A method for controlling a radio communication apparatus system and relative radio communication apparatus

Abstract

The present invention concerns a method for controlling a radio communication apparatus system where each apparatus comprises at least a radio transmitter (TX) and radio receivers (RX), in which each radio transmitter (TX) can perform an automatic selection of the transmission channel to optimize the reception of the radio receivers (RX), said selection of the transmission channel being made on the basis of the RSSI values of other signals that can be picked up transmitted by other radio transmitters (TX) of the system and, preferably, a credibility score (C) assigned to each RSSI value of the picked up signals.

Description

[0001] TITLE

[0002] A METHOD FOR CONTROLLING A RADIO COMMUNICATION APPARATUS SYSTEM AND RELATIVE RADIO COMMUNICATION APPARATUS

[0003] DESCRIPTION

[0004] The present invention concerns a method for controlling a radio communication apparatus system. In further detail, the invention concerns a method for controlling a system comprising several radio communication apparatuses. Each apparatus comprises at least a radio transmitter and radio receivers associated with said transmitter.

[0005] The present invention concerns in particular the field of radio guides. In the tourism sector, among others, radio apparatuses that permit real-time transmission of an audio signal from the transmitter to a plurality of receivers are particularly widespread.

[0006] These apparatuses allow a person, defined as the speaker, for example a guide, to speak to a certain number of listeners (tourists, visitors, etc.) via a radio transmitter to which a microphone is connected. The listeners, in turn, can listen to the voice of the speaker via a radio receiver to which an ear piece or a headset is connected.

[0007] In general, the transmitters used in radio guide apparatuses are configured to transmit the audio signal on a limited number of channels, each corresponding to a given frequency or frequency band.

[0008] With these apparatuses there is no limit to the number of receiver devices that can receive the audio signal transmitted by a transmitter. This means that any receiver device tuned to the channel where the transmitter transmits and at a distance within reach is able to reproduce the audio flow transmitted. For this to happen, however, the transmitter and the receiver must use the same transmission protocol.

[0009] Due to the huge number of radiofrequency apparatuses that are used for a whole range of purposes, to allow their coexistence, namely guarantee the operation thereof without reciprocal interference, regional, national and international rules exist that regulate radio channel occupancy.

[0010] Radio guide apparatuses are classified in the sector of “radiomicrophones”, which can operate only in given frequency bands or values, for example Sub Ghz (877 Mhz, 977 Mhz, etc.) or in Up Ghz, for example 2.4 Ghz.

[0011] With particular reference to said frequency bands assigned to “radiomicrophones”, although protocols are already implemented to limit interference between several transmitters that use the same frequency band, in practice the signal of the most powerful transmitter often causes interferences with the signals sent by the other less powerful transmitters.

[0012] In contexts where there are several transmitters operating simultaneously on a limited number of frequency bands, or channels, as often happens in the vicinity of very crowded tourist attractions (buildings, monuments, museums, art galleries, etc.), the problem of interferences and disturbances is particularly felt.

[0013] In the state of the art, a remedial solution currently used is to carry out, before commencing transmission, a manual search for a free channel (out of those available), namely where other transmitters physically nearby or with more powerful signals, which could generate interferences in the signal received by the receivers, are not already transmitting.

[0014] In these situations, however, the guide who wears the transmitter and the listeners who wear the receiver normally move continuously around the area to be visited.

[0015] Therefore, when a transmitter (or more than one) set to transmit on a given channel (or frequency or frequency band) moves near to receivers associated with another transmitter and set to receive on the same channel, it can generate disturbances and interferences. In these cases it is therefore necessary for at least one of the two transmitters, and the relative associated receivers, to modify their transmission / reception channel.

[0016] This method is clearly inconvenient since, whenever the guide changes the transmitter channel, all the receiver devices of the listeners must also be re-set in order to receive on the new channel.

[0017] This operation is obviously even more inconvenient if it has to be repeated various times during a visit.

[0018] In this context, the object of the present invention is to propose a method for controlling a radio communication apparatus system, in particular radio guide apparatuses, which overcomes the above drawbacks of the known art.

