VOICE TRANSMISSION SYSTEM

Description

[0001] The invention relates to a voice transmission system comprising a plurality of transmitting / receiving systems connected to a first common pilot workstation, according to claim 1.

[0002] State-of-the-art voice transmission systems are known which are used in military air traffic control or command and control applications. In such known systems, each controller or operator is equipped with a controller workstation featuring an input unit and a push-to-talk button. The controllers can access various shared radio stations to communicate with civil and military aircraft.

[0003] US 2017 / 0337823 A1 discloses a communication system comprising a first, public communication channel and a second, secure communication channel. For example, to control a civilian aircraft, the operator can send voice data directly to a first network switch of the first public communication channel, and to control a military aircraft, the operator can send voice data directly to a second network switch of the second secure communication channel, so that the voice data is encrypted by an encryption module before being transmitted. AT 518561 B1 discloses a communication system for voice communication with a number of workstations and a number of radio transmitting devices and radio receiving devices, between each of which control units are provided.If operating signals from multiple workstations are present simultaneously, the voice signals from one of the workstations are selected, or the voice signals from multiple workstations are superimposed, and the resulting voice signal is transmitted. EP 2658173 A1 also discloses a switch for selectively connecting a receiver to one of two signal sources.

[0004] Radio stations that are located in different geographical locations but can be reached via the same radio channel are logically grouped to enable air traffic controllers to cover large geographical areas for radio communication. Each air traffic controller typically uses several of these radio station groups in parallel. The air traffic controller can use each of the radio station groups either for reception only (RX) or for reception and transmission (TX). This RX / TX setting for each radio station group is referred to as the key-in mode designated.

[0005] Depending on the aircraft type and the current situation, radio communication can be encrypted (Secure / COMSEC ON) or unencrypted (Plain / COMSEC OFF). If a group consists of radio stations that support encrypted communication, the controller can switch between Plain / COMSEC OFF and Secure / COMSEC ON communication from the controller's workstation.

[0006] During the key-in mode, To ensure that the COMSEC setting selected by a controller does not affect the communication of another controller communicating with the same radio stations or radio station groups, the COMSEC setting must be consistent for all radio stations in a group and for all controllers using that radio station group. Therefore, the COMSEC setting is transmitted from the voice transmission system to all controller workstations currently using a particular radio channel.

[0007] Air traffic controllers, particularly in military applications, often use several radio station groups in rapid succession, transmitting classified information via individual radio station groups in encrypted mode, while transmitting non-classified information via other radio station groups in unencrypted mode. To do this, the air traffic controller must perform several steps: First, the air traffic controller selects the desired radio station group for transmission using the input unit at the air traffic controller's workstation and changes the key-in mode of this radio station group to TX. The controller can then start the actual radio transmission by pressing the push-to-talk button. If a different radio station group is to be used for the next transmission, the controller must key-in modethe first radio station group back to RX, set the next radio station group to TX and then use the Push-to-Talk button to send the next radio message.

[0008] In situations where the controller must frequently switch between radio station groups in secure or plain mode, the multitude of required steps places an additional workload on the controller, increasing the likelihood of potentially incorrectly selecting the radio station group with which to communicate. If multiple radio station groups are to be used simultaneously in secure or plain mode, the previously described workflow must be repeated for each individual radio station group.

[0009] After the workflow involves changing the key-in modeof the radio station groups, which must be communicated by the voice transmission system to all radio stations of the respective radio station group, the change of the key-in mode There is also a noticeable delay of a few seconds before the controller can start the transmission.

[0010] The object of the invention is therefore to provide a voice transmission system which overcomes the aforementioned disadvantages and, in particular, enables immediate start of transmission and reduces the sequence of work steps for switching between groups, so that the workload of the controllers is reduced, which significantly reduces the potential for human error in the form of, for example, the selection of an incorrect radio station group.

[0011] The invention solves this problem with a voice transmission system according to the preamble of patent claim 1 with the characterizing features of patent claim 1.

[0012] According to the invention, it is provided that the control and processing unit is designed to check, when the user assigns several radio station groups to a respective push-to-talk button, whether the same communication mode is assigned to the individual radio station groups.

