WO1999003253A1

WO1999003253A1 - Method and device using mobile telephones

Info

Publication number: WO1999003253A1
Application number: PCT/SE1998/001366
Authority: WO
Inventors: Per Olof Nerbrant
Original assignee: Telefonaktiebolaget Lm Ericsson
Priority date: 1997-07-11
Filing date: 1998-07-10
Publication date: 1999-01-21
Also published as: SE9702682L; SE512342C2; AU8368198A; EP1013064A1; SE9702682D0

Abstract

A method and an apparatus for allowing participants in a meeting or a conference to make contributions using a mobile telephone, or any other telephone, as a conference microphone are disclosed. The public telephone network is used in connection with a prior art loudspeaker system. A service node is used to connect the telephone network and the loudspeaker system. Participants can also select a channel to listen to on their telephones, for example, to hear a translation of the discussion.

Description

Method and Device Using Mobile Telephones

Technical Field

The present invention relates to communication during conferences and meetings, and in particular to a method and an apparatus for use in conferences, based on ordinary telephone equipment, for example cellular telephones.

Background of the Invention

It is common that participants in conferences are allowed to ask questions and make other contributions in connection with a presentation. In large conferences this requires a sound amplification system, typically with a number of loudspeakers installed, for example in the ceiling, and one microphone for each user, or one for a small group of users to share. In large meetings or conferences a large number of microphones are required, and it may be difficult to determine beforehand how many microphones are needed.

Alternatively, there may be wireless microphones, which may be moved between the users. This solution requires conference hosts or hostesses who will provide each speaker with a wireless microphone at the right time.

There are also room microphone systems, designed to capture the sound from a larger area comprising several individual speakers. Such microphones may conveniently be installed in the ceiling of the conference room. It is evident that this type of microphones will also capture undesired noise.

In addition, international conferences are often translated into several languages, and each user must be able to select the language he or she prefers. A common solution to this problem is to provide each participant, on request, with a headset with a wired connection to the sound amplification system and a device, which will allow each user to select a channel to listen to. Wireless connections such as radio, low frequency electromagnetic radiation fields or optical transmission may also be used. A similar situation to the above arises when groups of people are being guided in public places such as museums, and translation to different languages is wanted.

In the European patent application EP 0 187 696 a system for establishing communication between a number of persons in a meeting and a telephone system is described. A telephone comprising one or more microphones is used, whereby the microphones register sounds and transmit them to the telephone network. Signals received from the network are transmitted as pulsed infrared signals. Each person is equipped with an infrared receiver, which receives the signals and forwards them to an earphone.

Two services specified in the GSM standard are Voice Group Call, and Voice Broadcast respectively. In particular, the Voice Group Call Service, VGCS, teaches how to arrange for one person to speak to many listeners in a GSM system whereby all listeners use the same listening channel. One embodiment of the present mvention is based on the VGCS standard. However, whereas the service according to the referred standard has several disadvantages making it impractical for use in public conferences, the present invention solves this problem. In particular, a group, according to the standard, is static and intended to exist during a longer time, whereas a conference group is dynamic and changes from one conference to another in short time periods.

Summary of the Invention It is an object of the present invention to provide an apparatus, which will enable participants to make contributions in large meetings and conferences. It is another object of the invention to provide a voice amplification system for use in conference rooms and the like that is adaptable to virtually any size of the room and any number of participants. It is yet another object of the invention to provide a voice amplification system for use in conference rooms and the like, in which each participant can select a channel to listen to, for example for interpretation to another language.

It is still another object of the invention to enable conference participants outside the conference room to listen to the discussion and to make contributions over the same sound system as the conference participants.

It is another object of the invention to enable automatic announcement of the next speaker.

It is yet another object of the invention to provide an apparatus, which will enable automatic queuing of speakers and automatically connect the next speaker in the queue and amplify his or her contribution.

