GB2253542A - Improvements in and relating to telephone systems - Google Patents

Abstract

An apparatus to control access from individual telephone extensions to public or private telephone networks. Means are provided to effect a connection between an extension and a network or to prevent the connection occurring. A user of the extension enters an authorisation code which is received by authorisation code receiving means, and the code is compared with one or more access-enabling codes. If the code entered by the user is recognised by the apparatus as entitling access to the network by the user of the code the extension is connected to the network. If the code is not recognised by the apparatus, a connection of the extension to the network is not made. Processing means in the apparatus can record details of calls made and attribute to each code such information. The apparatus is suitable for use with other communications media such as facsimile machines, telexes, and radio communication channels. <IMAGE>

Description

IMPROVEMENTS IN AND RELATING TO TELEPHONE SYSTEMS This invention relates to apparatus which may be interposed between one or more existing telephone systems and one or more telephone networks and so enable greater control and better monitoring to be exercised over the use made of such telephone systems, and to telephone systems incorporating such apparatus.

Known telephone systems, or call routing apparatus, include interconnect circuits which connect a telephone extension to one or more public switched telephone networks (PSTN's) and/or interconnect circuits which connect a telephone to one or more private branch networks (PBN's - networks under private ownership and/or control). Telephone systems are also known in which a telephone may connected via interconnect circuits to one or more extension telephone sets which may be capable of making or receiving calls across any interconnect circuits which the system may have.

Known PBX designs based on stored program control (SPC) technology are capable of creating and maintaining an internally stored database which can be used to enable (or prevent) the connection of any telephone extension to any interconnect circuit. For example, SPC PBX's are known which can limit a specific telephone extension to internal calls only, preventing access to an outside line from that extension. Known SPC PBX systems can also enable or prevent calls with certain combinations of dialled digits (e.g.

international calls 010....) from being made across particular interconnect circuits which are otherwise permitted to be used by that extension. Other known facilities are available which control the permitted routing of incoming calls from interconnect circuits to specific extensions.

A common feature of many SPC PBX's is the output of data via an appropriate interface to an external device, the data giving details of all calls made and/or received by the PBX. For outgoing calls, these data commonly include the calling extension number, the date and time at which the call commenced, the telephone number or digits dialled, the ring and hold time (the duration of the call), and in some cases information about the true cost of the call obtained automatically by some means from the operator of the network across which the call was routed. Such an interface to an external device is commonly called a "call logging port", and the software in the external device which analyses the data output ia a call logging port is commonly called "call logging software".Such call logging software is likely to include facilities to output to a printer and/or storage device details of all calls made, including actual or estimated costs from a specified extension or group of extensions during a defined period.

The output from call logging software is useful for management control of the telephone system, but its usefulness is limited by the fact that although the system is capable of indicating from which extensions the calls were made it cannot identify the person making the call. This enables a person who is not authorised to make, for example, International calls, and whose extension will not afford access to International interconnect circuits, to use another person's extension which is capable of making such calls, either with or without the knowledge of the other person.

According to a first aspect the invention consists in apparatus for use with a telephone system comprising means to enable an extension telephone on that telephone system to be connected to an interconnect circuit which connects the extension with a selected interface to a private or public network system, means to prevent said extension from being connected to said network, authorisation code receiving means adapted to receive an authorisation code input to the system by the user at said extension, and recognition means which compares the authorisation code received at the receiving means with one or more access-enabling authorisation codes, the apparatus enabling a connection between said extension and said network to be effected if the authorisation code input by the user is recognised by the apparatus as entitling said extension to be connected to said interconnect circuit, and the apparatus preventing a connection from being made between said network and said extension if the authorisation code input by the user is not recognised as being an access-enabling code.

The apparatus is interposed between a PBX and PBN or PSTN and ensures that only people with the appropriate identification codes can make telephone calls.

The apparatus may have only one line into it and one line out of it, but will usually have around six lines in and dedicated connections to six lines out.

