Allocating speech items to mobile units communicating on a direct mode channel

IS 2 139 322 T3

DESCRIPTION

Assignment of speaking turns to mobile units that communicate directly on a channel.

Field of the invention

The present invention relates to a method for assigning speaking turns to mobile units that communicate directly on a channel. The method comprises the following stages:

send a transmission of a speech element through a first mobile unit during the first mobile unit's turn to speak on the direct mode channel, a second mobile unit that takes the turn of the floor, send a speech element transmission The second mobile unit passed through during the second mobile unit's turn to speak on the channel directly.

Background of the invention

The method of the invention is specifically designed for use in PMR networks (private mobile radios or professional mobile radios), that is to say, trunked networks that are topically corporate networks or public networks in which all channels are shared by one or more user organizations. In such networks, subscribers have individual subscriber numbers as well as collective numbers indicating the communication group or group of subscribers to which the subscriber belongs. Therefore, calls destined for subscribers of a specific group can be passed to members of that group.

The invention is suitable for use in mobile communication systems with digital radio paths, as well as analog radio paths. Analogue mobile communication systems are described, for example, in the publication MPT 1327, A Signaling Standard for Trunked Private Land Mobile Radio Systems (a signaling standard for trunked private land mobile radio systems), January 1988, revised and reprinted in November 1991, and in publication MPT 1343, Performance Specification, January 1988, revised and reprinted September 1991, both published by the Radiocommunication Agency of the UK Department of Commerce and Industry.

A collective call is one of the essential functions of a private radiocommunication system. A collective call is used, for example, in all kinds of operations involving more than one participant, particularly when an entire group must be constantly up-to-date on the progress of events. A conference call is a conference call in which all participants can speak in turn and can listen to each other. In collective calls the whole group is called by a common number. A single radio unit, for example a mobile unit or a radio telephone, ie a subscriber station, can belong to several groups programmed within the radio unit. The programming can be fixed, but can also be changed by the user of the mobile unit. The system stores information in the base stations related to each collective number. The collective call can cover one, several or all base stations within the service area of ​​the mobile telephone exchange or of several mobile telephone exchanges. When a collective call is made, a traffic channel is assigned in all the base stations related to the group, and each of said base stations transmits a collective call message that includes the group number and information about the group channel. assigned trophic. If the mobile unit recognizes the group number included in the group call message, it will switch to the traffic channel indicated in the group call message. Therefore, in principle, the mobile unit is always available for a collective call if it is located within the group's predetermined operational area and if it is not already busy with another collective call.

In addition to system channels in mobile radiocommunication systems, the radio system may employ direct mode channels, that is, the operation is in direct mode. Subscriber stations communicating in direct mode do not communicate directly with the radio network or their base stations. Direct mode channels are FDMA frequencies or TDMA time periods, in which radiotelephones or other units can communicate outside the system directly with each other, or via repeater stations, either with the base stations of the system or with other mobile units.

Direct mode channels are topically used in situations where, for example, a number of handheld telephones communicate with each other at a distance from the base station that does not allow the system channels to be used.

Another important utility of direct mode channels is to add capacity when the traffic in the system increases rapidly (for example in an incident) in a part of the service area of ​​the system, for example in a specific part of it.

A direct mode channel is called a simplex channel or simplex connection. A direct mode channel is a channel that is topically not available in any way for use by the system. It can be for example a channel having a channel spacing equal to that of a mobile communication system, for example 12.5kHz or 25kHz. Of the radio telephones that communicate on a direct mode channel, the sending radio telephone has tuned its transmitter to the channel and transmits voice or data information. The other radio telephones that are using direct mode channels have tuned their receivers to the same channel and heard the transmission directly.

Direct mode channel operation can use analog modulation or digital modulation. A radio-telephone that transmits on a channel can also send signaling information, such as information on user rights and priorities or information on the group that communicates on the channel, or traffic

ES 2 139 322 T3 of data. A direct mode channel can employ encryption or transmit pure, unprocessed speech.