To achieve these objects, the public telephone network is used in connection with a prior art loudspeaker system. A service node is used to connect the telephone network and the loudspeaker system. A person who wishes to make a contribution in the meeting can call the service node from an ordinary telephone in the Public Services Telephone Network (PSTN), or any other telephone. The service node can keep a list of the people who wish to speak in the meeting, prompt and receive certain information from them, such as their names, and announce them and connect them to the loudspeaker system when it becomes their turn.

The invention offers the following advantages:

It provides a flexible way to arrange for participants in a conference to make verbal contributions.

It also gives several opportunities to create a number of services which are of use in a conference, such as translation services, where the translators are not required to be present at the site of the conference. It enables the automatic tracking of names of speakers, the time used by each speaker etc.

The invention is flexible with respect to the number of conference participants, so that inconveniences caused by either too large or too small microphone mstallations can be avoided.

Brief Description of the Drawings

Figure 1 shows a conference system according to a first embodiment of the invention.

Figure 2 shows a conference system according to a second embodiment of the invention.

Figure 3 shows a conference system according to a third embodiment of the invention. Figure 4 describes the actions carried out by a user who wants to use the conference system.

Figure 5 describes the actions carried out when a user is connected and allowed to make a contribution.

Figure 6 describes an exemplary conference with three connections, each corresponding to a language translation.

Figure 7 describes a conference control means according to the present mvention.

Figures 8a - 8c illustrate the actions taken by a mobile terminal in response to an incoming signal.

Detailed Description of Embodiments

Figure 1 shows a conference system according to a first embodiment of the invention. The system comprises a service node 1 connected to a PABX9 through a signalling connection. A person can access conference functionality in said service node 1 by calling a special subscriber number routing the call to PABX9 and whereby t e service node can control PABX- functions through said signalling connection. The control of PABX functions can, e.g., use the ECMA (European Computer Manufacturers Association) standards for interconnection of switches and Computers. The service node 1 is also connected to a conference control means 5 through a signalling connection. In a preferred embodiment the service node 1 and the conference control means 5 are integrated. An mcoming call to the PABX 9. using a special subscriber number, is controlled by the service node whereby, e.g., the call can be routed to the loudspeaker through the conference control means 5. Other examples of commanding the PABX by the sendee node will be given in the following description.

A telephone 7, which is used for control and for connection to the loudspeaker system is also connected to the conference control means 5. As will be evident to the person skilled in the art, other types of terminals could be connected to the control means 5 for input of data. A data terminal, such as a personal computer, preferably with Internet connection, would be useful for setting up a conference and for continuous control and supervision.

The PABX 9 is connected to a Public Services Telephone Network (PSTN) 11. One or more telephones 13 may be connected to the PSTN 11. A PLMN 15 also has a connection to the public network PSTN whereby 17 denotes a gateway between said two networks. The mobile switching node 18 can route calls from a mobile terminal 19 to the PSTN network through the gateway.

The conference control means 5 has input means for input of data, for example about conference participants, which will be stored in the service node 1. Other relevant information may be the telephone numbers from which calls should be accepted, telephone numbers to language translators who may be located outside the conference room and connected to the conference through dial-up connections.

The service node may also be used to keep track of how long each speaker is allowed to talk. This is useful for example in conferences where each participant is allowed a total maximum time or where each contribution is limited to a maximum duration. When a participant making a contribution is about to exceed the time limit, or a predetermined period of time before this happens, the service node may initiate notification of the participant over the telephone connection used by the participant. Said notification can, e.g., be a pre-recorded message, which is connected to an ongoing speech connection by means of a conference bridge known in the art. Said conference bridge can be part of the conference control unit 5. Time limits, recording of messages and other data are input from terminals connected to the conference control means 5. At the time the service node orders the associated PABX to connect a speaker to the loudspeaker system, a timer is set in the service node whereby supervision can take place of speaker time. Other services related to the management of speakers in the conference are implemented as software in the service node by methods known to persons skilled in the art. The conference control means 5 further has a signalling connection with the service node, indicated in figure 1 as a dotted line, whereby control signals and data can be transferred from the control means 5 to the service node.

