Telecommunications systems are offering an increasingly sophisticated set of services to end users. An end user is able to subscribe to a large number of different services and often requires a plurality of different terminals for use with different services or sets of services. For example, the end user may have a standard telephone handset connected by a fixed telephone line to a telecommunications network (fixed telephone), in addition to (mobile telephone) for voice telephony services connected via a mobile or cellular telecommunications link to the telecommunications network, another terminal (facsimile device) for receiving and sending facsimile transmissions, another terminal (pager device) for receiving and displaying digital messages transmitted by radio from a transmitting station connected to the telecommunications network and yet another terminal (computer) for sending and receiving packet data services.

Each of these subscriber terminals may be associated with a separate connection to the telecommunications network and therefore may be accessible

from the telecommunications network by using a separate terminal identifier, such as a fixed or mobile telephone number. These various subscriber terminal identifiers, however, no relation to each other and are often allocated by a variety of separate telephony service providers. It is therefore difficult for persons wishing to communicate with the end user of a variety of different subscriber terminals, since that person must be able to recall each of the different telephone numbers or other terminal identifiers associated with each of the subscriber terminals associated with that end user.

Moreover, an end user may wish to change service providers for one or more of the types of communications service provided to him by his various subscriber terminals. For example, an end user may wish to change his mobile telephone service provider. In this case, the mobile telephone number allocated by the first service provider will no longer be operational, and a new, unrelated mobile telephone number must then by used by persons wishing to communicate with the end user via his mobile telephone. At each such changing of service provider, the end user must advise all persons likely to communicate with him of his change in mobile telephone number. Such a course of action is of course, inconvenient and time consuming for an end user, and for this reason end users are discouraged from switching from a service provider with whom they are dissatisfied to a new service provider.

An aim of the present invention is to offer easy access to persons wishing to contact an end user having a plurality of subscriber terminals each being accessible from a telecommunications network by different terminal identifiers.

With this in mind, the present invention provides a telecommunications system comprising a telecommunications network, a first subscriber terminal accessible from the telecommunications network by using a first terminal identifier, at least one second subscriber terminal associated with the first subscriber terminal and accessible from the telecommunications network by using a second terminal identifier, switching means for directing telecommunications signals within the telecommunications network and data storage means accessible from the telecommunications network, wherein the switching means include means

for detecting a telecommunications signal containing a pre-determined code and the first terminal identifier or portion thereof, and means for sending the first terminal identifier to the data storage means, the data storage means including means for receiving the first terminal identifier and determining an associated second terminal identifier and for sending that second terminal identifier to the switching means, the switching means further including means for receiving the second terminal identifier and means for subsequently sending the telecommunications signal to the second subscriber terminal as identified by the received second terminal identifier.

In this way, a third party is able to communicate with an end user having a variety of subscriber terminals accessible from a telecommunications network by a variety of terminal identifiers, by use of a first reference terminal identifier only.

For example, a third party may be able to communicate with an end user via his or her fixed telephone terminal by using the standard telephone number associated with that fixed telephone terminal. If the third party wishes to communicate with the end user by using a different subscriber terminal, such as the end user's mobile telephone or facsimile machine, the third party may be able to do so simply by using a pre-determined code, in addition to the first terminal identifier. The telecommunications system according to the invention is then able to convert this "pseudo"telephone number or other terminal identifier into a"real"telephone number or other terminal identifier, previously stored in a data storage means, in order to communicate with the end user via the desired subscriber terminal.

The first subscriber terminal and the at least one second subscriber terminal are preferably chosen from amongst the types of terminals comprising fixed telephone devices, mobile telephone terminals, facsimile terminals, pager terminals, or other video, audio or text transmission devices, the first subscriber terminal and the at least one second subscriber terminal being of a different type to the first subscriber terminal.

At least one of the first subscriber and the at least one second subscriber terminal may be connectable to the telecommunications network by a fixed telephone line.

At least one of the first subscriber terminal and the at least one second subscriber terminal may be connectable to the telecommunications network by a mobile telephone connection.