It will be appreciated that although described with reference to telephone networks the apparatus can control access to facsimile machines, telex's, radio communication channels and the like.

The apparatus preferably comprises control means adapted to run a control program, and may comprise database storing means. The database storing means may have recognised access-giving authorisation codes entered in them, either during manufacture of the apparatus or, more preferably, after manufacture. For example the authorisation codes could be stored in an EPROM, or other suitable means, such that the manager of the telephone system can enter the codes and the operations which can be performed (or which are prohibited) using the codes. The manager of the system could be a purchaser or hirer of the system or of the apparatus.

The authorisation code may define the functions of the PBX or telephone system which are available for use with that code. The authorisation code may have to or more strings of numbers (or other identification parameters) each string of which may be controlled by a different person. For example, the manager of a company's PBX system fitted with the apparatus may program the apparatus to recognise a first string of an identification code as relating to a first user, for example, a particular department within the company.

The code may have a second string which is allocated by the first user (head of that department) to a second user, for example, a person working under the department head to identify any call from that subordinate, or the second (or a third) string, may relate the call to a particular client or customer's account, or relate to any other identification purpose. The control of what the second (and third) strings identify may be retained by the manager of the apparatus, but is preferably given to the first user.

The apparatus may comprise processing means, da-ta storage means, and means for interconnecting with devices for data storage, print and/or display.

Preferably the apparatus incorporates means for generating speech messages or audible tone signals to a user via his telephone extension.

The apparatus preferably includes clock means for identifying the date, and the time of the beginning and end of calls. The clock means may also simply tell the time to the user upon dialling of an appropriate telephone number.

Power failure means may be provided to bypass the apparatus and connect the telephone extension to the PBX or PBN.

The apparatus may have an input port suitable for connection to means for inputting control instructions and/or data.

Preferably the apparatus comprises a database memory in which a database is stored, the database being interrogated by a control means, the control means limiting access to the system to people who can enter an acceptable authorisation code only, and limiting the nature and variety of the interconnect circuits connectable to the extension in correspondence with the predetermined limits associated with the entered authorisation code.

The control means preferably limits outgoing access to the PSTN to being within predetermined dates and within predetermined times of the day.

The apparatus may be so arranged that a control processor and stored database may be used to control the transfer of telephone calls originated on the telephone system by specific persons or for specific purposes by modifying the string of digits dialled.

The modification may be the complete translation of the digits to new digits or the insertion of additional information such as account codes, before transferring this string of digits to private and or public networks.

The control processor and stored database may be used to generate services such as reproducing speech messages giving the time and date, or outputting information from the stored database, on request by specific persons or for specific purposes.

Entry of an access code associated with a particular service will be necessary before the apparatus will generate that service.

Preferably the apparatus generates data records, and is capable of storing these records within the stored database or of outputting them to an external device for storage. The data records preferably contain information appertaining to each call or call attempt or service request, including the authorisation code used, the number dialled, the number output to the network, the date and time the call commenced, the duration of the call, and the identity of the interconnect circuits used to connect the call. The apparatus may be capable of receiving data records generated by the telephone system to which the apparatus is interconnected, and of storing these data records within the stored database or of outputting them to an external device for storage, and which data records may contain similar information about each call or call attempt as that set out in the preceding sentence.

A control program for the apparatus may be stored entirely within the memory of the apparatus, or may be partially stored within the memory of the apparatus and partially stored within the memory of an external computer. The execution of the control program may be entirely on the control processor within the apparatus, or may be partially on the processor within the apparatus and partially on the processor within an external computer.

The apparatus is preferably capable of formatting, sorting, analysing, costing, summarising, billing, or outputting for printing display or storage, or any other processing, data generated by the apparatus and concerned with the facilities used and of calls made and or calls attempted to be made, by an extension user on the system.

The apparatus is preferably an add-on unit adapted to be connected to an existing PBX's, PSTN's and PBN's. The apparatus may be adapted to be connected to the call logging port of the PBX.