A participant with a mobile telephone 19 can use this telephone as a conference microphone. Ordinary telephones 13 connected to the PSTN 11 may also be used, which will be convenient, for example, when someone outside the conference room wants to make a contribution. In this way people following a satellite broadcast of the conference or meetmg can also ask questions or make comments.

In this embodiment the loudspeaker system is any loudspeaker system known in the art, with at least one microphone 21 connected to it. The conference control means 5 comprise connectors for loudspeakers, microphones, telephones and other terminals. In addition, the conference control means 5 comprise control switches, circuitry for connecting said means to the service node for control signalling and to PABX to close a speech connection path. The conference control means can also contain amplifiers, timers and other circuitry implemented, e.g.. in microprocessor circuits according to methods known to a person skilled in the art. A second embodiment of the invention is shown m Figure 2 This embodiment is descπbed as bemg implemented m a Time Division Multiple Access (TDMA) s stem, such as the GSM system As in the first embodiment, the system comprises a loudspeaker system 103 connected to a PABX 102 through a conference control means 107 A telephone 109 and a microphone 111 are also connected to the conference control means 107 The PABX 102 is connected to the PSTN network 105 There is further a service node SN 101 which, m a preferred embodiment, is integrated with the conference control means 107 Preferably, this embodiment of the present mvention utilises the Group Voice Call Service specified m the GSM standard Accordingl , there is a Group Call Register, GCR108. connected to the MSC 104 of the GSM system 106 The PABX 102 has at least one subscription as dispatcher in said GSM system 106 allowing said PABX to initiate and disconnect voice group calls

The GSM system 106 is further connected to the PSTN network 105 through a gateway GMSC117 A. Base Transceiver Station BTS 115 is used to connect mobile terminals 119, 121 to PLMN

Each conference participant having a mobile termmal 119 can. by the present invention, use a number of conference services, which will now descπbed m detail A conference participant with a mobile termmal 119 can access a listening channel m order to listen to a specific language translation of the conference To each language translation there is a corresponding group call Said group call is set up by the conference mobile reference termmal 111 or a dispatcher termmal 109 which can either be located m the confeience room and comiected to the confeience control means 107 or be remote and connected as an ordinary telephone to PSTN 105 Each said group call is defined by a Group Identity stored m the Group Call Register according to the GSM/VGCS standard The mobile reference terminal 1 1 1 and the dispatcher termmal 109 are both having authority to initiate and to disconnect a voice group call Each of the wireless telephones 119 may comprise, or be connected to, a mobile control means 123, which may be used to download a protocol defining the user interface to the conference services, from the service node 101. This user interface is used, for example, to select a language to listen to, or to sign up to make a contribution.

The mobile control means 123, in general, here denotes the modifications of the terminal required in order to use the Voice Group Call Service provided by the network and for signal interchange with the service node SN. Figure 8a - 8c shows in more detail the function of the mobile control means 123.

One or more telephones 121 are used as reference telephones Preferably, the reference telephone 121 is only used as a reference telephone, and is not used by any of the participants. It then serves as a reference for the assignment of a listening channel corresponding to the traffic channel used by the reference 121. The reference phone 121, when connecting to a group call, also maintains the control signalling required by the mobile phone system. In a preferred embodiment, a said reference phone 121 is used by a speaker at the conference whereby the speaker uses the reference phone as a mobile microphone. In this embodiment, said reference phone has a SIM-card, e.g. issued by the operator, allowing the phone to connect as a dispatcher and receive a up- and downlink to the appropriate language version of the conference. It is obvious that there can be several phones having this access to the network. In the remaining of this description it is assumed that the network can provide a Voice Group Call Service according to the GSM standard.

As in the previous embodiment, traditional telephones 113 connected to the PSTN 105 may be used for connecting to the conference. In a preferred embodiment, these fixed phones are used by translation personnel, whereby one phone per translated lansuage is used. The detailed steps will now be described to set up and manage a conference to which language translators are connected.

