EMBODYING SAME

FIELD OF THE INVENTION

This invention relates to a telephone that is particularly suitable for use as a payphone and, more particularly, a payphone that is, at least when operated in a payphone mode, enabled for use according to value stored in an electronic operating purse. Still more particularly, but not exclusively, the invention relates to a wireless telephone of this type of which a cellular telephone is a typical example. The invention also relates to telephone systems including one or more of such telephones.

In this specification the term "purse", or in its more expanded form "electronic purse", is intended to mean any electronically operated memory means configured to store data representing a predetermined amount of money or, in the alternative, other value such as call-time, volume of data or call units, or any combination thereof and wherein the credit balance of the purse can be reduced progressively as services of an associated telephone are utilized.

The term "payphone" is intended to mean any telephone or communications terminal that typically operates on a prepaid basis irrespective of the manner of payment, and including, in particular, electronic payment effected by reducing the balance of credit value stored in an electronic purse.

The term "prepaid" means advance payment made in exchange for authorisation for a predetermined extent of usage of a payphone. Typically the advance payment assumes the form of an upfront payment of money, either in cash or cash value, but also includes the situation where a predetermined value of credit is given in advance.

The term "credit value" is intended to have a broad meaning in that it may represent a value in money; a value in units of any appropriate description; or a value represented by a quantity of data that can be transmitted and/or received.

The term "usage session" is intended to include any use of a payphone by or on behalf of a particular client whether it be constituted by a single call or multiple calls for the purpose of transmitting voice messages such as in a conversation; or transmitting data or any combination thereof.

BACKGROUND TO THE INVENTION

There is an appreciable demand for payphone services in many communities, typically rural and informal communities, in which the provision of a conventional payphone and its associated infrastructure is inappropriate and often not cost-effective.

There are numerous different ways in which equivalents of payphone services are provided. In its simplest form, an ordinary prepaid cellular telephone can be employed with a stopwatch or similar mechanism to time the duration of a call. The owner of the telephone will purchase prepaid airtime in the usual way, for example, by purchasing appropriate tokens, and will charge "clients" according to the duration and destination of each call.

Whilst this arrangement operates effectively, at least theoretically, in practice there are disadvantages to it. Most importantly, the relevant purse, may simply be a credit value recorded in the intelligent network platform or in the service provider's accounts, and is thus associated with the particular telephone and, where present, a particular SIM (subscriber identity module) card.

Alternatively, or in addition, the credit value is recorded in an electronic purse within the telephone itself. In this instance, in the event of a "client" fraudulently removing a fully operable telephone, the air time value may also be lost or, at best, can only be recovered with considerable difficulty. In the event that a "client" consumes more credit value than his or her prepayment or finances allow, losses will often be incurred by the telephone operator.

There are numerous sophisticated and relatively costly telephones and systems available in the market, including some that are available which may address these issues. However, as indicated above, the cost of such telephones and systems is inappropriate to the environment to which reference is being made.

OBJECT OF THE INVENTION

It is an object of this invention to provide a telephone and system embodying same in which the difficulties indicated above may be overcome, at least to some extent.

SUMMARY OF THE INVENTION

In accordance with one aspect of this invention there is provided a telephone having an electronic operating circuit the operation of which is enabled according to credit value stored in an operating purse and disabled in the event of inadequate credit value being present in the operating purse, the telephone being characterised in that the operating purse is an internal operating purse located within the telephone itself and transfer means are provided to transfer a predetermined amount of credit value for a particular usage session to the operating purse of the telephone from a separate bulk storage purse and wherein the transfer means includes an internal coupling circuit within the telephone that is adapted for co-operation with a cooperating coupling circuit associated with the separate bulk storage purse

intermittently such that at times when the two coupling circuits are in cooperating relationship, predetermined credit value can be transferred from the separate bulk storage purse to the internal operating purse on a usage session by usage session basis with residual credit value in the operating purse being capable of being returned to the separate bulk storage purse at the end of a usage session either automatically or at the option of a telephone operator..

It is an important further feature of the invention that the transfer means are also enabled to return residual credit value not utilised during any particular usage session from the operating purse to the separate bulk storage purse.