[0019] The object of the present invention is therefore to propose a method for controlling a radio communication apparatus system comprising at least one radio transmitter and some radio receivers, said method allowing various radio receivers associated with a given transmitter to receive an audio signal without interferences.

[0020] A further object of the present invention is to provide a method that allows completely automatic control of the radio communication apparatuses, without requiring interventions on the transmitters and receivers.

[0021] In particular, an object of the present invention is to provide a method that allows the transmitters and receivers to automatically change the respective transmission and reception channel to maintain the communication free of disturbances as far as possible.

[0022] An object of the present invention is also to propose a radio communication apparatus for use in a radio apparatus system, which overcomes the above-mentioned drawbacks of the known art.

[0023] These and other objects are achieved by a method for controlling a radio communication apparatus system in accordance with the attached claim 1.

[0024] In detail, the method according to the present invention allows the control of a radio communication apparatus system where each apparatus comprises at least a radiofrequency radio transmitter TX and radiofrequency radio receivers RX. The radio transmitter TX comprises at least one analog / digital converter, an antenna assembly, and a control unit connected to said analog / digital converter and to said antenna assembly.

[0025] The radio receiver RX comprises at least one digital / analog converter, an antenna assembly, and a control unit connected to the digital / analog converter and to the antenna assembly.

[0026] The radio transmitter TX is configured to transmit on a certain number N of channels CH.n, where each channel CH.n corresponds to a given frequency or, more typically, to a frequency band.

[0027] The transmitter TX is generally associated with a microphone to pick up the voice of a speaker. Said microphone can be movably connectable to the transmitter TX or can be integrated in the latter.

[0028] The receiver RX is generally associated with a sound reproduction source such as, for example, a headset, an ear piece, a loudspeaker, etc. Said sound reproduction source can be movably connectable to the transmitter RX or can be integrated in the latter.

[0029] The conversion of the analog signal (picked up by the microphone) into a digital signal, in the radio transmitter TX, and the reconversion of the digital signal into an analog signal (sent to the sound reproduction source), in the radio receiver RX, is carried out according to protocols for sending data in standard packages or packages known in the sector.

[0030] Furthermore each radio transmitter is associated with its own unique identification UID. Said unique identification can be included in the digital signals transmitted by the radio transmitter TX, for example as payload in each data package sent.

[0031] According to the present invention, the method comprises a step of automatic selection of the transmission channel CH.n for each radio transmitter of the system.

[0032] In further detail, the above-mentioned step of selection of the transmission channel comprises the following sub-steps. When the radio transmitter TX is switched on, the method carries out a scan of the radio frequencies (for example by means of a sweeping process) to pick up the signals emitted by other active radio transmitters of the system within a given range. Said scan is carried out on each of the N channels CH.n (namely on all the frequency band that can be used by the system) and said picked up signals are processed by the control unit of each radio transmitter TX.

[0033] Once a cycle of said scan has been completed, the method entails generating, via the radio transmitter control unit, a classification of the signals transmitted by other active radio transmitters on each of the N channels CH.n, if present.

[0034] In further detail, said classification is generated based on: an RSSI (Received Signal Strength Indicator) value of the signal of each radio transmitter TX; and, preferably, a credibility score C of the above-mentioned RSSI value of the signal of each radio transmitter TX.

[0035] Lastly, the method entails selecting as transmission channel, from among the N channels CH.n available, a channel CH.n where there are no other signals that can be picked up, namely where the channel is free, or, if signals are picked up on all the N channels, the one where the RSSI level of the other signals is the lowest.

[0036] According to a preferred variation which entails calculation of the credibility score C of the RSSI values of the picked up signals, the transmission channel is selected on the basis of an algorithm in which both the above-mentioned factors are considered, as will be described below.

[0037] The above-mentioned classification typically comprises, for each picked up signal, a score calculated as a function of the two above-mentioned parameters.

[0038] The scan of the signals on the N channels CH.n is repeated cyclically, at a certain time interval tl (for example 20 ms), so that said classification is continuously updated at each time interval.