In typical bus call traffic to private or professional radio mobile systems, there is a need to provide a normal "free space" feature , as generally two parties are communicating and the others just want to listen. In that case, it would be desirable that these two subscribers involved in the communication can end their speech before a third party can interrupt the communication with their speech element. In the methods of the prior art, no solution has been provided to the problem indicated for the operation of mobile units communicating on a channel directly.

Document WO 94/17642 A (Nokia Telecommunications Oy) refers to a procedure for the allocation of speech elements in a mobile center, said speech elements being requested simultaneously by subscribers belonging to the same group by means of of interfaces to a mobile center.

The solution provided by means of said reference refers to an entire mobile communication system comprising one or more mobile centers, base stations related to the above, and mobile stations connected to the base stations.

The reference does not describe a repeater for a direct mode channel or any other type of repeater, or parameters to be used in said repeater.

Document WO 95/24655 A (Nokia Telecommunications Oy) refers to a method for controlling a subscriber station operating on a direct mode channel in a radio system comprising a radio network containing at least one base station and subscriber stations, the radio system further comprising at least one repeater station that transfers the traffic between said at least one base station and the subscriber stations operating on the channel directly.

The reference exposes a mobile communication system that comprises a base station, subscriber stations connected to the previous one, and a repeater station that transfers the traffic between said base station and the subscriber stations operating on a (separate) channel of direct mode. The main idea inherent in this reference is to maintain a database in the repeater station that stores the identifiers of those subscriber stations, that is, mobile stations, that operate on channels directly in the coverage area of ​​said station. repeater.

Document WO-A-93 07723 (Nokia Telecommunications OY) discloses a procedure for making a collective call in a digital radio network where a plurality of mobile subscribers participating in a collective call wander in the area of ​​at least minus one base station. Following the procedure, the subscribers participating in the collective call are guided one by one to speak on the same radio channel. In order to be able to manipulate the traffic in a controlled manner at all times without the subscribers blocking said radio channel for speaking simultaneously, the base station receives information on the subscriber's desire to speak after said subscriber has indicated his desire to speak. By means of suitable signaling, the next subscriber to speak is selected at the base station based on a predetermined algorithm, and the base station transmits an indication of the turn to speak to the subscriber who at that moment will be the next to speak.

The problem with the solutions of the previous technique is that there is no system for direct mode channels that prioritizes the beginning of speech elements of mobile units participating in a collective call in such a way that for example two subscribers who have just participated recently in a communication they were given an opportunity to finish their dialogue before a third subscriber was given a turn to speak.

Brief description of the invention

The description that follows uses the following terms: a recent user is the same as the user who spoke before the user who left. A non-existent user is a user who gives up his turn to speak, that is to say, ends his speech element.

An objective of the present invention is to solve the problems related to the solutions of the prior art. Thus, the purpose of the invention is to carry out the priority of a recent user in a collective call in communication in a direct way. This means favoring the recent user in a group call on a direct mode channel.

This novel method to assign speech elements is achieved with the method of the invention, which is characterized by also comprising the stages of:

send priority information indicating which mobile user or which mobile users are or are prioritized to have the next turn to speak on the channel directly that come from the second mobile unit on the channel directly, in response to said information from priority, take the next turn to speak to said mobile unit indicated to be prioritized, send the transmission of said mobile unit during said next turn to speak.

A second embodiment of the invention relates to a method for assigning speech elements to mobile units communicating on a channel directly, the method comprising the following steps:

send a transmission from a first mobile unit during the turn of the first mobile unit on the direct mode channel, a second mobile unit that takes the floor, send a transmission of the speech element through the second mobile unit during the second mobile unit's turn to speak on the direct mode channel.

This method according to the second reali3

The use of the invention is characterized in that it also comprises the following stages:

send, from the second mobile unit on the channel directly, priority information indicating which mobile user or which mobile users are or are prioritized so that they have the next turn to speak on the channel directly, in response to said information from priority, take the next turn to speak to said mobile unit indicated to be prioritized, send the transmission of said prioritized mobile unit during said next turn to speak.

