NZ264418A

NZ264418A - Mobile radio network with computer controlled conference service unit

Info

Publication number: NZ264418A
Application number: NZ26441894A
Authority: NZ
Inventors: Manfred Bohm
Original assignee: Alcatel Australia
Priority date: 1993-10-14
Filing date: 1994-09-08
Publication date: 1996-10-28
Also published as: EP0649266A3; AU7291694A; DE4335031A1; EP0649266A2; FI944818A0; FI944818A; AU673763B2

Description

<div class="application article clearfix" id="description"> 2 6 4 Priority Dato(s): JlfchU&.|.33 Complota Specification FllSd: Class: (?)....IAS* i*So.ife'+.. ttfifekPftSlSife Dwf=v '■ O Jovmvi! T'o: 4 1 mem NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION " MOBILE RADIO NETWORK >, 0^ 000 3^) WE, ALCATEL AUSTRALIA LIMITED, w — , A Company of the State of New South Waies, of 280 Botany Road, Alexandria, New South Wales, 2015, Australia, hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: 1 26 4 a * # This invention relates to a mobile-radio network and s conference-service unit therefor. A mobile-radio network with mobile switching centre which switches point-to-point connections is known from the "Mobile-Radio Handbook" by J. Kedaj and G. Hentschel, 3rd edition, Neue Mediengesellschaft Ulm mbH, 1993. Chapter 4 gives a description of the mobile-radio network GSM (Global System for Mobile Communications) with Section 4.1.4.4. detailing the mobile switching centra in the GSM network. In this known mobile-radio network, the mobile switching centre switches "connections to mobile subscribers via the BSC (Base Station Controller) and BS (Base Station) and to the resident subscriber via the PSTN (Public Switched Telephone Network)". Accordingly, the mobile switching centre is designed to switch point-to-point connections. A conference calt service, i.e. a multipoint connection between a minimum of three subscribers is not possible. A conference service designated "Muiti-Party Service" for the GSM mobile-radio network is described in the recommendations of the European Institute for Telecommunication Standards (ETSI) "GSM 02.84, version 4.4.1" dt. October 1992 and "GSM 02.30, version 4.9.0", pages 11-13, dt. April 1993. The performance characteristics of the conference service essential for the generation of the user programs (software to execute the conference service) are described therein. The physical means (hardware) required to establish the conference service in the mobile-radio network are not described. Furthermore, a mobile-radio network for car fleet calling is known for DE 31 16 656 C2, where a mobile switching centre contains a conference service, making it suitable for switching point-to-multipoint connections. It is an object of the present invention to supply a mobile-radio network with simple means to execute a conference service, in particularly for the case when the mobile-radio network comprises mobile switching centres which exclusively switch point-to-point connections. According to the invention, there is provided a mobile-radio network comprising a mobile switching centre which switches point-to-point connections between mobile-radio subscribers within the mobile-radio network or between the mobile-radio subscribers and subscribers of a telecommunication network connected to the mobile-radio network, wherein a computer-controlled conference-service unit connected to the mobile switching centre and comprising interface circuits for simulating at least three subscriber lines each having one virtual subscriber associated therewith, controllable switching devices for switching point-to-multipoint connections between the virtual subscribers, and computer and control means for controlling connection setup processes, so that the mobile switching centre switches point-to-point connections between a respective one of the virtual subscribers, and a respective one of the subscribers. According to a further aspect of the invention, there is provided a computer-controlled conference-service unit for a mobile-radio network comprising a mobile switching centre which switches point-to-point connections between mobile-radio subscribers within the mobile-radio network or between the mobile-radio subscribers and subscribers of a telecommunication network connected to the mobile-radio network, wherein interface circuits which, to provide the connection to the mobile switching centre, simulate at least three subscriber lines each having one virtual subscriber associated therewith, computer and control means which control connection setup processes via the subscriber lines so that the mobile switching centre switches point-to-point connections between a respective one of the virtual subscribers and a respective one of the subscribers, and controllable switching devices which switch point-to-multipoint connections between the virtual subscribers to establish and release conference connections. A computer-controlled conference-service unit is supplied accordingly,to connect to a mobile switching centre, which simulates at least three subscriber lines, switching point-to-multipoint connections between them. The mobile switching centre does not require any means to establish and execute a conference service. The invention enables a simple establishment of a conference service even in existing mobile-radio networks which are only suitable for the switching of point-to-point connections. 