[0039] Figure 1 attached shows schematically an example of selection of the transmission channel for a transmitter TXF in a context where there are another five transmitters TXA, TXB, TXC, TXD, TXE which are transmitting on the physical channels CH.01, CH.07, CH.09 and CH.10 respectively.

[0040] The control unit of the radio transmitter TXF scans the signals that can be picked up on the various channels (ten in the example illustrated) and, for each channel where a signal is detected (CH.01, CH.07, CH0.9 and CH.10), it measures the RSSI value thereof, as shown in the table of figure 1.

[0041] The transmitter control unit then selects as transmission channel a free physical channel, for example the first free one in ascending numbering order.

[0042] In the example of figure 1, for the radio transmitter TXF the channel CH.02 will be selected as the transmission channel.

[0043] As can be noted, in the example illustrated, on the physical channel CHOI two radio transmitters TXA and TXB can transmit simultaneously since they can be identified by the respective different unique identifications UID. A radio receiver RX could therefore receive several signals (packages) on its own reception channel, but it will perform demodulation only of the signals containing the unique identification UID with which it is associated.

[0044] If the transmitter TXA is far enough from the receivers associated with the transmitter TXB and vice versa, the respective signals can share the channel without generating reciprocal interference.

[0045] According to the present invention, the method also comprises a step of pairing a radio transmitter TX, having a given unique identification UID, with radio receivers RX.

[0046] According to one aspect of the invention, said pairing step can entail the following substeps: a) transmitting with the transmitter TX on all the N channels CH.n a signal, containing information relative to the unique identification UID, to the transmission channel CH.n identified in the preceding step; b) configuring one or more radio receivers RX so that said one or said several radio receivers RX can receive on said selected channel CH.n.

[0047] In further detail, according to a preferred embodiment, the method entails: analysing, via the control unit of the receiver RX, the signals that can be picked up to detect the presence of information relative to a unique identification UID, and to a transmission channel CH.n; measuring the RSSI value of said signals that contain information relative to a unique identification UID and to a transmission channel CH.n; and if the RSSI value of a signal is above a given threshold value S, storing the unique identification UID contained in said signal as unique identification UID with which to associate the receiver RX.

[0048] Said pairing step, in general, is carried out keeping near to one another the transmitter TX and the receivers RX to be associated, so that the signal emitted by the interested transmitter TX is picked up by the receivers with a very high RSSI level (higher than the predetermined threshold value S), generally higher than any other signals of other transmitters within range.

[0049] The attached figure 2 schematically illustrates an apparatus with a radio transmitter TXA which is set to a pairing mode in which it sends on all the N channels a package P “PAIRING” with its unique UIDA and the selected channel. The radio receivers RX which are within range and which receive the package P with an RSSI signal level above a certain threshold store the information UIDA as identification of the radio transmitter RX whose audio packages they will be required to demodulate.

[0050] Assuming that the RSSI threshold is equal to -35dB, if a given radio receiver RX receives a package P, it will take it into consideration, storing the specific UID, if the RSSI value is below -35dB.

[0051] In the case shown, the transmitter TXA sends a package P with UIDA and the receivers RXi, RX2 and RX3 (having received the package P with a signal level above the threshold) store the UIDA as identification of their transmitter and the channel where the transmitter will send the audio packages. The radio receivers RX4 and RX5, having received the package P with a signal level well below the threshold, do not consider it addressed to them and discard it, maintaining their own UID already stored.

[0052] According to one aspect of the invention, the radio receivers RX can be kept in sleep mode when not in use; in this stand-by condition they are cyclically activated for a few milliseconds (for example 10 milliseconds every second) to pick up the signals of radio transmitters TX within range.

[0053] Thanks to the method of the present invention, it is possible to control a plurality of radio communication apparatuses, such as radio guides or similar, such that the transmission of the signal from a radio transmitter TX to associated radio receivers RX is free from interferences due to the signals of other apparatuses transmitting in the vicinity on the same radio channel, or any interferences are negligible.