The first subscriber terminal and the at least one second subscriber terminal may act to communicate with the same user, and in this way, the subscriber terminals may be associated with each other.

In one embodiment of the invention, the pre-determined code may correspond to the type of the second subscriber terminal. For example, a first pre- determined code may be used by a third party to specify the mobile telephone of an end user, a second pre-determined code may be used for a facsimile device, a third pre-determined code for a video device, etc.

In one embodiment of the invention, the data storage means may comprise a file server.

The data storage means may include one or more conversion tables each for storing a plurality of first terminal identifiers and at least one associated second terminal identifier.

In one embodiment, the switching means includes one or more service switching points forming part of an intelligent network. In this embodiment, the intelligent network may comprise a service control point connected to the service switching points and a service management system connected to the service control point. The data storage means may be connected to the service control point. In addition, the information contained within the one or more conversion tables in the data storage means may be maintained via the service management system.

In one embodiment, the telecommunications system further comprises a directory service database containing personal identification information relating to the end user of the first and at least one second subscriber terminal, in addition to the first and second terminal identifiers. The directory service database may be connectable to the data storage means in order to provide the first and second terminal identifiers for storage in the data storage means.

The telecommunication system may further comprise a directory assistance terminal connectable to the directory service database for accessing end user

personal information and first and second terminal identifiers from the directory service database.

According to another aspect, the present invention provides a method of communicating with at least one second subscriber terminal associated with a first subscriber terminal, the first and second subscriber terminals being accessible from a telecommunications network respectively by using a first and second terminal identifier, the telecommunications network including switching means for directing telecommunications signals within the telecommunications network, and data storage means accessible from the telecommunications network, the method comprising: (a) sending a telecommunications system to the switching means, the telecommunications signal containing a pre-determined code and the first terminal identifier or part thereof, (b) detecting, at the switching means, the pre-determined code and subsequently sending the first terminal identifier to the data storage means, (c) determining, in the data storage means, a second terminal identifier associated with the first terminal identifier, (d) sending the second terminal identifier to the switching means, and (e) subsequently sending the telecommunications signal from the switching means to the second subscriber terminal as identified by the received second terminal identifier.

The following description refers in more detail to the various features of the telecommunications system and method of communicating with at least one second subscriber terminal associated with a first subscriber terminal of the present invention. To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings where the invention is illustrated in preferred embodiments. It is to be understood that the telecommunications system and method of communication of the present invention are not limited to the preferred embodiment as illustrated in the drawings.

In the drawings:

Figure 1 is a schematic diagram of the telecommunications system of the present invention; Figure 2 is a schematic diagram showing part of the switching means and the data storage means of the telecommunications system of Figure 1; Figure 3 is a schematic diagram showing a method of using the telecommunications system of Figure 1 to communicate with at least one second subscriber terminal associated with a first subscriber terminal according to the present invention; and Figure 4 is a variant of the telecommunications system shown in Figure 1.

Referring now to Figure 1, there is generally shown a telecommunications system 1 comprising a telecommunications network 2, a first subscriber terminal 3, a second subscriber terminal 4 and a third party subscriber terminal 5. The telecommunications network may be of the type used to transfer information via public facilities, such as a public switched telephone network (PSTN), a packet switched data network (PSPDN) or integrated services digital network (ISDN), or private facilities such as a local area network (LAN).

The first subscriber terminal 3, in this example, is a standard telephone handset connected to the telecommunications network 2 by a fixed telephone connection. That is, all telecommunications to and from the subscriber terminal 3 occur as a series of electrical impulses on wires connecting the telephone handset 3 to the telephone network 2.

By contrast, the second subscriber terminal 4 may be a mobile or cellular telephone handset connected to the telecommunications network 2 via a mobile switching center 6 and base stations 7 and 8. The connection between the mobile telephone terminal 4 and the base station with which connection is established is thus a radio communication link forming part of a mobile telephone connection to the telecommunications network 2.