As a preliminary, figure 6 shows a PLMN network, preferably a GSM network 301. The figure, exemplary, shows two listening conference participants 302, 303 and a talking conference participant 304. Further, it is shown a speaker 305 connected to the PLMN network and an appropriate conference by means of a duplex connection. The figure also shows three language translators, each having a fixed telephone 306. 307 and 308 connected to the PABX 309. There is also shown a service node already described. Further, there is a conference control means 310 to which a loudspeaker system 311 is coupled. In a preferred embodiment the service node is integrated with the conference control means 310.

In a first step a conference is set up by the conference administration. The conference administration has subscribed, at the operator of PLMN301, to at least one voice group call service, said subscription associated with a directory number in PABX309, i.e., the PABX309 will act as a dispatcher of said at least one group call. As a dispatcher, PABX309 has authority to initiate as well as disconnect a group call and to use a duplex connection to the network.

The conference administration, further, creates an association in the service node, by an input device (not shown) coupled to the conference control means 310, said association linking a conference title and a number of said at least one group call service subscription corresponding to the number of language translations which will be offered during the conference. There will thus be one separate group call per language translation.

The conference administration further has access to the network identifier of each group call, i.e. the Group ID, and the group authentication key to be used for ciphering. The access to these data can be by reception of said data from the network operator at subscription time or, on request, when setting up the conference. In the latter case the network operator may invoke a charge to the conference administration corresponding to the number of conference participants who will subsequently download these data to their mobile terminals. It is also possible to access said data through a signalling connection to the Group Call Register GCR108. Said signalling connection can use any suitable protocol, e.g. the MAP protocol specified in the GSM standard.

Next we will describe the preparation of a conference. Exemplary, according to figure 6, there are three languages in the conference set-up shown. Accordingly, the conference administration initiates three group voice calls shown at 311. By a novel conference bridge these connections are connected to the corresponding translators such that the downlink corresponding to a first language is connected to a translator who translates said first language to a second language and whereby said second language translation is connected through the corresponding uplink to the appropriate conference for broadcasting. Figure 6 shows the various paths explicitly using different line types. Arrows indicate the direction of the path. Exemplary, a conference where most participants use Swedish as their native tongue, the Swedish translation is connected to the loudspeaker system in addition to a possible broadcast.

We shall now discuss the speakers having terminals 305. These terminals are exemplary connected directly to the PLMN and have SIM-cards, issued by the network operator, allowing access to subscribed conferences as dispatchers, i.e. allowing initiation and release of group calls. However, it is apparent, for a person skilled in the art that said terminals 305 can also be connected to the service node through a wireless connection, e.g. based on DECT. The terminal 305, in any case, has a duplex connection with the appropriate language version.

Certain measures have to be taken in order to arrange the speaking sessions such that a translator is given a fair chance to do the translation work. Thus, figure 6 shows an arrangement whereby a suitable management of voice channels is achieved, said arrangement, e.g., being integrated with the PABX. It is understood that all voice channels will be input to the PABX, either coming from the GMSC in a GSM network or from a local wireless system, e.g. a DECT system. The PABX is connected to the service node SN whereby certain data can be retrieved about a speaker who is identified by, e.g., the A-number. Thus, SN can determine which language a speaker has chosen to listen to. Assuming that this language is also the preferred language when speaking, the service node can order switching of an incoming voice channel to the appropriate translator.

A detailed description will now be given of the function of the arrangement according to figure 6.

In figure 6 there is shown three input signals to the PABX401. At 1. two signals are input of the same language. These signals may, exemplary, originate from a conference participant having requested to speak, and a speaker. The service node 402 can analyse the A-number included in signals 1 and derive the preferred language, being stored in the service node. Using the derived language, the service node 402 can control the switch SW1 to route the signals 1 to a selection means C l arranged so that only one of two input signals is let through. For example, the first signal, which appears, to the input of Cl mutes the second signal. The selection means C 1 is coupled to the telephone 403 occupied by a translator of language 1. The translated signal 2 is thereafter fed into the switch SW2 which can select the signal for output to the loudspeaker system, not shown, in addition for routing the signal, through the PABX, for broadcast on the appropriate listening channel.

