WO2001035612A1

WO2001035612A1 - Method and a terminal device with a call-back function

Info

Publication number: WO2001035612A1
Application number: PCT/FI2000/000977
Authority: WO
Inventors: Jarkko Manssila; Juha-Pekka Jauhiainen
Original assignee: Elisa Communications Oyj
Priority date: 1999-11-09
Filing date: 2000-11-09
Publication date: 2001-05-17
Also published as: AU1399401A; FI109387B; FI19992413A

Abstract

The invention relates to a telecommunications network terminal device equipped with a call-back function, which includes means for receiving the network identity of a first calling subscriber from the telecommunications network and means for identifying the received network identity. The terminal device disclosed also includes means for defining a call-back identity differing from the identified network identity and corresponding to the identified network identity, and means for sending the telecommunications network a connection-formation request directed to the defined call-back identity. In this case, the network identity of the calling subscriber can be, for example, the received normal calling-subscriber identity and the call-back identity a number in a virtual private network (VPN) related to the first calling connection. The invention also relates to a method for making a call back, in which the calling subscriber's network identity is received from the telecommunications network and identified. In addition, in the method to which the invention relates, a call-back identity differing from the identified network identity and corresponding to the identified network identity is defined and the telecommunications network is sent a connection-formation request directed to the defined call-back identity.

Description

Method and a terminal device with a call-back function

The present invention relates to a telecommunications network terminal device, according to the preamble to Claim 1, equipped with a call-back function, which includes means for receiving the calling subscriber's network identity and means for identifying the received network identity.

The invention also relates to a method, according to the preamble to Claim 14, for implementing a call back, in which the calling subscriber's network identity is received from a telecommunications network, and identified.

Telecommunications network terminal devices (in the following, referred to simply as terminal devices) such as telephones, equipped with a call-back function according to the state of the art and connected to a subscriber connection, are able to record the network identity, such as a telephone number, of a calling connection, after receiving a connection-formation request from the direction of the calling connection. Such terminal devices can send the telecommunications network a connection- formation request to the destination according to the calling connection's network identity, if the possessor of the terminal device with a call-back function wishes to call back the connection that initially called their subscriber connection. Thus, those possessing a terminal device have been able to reply or not reply to a call, without knowing the telephone number or the person whom they wish to call back.

In various intelligent-switching-centre-based services, a method is known in which the line telephones and mobile telephones of a customer's facilities can be connected to the same service, thus creating so-called virtual private network (VPN). In calls between the facilities in such a networking service, the customer dials numbers according to the service's numbering, e.g., 88 + the extension number, or even just the extension number. In the telephone network, the calling subscriber's numbers move in their normal form, so that the dialled number and the calling subscriber's number first received are in practice different numbers.

A problem in known terminal devices equipped with a call-back function is that, when the specific connection referred to by the calling subscriber's number is called back, the call connection is always routed according to the calling subscriber's number, though a more appropriate route may exist. In a call made in a networking service or a real private network, the received network identity of the calling connection can be a number in a normal network, so the connection making a call back using that number will not be charged according to the pricing of the networking service or the private network and/or provided with other private network services.

The invention is intended to eliminate the defects of the state of the art disclosed above and for this purpose create an entirely new type of telecommunications terminal device equipped with a call-back function. The invention is also intended to create a method for implementing a call back.

The invention is based on using a call-back identity differing from the calling connection's network identity, but referring to the same connection as the calling- connection network identity received by the terminal device connected to the subscriber connection. The terminal device is set to form a call-back identity from the received network identity of the calling connection. Alternatively, the terminal device may be set to use the received network identity of the calling connection to retrieve the call-back identity and enter the call-back identity to the telecommunications network, if the terminal device receives, from the interface, a call-back request according to the calling connection's network.

More specifically, the telecommunications network terminal device, according to the invention, equipped with a call-back function is characterized by what is stated in the characterizing section of Claim 1.

The method according to the invention for implementing a call back is, in turn, characterized by what is stated in the characterizing section of Claim 14.

Considerable advantages are gained with the aid of the invention. The terminal device identifies the caller from the normal network telephone number that it receives and permits an automated call back using a number series differing from the telephone number of the normal network, such as a telephone number according to the numbering of a networking service or some other desired number, for instance, a number definable by the operator transmitting the call, or by the telephone network. A normal network number and a differing telephone number, such as a networking number, referring to the same connection can be saved in the same memory location in the terminal device with a call-back function. Thus, separate memory locations are not necessary to save the different identities of the same connection, so that fewer memory locations are needed in the terminal device's telephone storage memory, making the storage memory easier to use.