Thus the apparatus can enable the owner of a relatively basic, simple system to improve that system by the attachment of the apparatus which permits the telephone system manager to create and maintain a list of authorisation codes to each of which may be attached privileges or limitations which may define, for example, the interconnect circuits which may be engaged by the user of that authorisation code ur the digits which that user may be permitted to dial across a specified interconnect circuit.

The apparatus may require that at any specified extension on an attached PBX an authorisation code be input via the telephone extension keypad or some other device before the normally dialled digits for a call to a required destination. The apparatus control program checks the authorisation code input against the stored database to ensure that the interconnect circuit required and digits dialled are permitted for that authorisation code. Details of all outgoing calls processed by the apparatus, including the authorisation code used for each call, may be output from the apparatus to an external device for subsequent analysis, printing and/or storage, or the analysis may be done inside of the apparatus itself.

According to a second aspect the invention consists in a telephone system comprising a public or private network, a telephone extension, and apparatus according to the first aspect of the invention interposed between the telephone extension and the network.

The invention will now be described by way of example only with reference to the accompanying drawings of which: Figure 1 illustrates schematically an example of a known telephone system in which a telephone is connected to a PSTN via an exchange line; Figure 2 illustrates schematically a more complex known telephone system; Figure 3 illustrates schematically a telephone system in accordance with the second aspect of the invention; and Figure 4 illustrates schematically apparatus in accordance with the first aspect of the invention.

Figure 1 shows a simple known telephone system in which a telephone 1 is connected to a Public Switched Telephone Network 2, via an exchange line 3. This is a typical arrangement for most household telephones.

Figure 2 shows a more complex known telephone system such as many medium or large sized offices may have and comprises many telephone extension sets 4 connected to a Private Branch Exchange (PBX) 5 which routes outgoing calls across any approved interconnect circuit to the required called destination (if that destination can be reached from that extension) . In the system shown in Figure 2 extension 4a can be connected to PSTN 6 (e.g. British Telecom PSTN), PSTN 7 (e.g. Mercury PSTN), and PBN 8, whereas extension 4b can make only internal calls on PBN 9. It is possible for the person who is normally limited to use of telephone 4b to use telephone 4a to make unauthorised calls. It will be appreciated that dotted lines 5' are purely schematic and that PBX's contain switching devices which may be provided in hardware or software.

Figures 3 and 4 illustrate the present invention in two aspects. Figure 4 shows add-on apparatus 10 adapted to be connected to an existing PBX, or as shown in Figure 3, to three different PBX's 11,12 and 13.

The apparatus 10 is in communication with the PBX's and in communication with a PSTN 14, a second PSTN 15 and first and second PBN's 16 and 17. PBX 11 is also in communication with PSTN 14, PBX 13 is also in communication with PBN 17, whilst PBX 12 is in communication with the apparatus 10 only (and of course a number of telephone extensions 12a and 12b).

PBX's 11 and 13 are also in communication with their telephone extensions lla,llb and 13a,13b respectively.

The apparatus 10 is connected to the PBX's 11,12 and 13 and to the PSTN's and PBN's by any approved means and comprises a housing 20 and chassis 21 designed to support and protect the internal hardware of the apparatus and to permit its secure standing or fixing in a position convenient to the telephone system or systems which are to be controlled and monitored (the Controlled System).The internal hardware of the apparatus comprises a power supply system 22; a power failure detection device 23; a control processor 24; a program memory 25 for the storage of a control program; a database memory 26 for the storage of temporary variables and of a database; a bus 27 for the transfer of control program instructions, data, speech signals, and control signals to and from the devices attached to the bus (described later); a speech device 28 for the electronic storage and reproduction of human speech or alternative audible tone signals; a clock device 29 to produce real time calendar and clock signals; interfaces to computer peripheral devices working in association with the control processor 24, including a printing interface 30, storage interface 31, and a display interface 32; an interface 33 for the input of data and operating instructions; interfaces 34 to call logging ports 35 of the Controlled System 11-13; interfaces 36 to the interconnect connect circuits to the Controlled System 11-13; interfaces 37 to the interconnect circuits to the Networks 14-17; and a bypass switch 38.