The invention further relates to a mobile unit communicating on a direct mode channel, comprising a memory element, a transceiver and a control unit for controlling the operation of the mobile unit.

The mobile unit of the invention is characterized in that it comprises a controller element to control the mobile unit so that it works so that after the completion of the speech element of the second mobile unit, it obtains the priority to start a speech element or request a turn to speak before the other mobile units communicate through said channel directly.

The invention is based on the idea of ​​recent user priority such that a speaking person gets a new speaking turn faster than any other mobile unit communicating on the channel directly. The goal is for the speaker preceding the terminating user to get a turn to speak, if desired, immediately after the termination of the terminating user's speech item, so that no other mobile unit / talker gets a call. turn to speak before such a recent user.

The basis of the invention lies in the idea that the priority of the person who precedes the user who is leaving (to obtain the next turn to speak) is increased in such a way that a turn to speak is granted to the same master easily as to the others. The recent user priority can also be carried out beyond various speech elements, in such a way that the procedure favors not only the previous user, but also the user or users who preceded them.

The idea of ​​the invention consists in that the second mobile unit that took a speaking turn after the speech element of the first mobile unit and that ends its speech element, that is to say that it is giving up its speaking turn, adds to its transmission of information on the fact that the person speaking who preceded the user who has withdrawn, that is, the first mobile unit, is prioritized to have the next turn to speak. In response to this information, the first mobile unit may, if it wishes, take the next turn of the floor without being disturbed by other (third) mobile units on the channel that want speaking turns by transmitting its speech elements. It is obvious that the priority of the recent user can be given to the immediately preceding user, ie the first mobile unit or to several recent users.

An advantage of the method and of the radio unit of the invention consists in that the problems of the solutions of the prior art are eliminated, that is to say that they allow the speaker who precedes the withdrawing user to be favored when the next speech element be assigned on a direct mode channel.

Brief description of the drawings

The present invention is described below with reference to the accompanying drawings, in which:

Figure 1 is a schematic view of a situation where subscribers participate in a collective call on a channel directly,

Figure 2 shows the communication of radio units according to the invention in a direct mode channel,

Figures 3a and 3b are flow charts illustrating the operation of a mobile unit looking for a transmission shift,

Figures 4a and 4b are flow charts illustrating the method according to the invention,

Figure 5 is a block diagram of a mobile unit according to the invention, which communicates on a channel in direct mode.

Detailed description of the invention

Figure 1 is a schematic view of a situation where subscribers participate in a collective call. Subscribers A1, A2, A3, using their mobile units referred to in the present invention, belong to the same call of group G1; the other subscribers participating in this collective call are not shown. The collective call was made on an MD direct mode channel. Subscribers A1 and A2 participate in the collective call speaking in turns, thus making a dialogue. According to the invention, both subscribers A1 and A2 who speak primarily assign speaking turns to each other, in such a way that the dialogue carried out by these two subscribers can be complete. The subscriber A3 would like to have a speaking turn, but according to the invention the speaking turns are allocated between the subscribers A1 and A2 only. Therefore, a subscriber A3 is prevented from obtaining a speaking turn until the dialogue between subscribers A1 and A2 has ended and the person who was previously speaking has finished his speech item. Arrow 10 in the figure indicates the exchange of speech elements between subscribers A1 and A2. According to the invention, the withdrawing subscriber A1 inserts into the transmission of his speech element information on the fact that the subscriber A2 preceding the withdrawing subscriber A1 is prioritized to have the next speaking turn. In response to this information, the previous subscriber A2 can, if he wishes, take the next turn to speak without being disturbed by the other mobile units A3 (third parties) on the channel directly wishing to speak by transmitting their speaking requests. or speech elements.

Figure 2 illustrates the communication of radio units UR1, UR2, UR3 according to the invention on a direct mode channel MD. Radio units can be mobile units or other entities.