2 6 44 In the following, the invention is described with the aid of a practical example and drawings, which show the following in schematic form: Figure 1 a conference connection between mobile-radio subscribers and subscribers of a public switched telephone network and Figure 2 a computer-controlled conference-service unit for the mobile-radio network. Figure 1 schematically shows a mobile-radio network PLMN and a public switched telephone network PSTN connected to it. The mobile-radio network shown here is designed according to the GSM standard. The mobile-radio network comprises a mobile switching centre GMSC and base stations BS connected to it. The mobile-radio network furthermore comprises a computer-controlled conference-service unit SERV, connected to the mobile switching centre. Within the mobile-radio network PLMN mobile-radio subscribers can be given a cordless connection to one of the base stations and can also be connected to the mobile switching centre via the corresponding connection between the base station and the mobile switching centre. In the example only two mobile-radio subscribers M1 and M2 and two base stations are shown. To further simplify the drawing, base-station controllers are also not shown. The mobile-radio subscribers M1 and M2 are connected to the mobile 264 4 1 switching centre GMSC via the base stations BS and the not shown base station controllers. The mobile switching centre in this example is designed as a socalled transit switching centre (gate way mobile switching centre). It establishes the connection of the mobile-radio network PLMS with a telecommunications network, in this example a public switched telephone network PSTN, by being connected to a switching centre of the telecommunications network. In this example the public switched telephone network PSTN comprises a switching centre EXCH, which, for the example has two subscribers T1 and T2 connected. Switching stations, located between these subscribers and the switching centre EXCH, such as for example subscriber extension stations and local exchange stations are not shown here. In the following, the setup, execution and release of a conference connection between the four subscribers M1 and M2, T1 and T2 is described. In accordance with the invention, the computer-controlled conference-service unit is supplied for this, said unit being connected to the mobile switching centre GMSC, there simulating at least three subscriber connections with each being assigned a virtual subscriber number. In this example the mobile switching centre GMSC is only equipped for the switching of point-to-point connections. The point-to-multipoint connections required for a conference connection are switched by the conference-service unit SERV. Figure 2 is used for a more detailed description of the subscriber ^ 6 4 4 1 conference and shows the computer-controlled conference-service unit SERV in schematic form. To be able to connect to the mobile switching centre the computer-controlled conference-service unit comprises interface circuits A, each simulating a subscriber connection 1, 2, 3, N. In this example four interface circuits are shown, each simulating a four-wire subscriber connection. Via a not shown adaptor circuit, the subscriber connections are linked to a multichannel transmission path which in turn is linked to the mobile switching centre. Each subscriber connection 1, 2, 3 and N, which is simulated by one of the interface circuits, is assigned a virtual subscriber M1, M2, T1, T2, i.e. the mobile switching centre cannot distinguish between the simulated subscriber connections and real subscriber connections. As well as the interface circuits the conference-service unit comprises controllable switching devices C, which are connected with each other via a conference bus and switch the point-to-multipoint connections between the virtual subscribers. The conference bus is designed as data and control bus. The conference-service unit furthermore comprises computer and control means, such as a central processor CPU which is connected to the data and control bus, and four subscriber control circuits 0, each being connected to one of the switching devices. A working memory MEM is also connected to the central processor CPU. The central processor controls the switching devices C in such a way that one of the virtual subscribers (M1') is connected 2 6 4 4 to the remaining other virtual subscribers. The subscriber control circuits D transmit control signals (e.g. DTMF signals) to establish connections via the simulated subscriber connections 1, 2, 3 and N, so that the mobile switching centre GMSC can establish point-to-point connections between real subscribers in networks M1, M2, T1, T2 and the virtual subscribers M1', M2', T1' and T2'. The subscriber control circuits 0 are also responsible for maintaining and releasing switched connections. In this example the conference-service unit comprises voice-input and voice-output means B, which are connected to the interface circuits and the subscriber control circuits. This enables a voice-controlled conference connection. Initially, a simple conference connection between the subscribers shown in Figure 1 is described. The computer controlled conference-service unit, which executes a conference service in the manner of an intelligent network function, is in the following called server SERV. To set up a conference, one of the subscribers, here for instance mobile-radio subscriber Ml, dials the subscriber number TN 007, which is assigned to the server within the mobile-radio network. Accordingly, the mobile switching centre