The interfaces 30 are connected to printers 39 which print out information about the use of the system as will be described later. The interfaces 31 and 32 are connected to electronic information storage and display means 40 and 41 respectively. Interfaces 33 are adapted to be releasably connected to a terminal 42, such as a microprocessor control unit which inputs data and operating instructions to the apparatus 10.

The internal hardware of the unit 10 is so designed that various combinations of the elements 22 to 38 may be inserted in the chassis 21 to meet the differing requirements of alternative embodiments of the apparatus. The arrangement of the elements 21 to 38 is best shown in Figure 4.

The interfaces 36 to the interconnect circuits of the Controlled System may connect to the Controlled System via its extension ports, or via exchange line ports, or via the Controlled Systems inter-PBX ports using known signalling means. In all these cases the different types of interface 36 which may be used are designed to answer automatically calls made via the corresponding types of port on the Controlled System, thus establishing an audio path to the extension telephone on the Controlled System which originated a call and to interpret signals or tones transferred to the apparatus via that audio path.

The interfaces 37 to the Networks may be of several kinds, those designed to connect to an exchange line to the Networks, and those designed to connect to the Controlled System via its extension ports, or via its inter-PBX ports using known signalling means. In all these cases the interface 37 is designed to initiate and to terminate a call, and to transfer a required string of dialled digits to the Networks using a known signalling means.

The control processor 24 is controlled by a control programme held in the programme memory 25. The control programme can conveniently be described in four parts.

The first part of the control programme contains those programme instructions (the Driver Code) which are concerned with the control and workings of the individual elements of the internal hardware 22 to 38 to ensure that these elements interact within the apparatus to achieve the overall working of the apparatus defined by other parts of the control programme. The Driver Code is stored in the programme memory 25.

The second part of the control programme contains those programme instructions (the Application Code) which are concerned with the interaction of the elements of the hardware in response to signals and/or data received via the various devices and interfaces connected to the apparatus 10 or part of it in order to ensure that the desired set of signals and data are output to the various devices and interfaces 22 to 38 in order to achieve the overall working of the apparatus in accordance with the desired functional operation of the apparatus 10 and system. The Application Code is stored in the programme memory 25.

The third part of the control programme contains those programme instructions (the Database Code) which are concerned with the creation and maintenance of a database (the Database) by the person who is the manager of the apparatus. The Database is stored in the database memory 26. The Database Code is preferably stored in the programme memory 25 and executes on the control processor 24. Alternatively the Database Code may be stored and execute on a computer external to the apparatus, such that the Database may be transferred to the database memory 26 via the interface 33 under the control of the Application Code.

The Database defines the following sets of data for each of several authorisation codes: the authorisation code or codes which will be required to be input via the interconnect circuits from the Controlled System on each occasion that an attempt is made to route a call via the apparatus 10 or to use its various facilities; the facilities of the apparatus which may be used for that authorised code; the restrictions which apply to a call attempt regarding the use of any set of interconnect circuits to connect the telephone extension to the Networks; the dialled digits which are transferred across specified interconnect circuits; the dates and times intervals such call attempts are allowed; the translations which may be required to any combination of dialled digits which are input from the Controlled System before their transference to the Networks; and any other information which may be programmed to be necessary before the call will be allowed to be connected. This last "other information" is not information which a user has to key in, but is information used in the subsequent analysis of the data.