[0054] In particular, thanks to the analysis of the signals that can be picked up in the same area and on the various channels available, the radio transmitter is able to automatically select the best channel, namely a free channel where no signals can be picked up or, in any case, a channel where the other signals of other transmitters have a low RSSI value, and therefore are less disturbing.

[0055] The adoption of the further parameter linked to the credibility of the RSSI values calculated furthermore avoids errors in selection of the transmission channel due to transitory conditions (increasing or decreasing) of the signal intensity of the other radio transmitters. For example, a first radio transmitter TX, detecting on a channel CH.n a modest RSSI value of a second radio transmitter TX (therefore theoretically not disturbing), could select said channel CH.n as the optimal transmission channel. After a few moments, said second radio transmitter TX could begin to occupy the channel CH.n with a high intensity signal (high RSSI).

[0056] Said condition can occur, for example, when said second radio transmitter TX is at a distance within range but, for a few moments, at the time of detection of the signal by the first radio transmitter TX, was partially shielded (for example it was behind a metal door or a particularly thick wall) and then resumed transmitting without any obstacles shortly after, thus causing the other transmitters to detect a much higher RSSI value.

[0057] According to a preferred embodiment of the invention, the credibility score C is therefore calculated as a function of the variation of said RSSI value after a certain number of scanning cycles of the channel.

[0058] More precisely, said credibility score C is calculated as a function of the time (number of detection cycles) during which the RSSI value detected for a given radio transmitter TX-ID remains within a predefined range, with respect to the RSSI value detected in the preceding detection cycle (t-1).

[0059] In further detail, according to a possible implementation mode, said score can be incremented, for example by one unit, whenever the RSSI value of a given transmitter TX-ID, in the following cycle, remains within a given range.

[0060] Analogously, said credibility score C can diminish when the RSSI value detected in a subsequent cycle is outside said range.

[0061] Preferably, the incremental units at each cycle have a lower value than the decremental ones.

[0062] Therefore, if for a given radio transmitter TX a low RSSI value is detected at time t (the current classification) whereas said value was high in the classification at time t-1 (namely the preceding classification), it could mean that the low value at time t is only transitory. On the other hand, if said RSSI value remains more or less constant (for example low) for an increasing number of cycles, also the credibility score C will gradually increase.

[0063] Figure 3 illustrates an example of selection of the transmission channel of a transmitter TXz, which has to select its own transmission channel from among ten channels available CH.01- CH.10.

[0064] From the scanning carried out by the radio transmitter TXz, signals of other transmitters are picked up on all the channels, namely there are no free channels. The control unit of the transmitter TXz will therefore implement the method described above considering both the RSSI level of the other signals and the respective credibility score C.

[0065] According to a preferred variation, classification of the signals of the other transmitters is obtained by calculating for each signal a score given by the product of the absolute RSSI value for the credibility score C.

[0066] In the example of figure 3, the channel where the respective signal has the highest score is the channel CH.09 where said score is 23.051 (namely, |-89| x 259). The radio transmitter TXz will therefore select said channel CH.09 as the transmission channel.

[0067] According to another aspect of the present invention, the method entails a radio transmitter TX of the system automatically changing the transmission channel when a condition of possible interference or disturbance occurs on a channel CH.n, on which at least two radio transmitters are transmitting.

[0068] In further detail, when on the same channel CH.n two or more radio transmitters TX are transmitting, the respective RSSI values of which are higher than a predefined threshold value, the control units of said radio transmitters TX are configured to change channel, for example according to one of the logics described below.

[0069] According to a first embodiment, it is the radio transmitter TX whose unique identification

[0070] UID (numerical or alphanumerical) is lower that changes the transmission channel. According to a second embodiment, it is the transmitter TX whose unique identification

[0071] UID (numerical or alphanumerical) is higher that changes the transmission channel.

[0072] According to other alternative embodiments, it is possible to establish the channel change priority between two radio transmitters TX based on their credibility score C. Said solution renders uniform the probability of incurring the channel change request for all the radio transmitters TX of the system, with respect to the two embodiments previously described, in which the radio transmitters TX with a unique identification having a low value are statistically more subject to the channel change request than those with a unique identification having high value or vice versa.