[0013] This configuration of a voice transmission system according to the invention advantageously allows a pilot to initiate radio messages to one or more radio station groups in the desired encrypted or unencrypted communication mode simply by pressing one of the at least two push-to-talk buttons. Since the respective radio station groups to be contacted, the respective selected transmission mode, and the respective selected communication mode are stored for each push-to-talk button, the pilot's workflow is significantly simplified, thus significantly reducing the risk of errors.

[0014] In particular, the workload of the user or the controller is reduced by the fact that radio transmissions of both confidential, encrypted and non-confidential, unencrypted radio messages are possible without additional inputs on the input unit, but simply by pressing one of the configurable push-to-talk buttons.

[0015] Furthermore, the embodiment according to the invention advantageously ensures that when several radio station groups are assigned to the individual push-to-talk buttons, by pressing the respective push-to-talk button, communication takes place only with radio station groups that are in the same communication mode and are therefore allowed or able to send out all confidential information that is to be encrypted or all information that is not to be encrypted.

[0016] In order to make a voice transmission system according to the invention usable for several controllers, it can be provided that the transmitting / receiving systems are connected to at least one further common controller workstation.

[0017] In order to ensure that, in a voice transmission system according to the invention which is used by several controllers, controllers at the additional controller workstations can also transmit radio messages to one or more radio station groups in the desired encrypted or unencrypted communication mode in a simple manner and without a complex work sequence, it can be provided that the at least one additional controller workstation comprises an additional loudspeaker for outputting radio messages to a user, an additional microphone for recording radio messages issued by the user, an additional input unit, and an additional control and processing unit with an additional buffer. wherein a reception / transmission mode or a transmission / reception transmission mode can be selected by the user via the further input unit for the individual radio station groups, and wherein an encrypted communication mode or an unencrypted communication mode can be selected by the user via the further input unit for the individual radio station groups, wherein the radio channels of the individual radio station groups and the respectively selected transmission mode are stored in the further buffer memory, and wherein the further pilot workstation comprises a further push-to-talk unit, wherein the further push-to-talk unit comprises at least two configurable push-to-talk buttons, wherein at least one radio station group and one communication mode can be assigned to each of the push-to-talk buttons by the user via the further input unit.

[0018] Since a new communication mode can be selected for the individual radio station groups when a new, additional pilot workstation is connected, it can be provided that the control and processing unit is designed to determine the current communication mode of the radio station group in question when a respective radio station group is used for the first time at the additional pilot workstation when an additional pilot workstation is connected, wherein it is provided in particular that the control and processing unit is designed to display the current communication mode of the radio station group in question to the user at the additional pilot workstation.

[0019] This embodiment of a voice communication system according to the invention advantageously ensures that the newly added user at the additional workstation always knows the current communication mode of all radio station groups, so that any unnecessary changes to the communication mode are avoided.

[0020] Since the communication mode selected for the individual radio station groups can also be actively changed by a user or pilot, for example if problems in the transmission quality are detected, or the selected communication mode changes due to a failure, e.g.the encryption device of a radio station changes and inadmissible combinations of radio station groups in the encrypted communication mode as well as in the unencrypted communication mode on the same push-to-talk button can arise in this way, it can be provided that the control and processing unit is designed to check, after the assignment of several radio station groups to a respective push-to-talk button, at predetermined time intervals, in particular continuously, whether the individual radio station groups are still assigned the same communication mode and, in the event of detection of a change in the communication mode of a radio station group, to end the assignment of the radio station group in question to the respective push-to-talk button.

[0021] In order to inform a user that inadmissible combinations of encrypted and unencrypted communication modes have arisen or are arising in the case of an existing assignment of several radio station groups to the same push-to-talk button or in the case of a newly selected assignment of several radio station groups to the same push-to-talk button, it can be provided that the control and processing unit is designed to issue a warning, in particular an optical and / or acoustic warning, to the user at a pilot workstation, in the event that, when a user assigns several radio station groups to a respective push-to-talk button, one of the radio station groups is not assigned the same communication mode and / or in the event that the assignment of a radio station group to the push-to-talk button has been terminated and / or in the event of a change in the communication mode of one of the radio station groups (CG) by the user of another pilot workstation, i.e. in the event that the communication mode of one of the radio station groups used at the relevant pilot workstation is changed by the user of another, different pilot workstation.