The fourth part of the control program contains those programme instructions (the Analysis Code) which are concerned with the formatting, sorting, analysing, costing, summarising, printing, display, storage and/or any other processing of data created by the apparatus and concerned with the facilities used and or calls or call attempts originated by the Controlled System and processed by the apparatus. This data may be stored in the database memory 26, or on the attached storage device 40 connected via the interface 31. The Analysis Code is stored in the programme memory 25, and executes on the control processor 24 and outputs results via the interfaces 30 to 33 to peripheral devices attached to the apparatus. Alternatively the Analysis Code may be stored and executed on a computer external to the apparatus, and output to that computer's own peripheral devices.

A telephone call is initiated by a user of an extension telephone, say extension 12a, dialling an appropriate code which the Controlled System has been set up to recognise as an instruction to route this call to the apparatus 10. For example, this code could be an extension number of the Controlled System if the apparatus were connected to an extension port, or it could be an access code for a group of exchange lines (typically the digit "nine"), or an access code for a group of inter-PBX circuits.

The interface 36 to the Controlled System 11-13 answers the incoming call from that extension automatically and establishes an audio path to the said extension telephone, and, under the control of the control processor 24, connects the speech device 28 to this audio path. The speech or tone device 28 outputs an appropriate message or tone to the said extension 12a inviting the user to input signals in response, for example, the message output by the device 28 to the extension 12a could be an invitation to input an authorisation code to identify the said user. This code is then input by that user by means of multi-frequency tones from the keypad of the extension telephone, or by some other means. For example the users identification code could be the number 1234 dialled into the extension at the invitation of the apparatus 10.

The interface 36 decodes the signals input from the Controlled System and transfers them via the bus 27 to the control processor 24 for processing in accordance with the control program. This processing includes checking for the validity of the authorisation code or codes input by the extension user against the Database stored in the database memory 26, the recognition of signals requesting a service to be performed by the apparatus, and the delivery of that service to the extension user.

Users of extensions 11a and 11b and PBX 11 can make calls without an authorisation code since PBX 11 is connected directly to PSTN 14. The apparatus 10 monitors calls going directly to the PSTN 14 (those which do not have an authorisation code) via the call logging port of PBX 11 and check the numbers called against its database to ensure that all personal calls, or calls to be charged, are being declared by the use of authorisation codes. If the apparatus 10 discovers that some people are not using an authorisation code to make calls which should be done using an authorisation code, it will identify the number called, the extension used, and the person who is likely to have called the number.For example, if the apparatus notices that user X has made six calls in the past to telephone number Y on their personal authorisation code, and that they are the only person to have called that number via PBX 11, there is a strong probability that any "undeclared" call to number Y routed via PBX 11 also comes from user X and is a personal call. The apparatus stores the suspect call and prints it out as such along with "declared" calls for user X at the end of the month or quarter.

PBX 12 must connect through the apparatus 11 and so the potential problem of undeclared calls is not relevant.

PBN 17 is connected directly to PBX 13 and the apparatus 10 monitors the direct connection calls in a similar manner to that which it does for PBX 11.

A typical call from a user from extension 12a may comprise the user trying to dial a number in Edinburgh on behalf of a client X. The user dials the string of digits required by the particular PBX to which the extension is connected which will result in an interconnect circuit to the apparatus being selected and in appropriate connection being made to the apparatus 10; the apparatus will answer the call automatically and will connect the user to the speech device 28. The speech device 28 requests the user's authorisation code, which he enters by pressing digits 1,2,3,4,5,6 on his telephone, and compares this authorisation code using the control processor to see whether that code entitles the user to make a call of the chosen category (for example long distance).The number entered is the number to be dialled plus a category indicator as to what type of call is being made (for example the categories could be private; business on behalf of the employer, the call not to be charged to a customer; or business to be charged to a customer). The apparatus 10 then checks that the authorisation code entitles the user to dial the chosen number on the chosen category and then allows the extension 12a to be connected to the PSTN 14 and the telephone which the user has tried to call. Thus calls with an authorisation code go through the apparatus 10.