[0073] Therefore, according to this variation, in a third embodiment it is the radio transmitter TX with lower RSSI value credibility level that changes the transmission channel.

[0074] In a fourth embodiment, on the other hand, it is the radio transmitter TX with higher RSSI value credibility level that changes the transmission channel.

[0075] In further detail, according to said third and fourth embodiments, when on the same channel CH.n two or more radio transmitters TX are transmitting whose respective RSSI values are higher than the predefined threshold value, both or all the transmitters (TX) send a signal containing information relative to the credibility score C of the other transmitter(s) involved.

[0076] In this way, each transmitter TX can receive the information relative to its own credibility score C detected by the other radio transmitters TX (according to the relative positions, a radio transmitter TX typically has a different credibility score C for each of the other transmitters of the system) so that the respective control units can compare the values.

[0077] These control logics serve to ensure that only one of the two radio transmitters TX in question performs the transmission channel change. In fact, if both changed channel simultaneously, the respective control units could select the same new transmission channel, thus triggering a new channel change situation. According to the invention, the method for changing the transmission channel is the same as the one implemented for the first selection of the transmission channel at the start-up of the transmitter, and described previously.

[0078] According to another aspect of the invention, when a radio transmitter TX has selected a new transmission channel on which to transmit, the method entails automatically changing the respective reception channel of all the associated radio receivers RX.

[0079] In further detail, according to the present invention, the method requires, once a new transmission channel on which to transmit has been identified, the radio transmitter TX to send on the current transmission channel CH.n (namely the one already in use) a signal containing information relative to its own unique identification (UID) and to the new transmission channel selected.

[0080] The radio receivers RX, which receive the above-mentioned signal, via their control unit, change the reception channel from the channel CH.n (in use) to the new channel communicated by the transmitter TX.

[0081] At this point, the transmitter TX begins to transmit on the new channel.

[0082] According to another aspect of the present invention, if a radio receiver RX does not receive the expected signals (namely data packages containing the unique identification UID of the associated radio transmitter TX) for a given time interval t3, the method provides for the following: scanning, with the radio receiver RX, all the N channels available until on one of said channels a signal is picked up comprising said unique identification UID (namely a payload corresponding to the unique identification of the transmitter) with which the radio receiver RX is associated; and configuring said radio receiver RX so that said radio receiver RX receives on the channel where said signal has been picked up comprising the expected unique identification UID.

[0083] The analysis of the signals detected during the scan and the setting of the new reception channel is carried out by the control unit of the radio receiver RX.

[0084] Said scanning of all the channels (called in jargon channel rollover) is carried out both if the receiver “loses” the packages containing the information relative to the channel change, and when said receiver is temporarily no longer able to receive signals from the transmitter (for example there is a shielding obstacle between them).

[0085] The above-mentioned objects of the present invention are further achieved by a radio communication apparatus, for use in a communication apparatus system, in accordance with the attached claim 11.

[0086] In detail, the radio communication apparatus comprises at least one radiofrequency radio transmitter TX and radiofrequency radio receivers RX.

[0087] The radio transmitter TX comprises at least one analog / digital converter, an antenna assembly and a control unit connected to said analog / digital converter and to said antenna assembly.

[0088] The radio receiver RX comprises at least one analog / digital converter, an antenna assembly, and a control unit connected to the analog / digital converter and to the antenna assembly.

[0089] Typically the radio transmitter and the radio receiver, since they are portable, also comprise a battery.

[0090] The radio transmitter TX is configured to transmit on a certain number N of channels CH.n, where each channel corresponds to a given frequency or frequency band.

[0091] The transmitter is further associated with its own unique identification UID. Said unique identification can be included in the digital signals transmitted by the transmitter, for example as payload in each data package sent. According to the present invention, the control unit of the radio transmitter is configured to automatically select the transmission channel.

