WO2000007349A1

WO2000007349A1 - Method and system for implementing the service in a telephone network and/or mobile communication network

Info

Publication number: WO2000007349A1
Application number: PCT/FI1999/000642
Authority: WO
Inventors: Ville SÄDE; Timo Kaisla; Jorma Jaakkola
Original assignee: Abacus Solutions Oy
Priority date: 1998-07-28
Filing date: 1999-07-28
Publication date: 2000-02-10
Also published as: FI981670A0; AU5166099A; FI981670A

Abstract

Method and system for setting up a connection in a telephone network comprising a network service node (SN), a first telecommunication terminal (1) and a second telecommunication terminal (2). In the method, an A-subscription sets up a connection with a B-subscription while the latter is busy. The A-subscription is given notice of this and a menu on the basis of which a desired service is selected from the A-subscription. After a connection has been succesfully set up from the service node (3) to the B-subscription, call setup is started from the service node (3) to the A-subscription, whereupon the A and B subscriptions are connected together.

Description

METHOD AND SYSTEM FOR IMPLEMENTING THE SERVICE IN A TELEPHONE NETWORK AND/OR MOBILE COMMUNICATION NETWORK

The present invention relates to a method as defined in the preamble of claim 1 and to a system as defined in claim 13 for implementing a call back function in a public telephone network (PSTN, Public Switched Telephone Network) or mobile subscriber network (PLMN, Public Land Mobile Network) .

In the text below, the expressions ' subscrip- tion¹, 'subscriber' and 'mobile station' are used. In this particular case, all these expressions can be taken as identical terms referring to one and the same concept .

In the traditional wired telephone network and also in present-day mobile subscriber networks, e.g. the GSM network (GSM, Global System for Mobile Communications) , when the called subscription is busy, it may be informed about a new incoming call e.g. via a call waiting function. In this case, the called sub- scriber may alternate between active calls using certain commands. There are also queueing procedures by which the caller can remain waiting until the called line becomes available. One alternative is naturally to try calling again later. However, utilizing the call waiting function, queueing up or trying again later as mentioned above is not always an adequate solution for the situation.

Further, it is known that a call back function working on a similar principle can be implemented in the wired telephone network e.g. in conjunction with a telephone switchboard. The switchboard functions as an "intelligent" network component and waits until the called subscriber hangs up. After this, the switchboard sets up a speech connection between the subscriber who has been trying to set up a call and the called subscriber. It is known that the CCBS (Call Completion to Busy Subscriber) service is a standardi- zed service in the GSM network. However, a drawback with the standardized CCBS service is that it requires CCBS software in every mobile switching centre (MSC) .

The object of the present invention is to eliminate the drawbacks referred to above or at least to significantly alleviate them.

A specific object of the invention is to disclose a new type of method and system in which a CCBS service can be implemented independently of the mobile service standard and the local exchange and terminal equipment .

As for the features characteristic of the invention, reference is made to the claims.

In the method of the invention, an A- subscription (calling subscriber) is setting up a call to a busy B-subscription (called subscriber) . The A- subscription is given an announcement and/or a menu, on the basis of which the A-subscriber selects a desired service. From the A-subscription, a command for turning on a service, e.g. call back, is sent e.g. in the form of tone frequency signals when the service gives a suitable message or signal tone. The command is transmitted in the telephone network to a network service node (SN) , which identifies it. The network service node continues trying to set up a connection to the B-subscription until the latter is on-hook or until some other kind of time-out is tripped. The service node sets up a connection to the A- subscription after call setup to the B-subscription has been successfully completed. After this, the network service node is ready to establish a speech connection between the A-subscription and the B- subscription.

By utilizing the invention, an operator can implement a service that improves its readiness to serve its customers. In addition, the invention can be easily and advantageously implemented in any telephone and/or mobile subscriber network.

In a preferred embodiment of the present invention, the A-subscription trying to set up a speech connection activates the call back function by means of a certain predetermined tone frequency (DTMF, Dual Tone Multi-Frequency) signal, and the A-subscription is given notice of the activation of the call back function. In addition, the B-subscription is also in- formed about the call back.

In a preferred embodiment of the invention, attempts to set up a connection to the B-subscription are repeated by the service node during a predetermined maximum length of time. Further, in a preferred embodiment of the invention, the time interval between call setup attempts made from the network service node to the B- subscription is changed and, moreover, call setup attempts made from the service node to the B- subscription are stopped after the lapse of a certain length of time.

In a preferred embodiment of the invention, the commands and/or menus used between the service node and the telecommunication terminals are generated by using USSD (USSD, Unstructured Supplementary Service Data) .