Figure 6 shows an example of a conference whereby the arrangement shown in figure 7 operates to effectuate the connections shown. The PLMN 301 comprises a bridge arrangement shown at 312. Said bridge arrangement can be part of an MSC in a GSM network. Two translators are shown at the telephones 306 and 307. Three conference participants are shown at 302,303. and 304. A speaker is shown at 305. The conference participants and the speaker have mobile telephones connected to PLMN 301. There are three different connections shown indicating three different languages. Each language is differentiated by the type of line used to indicate the routing of the corresponding voice connection. Thus, the speaker 305 is talking in a connection shown as a heavy line linking 305 to the conference at the bridge 312. The voice of the speaker is received by PABX309, which is also connected to the conference through the bridge 312. The PABX is controlled by the service node, which has stored data about language spoken by the speaker 305. Thus, the voice of the speaker can be routed to two translators 306, and 307. The corresponding translations are routed by the PABX309 to the group calls corresponding to said translations and broadcasted to the conference participants 302 and 303 respectively who have requested the corresponding listening channels. The voice of the speaker 305 is further coupled to the loudspeaker system 311 through the control means 310. The conference participant 304 has connected to the PABX 309 by a separate call through the PLMN network 301 in order to make a contribution or ask a question. The service node recognises the participant 304 to use the same language as the speaker and thus connects said participant to the corresponding group call. The participant 304 and the speaker 305 are thus both connected to the same group call and will be allowed to speak simultaneously which would cause difficulties for the translators 306 and 307. However, reminding the function of said arrangement being integrated with the PABX, it is understood that only the voice from one of 304, 305 will actually be routed to the translators.

A third embodiment of the invention is shown in Figure 3. The system comprises a service node 201, integrated with a PABX, connected to a PSTN network 205. A loudspeaker system 203 is connected to the conference control means 207. which in turn is connected to the PABX 201. A conference telephone 209 and a conference microphone 211 are also connected to the conference control means 207. The mobile connection means 215 may correspond to the base transceiver station of a mobile telephony system such as a GSM system, and 217 may correspond to a gateway between this mobile telephony system and a PSTN network 205. In this embodiment an external separate transmitting device 225 is used to define a small environment.

The transmitting device 225, preferably a transmitter of short range, for example an infrared transmitter or a radio transmitter, at regular intervals transmits the address of the service node 201, and a simple protocol for communication with said service node, to all telephones within the range of the transmitting device 225. One or more mobile phones 219 used with the invention each comprises a mobile control means 223 similar to the one used in the second embodiment.

The mobile control means 223 receives the information about the address of the service node and the protocol used. Having received the address information, the mobile telephone can connect to the service node automatically or in response to the user initiating commands according to the received protocol. The protocol is used in the mobile phone to allow a participant to notify the service node that he is present, by pressing a button. In response to pressing said button, the terminal establishes a communication with said service node whereby certain information may be exchanged. When the participant leaves the conference room, contact with the ttansmitting device 225 is lost and the service node 201 is informed that the participant is no longer present in the conference room.

The control logic needed is preferably comprised in the mobile control means 223. Upon detection that the signal from the transmitting device 225 has been lost, the control logic initiates a call to the service node 201, and transfers a message indicating that the mobile terminal 219 is out of range of the transmitter 225 and that the participant using the terminal 219 thus has probably left the conference room.

As shown in Figure 3, a display and control means 227 may be connected to the conference control means 207 to allow, for example, the chairperson of the meeting or conference to check the list of speakers and, if necessary, edit the list, or disconnect the current speaker. One possible implementation of such a function is described in EP 0 604 053, which describes a similar function for a telephone conference.

The activation and use of this service is shown in Figures 4 and 5.

Figure 4 describes the actions carried out by a user who wants to use the conference system.