[0092] In further detail, the control unit is configured to perform, at switch-on of the radio transmitter TX, a scan to pick up the signals emitted by other already active radio transmitters of the system located within a given range. The scan is performed on each of the N channels CH.n. The signals picked up are processed by the control unit to generate a classification of the signals transmitted by the other radio transmitters TX on each channel based on: a) an RSSI value of the signal of each radio transmitter TX; and, preferably, b) a credibility score C of the above-mentioned RSSI value of the signal of each radio transmitter TX.

[0093] The control unit of the radio transmitter TX is further configured to select as transmission channel, from among the N channels CH.n available, a channel CH.n where there are no other signals that can be picked up, namely where the channel is free, or, if signals are picked up on all the N channels, the one where the RSSI level of the other signals is lowest.

[0094] According to a preferred variation, the control unit is configured to calculate a credibility score C of the RSSI values of the picked-up signals.

[0095] The control unit is further configured to implement an algorithm for selection of the transmission channel, where said algorithm includes the above-mentioned factors, namely RSSI value and credibility score C.

[0096] The scan is repeated cyclically, typically with a predefined time interval tl, so that said classification is continuously updated at each time interval.

[0097] According to the present invention, the apparatus is configured to pair a radio transmitter TX having a given unique identification UID with one or more radio receivers RX.

[0098] According to one aspect of the invention, the control unit of the radio transmitter TX is configured to: a) transmit with the transmitter TX on all the N channels CH.n a signal containing information relative to the unique identification UID and to the transmission channel CH.n identified in the preceding step; and b) configure one or more radio receivers RX so that said one or said several radio receivers RX can receive on said channel identified (CH.n).

[0099] In further detail, according to a preferred embodiment, the control unit of the receiver RX is configured to: analyse the signals that can be picked up to detect the presence of information relative to a unique identification UID, and to a transmission channel CH.n; measure the RSSI value of said signals that contain information relative to a unique identification UID and to a transmission channel CH.n; and if the RSSI value of a signal is above a certain threshold, store the unique identification UID contained in said signal as unique identification UID with which to associate the receiver RX.

[0100] Further characteristics of the radio communication apparatus of the present invention have been described above with reference to the method used by said apparatus.

[0101] The present invention, as described and illustrated, is subject to modifications and variations falling within the scope of the inventive concept; furthermore, all the details can be replaced by other technically equivalent elements.

Claims

CLAIMS1. A method for controlling a radio communication apparatus system, where each radio communication apparatus comprises at least a radiofrequency radio transmitter (TX) and radiofrequency radio receivers (RX), wherein the radio transmitter (TX) comprises at least an analog / digital converter, an antenna assembly, and a control unit connected to said analog / digital converter and to said antenna assembly, wherein the radio receiver (RX) comprises at least a digital / analog converter, an antenna assembly, and a control unit connected to the digital / analog converter and to the antenna assembly, wherein the radio transmitter (TX) is configured to transmit on a number N of channels (CH.n), each channel comprising a given frequency or frequency band, wherein each radio transmitter (TX) is associated with a unique identification (UID) included in the transmitted signals, the method comprising a step of automatically selecting the transmission channel for each radio transmitter (TX) of the system, said transmission channel selection step comprising the following sub-steps: a) carrying out a scan to pick up the signals emitted by all the already active radio transmitters of the system within a given range, said scan being carried out on each of the N channels (CH.n) and said picked up signals being processed by the control unit of each radio transmitter (TX); b) generating a classification of the signals transmitted by the other radio transmitters (TX) of the system on each of the N channels based on: an RSSI value of the signals that can be picked up transmitted by the other radio transmitters (TX) of the system and, preferably, a credibility score (C) assigned to each RSSI value of the signals picked up; andc) selecting as transmission channel, from the N channels available, a channel (CH.n) where there are no other signals that can be picked up, namely where the channel is free, or, if signals have been picked up on all the N channels, the one where the RSSI level of the other signals is lowest.

2. The method according to claim 1, further comprising a step of coupling a radio transmitter (TX), with a given unique identification (UID), with one or more radio receivers(RX), where said coupling step comprises the following sub- steps: a) transmitting with the transmitter (TX) on all the N channels (CH.n) a signal containing an information relative to its own unique identification (UID) and the selected transmission channel (CH.n); and b) configuring one or more radio receivers (RX) so that said one or said several radio receivers RX can receive on said selected channel (CH.n).