[0022] A pilot workstation of a voice transmission system according to the invention can be designed to be particularly compact, clear and easy to operate for the user if the loudspeaker and / or the microphone and / or the push-to-talk unit are arranged in or on a headset or are included by the headset.

[0023] To particularly efficiently avoid delays in the transmission of radio messages, the user can assign at least one radio station group for which the transmit / receive transmission mode is selected to each of the push-to-talk buttons via the input unit. This advantageously ensures that the at least one radio station group is already in transmit / receive mode, allowing the user to begin their transmission immediately.

[0024] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

[0025] The invention is schematically illustrated below in the drawings using particularly advantageous, but not restrictive, embodiments and is described by way of example with reference to the drawings.

[0026] The following shows schematically: Fig. 1 an embodiment of a pilot workstation of a voice communication system according to the invention, Fig. 2 a schematic example of a group of radio stations that receive or transmit radio signals from the transceiver stations of the voice communication system connected to two controller workstations.

[0027] In the following exemplary embodiment, the operational use of a voice transmission system VCS according to the invention is explained in more detail, the controller working positions CWP1, CWP2 of which are each equipped with a push-to-talk unit 7 with two configurable push-to-talk buttons. Initial situation

[0028] Two military air traffic controllers are carrying out a mission together and require reliable radio communication with their own military aircraft, with military aircraft from neighboring countries, and with civil aircraft that are in close proximity to their own forces or military aircraft.

[0029] To ensure increased reliability, the two air traffic controllers are located in separate buildings and use an innovative voice transmission system (VCS) for both communication between them via telephone and communication with the aircraft via radio. Each controller has a controller workstation (CWP1, CWP2).

[0030] A first such pilot workstation CWP1 is shown schematically in Fig. 1and has an input unit 1, for example a touchscreen. In the exemplary embodiment, the pilot workstation CWP1 is Fig. 1 several audio devices, namely a headset 3, a telephone handset 4 and a loudspeaker 2 are connected (see Fig. 1 ). Both communication modes, radio and telephony, are provided by the voice transmission system (VCS) and can be transmitted via the same audio devices. Voice messages are transmitted to the user, i.e., the pilot, via loudspeaker 2, and voice messages transmitted by the pilot are recorded via microphone 5.

[0031] The voice transmission system (VCS) comprises multiple transceivers for transmitting and receiving radio signals to and from a plurality of radio station groups (CG). Each such radio station group (CG) comprises a plurality of geographically distributed radio stations 7a, 7b, and 7c, each capable of transmitting and receiving voice radio messages on the same radio channel. The transceivers are connected to the pilot workstations (CWP1, CWP2). This connection is implemented via a network (6), to which all pilot workstations and transceivers of the voice transmission system (VCS) are connected. The network enables the transmission of digital voice data, control commands, and status information.

[0032] Using input unit 1, each controller can enter or select a reception / transmission mode (RX) or a transmission / reception mode (TX) for the individual radio station groups (CG). Furthermore, each controller can use input unit 1 to select an encrypted communication mode (S) or an unencrypted communication mode (P) for the individual radio station groups (CG).

[0033] In order to store these settings selected for the individual radio station groups CG, the first pilot workstation CWP1 comprises a control and processing unit with a buffer in which not only the selected transmission mode for a respective radio station group CG, but also the radio channel via which the respective radio station group CG communicates can be stored.

[0034] The first controller workstation CWP1 further comprises a push-to-talk unit 7, which in the exemplary embodiment is housed in the connecting cable between headset 3 and controller workstation CWP 1. In the exemplary embodiment, the push-to-talk unit 7 has two configurable push-to-talk buttons. Each of the push-to-talk buttons PTT1, PTT2 can assign one or more radio station groups CG and a communication mode to the controller using the input unit 1. The information about which radio station groups CG with which communication mode have been assigned to a respective push-to-talk button PTT1, PTT2 by the controller can advantageously also be stored in the buffer.