Step S41 : The user calls the service node, and identifies himself. . The identification can be done by means of the calling subscriber number, which has also been requested at the registration to the conference and stored in the service node. The identification may also include a digit code to verify that this caller is authorised to be connected to the conference system. Said digit code may have been received in connection with signing up for the conference and delivered to the participant prior to the conference. It is only necessary to supply the code once to inform about the presence of the participant. A registered participant will then receive from the service node the Group Identity and authentication key corresponding to the selected choice. The terminal stores the Group Identity and group authentication key on the SIM

Step S42: The user is prompted to select the desired kind of service, e.g. in which conference to participate in, and does so. The indication of a service can, e.g., be by means of a special subscriber number. In one embodiment of the present invention, comprising the service node being integrated in a GSM network having a voice group call service, said indication can be through the terminal requesting an up link. The conference service software may interpret the channel request as a request to speak and inserts the calling participant in a speaker queue.

The user may be offered a choice of several different options according to a user interface presented on the calling terminal. Step S43 : If the user wants to listen to a speech channel, go to step S44. If the user wants to make a contribution, go to step S46. If the user wants to cancel a previous request, go to step S48.

Step S44: The user is prompted to join the conference and select the channel he wants to listen to. This may for example be a translation of the discussion to a selected language.

Step S45: The connection is now set up and the connection is released. The terminal will subsequently receive regular notifications from the network of the conferences signed up for. The notifications will commence as soon as dispatcher terminal 306- 308 (figure 6) has initiated a group call to deliver at least one translation of the conference. A terminal responding to a said notification will then receive a listening channel from the network, and the user can listen to the selected speech channel on the telephone. End of procedure.

Step S46: An optional step, in which the user is prompted to enter certain data over the telephone line. This may be, for example, the kind of contribution, e.g. question, comment or new information.

Step S47: The user hangs up and waits to be notified when it is his turn to speak. End of procedure.

Step S48: An optional step in which the user is asked to verify that the previous request should be cancelled.

Step S49: The previous request is cancelled. End of procedure.

The selection of service carried out in step S42 could be omitted, if only one service was offered, or if different telephone numbers were available for the different services In the latter case, each of said phone number dialled would connect the user to the service node, and at the same tune identify the desired service

In step S42. the user may. for example, order a translation Other services which the user may order repeatedly during the conference, are shown m the list below

• Register to speak, for example to β make a new contribution

• make a short comment to current speaker, which may be made immediately after the current speaker has finished

• Cancel a previous request

• Request operational data, such as

• information about the participant's position m the queue of speakers

• information about approximate waiting time • remaining time allotted for contribution

If the system was used for the purpose of providmg information, for example, the guidmg of tourists m a museum oi the like, the users might be offered a choice of language to listen to, and the department or room m the museum for which mformation was desired Upon selection, the user's telephone would then be tuned m to receive the desned information, m the desned language

A conference control device for lettmg individuals connect to a telephone conference is descπbed ιn EP 0 617 538 The device is mtended for telephone conferences, but could, with minor modifications, be used as part of the mvention Callers identify themselves by pressmg predetermined buttons to send DTMF signals to the control means, which can connect one or more users at a time The callers are placed in a queue, may use DTMF signalling to activate certain services, request the desired lansuage. and so on An apparatus for interactive call handling is described in EP 0 342 295. When a caller is to be connected, it is first checked that the caller is authorised to be connected. The user is then prompted to enter information. This apparatus is intended for gathering statistical information or for registering answers to TV show games or similar applications. However, a similar solution may be used for registering callers according to the invention, the speaking time used by each caller, the desired language, and so on.

Figure 5 shows the steps that are performed when the next speaker in turn is connected to the network to make his contribution.

Step S51: The current speaker has finished and hangs up.

Step S52: The service node requests a connection to the next speaker.