When calling back, the customer can easily use the networking service numbering, without having to separately key it in or select it from the memory, to benefit from the pricing and possible additional services of the networking service.

The invention allows the telephone storage memory of the terminal device with a callback function to be utilized to save both the real received calling-subscriber number and the networking service number to be used when calling. This can be exploited in various call situations. A caller calling the customer can be identified from the network identity of the calling connection, in this case the normal network calling-subscriber number, which is saved in the memory. Similarly, the benefits of the networking service can be provided in outgoing calls, by using a second number according to the networking service numbering, referring to the same connection, i.e. its call-back identity. This allows the networking service's benefits, such as pricing and possible additional services to be exploited when forming a call-back or other (e.g., call) connection to the relevant connection, without the customer having to separately key in the networking number or select it from the terminal device's telephone memory storage.

In the following, the invention is examined with the aid of examples and with reference to the accompanying drawings.

Figure 1 (example 1) shows one telecommunications network terminal device, according to the invention, equipped with a call-back function.

Figure 2 (example 2) shows another telecommunications network terminal device, according to the invention, equipped with a call-back function.

The example according to the flow chart of Figure 3 shows a method for implementing a call back with the aid of a telecommunications network terminal device, according to the invention, equipped with a call-back function. Example 1 , one terminal device, according to the invention, with a call-back function.

The terminal device 10 with a call-back function includes a logic system 11 and a data- transmission channel 12. Logic system 11 includes an interface 14, a memory element 15, and a logic element 16. Though in this example terminal device 10 is connected to a subscriber connection 13, it can also operate in several subscriber connections in turn.

Terminal device 10, equipped with a call-back function according to the invention, includes logic system 11 and a data transmission channel 12 between subscriber connection 13 and logic system 11. In the basic case, data transmission channel 12 is a transmission line connected from subscriber connection 13 directly to logic system 11, or a wireless connection between subscriber connection 13 and logic system 11. Data transmission channel 12 between subscriber connection 13 and logic system 11 can also be arranged using some other kind of telecommunications connection. What is essential, is that data can be transferred in data transmission channel 12 between subscriber connection 12 and logic system 11.

Logic system 11 comprises an interface 14, a memory element 15 for saving the information received from data transmission channel 12, and a logic element 16 able to receive excitations from data transmission channel 12, memory element 15, and interface 14, and able to form signals in response to these excitations and enter these signals in data transmission channel 12 and memory element 15.

Interface 14 is a system permitting the customer to operate the terminal device according to the invention, e.g., to browse the memory element and make calls. The control operations carried out by the user of the terminal device act as excitations to interface 14, with control signals being formed as responses to these control operations, the signals controlling the interface's logic element 16. For example, interface 14 can be the key-pad of a key telephone and a display element connected to it.

Memory element 15 is a system with at least one memory location, in which digital information can be saved as a response to a calling-connection identity received from a subscriber connection and as a response to excitations received from interface 14 and/or logic element 16. For example, memory element 15 can be an integrated circuit, in which binary values can be entered and saved in memory locations addressed with binary values, the saved binary values being retrieved from the memory element m i response to excitations according to the binary addresses of the said memory locations.

Logic element 16 is a system set to form a response to excitations received from its data transmission channel 12, interface 14, and memory element 15 and to send the signal thus formed to interface 14, memory element 15, and/or data transmission channel 12 according to each excitation. Logic element 16 is set to enter a binary value, according to the call-back identity, in memory element 15, as a response to the calling-connection network identity received in the calling-subscriber-identity field contained in a call- formation request received through data transmission channel 12 from subscriber connection 13. Logic element 16 may also, or instead be set to send data transmission channel 12 a connection-formation request, according to the call-back identity differing from the calling connection's network identity, in response to the calling subscriber's network identity (or part of it), received in the calling-subscriber-identity field, and saved in memory element 15 and entered in logic element 16.

Logic element 16 can be set to form a response, according to the call-back identity, from an excitation according to the calling subscriber's network identity, by setting the logic element to remove a specific first character-string from the excitation according to the calling subscriber's network identity and/or to add a specific second character-string to it. The logic element can comprise, e.g., a microprocessor and possible memory circuits and mass memories, from which the microprocessor is set to retrieve data.