In addition to the subscriber terminals 3 and 4 respectively connected to the telecommunications network by a fixed telephone line and a mobile telephone connection, various other types of terminals may be accessible from the telecommunications network 2. For example, one or more facsimile terminals,

pager terminals, or other terminals for receiving video, audio, text or other data information may also be connected to the telecommunications network 2.

The telecommunications network comprises switching means for directing telecommunications signals within the telecommunications network. In Figure 1, these switching means include a series of telephone exchanges for analyzing the header or address information in a telecommunications signal and directing that telecommunications signal, via a series of similar telephone exchanges and interconnecting communications links, to a destination telecommunications terminal, such as a telephone, facsimile machine, etc..

According to the invention, the telecommunications system 1 also includes data storage means 11 accessible from the telecommunications network 2, in this case, via permanent connections 12 and 13.

Figure 2 shows in more detail one embodiment of a switching exchange 10, subscriber terminals 20,21 and 22 and the data storage means 11. The part of the telecommunications network interconnecting the data storage means and the switching exchange 10 is represented in Figure 2 by the reference numeral 23.

The switching exchange 10 includes a subscriber line interface circuit 24, a switching matrix 25 and a trunking line interface 26. The switching exchange 10 also includes a control circuit 27 and a memory circuit 28. The control circuit 27 is connected to both of the interface circuits 24 and 26 and the switching matrix 25 and is adapted to operate each of the circuits to switch a telecommunications signal arriving from any one of the subscriber terminals 20,21 or 22 through to any one of the plurality of output connections of the trunking interface circuit 26. The memory circuit 28 contains codified instructions or program steps which determine the functionality of the control circuit 27. In particular, the memory device 28 includes program instructions 29 for detecting the presence of certain information contained within the header or address field of a telecommunications signal originating from any one of the subscriber terminals connected to the input of the switching exchange 10. The memory portion 28 is adapted to detect a telecommunications signal containing a pre-determined code and a terminal

identifier such as a telephone number by which a first subscriber terminal may be accessed from the telecommunications network.

In addition, the memory device 28 includes program instructions 30 for causing the subscriber terminal identifier detected by the set 29 of program instructions to be forwarded to the data storage means 11, and a further set 31 of program instructions for directing a telecommunications signal received from one of the subscriber terminals 20,21 or 22 to a subscriber terminal identified by a further subscriber terminal identifier sent from the data storage means in response to the query originated by the set of program instructions 30.

The data storage means 11 comprises an interface circuit 40 for receiving and transmitting signals to and from the remainder of the telecommunications network 23. A control circuit 41 is connected to the interface circuit 40 and is adapted to control the operation of the data storage means 11 via a memory device 42 which contains a series of instructions for determining the functionality of the control circuit 41. In particular, the memory device 42 includes a set of control instructions 43 for detecting the presence of a terminal identifier in a signal received from the telecommunications network 23. In addition, the data storage means includes storage devices 44,45 and 46 each for storing a list of subscriber terminal identifiers and corresponding identifiers of subscriber terminals associated with that terminal. The data storage means 11 may comprise one or more such storage devices, in particular for storing such"look-up tables"for differing types of subscriber terminals which may be associated with the one reference subscriber terminal.

The memory device 42 may further comprise a series of instructions 47 for instructing the control circuit 41 to look up the terminal identifier of a subscriber terminal associated with the terminal identifier detected by the data storage means 11.

In addition, the memory device 42 may include a set of instructions 48 for formatting and sending the associated subscriber terminal identifier retrieved from the storage devices 44-46 to the switching exchange 10.

The operation of the telecommunications system shown in Figures 1 and 2 will now be described with reference to Figure 3. Initially, the user of subscriber terminal 5 may wish to contact the user of subscriber terminal 3, but rather than contacting that user by a fixed telephone connection may wish to communicate via the user's mobile terminal 4. In this example, the subscriber terminal 3 may be the user's first or reference terminal, whilst the mobile telephone device 4 may be the user's second terminal associated with the first terminal 3. The first subscriber terminal 3 is accessible from the telecommunications network 2 by using a first terminal identifier, such as the telephone number 03-9559-2448. The second subscriber terminal 4 associated with the first subscriber 3 may be accessible from the telecommunications network 2 by using a second terminal identifier such as the telephone number 0412-567862.