Further features of the invention provide for the separate bulk storage purse to be embodied in a portable purse module, typically having the security aspects of a smartcard, but preferably having the physical appearance of an access tag or key case; and for the two coupling circuits to be selected from circuits having co-operating physical electric contacts (a plug-in configuration) in which instance the power supply of the telephone can energise the entire composite circuit, a proximity (so-called contact-less) type of coupling arrangement in which case the separate bulk storage purse may have its own internal power supply but alternatively may require no power supply within it and can rely on power transmitted to it from the telephone, or a short range radio frequency coupling or any other suitable means of coupling such as optical, auditory, ultrasonic or other appropriate short range coupling between the two coupling circuits in which case the separate bulk storage purse generally has its own power supply.

Still further features of the invention provide for the telephone to be a wireless telephone, typically a cellular or cordless telephone, and typically having a physical or virtual subscriber identity module (SIM), electronic serial number or similar means of providing subscriber and/or equipment identification and authentication in a wireless network; for the wireless

telephone to have means for acquiring, by wireless communication or by means of a user interface, encrypted data representing bulk credit value (that is inaccessible to the telephone and its operating purse directly) for onward transfer by means of said coupling circuit or by keypad entry to the separate bulk storage purse, in which case such encrypted data is preferably stored, as may be necessary, in a transfer purse provided in the telephone and from where it is transferable to the separate bulk storage purse upon coupling therewith; and for means to be provided for enabling any part of the credit value in the separate bulk storage purse to be transferred by wireless communication to another similar telephone and its associated bulk storage purse that forms part of a limited group of such telephones.

A still further feature of the first variation of the invention provides, in the case that short range electromagnetic coupling is employed between the telephone and the separate bulk storage purse, for the telephone to have a disabling circuit embodied therein, whereby the telephone is disabled at all times that it moves beyond a predetermined physical distance from the separate bulk storage purse.

The invention also provides a payphone system in which one or more telephones as defined above are associated with a computerised credit facility for providing bulk credit value to said separate bulk storage purse, from time to time, and wherein the computerised credit facility includes an encryption facility that utilises a secret key shared with the separate bulk storage purse so as to effectively require a particular separate bulk storage purse to obtain bulk credit value exclusively from one or other computerised credit facility with which the secret encryption keys are shared.

Further features of the payphone system provide for the telephone to include a transfer purse into which encrypted data may be transferred wirelessly from the computerised credit facility or by other suitable means such as keypad entry of a token representing encrypted bulk credit value and wherein the

secret key utilised for encrypting and decrypting the credit value containing data is unknown to the telephone thereby rendering the credit value containing data unusable directly on the telephone without prior decryption by the separate bulk storage purse.

Clearly, this secret encryption key will be different from that shared between the telephone and the separate bulk storage purse, where such a secret encryption key is employed.

The above and other features of the invention will become more apparent from the following description of one embodiment thereof with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:-

Figure 1 illustrates a telephone and separate portable purse module that include the necessary circuitry for implementing one embodiment of the invention;

Figure 2 is a schematic block diagram of one embodiment of wireless telephone according to the present invention;

Figure 3 is a schematic block diagram of one embodiment of portable purse module and separate bulk storage purse for use in conjunction with the telephone illustrated diagrammatically in Figure 1 ; and,

Figure 4 is a schematic illustration of a system embodying a plurality of telephones and separate bulk storage purses of the type illustrated in Figures 1.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

Referring firstly to Figures 1 and 2 of the drawings, a substantially conventional wireless telephone (1), typically a digital cellular telephone or a personal communications device, has a wireless transceiver (2) and associated antenna (3); and means for authentication of the subscriber or equipment (4) to provide a user access to the services of a wireless telephone network(s).

The telephone (1) further typically has a speaker (5); a microphone (6); a ringer (7); a battery (8); a keypad (9); a display (10) as user interface; a microprocessor (11) for securely executing software (the handset application) and encrypting and decrypting value containing data; and a secure memory (12). The microprocessor and secure memory may either be discrete but are preferably embedded in a secure baseband processor of the transceiver module (2).

The secure memory includes an operating purse (13) that is adapted to retain data representing credit value that is to be available for a particular usage session, the data being encrypted using an operating key (14) and a secret key (15) shared between the telephone (1) and a separate portable purse module (16) (see Figures 1 and 3) housing the separate bulk storage purse. The secure memory also includes a transfer purse (17) adapted to retain encrypted data that embodies bulk credit value for ultimate transfer and credit to the separate bulk storage purse and that will be further described below.