ES 2 139 322 T3 are provided with a radio apparatus that serves to communicate on a channel directly. The radio units can also be relay stations for mobile communication systems. The invention works in principle as described with reference to the Figure

1. The method of the invention can be carried out for example in the following ways:

1. ) The mobile unit counter increments up in each case after a new speech item; This will be explained with reference to Figure 3, and

two. ) Explicit addressing, by means of which the withdrawing user expressly indicates the subscriber or subscribers who are or are authorized to have the next turn to speak on the channel directly; This will be explained with reference to Figure 4.

Figures 3a and 3b show flow diagrams of the method of the invention. Here a recent user priority counter built into mobile units is used. In this way the mobile unit keeps a record of how many speaking turns have been taken after said mobile unit had a speaking turn. This method works in such a way that the mobile unit that ends its speech element adds to its transmission information about how many recent users are favored when the next speech element is assigned.

According to this form of realization of the invention, that is, the alternative with a counter, the procedure is such that whenever a mobile unit gives up a turn to speak, that is, it stops talking and possibly stops pressing the push button To speak, reset your priority counter (Figure 5) to the initial value, for example, 1. The counter value is incremented whenever another mobile unit takes a turn to speak and begins to speak. It is also possible to increment the counter in response to a message informing the mobile unit that another mobile unit has given up its turn to speak. When the mobile unit ends its speech element, that is, it gives up its turn to speak, it informs the other mobile units about this fact in its transmission. The transmission of the mobile unit may also include an order to other mobile units to take a turn to speak in such a way that the order only gives priority for one turn to speak to the mobile units whose priority counter has a given value, for Example 1 or 2, if specifically the two preceding mobile units were given the right to speak, that is, they will be favored. Naturally, said withdrawal message can include any priority parameter value, depending on which recent or remote preceding mobile unit is to be favored.

In the method, the withdrawing user's mobile unit indicates to the other mobile units how many recent users are favored. Typically, only one mobile unit / recent user is favored. However, the method also makes it possible to favor several preceding mobile units. It should be noted that the information included in the desisting user transmission about how many recent users are favored can also be in a direct mode channel specific parameter.

When a recent user wishes to speak after the termination of the speech item, this must be indicated to the mobile unit even before the termination of the speech item of the withdrawn mobile unit. One way to indicate this is to press a push-to-talk button on the mobile unit whose user wishes to have the next speaking turn.

A mobile unit searching for a transmission turn stores information on how many speaking turns have been taken after it last sent its transmission as a speech element for the collective call in question. If this mobile unit specifically transmitted the previous speech item, the recent user counter parameter of that mobile unit is 1.

The transmission location is calculated using the starting location of the first random access frame and the count of the recent user of the mobile unit attempting to transmit.

The mobile unit can begin transmission if any of the preceding transmission locations have not been used. This is determined by the mobile unit receiving an acknowledgment message from a non-existent mobile unit. If there is no acknowledgment from the absent mobile unit or if the acknowledgment is negative, the mobile unit starts to send a request for a speaking turn in the normal manner (first attempt).

The flowcharts shown in Figures 3a and 3b illustrate the operation 301 of a mobile unit UR searching for a transmission turn. The mobile unit receives in 302 communications on a direct mode channel. Simultaneously, the mobile unit UR checks at 303 whether the recent user / subscriber speech element is ending. If the speech element does not end, the mobile unit operation returned to the preceding step 302, in which the mobile unit was receiving communication. If, on the other hand, the speaking element ends, the mobile unit UR checks at 305 whether its user has requested a speaking turn. If not, 306 the mobile unit UR waits 307 for the user's speech item or starts communication. In the next step 310, it is examined whether the user has requested a speaking session, and if he has,

315, the execution of the method continues to stage

316, in which it is verified whether the priority of the recent user is invoked or activated. If, on the other hand, it has been found in step 10 that the user has not requested a speaking time at 311, it is verified in the next step 312 whether the communication begins. If not, the execution of the method returns in 313 to step 307, in which the user's speech element or the beginning of the communication is expected. If, on the other hand, communication starts, the recent user counter is incremented up one step.