[0035] The additional pilot workstation CWP2 of the additional pilot, which is in Fig. 2is shown, is equipped in the exemplary embodiment in the same way as the first pilot workstation CWP1, i.e. has an additional loudspeaker, an additional microphone, an additional input unit, an additional control and processing unit with an additional buffer, an additional push-to-talk unit, etc.

[0036] To carry out their mission, the two air traffic controllers were assigned the coverage frequencies or radio channels V-01, U-02, U-03, and U-04 during a prior planning phase. These radio channels are accessible to four different CG radio station groups. While radio channel V-01 operates in the civilian part of the VHF band, radio channels U-02, U-03, and U-04 are radio channels of CG radio station groups in the military part of the UHF band. All CG radio station groups in the exemplary embodiment consist of three radio devices each, located at three different radio sites. These radio sites are distributed across the operational area so that every point can be reached from at least one of the three locations (see Fig. 2 ).

[0037] All radios within a radio station group (CG) receive and transmit on the same radio frequency or radio channel. Each air traffic controller has the option of selecting one or more of the radios in a radio station group (CG) for reception. If multiple radios in the same radio station group (CG) are selected for reception, an inventive voice transmission system (VCS) offers the option of automatically routing the audio signal of the radio with the best received signal quality to the controller. All aircraft that are to be reached on a radio station group (CG) also have their radios tuned to the respective frequency.

[0038] The civilian radio station group CG with radio channel V-01 is familiar to both civilian and military air traffic and is used for coordination purposes. It can be assumed that all aircraft in the operational area can be reached on this radio frequency.

[0039] The CG radio station groups with radio channels U-02, U-03, and U-04 were communicated to the pilots during the mission briefing and are used to transmit mission-relevant information that may be subject to confidentiality. To ensure the confidentiality of the information exchanged, an encrypted communication mode S is used with an encryption method implemented by key devices.

[0040] The encryption devices convert an outgoing voice signal into an encrypted voice signal before the actual transmission through the radio. This signal can only be decrypted by the receiver using a similar encryption device with an identical key. For receivers who do not have the corresponding encryption device and the appropriate key, an intercepted transmission remains unintelligible.

[0041] Such a key device is present on each of the radio stations of the CG radio station groups with radio channels U-02, U-03, and U-04, both on the ground and on board military aircraft. Keys for radio channels U-02 and U-04 were generated in advance and loaded into the key devices both on the ground and in the aircraft.

[0042] The CG radio station group with radio channel U-03 does have encryption devices, but is operated unencrypted for the current mission described, i.e., in unencrypted communication mode P. While the radio channels U-02 and U-03 are only used by our own aircraft, the CG radio station group with radio channel U-04 is also known to military aircraft from a friendly neighboring country and can be used for coordination with them.

[0043] This results in the following configuration of the radio station groups CG: radio channel Frequency band use Encryption possible Encryption active Push-to-Talk button V-01 VHF Civil No No PTT 1 U-02 UHF Military national Yes Yes PTT 2 U-03 UHF Military national Yes No PTT 1 U-04 UHF Military international Yes Yes PTT 2 Preparation

[0044] In preparation for the mission, both air traffic controllers assign the CG radio station groups with radio channels V-01 and U-03, which are in transmit / receive mode TX, to the push-to-talk button PTT 1. This allows the two unencrypted CG radio station groups, i.e. the CG radio station groups that are in unencrypted communication mode P, to be operated jointly, and the air traffic controllers can transmit the same radio message in both the VHF and UHF bands simultaneously.

[0045] The encrypted radio station groups CG with the radio channels U-02 and U-04, i.e. the radio station groups CG that are in the encrypted communication mode S and in the transmit / receive mode TX, are configured by both air traffic controllers to the push-to-talk button PTT 2.