The telephone (1) also has an internal coupling circuit (18). The coupling circuit may assume any one or more of many different forms such as a contact-less smartcard reader/writer, an external connector socket, wireless interfacing means such as IrDA, Bluetooth, ZigBee or other short range optical, auditory or electromagnetic interfacing means, and in a more

sophisticated version of the electronic storage unit, a docking connector (19) as a means for coupling with the separate bulk storage purse. In the further description below, however, the coupling circuit will be assumed to be a contact-less smartcard reader/writer.

The separate portable purse module (16) (detailed schematically in Figure 3) has a cooperating internal coupling circuit (20) for intermittent coupling with the telephone (1). Coupling is, in this instance as indicated above, achieved between a separate bulk storage purse (21) embodied in a smartcard and a cooperating contact-less smartcard reader/writer in the telephone (1). In this instance, the separate bulk storage purse need have no power supply or battery within it and can rely on power transmitted to it from the telephone by way of the coupling means and circuitry (22) in the separate bulk storage purse adapted to develop energy inductively and store it capacitively.

Alternatively, the internal coupling circuits (18) and (20) of the telephone and separate bulk storage purse may be co-operating wireless interfacing means in which instance additional power supply means, typically a battery, would generally power the circuitry of the separate bulk storage purse.

As a further alternative, coupling may be achieved by means of co-operating physical electric contacts (a plug-in configuration) in which instance the composite circuit is simply energised by the power supply of the telephone.

In this embodiment of the invention the separate portable purse module (16) also has electronic circuitry providing a secure memory that serves as the separate bulk storage purse (21) and a microprocessor (23) for encrypting and decrypting value containing data using an encryption key (24) and a shared secret key (25) shared with the telephone. A more sophisticated portable purse module may also have a display (26) and/or a keypad (27), although this is not essential as the display and keypad of the telephone can generally be used for all necessary purposes at times when coupling is in

effect. In the event that a docking station is provided on the telephone, a cooperating docking station (19a) is provided on the portable purse module.

As indicated above, the separate bulk storage purse and associated circuits are, in this embodiment of the invention, embodied in the portable purse module that assumes a suitable physical form such as that of a tag that may be attached to a key-ring (29) or other convenient item of paraphernalia that is easily portable and can be held in a secure manner by a telephone operator.

It will be understood that, in use, the separate bulk storage purse (21) is utilised to store the bulk of available credit value and that selected portions of that bulk credit value are transferred to the operating purse (13) in the telephone from time to time, and preferably preparatory to each usage session on the telephone.

As a general rule the telephone, when not in use, will be in a locked condition and therefore unusable without the entry of predetermined identification data. The telephone therefore needs to be unlocked by a telephone operator utilising appropriate identification data. The identification data could be a simple PIN number or could, according to the availability and cost of more sophisticated technology, be of a biometric nature, for example fingerprint, voice or retina recognition. The relevant identification data is stored in the storage purse module and, accordingly, coupling is required in order to achieve unlocking of the telephone. The operational procedure may be carried out by entering the required details by way of the keypad on the telephone and coupling the telephone and portable purse module (16) so that the relevant transfer can take place.

If no credit is available from the separate bulk storage purse or the bulk storage purse is not coupled with the telephone within a predetermined time period the operation will be aborted and the handset will return to a locked

state. If the telephone was powered down with an authorized amount of credit value in the operating purse, the handset will, on power-up, remain locked until authorization for the use of the operating purse has been obtained from the separate bulk storage purse. Once previously authorised credit value is once more authorized, or fresh credit value is dispensed successfully, the handset will become unlocked and operational.

In dispensing fresh credit value appropriate data together with a random number generated by the handset application is transferred, after encryption with the operator key (14) and the secret key (15), from the separate bulk storage purse (21) to the operating purse of the telephone.

The credit value data transferred to the telephone (1) is decrypted by the microprocessor (11) using the operating key (14) and the shared secret key (15) so as to be immediately available in the operating purse for use. Clearly, at the time of transfer of the credit value from the separate bulk storage purse, the relevant amount is deducted from the balance contained in the separate bulk storage purse (21).

Typically, credit value is transferred to the telephone against prepayment of the relevant credit value together with any service charge applicable and the telephone is then handed to the user for usage in the unlocked condition.

As a usage session progresses, the credit value stored in the operating purse is reduced by the microprocessor progressively according to a billing algorithm and any stored billing data. Should the usage session endure until all of the available credit value in the operating purse has been consumed, the telephone will automatically switch off and lock once more.