GMSC switches a point-to-point connection between the mobile-radio subscriber M1 and the virtual subscriber M1', associated with the fixed subscriber number. After switching this connection, the server is activated via the corresponding simulated subscriber connection 1. The computer and control means as well as the voice-input and voice- ® 4 4 | output means of the server generate an audio answer message, such as for example, "This is the automatic conference service. Please state the number of subscribers you wish to speak to." This message is relayed to mobile-radio subscriber M1 via the switched connection, the subscriber then acoustically enters the required number (here e.g. "three"). After receiving this message, the server SERV records the number by keeping a further three interface circuits A available for the desired conference connection and storing the number of subscribers in memory MEM. Then the server generates another voice message, such as for example "You wish to speak to three subscribers. Please state the subscriber number of the first subscriber." After receiving this message, the mobile-radio subscriber states the desired subscriber number, which is then stored in memory by the server. The other subscriber numbers are acquired in the same manner and then the conference connection is set up. The corresponding subscriber control circuit D controls the connection setup via the other three activated subscriber connections 2, 3 and N (frequency selection or pulse selection), so that the mobile switching centre and, if applicable, other exchanges switch a connection between the virtual subscribers MV, T1' and T2' and the requested conference subscribers M2, T1 and T2. The setup of the conference connection can be done with voice support messages, such as for example "This is the automatic conference 26 4 4 1 service. You are requested to participate in a conference. Are you ready?". If the requested subscriber acoustically declines his participation in the conference or this subscriber cannot be contacted (subscriber connection engaged or subscriber does not respond within a certain time frame), the server records this and sends a voice message to the mobile-radio subscriber requesting the conference. All contactable subscribers are switched to the conference bus via switching devices C. The actual interconnection of the subscriber channels can be done according to known processes. As an example, the signal levels on the subscriber channels are evaluated. The subscriber channel with the current priority signal level (speaker) is assigned with the other subscriber channels (listeners). An interruption of a connection can be detected by continuous evaluation of the signal levels which is conducted in the voice-input and voice-output means (B). A renewed establishment of this connection can then be executed via the subscriber control circuits (D). The computer controlled conference service unit presented here enables the establishment of a mobile-radio network with conference services in a simple manner. The conference-service unit SERV, similar to a multitude of additional subscribers M1', M2', T1' and T2', is connected to the mobile switching centre GMSC which need not be equipped for a connection of point-to-multipoint connections. A mobile-radio subscriber number TN 007 is assigned to the conference-service unit, so that by dialling this number the 10 conference service can be requested by each subscriber within the mobile-radio network PLMN, or by another network PSTN connected to this mobile-radio network, i.e. the conference-service unit is dialled like a normal mobile-radio subscriber. The voice-input and voice-output means B enable a very simple execution of the conference service, in particular for the mobile-radio subscribers. A complicated operation of subscriber terminal to establish and execute a conference connection (keyboard input, etc) is not required. Particularly advantageous is a conceivable design of the voice-input and voice output means B, which enables a voice-controlled execution of the conference in various languages. For this purpose the shown networks are designed as ISDN networks, so that the country code can be evaluated using the signallings of the subscriber numbers participating in the conference call. Then it is possible to determine in which countries the subscr'bers of a conference call reside. It is also conceivable to determine the language requested by the subscribers with the aid of language samples. The shown mobile-radio network PLMN is established for a conference service which is executed solely in the conference-service unit SERV supplied for it. This structure corresponds to an intelligent network and can therefore be easily expanded and matched to various requirements. For example, the conference-service unit is able to execute several conference connections independent of each other. This requires a corresponding number of interface circuits A, switching devices C and subscriber control circuits D. The shown mobile-radio network is designed as a cellular mobile-radio network according to GSM. However, multiple other designs are conceivable, in particular as DCS-1800-mobile-radio network or as TETRA-multiplex radio network. Applications in cordless office communications are also conceivable, as for example the connection of the conference-service unit to a cordless telecommunications system. 12 </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 4 4 What we claim is:

1. A mobile-radio network comprising a mobile switching centre which switches point-to-point connections between mobile-radio subscribers within the mobilerscMo network or between the mobile-radio subscribers and subscribers of a telecommunication network connected to the mobile-radio network, wherein a computer-controlled conference-service unit connected to the mobile switching centre and comprising interface circuits for simulating at least three subscriber lines each having one virtual subscriber associated therewith, controllable switching devices for switching point-to-multipoint connections between the virtual subscribers, and computer and control means for controlling connection setup processes, so that the mobile switching centre switches point-to-point connections between a respective one of the virtual subscribers, and a respective one of the subscribers.

2. A mobile-radio network as claimed in claim 1, wherein the conference-service unit is assigned at least one mobile-radio-subscriber number by which one of the subscribers requests the setting up of a conference call between him and others of the subscribers.

3. A mobile-radio network as claimed in claim 1, wherein the conference-service unit includes voice-input and voice-output means for the voice-controlled establishment and release of a conference connection.

4. A computer-controlled conference-service unit for a mobile-radio network comprising a mobile switching centre which switches point-to-point £ 6 4 4 | connections between mobile-radio subscribers within the mobile-radio network or between the mobile-radio subscribers and subscribers of a telecommunication network connected to the mobile-radio network, wherein interface circuits which, to provide the connection to the mobile switching centre, simulate at least three subscriber lines each having one virtual subscriber associated therewith, computer and control means which control connection setup processes via the subscriber lines so that the mobile switching centre switches point-to-point connections between a respective one of the virtual subscribers and a respective one of the subscribers, and controllable switching devices which switch point-to-multipoint connections between the virtual subscribers to establish and release conference connections.

5. A conference-service unit as claimed in claim 4, wherein the controllable switching devices control the connection setup processes in response to requests sent by at least one of the subscribers, and that at least one of the simulated subscriber lines is assigned a mobile-radio-subscriber number by which said subscriber requests the setting up of a conference call between him and others of the subscribers.

6. A conference-service unit as claimed in claim 4, including voice-input and voice-output means which, for the voice-controlled establishment and release of conference connections, evaluate telephone messages from the subscribers, and generate voice messages for said subscribers, respectively. 2 6 4 4

7. A conference-service unit as claimed in claim 6, wherein the voice-input and voice-output means evaluate requests and generate voice messages, respectively, in several languages.

8. A conference-service unit as claimed in claim 6, wherein the computer and control means detect interruptions in individual point-to-point connections with the aid of the voice-input and voice-output means, the computer and control means then controlling the re-establishment of the respective interrupted connection.

9. A conference-service unit as claimed in claim 4, wherein to release the conference connection, the computer and control means control connection release processes so that the mobile switching-centre successively releases the point-to-point connections between the virtual subscribers and the subscribers.

10. A mobile radio network, substantially as herein described will reference to Figures 1 - 2 of the accompanying drawings.

11. A computer-controlled conference-service unit, substantially as herein described will reference to Figures 1 - 2 of the accompanying drawings. ALCATEL AUSTRALIA LIMITED B. O'Connor Authorized Agent P5/1 /1703 15 </div>