Example 2, a second telecommunications network terminal device, equipped with a call-back function according to the invention.

Terminal device 20 includes means for receiving the calling subscriber's network identity from a telecommunications network 21 and means for identifying 22 the received calling subscriber's network identity. It also includes means for defining 23 a call-back identity differing from, and corresponding to the received identified network identity, as well as means for sending 24 the telecommunications network a connection- request, directed to the defined call-back identity. The means for defining 23 a call-back identity can include means for generating a call-back identity from a known network identity 27. In addition to, or instead of these, the means for defining the call-back identity include means for logically combining 25 the known network identity and the call-back identity programmed to correspond to it. These means can include further means for saving in a data structure the identified network identity and related call-back identity as data 26 bound to each other.

The means for receiving the calling subscriber's network identity from telecommunications network 21 allow terminal device 20 to receive a calling- connection network identity sent from a subscriber connection, during a connection- formation request sent to another subscriber connection. Such means may include the data transmission channel 12 referred to in the previous example and possibly the system components, such as transmitters and receivers, maintaining it. The means for identifying 22 the network identity of the calling subscriber are means that permit network terminal device 20 to distinguish the calling-subscriber identity contained in the connection-formation request, i.e. the network identity of the calling connection, from a signal received in the data transmission channel 12 and to perform operations individuated with the received network identity, such as saving the calling connection's network identity, and/or data from the connection- formation request originating from the calling connection. Logic system 11, referred to in the previous example, can include means for identifying the calling subscriber's network identity.

Terminal device 20 also includes means for defining 23 a call-back identity differing from and corresponding to the identified network identity. These means can form a call- back identity routing the call to a connection according to the identified network identity, e.g., a virtual switching-centre number, after receiving the identified network identity, e.g., a normal network number. Such means can include the elements of logic system 11 of the previous example, logic element 16 and memory element 15, as well as means for logically combining 25 the network identity and call-back identity and, in addition to, or instead of them, means for replacing part of the identified network identity with part of the call-back identity 29. Terminal device 20 also includes means for sending 24 the telecommunications network a connection-formation request directed to the defined call-back identity. These means are set to send the telecommunications network a connection-formation request according to the call-back identity differing from the received and identified network identity. Such means can include the previous example's logic system 11 and data transmission channel 12. The means for logically combining 25 the identified network identity and the call-back identity programmed to correspond to it can be set to attach a definition to the saved call-back identity and to the saved network identity showing that these data are connected to each other. Such a definition can be recursive and can, for instance, refer to the memory location where one of the identities is saved, or it can be a specific code saved in either the saved identity or part of it, in which the specific code can differ when attached to different identities. However, the specific code is such that the means used in the terminal device to retrieve saved data can be set to interpret it as connecting the codes to each other. The identities can also be logically combined by using specific physical locations to save identities corresponding to each other. Examples of means for logically combining 25 the identified network identity and corresponding programmed call-back identity are the previous example's logic element 16 and memory element 15.

The means examined here for logically combine 25 the identified network identity and correspondingly programmed call-back identity can include means for saving the identified network identity and the related call-back identity as data bound to each other

26 in a data structure. The means can include means for retrieving 28 saved data. The means for saving the identified network identity and related call-back identity in a data structure as data bound to each other 26 include hardware and software set to save the identified network identity and call-back identity in a previously created data structure, or to create a data structure and save the network identity and call-back identity in it.

Examples of such means are logic system 11 and a computer program set to install a data structure in logic system 11. The means for retrieving 28 data are hardware and possible software set to retrieve saved data, such as a network identity or call-back identity, from the data structure and physical location where it is saved. Examples of means for retrieving 28 saved data are logic element 16 and memory element 15.

The means, which may be incorporated in the means for defining 23 a call-back identity, to generate a call-back identity from an identified network identity 27, form equipment parallel to or replacing the means for logically combining 25 the identified network identity and correspondingly programmed call-back identity. The system set to form a call-back identity in response to a received network identity, or part of it, of a calling connection form such means. Logic element 16 of the previous example can be used as a device to generate a call-back identity from an identified network identity. The means for generating a call-back identity from an identified network identity 27 can include means that can be set to replace part of the network identity with a call-back identity part 29. This means in practice that the disclosed means can, for instance, remove the initial part of the received telephone number or other network identity and replace it with an initial part according to the desired call-back identity. For example, if correctly set, logic element 16 of the previous example can act as such an element.