In this example, the storage device 44 has maintained therein a look-up table including the first terminal identifier 03-9559-2448, and the associated second terminal identifier 0412-567862. If the user were also to have other types of subscriber terminals, such as facsimile terminals and pager terminals, etc, the first terminal identifier and the associated terminal identifiers by which these terminals may be accessed from the telecommunications network would similarly be stored in the additional storage devices, such as those referenced 45 and 46.

According to the present invention, a pre-determined code is allocated by the network operator maintaining the data storage means 11 to indicate that the user of the subscriber terminal 5 wishes to contact the user of the subscriber terminal 3 through his mobile telephone terminal 4. For example, the pre- determined code"44"may be used. As shown in step 60 of Figure 3, the user of the subscriber terminal 5 may compose the pre-determined code 44 followed by the first terminal identifier normally used to access the first subscriber terminal 3.

This information is included into the header of a telecommunications signal sent to one or more of the telephone switching exchanges 10 forming the switching means directing telecommunications signal within the telecommunications network 2.

This telecommunications signal is analyzed by the control circuit 27, acting according to the instruction contained in the set of program steps 29, in order to

detect the pre-determined code and the first terminal identifier contained therein. If the pre-determined code is thus detected, the control circuit 27 acting according to the set of program steps 30 generates a query command and sends the first terminal identifier at step 62, together with the pre-determined code to the data storage means 11.

In step 63, the control circuit 41 of the data storage means 11, acting under the control of the set of program steps 43 acts to detect the pre-determined code 44 and determine therefrom that a mobile telephone number corresponding to the first terminal identifier is being requested. The control circuit 41, this time acting according to the program steps 47, acts to read the information stored in the look- up table 44 to determine the second terminal identifier stored as being associated with being the first terminal identifier received from the telephone switching exchange 10. Once this second terminal identifier has been read, the control circuit 41, acting according to the set of instructions 48, acts to generate at step 64, a response signal including the second terminal identifier back to the telephone switching exchange 10 having originated the query command.

The switching exchange 10, upon receipt of this second terminal identifier, is then adapted, by the control circuit 27 acting according to the set of program steps 31, to direct the telecommunications signal originating from the subscriber terminal 5, to the subscriber terminal accessible from the telecommunications network by using that received second terminal identifier, in this case the mobile telephone device accessible by using the mobile telephone number 0412-467862.

Upon receipt of the incoming call, the mobile telephone device 4 will ring and the user may choose to accept or refuse the incoming call.

Accordingly, it is possible for a third party to contact a user on any one of a number of additional terminals so long as they are able to compose the terminal identifier of a first reference subscriber terminal and are aware of the code or codes for accessing the various types of additional terminals which may be associated with that first terminal.

Whilst the example shown in Figures 1 and 2 includes the possibility of the subscriber storing terminal identifiers for accessing several different terminals or

several different sorts of terminals associated with a first terminal it is to be appreciated that in other embodiments of the invention, provision may not be made to enable a third party to distinguish between different categories. In this case, only one pre-determined code would be required in order to enable a third party to access a user on his designated additional terminal. In this case, it would not be necessary for the switching exchange 10 to send, at step 62, the value of the pre- determined code to the data storage means 11, there being only one look-up table to access upon receipt of the first terminal identifier. The pre-determined code composed by the user of the subscriber terminal 5 need only be sent by the switching exchange 10 to the data storage means 11 if provision is made for the user of the subscriber terminal 5 to contact the user of the subscriber terminal 3 on more than additional subscriber terminal associated with that first terminal.