[0046] When the controller assigns or assigns multiple radio station groups (CG) to the same push-to-talk button (PTT1, PTT2), the control and processing unit checks whether the individual radio station groups (CG) are assigned the same communication mode. This reliably prevents the unintentional transmission of confidential voices on an unencrypted radio channel or to one or more radio station groups in unencrypted communication mode (P).

[0047] In the example shown, both controllers can now listen to radio traffic on all four CG radio station groups simultaneously without any further operations on the touchscreen of the VCS voice transmission system thanks to the selected assignment of the CG radio station groups to the PTT1 and PTT2 push-to-talk buttons. Furthermore, they can optionally transmit simultaneously on the two unencrypted CG radio station groups using radio channels V-01 and U-03 by pressing the PTT 1 push-to-talk button, or on the encrypted CG radio station groups using radio channels U-02 and U-04 by pressing the PTT 2 push-to-talk button.

[0048] Thus, messages spoken by the respective pilot into microphone 5 are only transmitted to those radio station groups CG that are assigned to the push-to-talk button that has just been pressed. Sequence

[0049] During the mission, the first of the two controllers encounters problems communicating with one of the aircraft from the friendly neighboring country via the CG radio station group on radio channel U-04. Because he attributes these problems to encryption, he switches the CG radio station group on radio channel U-04 from encrypted communication mode S to unencrypted communication mode P. Technically, this switchover is communicated from the first controller workstation, CWP1, to all three radios of the respective CG radio station group participating in radio channel U-04.

[0050] Each of these radio devices switches to unencrypted communication or unencrypted communication mode P and shares this information with all other components of the voice transmission system (VCS) with which it is connected. In the exemplary embodiment, this particularly affects the additional controller workstation CWP2 of the second controller, which is located in a different building and therefore has no knowledge of the communication problems and the resulting switch to unencrypted communication mode P.

[0051] The software stored on the control and processing unit at the second controller's additional workstation CWP2 detects that switching from radio channel U-04 to the unencrypted communication mode P has resulted in an inadmissible combination of encrypted and unencrypted radio station groups CG on the push-to-talk button PTT2.

[0052] In order to prevent unintentional transmission of confidential speech on radio channel U-04, in the exemplary embodiment the control and processing unit of the controller workstation CWP2 automatically removes the radio station groups CG with the radio channel U-04 from the push-to-talk button PTT2 and informs the controller of this fact by means of a warning tone emitted in the headset and by means of a visual error message on the touchscreen or input unit 1.

[0053] The status of the radio station groups CG has changed as follows: radio channel Frequency band use Encryption possible Encryption active Push-to-Talk button V-01 VHF Civil No No PTT 1 U-02 UHF Military national Yes Yes PTT 2 U-03 UHF Military national Yes No PTT 1 U-04 UHF Military international Yes No no

[0054] This embodiment of a voice transmission system according to the invention with a check for impermissible combinations of radio station groups CG in the encrypted communication mode S and in the unencrypted communication mode P on the same push-to-talk button ensures reliable separation of radio transmissions in security areas and the controllers are notified of any changes in the security settings of the currently used radio channels.

[0055] The error can now be further handled manually by the controller, for example by one of the following measures: Assign the now unencrypted radio station group CG with radio channel U-04 to the push-to-talk button PTT1, whereby the three unencrypted radio station groups CG with radio channels V-01, U-03, and U-04 are operated via the same push-to-talk button. If transmission on radio channel U-04 is not required, radio channel U-04 can be switched to receive-only operation, for which no assignment to a push-to-talk button is required. Switch radio channel U-02 to unencrypted communication or unencrypted communication mode P and reassign the radio station group CG with radio channel U-04 to the push-to-talk button PTT2.

[0056] While the encryption mode or the encrypted communication mode S or the unencrypted communication mode P of a frequency or a radio channel of a radio station group CG is the same for all controllers, the assignment to a push-to-talk button can be made by each controller separately and without affecting other controllers.

