case several messages have been received upon the proper SIM card 72 being installed in pager 50.

By allowing messages to be received, but not presented to the user until a proper SIM card 72 has been installed in the pager's SIM card reader, helps prevents the illegal cloning of pagers, since only the pager which has the proper SIM card 72 installed will allow messages to be presented to the user (e.g., either via the display or in the case of voice messages via the pager's speaker). The use of a SIM card 72 in pager 50 also allows one paging subscriber to own several different types of pagers and still only require him to pay a single paging subscription. The paging service provider can issue one specially programmed SIM card 72 to each pager subscriber. The SIM card 72 protects the paging service provider since only one of a users many pagers can be in use at any given point in time. While at the same time, the paging subscriber who owns several pagers is guaranteed of not missing his messages or information services since messages addressed to his different pagers are all received. If the pager 50 receives encrypted messages, placing the encryption /decryption algorithms on the SIM card 72, would help avoid some of the export issues presently in effect regarding the shipment of encryption products. Using the present invention, pagers could be shipped without any encryption/ decryption algorithms and each individual country pagers are shipped to could use their own encryption /decryption algorithms which they would program into the SIM cards they provide users.

While the preferred embodiments of the invention have been illustrated and described, it will be clear that changes, variations, substitutions and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims.

What is claimed is:

Claims

1. A method for providing subscriber identification protection to a communication receiver, comprising the steps of: receiving a message at the communication receiver; storing the message; and allowing the presentation of the message only if a proper subscriber identification module (SIM) card is coupled to the communication receiver.

2. A method as defined in claim 1, comprising the further step of: determining if the received message is directed for the communication device before storing the message.

3. A method as defined in claim 2, wherein the received message is not stored if the message is determined not to be directed for the communication device.

4. A method as defined in claim 1, wherein the received message is encrypted and the communication receiver stores the received message without the message being decrypted if the proper SIM card is not coupled to the communication device.

5. A method as defined in claim 4, wherein the received message which is encrypted is decrypted if the proper SIM card is coupled to the communication receiver.

6. A method as defined in claim 5, wherein the proper SIM card contains the algorithm used to decrypt the received message which is encrypted.

7. A method as defined in claim 1, wherein the stored message is erased if an improper SIM card is coupled to the communication receiver.

8. A method as defined in claim 1, wherein the message is stored in the proper SIM card if it is coupled to the communication receiver.

9. A method for determining whether or not to present messages which have been received by a pager, comprising the steps of: receiving a message at the pager; determining if the message is addressed for the pager; storing said message if it is determined to be addressed for the pager; determining if a proper subscriber identification module (SIM) card is coupled to the pager; and presenting said message only if it is determined that the proper SIM card is coupled to the pager.

10. A method as defined in claim 9, wherein the step of presenting said message comprises displaying at least a portion of the message.

11. A method as defined in claim 9, wherein the step of presenting said message comprises presenting said message via audio.

12. A method as defined in claim 9, wherein the stored message is deleted if it is determined that an improper SIM card is coupled to the pager.

13. A method as defined in claim 9, wherein if the message received by and addressed to the pager is encrypted, it is stored in an encrypted fashion if the proper SIM card is not coupled to the pager.

14. A method as defined in claim 13, wherein the encrypted message which is stored is decrypted and stored as a decrypted message after the proper SIM card is coupled to the pager.

15. A selective call receiver, comprising: a receiver section for receiving a message addressed for the selective call receiver; a memory for storing said message; a message presentation device; a subscriber identification module (SIM card) reader for receiving a SIM card; and a controller coupled to the memory and the message presentation device, the controller storing the message addressed for the selective call receiver in memory and preventing the presentation of the stored message by the message presentation device if a proper SIM card is not coupled to the SIM card reader.

16. A selective call receiver as defined in claim 15, wherein the message presentation device comprises a display.

17. A selective call receiver as defined in claim 15, wherein the message presentation device comprises a speaker.

18. A selective call receiver as defined in claim 15, wherein the received message is encrypted and the controller does not decrypt the encrypted message until a proper SIM card is installed in the SIM card reader.

19. A selective call receiver as defined in claim 15, wherein the controller upon a SIM card being inserted into the SIM card reader determines if the

SIM card is a proper SIM card by comparing information stored in the SIM card with information stored in the selective call receiver.

20. A selective call receiver as defined in claim 15, wherein the controller deletes the stored message if it determines that an improper SIM card has been installed in the SIM card reader.

21. A selective call receiver as defined in claim 15, wherein the selective call receiver comprises a pager.