If the call is permitted the output of appropriate signals from the processor 24 is connected via the bus 27 to the appropriate interface 37 to the Networks defining the call destination required. The control processor 24 then either recognises that the call attempt has been abandoned by the extension telephone user and records the fact at printer 39 or store 40 or recognises that a call has been connected, times the call, recognises that the call has been terminated normally by the extension user and records that fact.

Upon completion of a call or call attempt across the interface 36 from the Controlled System, the control processor 24 causes a data record to be created, which may be encrypted, defining details of the call or call attempt, including, inter alia, the date and time of commencement, the authorisation code used, the service requested or the dialled digits input via the interface 36, the dialled digits output via the interface 37, and the duration of the call. The data record so created may be stored in the database memory 26, or output via one or more of the interfaces 30 to 33 for further processing by the Analysis Code part of the control program.

The interface 34 to the call logging ports of the Controlled System may be used to input to the apparatus 10 the call records output by the Controlled System, for transfer via the bus 27 to the processor 2t for subsequent processing by the control program and for output via one or more of the interfaces 30 to 33, to the attached peripheral devices. Such call records may be further processed by the Analysis Code part of the control program.

The interface 33 may be used for the input and output of appropriate signals to an external computer or device which may be used to execute the Database Code and Analysis Code parts of the control programme.

If an invalid authorisation code is input into the apparatus the control processor 24 allows a limited number of repeat attempts to insert a valid code. The speech device 28 may give the user information on the number of further attempts available and may invite the user to try again. If the limited number of attempts is exceeded the extension may become inoperable for outgoing calls for a predetermined time, and an alarm signal may be generated, for example at a telephone receptionists display and the event recorded on the record kept by the apparatus 10.

Each authorisation code may be restricted for use at specific interconnect circuits 36 only, thus an authorisation code which works at extension 11a may not work at extension 12a. This adds a further degree of security against unauthorised use of someone else's code.

If an acceptable authorisation code is used at a telephone extension, but the user tries to dial a number which they are not authorised to dial, the apparatus will not allow the call to be connected and will inform the user of this.

Upon failure of the electricity supply to the power supply system 22, the power failure detection device 23 causes the bypass switch 38 to operate which causes the interconnect circuits to the Controlled System and to the Networks to be disconnected from the apparatus, and in some embodiments, causes these interconnect circuits to be connected together, thus effectively bypassing the apparatus 10 so that calls may still be made from the Controlled System.

The system described thus controls access to telephone lines by identification codes associated with people, rather than telephone extensions. The system allows for automatic print outs (from the printers 39) of details of all calls made in a period, and can even be arranged to print out automatically a list of all calls made using a specific person's identification code, and may be able to group the calls into predetermined classes - for example business and personal. The classification of a call into business or pleasure could be made on the basis of a supplementary identification code input by the user, or by the apparatus 10 itself if it incorporates all numbers dialled in its database memory 26 and an appropriate associated classification.For example, the telephone numbers of all existing customers could be taken to be "business" calls, and all other telephone numbers as "private" calls.

The apparatus may have software to print out numbers dialled more frequently than a predetermined level.

The apparatus may be arranged to generate bills automatically based on the recorded information as to the destination, duration, and classification of calls made on behalf of different entities. The apparatus may include differential charging rates for different classifications of call.

A second example of the use of the apparatus 10 is as follows. The apparatus is an add-on unit permanently wired to the PBX 12 which is at an office block. The PBX serves three companies in the building. Each call coming out of the building has to go through the apparatus 10 and requires an identification code. Each acceptable identification code includes a first string identifying the company to whom the identification code is allocated, a second string identifying a person with the company, and a third string identifying other information.

One of the companies in the building is a firm of Solicitors and their Senior partner, or apparatus manager, is given the ability to program the apparatus with, say, six groups of first identification strings each of which identifies a partner within the firm.

Each partner is then individually given his identification code group, say 9876. The identification numbers recognised by the apparatus 10 are in this example eight digit numbers.