When the turn has come to the next conference participant, a procedure is invoked whereby the addressed participant is connected to the service node as a speaker. Said procedure may be implemented in a plurality of ways, whereby one method comprises the service node launching a voice message through the downlink and/or loudspeaker requesting the addressed participant to connect to the server. In another embodiment, the service node makes the connection to the participant in turn to speak. Still another embodiment entails the terminal, when identifying the incoming page as coming from the service node, responding by dismissing the mcoming call and instead initiating a call back to the service node. In still another embodiment, the service node is integrated with MSC whereby the service node, e.g. through a MAP interface, can order MSC to initiate an uplink request access signal to all terminals registered in the queue of speakers. In response to receiving the uplink request signal from the terminal in turn to connect as speaker, said terminal is connected whereas the other terminals responding to said uplink request access signal are only registered by MSC and the service node as still being present and prepared to connect when their turn comes. Step S53: The next speaker is announced according to the information entered in step S46 of Figure 4. This may be done using a synthesised voice in the conference control means, or the information may be displayed on screen to the chairperson of the meeting, who makes the announcement.

Step S54: The next speaker is connected to the conference.

Step S55: The user makes his contribution and hangs up. End of procedure.

The service node, the conference control unit and the loudspeaker system may be found locally, in connection with the conference facilities. The telephone networks, including the PSTN network, the Mobile Switching Centre (MSC) and the Base Transceiver Station (BTS) are preferably parts of the ordinary mobile telephone network, which are utilised for the purposes of this invention.

In the foregoing, several instances have been described when a mobile terminal takes responsive actions on incoming signals, the responsive actions being dependent on the terminal mode. Figure 8a - 8c summarise said responsive actions.

In figure 8a, the following steps are taken by the terminal in response to user actions and/or reception of signals from the service node.

Step S801: The terminal is in an idle state.

Step S802: With the terminal initially in an idle state, the user makes a first call to the service node.

Step S803: The terminal receives code from the service node representing a user interface and program logic for execution by terminal processing means. User makes a selection of conference title from said user interface. Step S804: The terminal receives identity of conference and authentication key for ciphering.

Step S805: The call is disconnected and terminal is prepared to receive notifications regarded, e.g., requests to speak.

In figure 8b, the terminal is in an idle state and receives a notification about a conference being initiated. The steps taken by the terminal are as follows.

Step S811: The terminal is initially in an idle state.

Step S812: The user is alarmed of the reception of a notification concerning a conference whereby the user responds to the notification, e.g., by pressing a button.

Step S813: The terminal receives information about the listening channel from the network and tunes to assigned channel.

Step S814: Terminal state is changed to listening. The user can listen to the requested language translation of the selected conference.

In figure 8c the terminal is initially in a listening state when pagings or notifications are received from the network initiated by the service node. The terminal takes the following steps.

Step S823: The terminal is in listening state

Step S824: In response to a page, the next step is S825. In response to a notification, e.g. through a signalling channel in a cellular system, the next step is S830. Step S825: Depending on implementation of application software in terminal, either step S826 or step S828 is taken.

Step S826: Terminal responds to page by disconnecting and initiating a call back to the service node.

Step S827: User can speak to the conference using the established channel.

Step S828: User responds to page whereby a connection is established with the service node and initiated by the service node.

Step S829: User can make a contribution.

Step S830: If a flag has been set at step S46 (figure 4) when the user made a request to speak, the terminal goes to step

Step S831: The terminal requests an uplink.

Step S832: The user makes a contribution.

Claims

1. A conference control apparatus for controlling speech contributions to a conference, characterized in that it comprises: - at least one mcoming telephone line;

- means for registering callers connecting to said conference control apparatus by means of a telephone, in a queue;

- means for establishing a connection to said callers at least one on said at least one telephone line one at a time, according to the queue order; - means for distributing mcoming speech on said at least one telephone line to a sound amplification system.

2. A conference control apparatus for controlling and distributing speech contributions to a conference, characterized in that it comprises: - at least one incoming and at least one outgoing voice channel;

- means for distributing said at least one mcoming voice channel to at least one receiver (306, 307) and at least one outgoing voice channel from said at least one receiver (306, 307) to said at least one outgoing voice channel.