The example according to the flow chart of Figure 3 shows a method permitting a terminal device equipped with a call-back function to make a call back to a first connection after receiving a call from the said first connection. The method comprises the following stages:

101) In the subscriber connection, a connection-formation request from the direction of the first connection is received from the telecommunications network. At this point, means for receiving a calling subscriber's network identity from the telecommunications network receive the calling subscriber's identity.

102) A choice then arises of whether to answer the received connection-formation request, stage 103, or not to answer it, stage 104.

103) The connection-formation request is not answered. In this case, a reference to the memory location containing the network identity of the first connection is saved in logic element 11 of the terminal device. Means for identifying the received network identity of the calling subscriber then separate the network identity of the first connection from the signal coming from data transmission channel 12, i.e. identify the network identity of the calling connection.

or

104) The connection- formation request is answered and a connection is formed. In this case too, a reference to the memory location containing the network identity of the first connection is saved in logic element 11 of the terminal device. Here too, means for identifying the network identity of a calling subscriber separate the network identity of the first connection from the signal coming from data transmission channel 12. Data on the connection-formation request coming from the first connection has been saved in terminal device 10, the network identity of the first connection has been identified, and the user of terminal device 10 can call the first connection back.

105) Terminal device 10 equipped with a call-back function receives a control signal from interface 14 to form a call back to the first connection, the reference bound to the identity of which having been saved in logic element 11 of the terminal device in stage 103 or in stage 104.

106) A choice arises, in which logic element 11 of terminal device 10 decides whether, in response to the network identity of the first connection and the control signal received from interface 14, it will form or retrieve the call-back identity differing from, and referring to the network identity of the first connection and forms or retrieves the call-back identity if required. The means for defining a call-back identity differing from, and corresponding to the identified network identity then define the call-back identity.

In cases in which terminal device 10 has not formed a call-back identity from the network identity of the first connection, operations take place according to stages 107 — 108 of the flow chart. In cases in which the terminal device has formed a call-back identity from the network identity of the first connection, the procedure is according to stages 109 - 110 of the flow chart.

107) The terminal device sends the telecommunications network a connection- formation request according to the network identity of the first connection.

108) Connection formation commences on the basis of the network identity of the first connection.

109) Terminal device 20 sends the telecommunications network a connection- formation request according to the defined call-back identity, such as a virtual private network (VPN) number. Means for sending a connection-formation request directed to the defined call-back identity then send the telecommunications network a connection- formation request according to the defined call-back identity, e.g., a request containing the virtual switching-centre network number.

110) Connection formation begins on the basis of the call-back identity. The invention can also be applied in the following ways.

The terminal device equipped with a call-back function according to the invention, or more specifically the means included in it for defining a call-back identity differing from, and corresponding to the identified network identity, can be used to change specific area-code prefixes, which may have been received from the interface of the terminal device through intercom dialling or directory searches, i.e. the most significant parts of the identified network identity, into specific other area-code prefixes, thus creating call-back identities, differing from the identified network identities, to be sent to the telecommunications network.

The means for replacing part of the network identity with part of the call-back identity can replace a part of the network identity other than the initial part, and/or the replacement part can be attached, using certain means according to the invention, to a different location in the network identity to that from which the replaced part was removed. The replaced part or the replacement part can also be an empty group.

The terminal device with a call-back function can be used with the identified network identity and the call-back identity logically combined. Thus, the calling connection identity and the call-back identity can be linked to form logically connected data for the terminal device. Similarly, the terminal device equipped with a call-back function according to the invention can also be used as disclosed above to retrieve saved data.

This application and particularly the Claims use the following definitions to refer to the following terms.

A network identity and a call-back identity, which is also a network identity, are identifiers, such as telephone numbers, referring to a specific subscriber connection in a telecommunications network. Examples of a network identity are a telephone number used in a company's real or virtual private network and a telephone number used in a public switched telephone network (PSTN) or in a public land mobile network (PLMN).

A connection-formation request according to a network identity is a message in digital or analog form, containing a specific network identity.