Returning now to Figure 1, in addition to the previously described elements of the telecommunications system 1, there may additionally be included a directory service database 70 for storing personal identification information, such as the name and address, of the user of the subscriber terminal 3 and associated subscriber terminal 4. Provision may be made for this database to import the terminal identifiers stored in the data storage means 11 in order that a directory listing may be generated showing, for example, the names and address of all users subscribing to the above described service and the first terminal identifier of that user. In addition, the directory service database may add one or more characters after the listing of each first terminal identifier to indicate whether that user has listed one or more associated subscriber terminals. For example, if a particular user has stored in the data storage means 11 a subscriber terminal 11 for a mobile telephone, facsimile machine and pager the listing of his first terminal identifier may be followed by the indications of"M","F", and"P". These indications will then act to inform a person viewing the directory that that particular user could be contacted on either their mobile telephone. facsimile machine or pager, simply by composing a pre-determined code to identify the type of terminal, followed by the first subscriber identifier. This would the avoid the need to separately list each of the subscriber identifiers in a directory listing.

Furthermore, access means 71 may be provided in order to enable a directory assistance operator to access and possibly alter the contents of either or both the directory service database 70 and the information stored in the data storage means 11. Such directory assistance operators may be contact from the telecommunications network 2 by users of the above described service in order that the information contained in the directory service database 70 and the data storage means 11 is current.

In other embodiments of the invention, access to the directory service database and the data storage means 11 may be provided through various other interface means, such as the World Wide Web, in order that users are able to directly access and update their own personal information.

Referring now to Figure 4, there is shown a variant of the telecommunications system referred to in Figures 1 and 2. In this Figure, the telecommunications system 100 includes the same subscriber terminals 3,4 and 5 as shown in Figure 1. The subscriber terminal 4, once again, is connected to a telecommunications network by a mobile switching center 6 and associated base station 7 and 8.

In this example, however, at least part of the switching means for directing telecommunications signals within the telecommunications network consists of switching exchanges 110 which include a service switching function 111.

Accordingly, each of the switching exchanges 110,111 constitute a service switching point within an intelligent network. Each of the service switching points are connected to a service control point 112 which, in turn, is connected to a service management system 113. According to such an arrangement, each service switching point reacts to specific service triggers and initiates queries to the SCP over a common channel signalling network, such as the signalling system number 7 (SS7) network. The SCP reacts upon the query from the SSP and returns a message containing the data and instructions to complete the service. A service management system is linked to the SCP and supports the administration of a customer record within the SCP.

In this variant of the telecommunications system, the SCP contains a service logic program used for providing an intelligent network service, such as that required to detect the presence of a pre-determined code and subscriber terminal identifier in a telecommunications signal, and to query a data storage means as to the"real"terminal identifier used to access the subscriber terminal in question.

Such a service logic program is sent to the SCP from the SMS. Typically, the user of subscriber terminal 5 would dial a pre-determined code followed by the first terminal identifier used to communicate with the subscriber terminal 3. A call control function within the SSP is programmed to identify the presence of the pre- determined code and interprets this as a request for service by the intelligent network. The service switching function of the SSP interprets the request for the intelligent network service from the calling party and forms a standardized service for a request which it then sends to the SCP.

The SCP receives the request and decodes it. After this, it encodes and sends a standardized response to the SSP. The response would include instruction for the SSP to send the first terminal identifier information, and possibly the pre- determined code, sent by the user of the subscriber terminal 5 to the data storage means 11 in order to determine the subscriber terminal identifier of the subscriber terminal that the calling party wishes to contact. When this information is returned to the SSP, a request is once again formed and sent to the SCP. The SCP once again returns a command to the SSP and instructs it to direct the telecommunications signal originated from the subscriber terminal 5 to the intended subscriber terminal for receiving that signal.

The instructions determining the manner in which the SCP responds to service requests from the SSPs is sent to the SCPs from the SMS. Provision may be provided, via interface means 114, for a network operator or other user to maintain and update these instruction via the SMS 113. In addition, access may be provided via the SMS to the contents of the data storage means 11.

Finally, it should be appreciated that modifications and/or alterations may be made to the telecommunications system and method of communicating with at least one second subscriber terminal associated with a first subscriber terminal without departing from the ambit of the present invention described herein.