IS 2 139 322 T3

If in step 310 the user had requested in 315 a speaking time, the method proceeds to step 316, in which it is examined whether the recent user priority according to the invention is invoked or activated. Otherwise, the method proceeds to step 317, in which the first starting location is set to be the same as the transmitting location of the first request for a speaking session, added with the number of recent users. It is also possible to establish that this first starting location is higher than the previous one, that is, higher than the transmission location of the first request for a speaking session added with the number of recent users. Next, step 318 takes the method to the normal first-try procedure.

If, on the other hand, it has been found in step 316 that the priority of the recent user according to the invention is invoked or activated, at 319, the method proceeds to step 320. This step examines whether the number of recent users is greater or greater. equal to the value of the recent users counter. Otherwise, the execution of the method stops at step 317 from which the method passes at step 318 to the procedure of the first attempt. If, on the other hand, the number of recent users is greater, by 322, than the value of the recent users counter in step 320, the location of the transmission of the speaking request is set in step 323 so that let it be the transmission location of the first request for a speaking session added with the value of the recent users counter. Then, in step 325, the location of the next transmission is expected. After that, the location of the request for a speaking time is examined in step 326. If the location is not correct, in 327, the method goes to step 324, in which it is examined if the communication begins. If, on the other hand, the transmission location is correct, a request to speak is sent in step 330 using the reserved transmission location, after which in step 331 it is examined whether a positive acknowledgment from the mobile unit UR desist has arrived. Otherwise, at 332, the execution of the method proceeds to step 317, where the first-try start location is established. If, on the other hand, the acknowledgment from the withdrawing mobile UR unit is positive, the method proceeds to step 333, in which the mobile unit is sending its transmission. The method then proceeds to step 334, in which it is verified whether a speech item completion request arrives from the user. If there is no speech element completion request 335 from the user, the execution of the method returns to step 333, where communication was sent. If, on the other hand, a request for the termination of a speech element arrives from the user, the execution of the method is continued from step 336 in which the mobile unit that gives up the turn to speak communicates to the other mobile units in the speech channel. direct mode the priority information with which the other mobile units are informed that they can try to take the next turn to speak if their recent users counter has the value 1. This value is an example of favoring the user who had a turn to speak immediately before the withdrawing subscriber. It is of course also possible to set the priority parameter to some other value, which means that another recent user or more than one recent user is favored.

Figures 4a and 4b are flowcharts illustrating a method according to another embodiment of the invention, which uses explicit routing when a non-existent user assigns speech elements to mobile units waiting to have the next speaking turn.

In this embodiment, the procedure is such that when a mobile unit receives from its user an indication that the user wishes to have the next speaking session, the mobile unit stores the identifier of the recent user (mobile unit). When the user then completes his speech item, the mobile unit sends an announcement to the recent user in its transmission. In response to this prompt, the recent user can take the floor if he wishes.

In this method, the user who ends his speech item, that is to say, the quit user, that is, the UR mobile unit, unambiguously indicates the address to the recent user or users.

When the recent user wishes to speak after the speech item, this must be indicated to the UR mobile unit before the end of the speech item. In Figure 4, this indication is shown in step 408, in which it is verified whether the user has requested a turn to speak. If the recent user wishes to have a speaking turn, he can signal his wish, for example by pressing his push button to speak.

If the address of the UR mobile unit is the same as that indicated as the address of the preceding UR mobile unit (recent user) in the transmission of the speech element of the discontinued UR mobile unit, the UR mobile unit can take advantage of the possibility of a request for a speaking time that is reserved for the preceding mobile unit.

The broadcast location is counted using the starting location of the first random access box.

If there is no acknowledgment from the withdrawn UR mobile unit or if the acknowledgment is negative, the UR mobile unit begins the request for a turn to speak in the normal manner, according to the first attempt procedure explained above.