A call-back request according to the network identity of the first calling connection refers to a message received from the interface of the terminal device, commanding the terminal device to form a connection, e.g., a telephone connection, based on the received network identity of the first calling connection. Such a connection-formation request can be a message containing the network identity of the first calling connection, such as a message relating to number dialling. Or it can be intercom dialling to make a call back, based on a received network identity, in this case the network identity of the first calling connection.

Claims

Claims:

1. A telecommunications network terminal device equipped with a call-back function, which includes

- means for receiving the network identity of a calling subscriber from a telecommunications network (21), and

means for identifying the received network identity of the calling subscriber (22),

characterized in that the terminal device includes

- means for defining a call-back identity differing from the network identity and corresponding to the identified network identity (23), and

- means for sending the telecommunications network a connection-formation request directed to the defined call-back identity (24).

2. A terminal device according to Claim 1, characterized in that it includes means for logically combining the identified network identity and the corresponding programmed call-back identity (25).

3. A terminal device according to Claim 2, characterized in that it includes

- means for saving, in a data structure, the network identity and the call-back identity as data bound to each other (26), and

means for retrieving the saved data (28).

4. A terminal device according to one of Claims 1 - 3, characterized in that it includes means for generating (27) a call-back identity from the identified network identity.

5. A terminal device according to one of Claims 1 - 4, characterized in that it includes means for replacing part of the identified network identity with part of the call-back identity (29).

6. A terminal device according to one of Claims 1 - 5, characterized in that the network identity and/or the call-back identity is a telephone number used by a public switched telephone network (PSTN) or a public land mobile network (PLMN).

7. A terminal device according to one of Claims 1 - 6, characterized in that the call- back number is a telephone number in a virtual private network.

8. A terminal device according to one of Claims 1 - 7, characterized in that the callback identity is a telephone number in the private network of an individual corporation or of a group of corporations.

9. A terminal device according to one of Claims 1 - 8, characterized in that it includes a logic system (11) and a data transmission channel (12) between the logic system (11) and the subscriber connection (13).

10. A terminal device according to Claim 9, characterized in that its logic system (11) includes an interface (14), a memory element (15), and a logic element (16).

11. A terminal device according to one of Claims 9 - 10, characterized in that its logic system (11) is set to save data on the network identity of the calling connection as a response to a connection-formation request, in connection with which the network identity of the calling connection is received in the subscriber connection.

12. A terminal device according to one of Claims 9 - 11, characterized in that its logic system is set to send the telecommunications network, through the data transmission channel and subscriber connection, a connection-formation request, including an identity modified as its destination identity, in response to a control signal, received by the logic system from the subscriber connection, which control signal differs from the connection-formation request with the modified identity, that may be sent from the subscriber connection.

13. A terminal device according to one of Claims 9 - 12, characterized in that the logic system's logic element (16) and its memory element (15) form the means for logically combining the identified network identity and the call-back identity, and/or the means for generating a call-back identity from the identified network identity, and/or the means for replacing part of the identified network identity with part of the call-back identity.

14. A method for making a call back, in which

the calling subscriber's network identity is received from the telecommunications network (101), and

- the received calling subscriber's network identity is identified (103, 104),

characterized in that

- a call-back identity is defined, differing from and corresponding to the identified network identity (106), and

- a connection-formation request directed to the defined call-back identity is sent to the telecommunications network (109).

15. A method according to Claim 14, characterized in that when the call-back identity is defined, the identified network identity and the call-back identity are combined logically.

16. A method according to Claim 15, characterized in that the network identity and callback identity are saved in the data structure as data bound to each other and the saved data are retrieved.

17. A method according to Claim 14, characterized in that the call-back identity is generated from the identified network identity.

18. A method according to Claim 17, characterized in that, when generating the call- back identity, part of the identified network identity is replaced with a specific character string.

19. A method according to Claim 18, characterized in that the most significant part of the identified network identity is replaced with a specific character string.

20. A method according to one of Claims 14 - 19, characterized in that the network identity is a telephone number used in a public switched telephone network (PSTN) or in a public land mobile network (PLMN).

21. A method according to one of Claims 14 - 20, characterized in that the call-back identity used in the method is (109) a telephone number used in a virtual private network.

22. A method according to one of Claims 14 - 21, characterized in that the call-back identity used in the method is a telephone number used in the private network of an individual corporation or a group of corporations.