The individual partner is then able to allocate a second string of numbers to identify other parameters.

Partner A allocates the last four digits of his group of numbers on a one-to-one basis with individual client accounts which he intends to charge automatically for outgoing calls. Any calls which are made using 9876 abcd then identifies the call as being from partner X of the firm of Solicitors and to be charged to the client corresponding to abcd.

A second partner B has two articles clerks working under him and wishes to keep a track of their telephone calls and so allocates his second string as follows: the number five for the fifth digit identifying clerk number one, and the number six for the fifth digit identifying clerk number two (the clerk - identifying digit need not be the same for each clerk if a further safety factor is required). The clients of partner B are then given account identifying numbers as the sixth, seventh, and eighth numbers of the identification codes. Thus the second string for partner B is in effect two strings: a one-digit articled clerk - identifying string and a three-digit client-identifying string.

Secretaries and other staff will have identification codes so that they can make any outgoing personal calls that they wish to.

The individual partners A and B can input their own correlations between their second string identification numbers and the information encoded by them. Thus the apparatus manager need not know the identification codes of the partners or clerks.

It will of course be appreciated that in the eight digit codes there are very many combinations of numbers which will not be recognised as an authorisation code.

This deters people from trying numbers at random until they chance upon an acceptable code before making expensive private calls. It will also be appreciated that in practice the partners A and B will be given a random set of eight digit numbers to allocate as they wish. This reduces the chance of someone being able to guess someone else's code from a knowledge of their own code.

The apparatus 10 is programmed by the manager to off-load its memory record of all calls made in a preceding month once a month to a printer to print out automatically bills for each client and a notification to each employee of the firm of their personal calls in that month and the cost of them.

Another example of a modification of the apparatus previously described is that it could include provisions for pre-payment for calls (usually personal calls). For example the user could pay a predetermined amount for a personal user I.D. code, say 10, and the data base of the apparatus be informed of this. The apparatus would then credit the user with credits and allow the user to make 10 worth of telephone calls on that user ID. Once the 10 worth of credits had been used up the apparatus could block the making of any further calls on that user ID, and may either enter negative credits, or debits, on that user ID's credit store, or may cut the existing call off.

The user may be able to re-stock his account in order to be able to use his ID number again, or may be issued with a new ID number when he advances more money for telephone calls.

Of course, the user may not be a personal user but could be a company operating within an overall telephone system under the control of the apparatus and the amount of the predetermined credits could be very much larger than 10.

One area where such a pre-payment system may work well is for patients, visitors or staff of hospitals.

The apparatus and system may, of course, operate with portable or remote telephones such as radio telephones.

Claims (30)

1. Apparatus for use with a telephone system comprising means to enable an extension telephone on that telephone system to be connected to an interconnect circuit which connects the extension with a selected interface to a private or public network system, means to prevent said extension from being connected to said network, authorisation code input to the system by the user at said extension, and recognition means which compares the authorisation code received at the receiving means with one or more access-enabling authorisation codes, the apparatus enabling a connection between said extension and said network to be effected if the authorisation code input by the user is recognised by the apparatus as entitling said extension to be connected to said interconnect circuit, and the apparatus preventing a connection from being made between said network and said extension if the authorisation code input by the user is not recognised as being an access-enabling code.

2. Apparatus according to claim 1 which has a plurality of communication lines leading into it and a plurality of dedicated connections to a pluarality of communication lines leading out of it.

3. Apparatus according to claim 1 or 2 which further comprises control means adapted to run a control program and/or database storing means.

4. Apparatus according to claim 3 in which the database storing means has recognised access-giving authorisation codes entered in them, either during manufacture of the apparatus or after manufacture.

5. Apparatus according to claim 4 in which the authorisation code defines the functions of a PBX or telephone system which are available for use with that code.

6. Apparatus according to claim 5 in which the authorisation code has two or more strings of numbers (or other identification parameters) each string of which may be controlled by a different person.

