JP2003528496A - Short-range wireless communication system using electronic portable device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a system which enables two or more persons in a group of persons to communicate by the same portable electromagnetic wave transmitting / receiving device. SOLUTION: In order to allow several persons to communicate with each other on the same public frequency channel, each of them comprises public communication analog means (1, 2, 3, 14, 15), With the ability to listen to another person's conversation, as well as digital means of private communication (4,5,12) to allow only between two persons, except to listen to another person's conversation A system comprising a portable device with control means (4) for a pair of persons to communicate with each other on a private channel, and to automatically and alternately switch from the public communication mode to the private communication mode.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to a short-range wireless communication system between persons in the same group, and more particularly to a system that enables two persons in a group of persons to communicate with each other by the same portable electromagnetic wave transmitting / receiving device.

[0002]

[Prior art]

Known wireless communication systems using portable or portable wireless communication transceivers are, in fact, very inconsistent and their interoperability is very limited, on the contrary, the basic communication requirements of the current life. Can not even be satisfied. Also, if you see a police officer asking for information on the other side of the intersection,
Confidentially communicate with unknown people you meet at intervals, call taxis in town corners, chat with people driving cars, participate in games at shopping centers, and help You can't ask for them, find them, or listen to information messages. Illustratively, police radiotelephones cannot spontaneously communicate with mobile terminals of certain GSM-type cellular communication networks.

The << walkie talkie >> type of relatively short distance communication system or << civil band >> wireless communication system has the analog nature of the technology used.
It is inadequate to guarantee this type of service as well, as it is inevitable that several persons will interact on the same frequency channel, which is considered a significant offensive eavesdropping. Systems that include fully digital transceivers do not answer that question. This is because such systems require the use of confidential codes and calling numbers to establish communications, which is essentially the book that a person must be able to communicate without revealing anything to the system. This is because it cannot be considered within the framework of the intended use of the invention. On the other hand, in this system, for example, a complicated and expensive synchronizer which should be used in the ALOHA type must be provided so that it can be used in the network and the temporary multiplexing of radiation can be performed correctly. The above transmitter must be created for distribution.

[0004]

[Problems to be Solved by the Invention]

An object of the present invention is to provide a short-range wireless communication system between two persons of the same group of persons without using a confidential code to initiate the communication,
The purpose is to eliminate the above-mentioned inconvenience.

Another object of the invention is a short-range of the type described above in which any two persons of a group of persons can initiate communication using public analog channels and establish communication on private digital channels. A wireless communication system is provided.

[0006]

[Means for Solving the Problems]

To that end, the present invention includes a private analog communication means for allowing only a pair of persons to communicate, wherein the persons in the pair communicate with each other on a private channel, except for listening to the voice of another person, and from a public communication mode. Each mobile device having several persons communicating within the group on the same public frequency channel, characterized in that it includes control means for automatically and arbitrarily switching to a private communication mode. A group of persons can communicate within a group using the same portable electromagnetic wave transmitter / receiver device, including public communication analog means for enabling each person to hear and intervene in the conversation of another person. A short-range wireless communication system is intended.

According to another feature of the invention, each mobile device performs scanning of a private channel, interrupting said scanning on the channel while a user of the other channel establishes private communication, or In the absence of another such user, it includes means for automatically searching for a free private channel operated by programmed control means for interrupting the scanning of the free first private channel. In the latter case, all other users operating private channel auto-discovery means are conducting private communications.
The procedure for transitioning from public channel communication to private channel communication is described in more detail below. Primarily, the invention has the advantage that it is possible to guarantee the confidentiality of a voluntary connection and complete communication between two persons without the use of a confidential code. Because each mobile device is usually connected permanently via analog channels, each person can always use their own choices, or strictly confidentially on private channels that the system automatically assigns, to open public channels. You can listen and intervene to refer another person by requesting that you wish to communicate with.