In the flow charts of Figures 4a and 4b, steps 401-415 correspond to steps 301-319 of Figures 3a and 3b. The method proceeds to step 316 shown in Figures 4a and 4b if it has been found in step 412 that the recent user priority discussed above is invoked or activated on the mobile unit that spoke during the preceding speaking time. In such a case, it is examined in step 416 whether the address of the recent user is the same as the address of the mobile unit itself. Otherwise, the execution of the method passes in 417 to step 413, which has been explained as step 417 in the flow chart of Figure 3a. If, on the other hand, I gave it

ES 2 139 322 T3 recent user receipt is the same as the address of the mobile unit itself, the execution of the method goes to step 418, in which the mobile unit sends a request for a turn to speak to the withdrawn mobile unit who sent a message indicating the completion of his transmission. As a next step, the mobile unit wishing to speak verifies in step 419 whether a positive acknowledgment to the request for speaking time made by the mobile unit wishing to speak arrives from the withdrawing mobile unit. If the acknowledgment is negative, at 420, or if no acknowledgment arrives, the execution of the method proceeds to step 413 explained above, and from there to the first attempt procedure. If, on the other hand, the acknowledgment from the withdrawn mobile unit is positive, the execution of the method proceeds to step 421, in which the mobile unit stores the address of the previous (withdrawn) user and begins to transmit, that is, take the turn to speak. As long as the user of said mobile unit does not provide at 423 a request to end the speech element, that is, he releases the push button to speak, said mobile unit sends his transmission, that is, he maintains his turn to speak. When a speech element termination request arrives from the user of the mobile unit, that is, when the user releases the push-to-talk button, the mobile unit communicates at 424 with the other mobile units communicating on the mode channel. Direct the priority information, adding the recent user address to its transmission, if the recent user priority is invoked or activated.

In the operation according to another form of embodiment of the invention, the procedure is such that said priority information is a speech element identifier information that indicates the identifier of one or more preceding speech elements whose users are prioritized so that they have the following turn to speak. Here, said speech element identifier information is compared in the mobile units that have received said priority information with the information stored in the mobile unit about the identifiers of the speech elements that said mobile unit has had. If said comparison shows that the mobile unit was prioritized to have the next turn to speak and the user of said mobile unit has indicated his desire to have the next turn to speak, said mobile unit takes said next turn to speak, unless another mobile unit indicated to be prioritized has previously reserved said next speaking time.

Figure 5 is a block diagram of a mobile unit 500, that is, a radiotelephone that is used by a subscriber, mobile unit, or subscriber station, communicating on a channel directly. The function of the transceiver (TX / RX) 501 is to tune the radio channel used in each case. Transceiver 501 incorporates an antenna 502 connected to a radio path TR. Radio frequencies between 60 MHz and 1000 MHz (VHF and UHF frequencies) are normally used, although other frequencies can also be used. Analogue modulation can be used in the TR radio path, normally the demodulation mode being phase modulation. They can also be used in other modulation modes. For example, a voice frequency subcarrier can be used for signaling transmission. The radio path can also be carried out digitally. The mobile unit can adapt and communicate on the uplink and downlink frequencies of the direct mode channel. The user interface 505 comprises an electro-acoustic transducer element, commonly an earpiece 506 and a microphone 507, and possibly keys for initiating and ending a call and their selection. Since in a trunked system and especially in a direct mode channel communication on a TR radio path is conveniently simplex, the handset generally also has a push button to speak, which must be depressed during the speech element. Push-to-talk button not shown in Figure.

The function of the control unit 503 is to control the operation of the mobile unit. The control unit 503 has access to the user interface 505 from which it obtains pulses for the initiation and termination of a call, for example. The control unit 503 may also provide the user with audio signals or visual signals related to the operation of the radiotelephone and / or the radio mobile system through the user interface 505.