[0057] This is operationally relevant and advantageous to enable flexible use of the radio station groups CG by the air traffic controllers. The consistency rules or consistency check of the control and processing unit of the air traffic controller workstations CWP1, CWP2 in a voice transmission system VCS according to the invention prevents the assignment of encrypted and unencrypted radio station groups CG to the same push-to-talk button in the exemplary embodiment.

[0058] If only encrypted or only unencrypted radio station groups (CG) are used, the system also allows for any allocation of the radio station groups (CG) to the two push-to-talk buttons. Since the assignment of the radio station groups (CG) to push-to-talk buttons takes place at the respective controller workstations (CWP1, CWP2), thus eliminating the need for communication with other system components, the mechanism advantageously operates with virtually no delay and without impact on other participants in the system.

[0059] The control and processing unit of the respective pilot workstation CWP1, CWP2 can optionally perform additional consistency checks to prevent confidential radio messages from being transmitted to radio station groups CG in unencrypted communication mode P: For example, when a radio station group CG is used for the first time at another pilot workstation CWP2, the control and processing unit can determine the current communication mode of the radio station group CG and display it to the user. This ensures that the newly added user at the pilot workstation CWP2 is informed of the current status of all radio station groups before making any changes to the communication mode.

[0060] Furthermore, after assigning multiple radio station groups (CG) to a respective push-to-talk button, the control and processing unit of the respective controller workstation CWP1, CWP2 can optionally check at specified intervals whether the individual radio station groups (CG) are still assigned the same communication mode, or whether the communication mode of individual radio station groups (CG) has changed. In this case, the control and processing unit terminates the assignment of the respective radio station group to the respective push-to-talk button to prevent confidential radio messages from being transmitted in the unencrypted communication mode P.

[0061] Generally, when such inconsistencies or impermissible combinations of radio station groups CG in encrypted and unencrypted communication modes are detected on the same push-to-talk button by the control and processing unit, there is the possibility that—as in the exemplary embodiment—a visual and / or acoustic warning message is issued to the controller at their controller workstation CWP1, CWP2. This can be warning tones, light signals, graphical user interfaces with a warning message displayed on the input unit, or the like.

[0062] Such warnings may be issued, for example, if when several radio station groups CG are assigned to a respective push-to-talk button, one of the radio station groups CG is not assigned the same communication mode, the assignment of a radio station group to the push-to-talk button is terminated by the control and processing unit, the communication mode of one of the radio station groups CG used at the relevant pilot workstation is changed by the user of another, different pilot workstation.

[0063] In general, a push-to-talk unit 7 according to the invention can of course also have more than two push-to-talk buttons. In this way, the controllers can communicate even more flexibly and efficiently with different radio station groups CG and, for example, assign two push-to-talk buttons to radio station groups CG in encrypted communication mode S. This ensures, for example, that confidential radio messages can be transmitted to different radio station groups CG in encrypted communication mode S depending on the selected push-to-talk button, depending on their content.

[0064] Although the above-described embodiment of a voice transmission system according to the invention was explained in connection with aviation, a voice transmission system according to the invention can also be used in other areas of application in which several radio channels have to be operated in rapid succession, such as in connection with public safety, This is especially true where dispatchers at an emergency call center must communicate with emergency personnel spread across a larger geographical area via radio. The dispatchers (who correspond to the air traffic controllers in the above example) work in emergency call centers at workstations similar to the controller workstations CWP1 and CWP2 in the above example.