In all other instances, at the end of the usage session, and when the user has hung up, credit value remaining in the operating purse may be returned to the separate bulk storage purse by coupling the telephone and separate

bulk storage purse (21) and entering and appropriate instruction on the keypad of the telephone. At this time the data representing credit value being returned is encrypted once more and the telephone reverts to a locked condition.

In a more advanced version of the system that has been mentioned above and in which wireless coupling means are employed between the telephone (1) and the separate bulk storage purse, the use of the telephone may further be controlled by the existence of coupling, albeit intermittent, between the portable purse module and the telephone. In particular, the arrangement may be such that the telephone automatically becomes locked and therefore unusable in the event that coupling between the two is interrupted for longer than a predetermined time period.

Inputting of the necessary instructions into the keypad of the telephone may, in the event that the separate portable purse module (16) has its own keypad, be substituted by inputting the instructions into that keypad.

Additional bulk credit value can be inputted into the separate bulk storage purse from time to time as may be required in many different ways, including the use of tokens and prepaid vouchers in well-known manner, typically by way of the telephone keypad as user interface (presuming that the separate bulk storage purse does not have one). However, it is preferred that additional bulk credit value be available wirelessly, typically from a computerised credit facility to which the particular telephone is linked.

Thus, in the preferred system of the invention, one or more telephones and separate bulk storage purses of the type described above are linked to a particular computerised credit facility (30) from which quantums (31) of bulk credit value can be drawn from time to time, generally against credit held in, or made available but, the computerised credit facility. The quantums of bulk credit value assume the form of encrypted data containing the relevant bulk

credit value and the encryption is effected using a secret encryption key that is shared between the relevant circuit of the separate bulk storage purse and the computerised credit facility.

This process is initiated by the telephone operator inputting a request to acquire a quantum of bulk credit value into the keypad of the telephone which causes the necessary message to be transferred, firstly to the relevant separate bulk storage purse, which makes up and transmits, via the telephone, a request for the relevant credit value to the computerised credit facility. In the event that credit is available to the particular telephone operator, the computerised credit facility transmits encrypted data containing the relevant credit value to the telephone from which the request was received.

The credit containing data is thus obtained wirelessly utilising the telephone that, at the time of acquiring the relevant quantum of bulk credit, need not be coupled to the recipient bulk storage purse due to the presence of the transfer purse (17) in the telephone. Receipt of such encrypted data representing the relevant credit value may be employed to trigger a message on the screen of the telephone requesting coupling of the separate bulk storage purse with the telephone in order that the received credit value can be transferred to the storage purse.

The secret key utilised for the encryption of this data and that is shared between the separate bulk storage purse and computerised credit facility is unknown to the telephone and the credit value received and stored in the transfer purse in the telephone is thus useless to the telephone itself without first being transferred to, and processed by, the relevant separate bulk storage purse. This mechanism ensures that bulk credit value for services provided by the telephone (1) can only be purchased from a computerised credit facility that has access to the secret key shared with the relevant separate bulk storage purse or purses.

It is envisaged that telephones of the type described above will, in practice, typically be arranged in groups with the telephones and separate bulk storage purses of each group being associated with a particular computerised credit facility typically controlled by a group controller who may, for example, be the owner of a group. The system can thus be used effectively in a franchise type of operation.

The telephones of a group are preferably enabled such that transfer of credit value between different telephones, which have been linked together in a group during deployment, can be achieved in the general manner indicated above simply by directing the data containing credit value from one telephone to another. This is indicated by numeral (32) in Figure 4. The telephones could still further be arranged in smaller subgroups in which a single separate bulk storage purse services the operating purses of more than one telephone.

It will be understood that, in use, the telephones described above have substantially enhanced security in that only an amount of credit value in respect of which payment has been made, or at least authorised, is transferred to the telephone operating purse for any one usage session. Immediately the credit value has been consumed the service is terminated. Any residual credit value can be returned to the storage purse as indicated above and a user can be refunded accordingly.

In the event that the telephone is misappropriated, the credit value that is present in the separate bulk storage purse remains securely held by the operator, and is safe. Utilising the telephone and separate bulk storage purse described above in conjunction with a computerised credit facility enables an extremely simple yet highly effective control to be exercised over a telephone group.