The control unit 503 was connected to the TX / RX transceiver 501. The channel used by the transceiver is determined by the control unit 503, which means that the transceiver 501 tunes to the channel, that is, the radio frequency, determined by the unit. control 503 and to a suitable period of time. The mobile unit of the invention serves to tune to a direct mode channel and to two uplink and downlink channels (frequencies) of the system channels as well as to a desired period of time of the channel. Transceiver 501 is also activated under the control of control unit 503. Control unit 503 receives and sends signaling messages through transceiver 501. A mobile unit 500 according to the invention, which communicates on a channel directly, can for example be used in a radio system comprising a radio network with at least one base station and subscriber stations and possibly one or more relay / transfer stations that transmit communications between at least one base station and subscriber stations that communicate on the channel directly.

Said mobile unit communicating in a direct mode channel comprises a memory element 510, a transceiver 501 and a unit 503 for controlling the operation of the mobile unit.

A mobile unit UR1, UR2, 500 (Figure 5) according to the invention comprises: a controller element 516 to control that the mobile unit UR1 operates in such a way that it obtains the priority to start a speech element or so7

ES 2 139 322 T3 bidding a speaking turn after the end of the speech element of a second UR2 mobile unit before the other UR3 mobile units communicate on the channel directly.

The mobile unit according to the invention is characterized in that said controller element 516 to control the mobile unit UR1 was adapted to provide the first mobile unit UR1 with the priority to start a speech element or request a turn to speak immediately after the end of said element. speech element of the second mobile unit UR2 within a predetermined period of time.

The UR1 mobile unit; 500 (Figure 5) of the invention also comprises: an addition element 517 to add information to the transmission of the mobile unit UR1 when the mobile unit UR1 gives up its previous turn to speak, indicating the information that the mobile unit UR1 wishes to have priority to start a speech element or request a speaking turn immediately after the termination of the speech element of the second UR2 mobile unit that took the next speaking turn.

The mobile unit of the invention also comprises transmission means 511 for sending priority information indicating which mobile unit or units is or are prioritized to request the next turn to speak on the channel directly.

The mobile unit of the invention further comprises a 512 priority counter. The value shown by the counter indicates the number of speaking turns taken by other mobile units after the speech element of said mobile unit.

In the mobile unit of the invention, said transmission means are adapted to insert within said priority information said priority parameter value, indicating how many recent users are favored.

The mobile unit of the invention further comprises comparator means 513 for comparing in step 320 the value of the priority parameter included in the priority information received by said mobile unit with the value stored in the priority counter 512 of the mobile unit and , in response to said comparison, if said comparison shows that said mobile unit is prioritized so that it has the next turn to speak, direct said mobile unit to take the next speaking turn, unless another mobile unit indicated to be prioritized has previously reserved said next speaking turn.

Likewise, said transmission means 511 in said mobile unit is adapted to insert into said priority information the identifier of the mobile unit that had the previous turn to speak, in response to which said preceding mobile unit takes the next turn to speak.

The mobile unit of the invention also comprises a speech element initiation element 514 that responds to the identifier of the first mobile unit included in the priority information sent by the second mobile unit UR2, so that said mobile unit takes the next turn. word of mouth.

The mobile unit of the invention is further characterized in that said transmission means 511 is adapted to include in said priority information information on the identifier of the speech element that indicates the identifier or identifiers of the preceding speech element or elements whose users are prioritized so that have the next turn to speak.

The mobile unit of the invention further comprises comparator means 515 for comparing the information on the speech element identifier included in the priority information received by said mobile unit with the information stored in said mobile unit on the identifiers of the speaking turns. that said mobile unit had had, and in response to said comparison, if said comparison shows that said mobile unit is prioritized to have the next speaking time, direct said mobile unit to have the next speaking time, unless another mobile unit indicated to be prioritized has previously reserved said next speaking turn .

The accompanying drawings and the description thereof are only intended to illustrate the idea of ​​the invention. The method and mobile unit according to the invention for assigning speech elements to mobile units communicating on a channel directly may vary in their details within the scope of the claims. Although the invention has been discussed above primarily in the context of private or professional radio mobile units, it can also be used with other radio telephones or other mobile mobile phone units.