7. Apparatus according to any preceding claim which comprises processing means, data storage means, and means for interconnecting with devices for data storage, print and/or display.

8. Apparatus according to any preceding claim which incorporates means for generating speech messages or audible tone signals to a user via his telephone extension.

9. Apparatus according to any preceding claim which includes clock means for identifying the date, and the time of the beginning and end of calls.

10. Apparatus according to any preceding claim in which power failure means is provided to bypass the apparatus and connect the telephone extension to the PBX or PBN in the event of power failure.

11. Apparatus according to any preceding claim which has an input port suitable for connection to means for inputting control instructions and/or data.

12. Apparatus according to any preceding claim which further comprises a database memory in which a database is stored, the database being interrogated by a control means, the control means limiting access to the system to people who can enter an acceptable authorisation code only, and limiting the nature and variety of the interconnect circuits connectable to the extension in correspondence with the predetermined limits associated with the entered authorisation code.

13. Apparatus according to any preceding claim in which the control means limits outgoing access to the PSTN to being within predetermined dates and within predetermined times of the day.

14. Apparatus according to any preceding claim in which the control means limits outgoing access to the PSTN to exclude a predetermined range or group of dialled digits.

15. Apparatus according to any preceding claim which is provided with a control processor and stored database which are so arranged that the control processor controls the transfer of telephone calls originated on the telephone system by specific persons or for specific purposes by modifying the string of digits dialled.

16. Apparatus according to claim 15 in which the modification is the complete translation of the digits to new digits or the insertion of additional information such as account codes, before transferring this string of digits to private and or public networks.

17. Apparatus according to claim 15 or claim 16 in which the control processor and stored database can be used to generate services such as reproducing speech messages giving the time and date, or outputting information from the stored database, on request by specific persons or for specific purposes.

18. Apparatus according to any preceding claim which generates data records, and is capable of storing these records within the stored database or of outputting them to an external device for storage.

19. Apparatus according to claim 18 in which the data records contain information appertaining to each call or call attempted or service request, including the authorisation code used, the number dialled, the number output to the network,the date and time the call commenced, the duration of the call, and the identity of the interconnect circuits used to connect the call.

20. Apparatus according to any preceding claim which is capable of receiving data records generated by the telephone system to which the apparatus is interconnected, and of storing these data records within the stored database or of outputting them to an external device for storage.

21. Apparatus according to any preceding claim in which a control program for the apparatus is stored entirely within the memory of the apparatus.

22. Apparatus according to any one of claims 1 to 20 in which the control program for the apparatus is partially stored with the memory of the apparatus and partially stored within the memory of an external computer.

23. Apparatus according to any preceding claim which is capable of at least one or more of sorting, analysing, costing, summarising, billing, or outputting for printing display or storage, or any other processing, data generated by the apparatus and concerned with the facilities used and of calls made and of calls attempted to be made, by an extension user on the system.

24. Apparatus according to any preceding claim which is an add-on unit adapted to be connected to an existing PBX, PSTN or PBN.

25. Apparatus according to claim 24 which is adapted to be connected to the call logging port of the PBX.

26. Apparatus according to any preceding claim which requires that at any specified extension on an attached PBX an authorisation code be input via the telephone extension keypad or some other device before the normally dialled digits for a call to a required destination, the apparatus' control program checking the authorisation code input against the stored database to ensure that the interconnect circuit required and digits dialled are permitted for that authorisation code.

27. Apparatus according to claim 26 in which details of all outgoing calls processed by the apparatus, including the authorisation code used for each call, are output from the apparatus to an external device for subsequent analysis, printing and/or storage.

28. Apparatus according to claim 27 in which the analysis is done inside of the apparatus itself.

29. Apparatus for use with a telephone system substantially as herein described.

30. A telephone system substantially as herein described.

30. A telephone system comprising a public or private network, a telephone extension, and apparatus according to any one of claims 1 to 29 interposed between the telephone extension and the network.