Further, in a preferred embodiment of the invention, the commands and/or menus used between the service node and the telecommunication terminals are generated by using WAP (WAP, Wireless Application Protocol) .

In a preferred embodiment of the invention, the commands and/or menus used between the service node and the telecommunication terminals are generated by using SMS (SMS, Short Message Service) .

Further, in a preferred embodiment of the invention, for each service in a service menu, there is a given tone frequency signal corresponding to the service .

A preferred embodiment of the system of the invention for implementing a call back function in a telephone network comprises a network service node, a first telecommunication terminal and a second telecommunication terminal . The service node is capable of receiving a command sent by the A-subscription, and it comprises means for setting up a connection to the B- subscription, for setting up a connection to the A- subscription and means for establishing a connection between the two call legs started by the service itself. Further, the first and second telecommunication terminals comprise means for sending tone frequency signals. Moreover, the service node comprises means for receiving control signals coming from the A-leg.

In a preferred embodiment of the present invention, the network service node comprises means for identifying tone frequency signals and, moreover, the service node comprises means for giving notice of an activated service.

Further, in a preferred embodiment of the present invention, the telecommunication terminals comprise means for handling USSD messages and/or SMS messages and/or WAP messages.

In a preferred embodiment of the present invention, the service node comprises means for handling USSD messages and/or SMS messages and/or WAP messages .

As compared with prior art, the present in- vention has the advantage that the service implemented is independent of the network signalling used in the mobile subscriber network and/or telephone network. In addition, the service is independent of the terminal and/or radio interface. A further advantage can be recognized in the fact that the calling subscriber avoids useless re-attempts to set up a connection. In the following, the invention will be described in detail by the aid of a few examples of its embodiments with reference to the drawings, wherein

Fig. 1 presents an embodiment of the system of the present invention,

Fig. 2 presents a signal flow diagram illustrating the principle of call back according to an embodiment of the present invention.

Fig. 1 represents a system according to the present invention, comprising a mobile subscriber network MSN and, connected to it, a first mobile station 1 and a second mobile station 2. The mobile subscriber network MSN comprises a service node SN with a first mobile switching centre 4 (MSC) and a second mobile switching centre 5 connected to it. The first 1 and second 2 mobile stations comprise means 12 for sending tone frequency signals. The service node 3 comprises means 6 for receiving a command coming from the A- subscription, means 7 for setting up a connection to the B-subscription, means 8 for setting up a connection to the A-subscription and means 9 for setting up a connection between the A and B subscriptions. Moreover, the service node 3 comprises means 10 for identifying tone frequency signals and means 11 for giving notice of an activated service. Furthermore, the telecommunication terminals 1 and 2 comprise means 12, 14 and 16 for handling USSD and/or SMS and/or WAP messages. The service node 3 comprises means 13, 15 and 17 for handling USSD and/or SMS and/or WAP messages. The means 6 - 11, 13, 15 and 17 presented in

Fig. 1 are implemented in a manner known in itself, e.g. using program blocks and computers, and they will therefore not be described here in detail.

Fig. 2 presents an example of a signal flow diagram representing a call back function as provided by the invention. From an A-subscription 1, a call setup attempt (20,21) is sent to a B-subscription 2 in a mobile subscriber network. The call setup request is routed from a mobile switching centre 4 as presented in Fig. 1 to the service node 3 in charge of call setup requests made from the A-subscription and/or those addressed to the B-subscription. The service node 3, as presented in Fig. 1, transmits the call setup request to mobile switching centre 5, which directs the call setup request to the B-subscription 2 to be reached. As the B-subscription 2 is busy, a busy signal, arrows (22) and (23), is sent to the network service node 3 and further to the A-subscription 1. At the same time, a service menu (24) is sent to the A- subscription 1. Based on the menu, a desired service, in this example call back, is selected from the A- subscription 1. A command (25) for the activation of call back is sent from the A-subscription 1 to the service node 3. Once call back has been selected, a corresponding notice (26) is sent from the service node 3 to the A-subscription 1. The service node 3 starts setting up a call (27) to the B-subscription 2. The B-subscription is still busy (28) and sends a busy signal back to the service node 3. Upon the lapse of a certain length of time, a new attempt to set up a call (29) to the B-subscription 2 is made. This time, the B-subscription is on-hook (30) and a corresponding signal is sent back to the service node 3. At the same time, a notice (31) regarding call back is sent to the B-subscription. The service node 3 now starts call setup (32) to the A-subscription 1. The A-subscription 1 is also on-hook (33) , so a speech connection (34) can be set up between the subscriptions.