Claims

1. Voice communication system (VCS) comprising a plurality of transmitting / receiving systems for transmitting and / or receiving radio signals to a radio station group (CG) and / or from a plurality of radio station groups (CG), wherein the radio station groups (CG) each comprise a plurality of geographically distributed radio stations (7a, 7b, 7c) and wherein voice radio messages are each transmitable on different radio channels to the individual radio station groups (CG) and / or receivable by the individual radio station groups (CG), - wherein the transmitting / receiving systems are connected to a first common controller workstation (CWP1), - wherein the first controller workstation (CWP1) comprises a loudspeaker (2) for outputting voice radio messages to a user, a microphone (5) for receiving voice radio messages emitted by the user, and an input unit (1), - wherein via the input unit (1) a receive transmission mode (RX) or a transmit / receive transmission mode (TX) is selectable by the user for the individual radio station groups (CG), and - wherein via the input unit (1) an encrypted communication mode (S) or an unencrypted communication mode (P) is selectable by the user for the individual radio station groups (CG), - wherein the first controller workstation (CWP1) comprises a push-to-talk unit (7), and - wherein the first controller workstation (CWP1) comprises a control and processing unit, wherein the control and processing unit comprises a buffer memory and wherein the radio channels of the individual radio station groups (CG) as well as the respectively selected transmission mode are stored in the buffer memory, and - wherein the push-to-talk unit (7) comprises at least two configurable push-to-talk buttons (PTT1, PTT2), wherein via the input unit (1) each of the push-to-talk buttons (PTT1, PTT2) is assignable by the user to at least one radio station group (CG) and one communication mode, characterized in that the control and processing unit is designed to check whether the same communication mode is assigned to the individual radio station groups (CG) when several radio station groups (CG) are assigned by the user to a respective push-to-talk button (PTT1, PTT2).

2. Voice communication system (VCS) according to claim 1, characterized in that the transmitting / receiving systems are connected to at least one further common controller workstation (CWP2).

3. Voice communication system (VCS) according to claim 2, characterized in that the at least one further controller workstation (CWP2) comprises a further loudspeaker for outputting voice radio messages to a user, a further microphone for receiving voice radio messages emitted by the user, a further input unit, and a further control and processing unit with a further buffer memory, - wherein via the further input unit a receive transmission mode (RX) or a transmit / receive transmission mode (TX) is selectable by the user for the individual radio station groups (CG), and - wherein via the further input unit an encrypted communication mode (S) or an unencrypted communication mode (P) is selectable by the user for the individual radio station groups, - wherein the radio channels of the individual radio station groups (CG) as well as the respectively selected transmission mode are stored in the further buffer memory, and - wherein the further controller workstation (CWP2) comprises a further push-to-talk unit, wherein the further push-to-talk unit comprises at least two configurable push-to-talk buttons, wherein via the further input unit each of the push-to-talk buttons is assignable by the user to at least one radio station group (CG) and one communication mode.

4. Voice communication system (VCS) according to any one of the preceding claims, characterized in that the control and processing unit is designed to determine the current communication mode of the respective radio station group (CG) when a further controller workstation (CWP2) is connected when a respective radio station group (CG) is used for the first time at the further controller workstation (CWP2), wherein it is in particular provided that the control and processing unit is designed to display the current communication mode of the respective radio station group (CG) to the user at the further controller workstation (CWP2).

5. Voice communication system (VCS) according to any one of the preceding claims, characterized in that the control and processing unit is designed to check at specified intervals after the assignment of several radio station groups (CG) to a respective push-to-talk button (PTT1, PTT2) whether the same communication mode is still assigned to the individual radio station groups (CG) and, in the event of detecting a change in the communication mode of a radio station group (CG), to terminate the assignment of the respective radio station group (CG) to the respective push-to-talk button (PTT1, PTT2).

6. Voice communication system (VCS) according to any one of the preceding claims, characterized in that the control and processing unit is designed to output a warning, in particular a visual and / or acoustic warning, to the user at a controller workstation - in the event that when several radio station groups (CG) are assigned by a user to a respective push-to-talk button (PTT1, PTT2), one of the radio station groups (CG) is not assigned the same communication mode, and / or - in the event that the assignment of a radio station group (CG) to the push-to-talk button (PTT1, PTT2) has ended, and / or - in the event of a change in the communication mode of one of the radio station groups (CG) by the user of a further controller workstation.

7. Voice communication system (VCS) according to any one of the preceding claims, characterized in that the loudspeaker (2) and / or the microphone (5) and / or the push-to-talk unit (7) are arranged in and / or on a headset (3).

8. Voice communication system (VCS) according to any one of the preceding claims, characterized in that via the input unit (1) each of the push-to-talk buttons (PTT1, PTT2) is assignable by the user to at least one radio station group (CG) for which the transmit / receive transmission mode (TX) is selected.