3. The method according to claim 1 or 2 in which, where calculation of the credibility (C) score of the RSSI values of other signals picked up is scheduled, the transmission channel is selected based on an algorithm that comprises both said RSSI values and the respective credibility (C) scores.

4. The method according to claim 3, wherein for each signal picked up on each channel, a score is calculated given by the product of the absolute value of the RSSI value multiplied by the credibility score (C).

5. The method according to any one of the preceding claims, wherein the credibility (C) score of the RSSI values of the picked up signals of other radio transmitters (TX) is calculated as a function of the variation of said RSSI values at each scanning cycle of each channel.

6. The method according to any one of the preceding claims, which comprises a step of automatically changing the transmission channel of at least one radio transmitter (TX) of the system when, on the same channel (CH.n), at least two radio transmitters (TX) are transmitting,of which the respective RSSI values of the signal are higher than a predefined threshold value.

7. The method according to claim 6, wherein the transmission channel change is performed according to one of the logics described below: the radio transmitter (TX) with lower unique identification (UID) changes the transmission channel; the radio transmitter (TX) with higher unique identification (UID) changes the transmission channel.

8. The method according to claim 6 or 7, wherein a new transmission channel (CH.n) is selected according to the steps described in one of the claims from 1 to 5.

9. The method according to one of the claims from 6 to 9, wherein once the control unit has selected a new transmission channel (CH.n), the radio transmitter (TX) sends on the transmission channel (CH.n) already in use an information signal containing information relative to its own unique identification (UID) and to the new transmission channel selected, and wherein the radio receivers (RX) that receive the above-mentioned signal are configured to select the new channel (CH.n) selected as reception channel.

10. The method according to any one of the preceding claims, wherein, if a radio receiver (RX) does not receive signals comprising the unique identification (UID) of the associated radio transmitter (TX) for a given time interval: the control unit of the radio receiver (RX) will scan all the N channels (CH.n) available until, on one of said channels, a signal is picked up comprising said unique identification (UID) with which the radio receiver (RX) is associated; and said radio receiver (RX) will be configured so that said radio receiver (RX) receives, on the channel where it has been picked up, said signal comprising the expected unique identification (UID).

11. A radio communication apparatus, for use in a communication apparatus system, said apparatus comprising at least a radiofrequency radio transmitter (TX) and radiofrequency radio receivers RX), wherein the radio transmitter (TX) comprises at least: an analog / digital converter; an antenna assembly; and a control unit connected to said analog / digital converter and to said antenna assembly; wherein the radio receiver (RX) comprises at least: a digital / analog converter; an antenna assembly; and a control unit connected to the digital / analog converter and to the antenna assembly; wherein the radio transmitter (TX) is configured to transmit on a number N of channels (CH.n), each channel comprising a given frequency or frequency band, wherein each radio transmitter (TX) is associated with a unique identification (UID) included in the transmitted signals, wherein the control unit is configured to automatically select the transmission channel, said control unit being further configured to: a) perform a scan to pick up the signals emitted from active radio transmitters (TX) of the system within a given range, said scan being performed on each of the N channels (CH.n) and said picked up signals being processed by the control unit of each radio transmitter (TX); b) generate a classification of the signals transmitted from other radio transmitters (TX) of the system on each of the N channels based on: an RSSI value of the detectable signals transmitted by the other radio transmitters(TX) of the system and, preferably,a credibility (C) score assigned to each RSSI value of the picked up signals; c) select as transmission channel (CH.n), from among the N channels available, a channel (CH.n) where there are no other signals that can be picked up, namely where the channel is free, or, if signals are picked up on all the N channels, the one where the RSSI level of the other signals is lowest.

12. The radio communication apparatus according to claim 11 , in which, where the control unit is configured to calculate the credibility (C) score of the RSSI values of the picked up signals, said control unit is further configured to implement an algorithm for selecting the transmission channel, where said algorithm includes the RSSI values and the respective credibility (C) scores.

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