The invention is not restricted to the examples of its embodiments described above, but many variations are possible within the scope of the inventive idea defined in the claims

Claims

1. Method for setting up a connection in a telephone network comprising a service node (SN) , a first telecommunication terminal (1) and a second telecommunication terminal (2) , in which method an A- subscription 1 sets up a connection with a B-subscription while the latter is busy, c h a r a c t e r i z e d in that a command for activating call back is sent from the A-subscription; the command is transmitted to the service node (3) or a corresponding other service base; call setup to the B-subscription is started from the service node (3) or corresponding other service base; after successful call setup to the B-subscription, a connection to the A-subscription is set up; and the A-subscription and the B-subscription are connected together.

2. Method as defined in claim 1, c h a r a c t e r i z e d in that a command for activating call back is sent from the A-subscription to the service.

3. Method as defined in claims 1 and 2, c h a r a c t e r i z e d in that the A-subscription is given notice of the activation of call back.

4. Method as defined in claims 1 - 3, c h a r a c t e r i z e d in that the B-subscription is given notice of the activation of call back.

5. Method as defined in claims 1 - 4, c ha r a c t e r i z e d in that call setup attempts are repeated from the service node (3) to the B-subscription at most during a predetermined length of time .

6. Method as defined in claims 1 - 5, c h a r a c t e r i z e d in that the time interval between the attempts made from the service node (3) to set up a call to the B-subscription is changed.

7. Method as defined in claims 1 - 6, c h a r a c t e r i z e d m that the attempts made to set up a call from the service node (3) to the B- subsc╧Çption are stopped after the lapse of a prede- termmed length of time.

8. Method as defined in claims 1 - 7, c h a r a c t e r i z e d m that, when the B-subsc╧Çp- tion is busy, a notice and/or a service menu is given to the A-subscription, on the basis of which a desired service is selected from the A-subscription.

9. Method as defined in claims 1 - 8, c h a r a c t e r i z e d m that the commands and/or menus between the service node (3) and the telecommunication terminals (1,2) are generated by using USSD (USSD, Unstructured Supplementary Service Data) .

10. Method as defined in claims 1 - 9, c h a r a c t e r i z e d in that the commands and/or menus between the service node (3) and the telecommunication terminals (1,2) are generated by using WAP (WAP, Wireless Application Protocol) .

11. Method as defined in claims 1 - 10, c h a r a c t e r i z e d in that the commands and/or menus between the service node (3) and the telecommunication terminals (1,2) are generated by using SMS (SMS, Short Message Service) .

12. Method as defined in claims 1 - 11, c h a r a c t e r i z e d in that, for each service m the service menu, there is a given tone frequency signal (DTMF) corresponding to the service.

13. System for implementing call setup m a telephone network comprising a service node (3), a first telecommunication terminal (1) and a second telecommunication terminal (2), charact eri zed m that the service node (3) comprises means (6) for receiving control signals coming from an A-leg; means (7) for setting up a connection to a B-subscription; means (8) for setting up a connection to an A-subscription; and means (9) for establishing a connection between the two call legs set up by the service.

14. System as defined in claim 13, c ha r a c t e r i z e d in that the first telecommunication terminal (1) and the second telecommunication terminal (2) comprise means (12) for sending tone frequency signals (DTMF) .

15. System as defined in claims 13 - 14, c h a r a c t e r i z e d in that the service node (3) comprises means (10) for identifying tone frequency signals (DTMF) .

16. System as defined in claims 13 - 15, c h a r a c t e r i z e d in that the service node (3) comprises means (11) for giving notice of an activated service .

17. System as defined in claims 13 - 16, c h a r a c t e r i z e d in that the telecommunication terminals (1,2) comprise means (12) for handling USSD messages .

18. System as defined in claims 13 - 17, c ha r a c t e r i z e d in that the service node (3) comprises means (13) for handling USSD messages.

19. System as defined in claims 13 - 18, c h a r a c t e r i z e d in that the telecommunication terminals (1,2) comprise means (14) for handling SMS messages.

20. System as defined in claims 13 - 19, c h a r a c t e r i z e d in that the service node (3) comprises means (15) for handling SMS messages.

21. System as defined in claims 13 - 20, c h a r a c t e r i z e d in that the telecommunication terminals (1,2) comprise means (16) for handling WAP messages .

22. System as defined in claims 13 - 21, c h a r a c t e r i z e d in that the service node (3) comprises means for handling WAP messages (17) .