3. A conference control apparatus controlling and distributing speech contributions to a conference, characterized in that it comprises:

- at least one mcoming and at least one outgoing voice channel;

- means for distributing said at least one incoming voice channel to at least one receiver (306, 307) and at least one outgoing voice channel from said at least one receiver (306, 307) to said at least one outgoing voice channel.

- means for establishing a connection to said callers at least one on said at least one telephone line one at a time, according to the queue order; - means for distributing incoming speech on said at least one telephone line to a sound amplification system.

4. A conference control apparatus according to claim 1, 2 or 3, characterized in that it comprises service means (1; 101; 201) and conference control means (5; 107; 207) for registering callers in a queue and connecting one caller at a time in the order of the queue.

5. An arrangement for enabling participants in a conference to make contributions to the conference, characterized in that it comprises the following:

- a telephone network (11; 105; 205) to which telephones (13; 113) may be connected;

- connection means (7, 21; 109, 111; 209, 211) for connecting the calls in said telephone network (11; 105; 205) with a sound amplification system (3; 103; 203); - conference control means according to any one of the claims 1 to 4,

- terminals (19; 119; 219), each of which is connectable to at least one telephone line for communication of voice and data with said conference control means.

6. An arrangement according to claim 5. characterized in that mobile telephones (19; 119, 121; 219) may be used, and that mobile connection means (15, 17; 115, 117; 215, 217) are connected to the PSTN to terminate the calls made from the mobile telephones.

7. An arrangement according to claim 6, characterized in that the mobile connection means (15, 17; 115, 117; 215, 217) and the mobile telephones (119, 121; 219) used are part of a TDMA network, such as the GSM network.

8. An arrangement according to claim 6 or 7, characterized in that the mobile telephones (119, 121; 219) comprise mobile control means (123; 223), used for controlling the mobile telephones.

9. An arrangement according to claim 8, characterized in that the mobile control means (123; 223) are used to download protocol information and to enable a connection between the mobile telephones (119; 121; 219) and the mobile connection means (15, 17; 115, 117; 215, 217).

10. An arrangement according to any one of claims 5-9, characterized in that it comprises a transmitting device, which may be connected by wireless connections to one or more of the mobile telephones to transmit information to the mobile control means of the mobile telephones.

11. An arrangement according to any one of the claims 5-10. characterized in that it comprises a display and control means (227) connected to the conference control means for, among other things, displaying a list of the callers in the queue.

12. An arrangement according to claim 11. characterized in that the display and control means (227) also allows editing of the list of callers, manual connection of a new speaker or manual disconnection of the current speaker.

13. An arrangement according to claim 12, characterized in that the control means (123; 223) is adapted to report to the service node when the connection between the mobile telephone (119; 219) associated with said control means (123; 223) is lost.

14. A method for allowing participants in a meeting or a conference to make a verbal contribution, which will be amplified by a sound amplifying system, characterized by the following steps:

- A user who wants to make a contribution connects to a control means in the telephone network by dialling a specific number on a telephone, identifies himself or herself, and is thereby registered in the queue of speakers; - The connection between the user and the control means is broken; - When the user is next in the queue of speakers, the control means initiates the connection to the user;

- The user makes his or her contribution and hangs up.

15. A method according to claim 14, characterized in that mobile telephones are used, and that mobile connection means are used to establish the connection to the control means.

16. A method according to claim 14 or 15, characterized in that a list of speakers is displayed for viewing and/or editing by means of a conference control means.

17. A method for providing participants in a conference or a meeting with translations of the lectures, speeches, and/or discussion, characterized in that telephones connected to a telephone network are used as receiving units, the method comprising the following steps:

- The participant dials a specified number to connect to a control means in the network;

- The conference control means prompts the participant to identify himself or herself and to select the language of translation; - The user selects the desired language;

- The conference control means connects the telephone to the correct channel.