The present invention also provides near-perfect voice quality by operating on several bi-directional frequency channels, as well, by utilizing weak transmit power of, for example, 50 mW or less and temporally multiplexed digital wireless communication techniques. Is obtained. By using the weak transmission power, the user is subject to all usage control restrictions on the channel, for example, a restriction on the transmission power of 50 mW or more D
The advantage is that it escapes the rules according to the ECT standard. The benefits of this technical choice are double: on the one hand, a comfortable listening experience without fatigue due to the high listening quality, and on the other hand, the short reach of the transmitter, which causes interference caused by third-party mobile devices. By limiting the possibility of each mobile device, it is possible to turn each mobile device into a practical and direct application.

[0009]

DETAILED DESCRIPTION OF THE INVENTION

A system according to the present invention is very close to a plurality of identical radios that allow two or several people using the system to communicate very closely over a short distance, for example of the order of 300 meters. A person comprising a communication transceiver handheld device and wishing to communicate may or may not be directly in the field of view, or may be mobile with respect to the other. The system has two main modes, the first mode in which each person hears all other person's calls and sends them to the system,
And a second mode in which only two people can communicate with each other in addition to listening to another person's call.

In the first mode of operation, conversations between persons take place on the public analog channel described above, and are unlimitedly available to all users whose mobile device selects the same public channel for transmission and reception. In this mode of operation, the establishment of communication is not governed by the protocol if it only provides a scheme similar to that used in the << Civilian Band >> system, and subsequently, if desired, managed. Done on a common public channel that allows a person to make a first contact on a private channel available for. In the second mode of operation, conversations between persons have to be done on digital channels of the << Private >> frequencies mentioned above. In this mode of operation, a protocol is provided to establish communication between two persons. The protocol envisions automatically assigning a free << private >> channel to two persons who have indicated on the public channel their intention to communicate on the << private >> channel. According to the protocol, a << private >> channel is assigned to the first person who actually requested it.

FIG. 1 shows an illustration of the distribution of the public frequency channel n + 1, denoted C _{0 to} C _n , and the private channel m + 1, denoted P _{0 to} P _m , where the channel is in some cases centered. It can be an image of each other over frequency. A monitoring frequency band is provided in order to separate the private and public channels well. Each mobile device according to the invention is specially designed to transmit audio in alternation and the band size of each channel can be several KHz. According to the preferred mode used in the present invention, the public channel is modulated in frequency and the private channel is modulated with a frequency displacement according to the modulation method known by the English abbreviation FSK of << Frequency Shift Keying >>. However, it is likewise possible to choose another type of modulation for the public channel, such as amplitude modulation, or the English abbreviation MSK or the phase displacement modulation known from QPSK. In order to achieve this goal, the mobile device consists of a transmitting / receiving antenna 1, a transmitting module 2 and a receiving module 3, as shown in FIG. 2, the latter two being shown inside the dotted lines. A signal processor 4 connected to the inputs and outputs of the transmitter module 2 and the receiver module 3, respectively, is in a known manner voice coding, data forming, channel coating, and digital modulation of the transmitted signal, and the receiver module 3 receives. Programmed to ensure data decoding. The key or push button unit 4a is the processor 4
Is connected to and guarantees control in the private and public operating modes and selection of the corresponding frequency channels. In some cases, the microprocessor 4 can be connected to an external memory (not shown) of the microprocessor 4 in order to store the message and send it in real time or gradually with a delay time.

The transmission path 2 is a modulator F of a frequency modulated by frequency and / or frequency displacement.
It includes a lower radio frequency unit consisting of an M / FSK 5, an amplifier 6 whose output is connected to the antenna 1 via a transmit / receive switch 7 and a transmit filter 8.

The reception path 3 includes a lower radio frequency unit including a reception filter 9, a low noise amplifier 10, a frequency transfer device 11, and a demodulator 12 for the signal FM / FSK,
These elements are connected in series with one another in this order via the antenna 1 and the switch 7 to the signal processor 4. The signal demodulator 12 supplies the test signal RSSI indicating the energy of the demodulated signal to the processor 4. This signal is used in the free channel search process, as detailed in the description below.

The modulator 5 includes a frequency synthesizer (not shown) which is voltage-controlled by the signal processing microprocessor 4. The modulator 5 supplies the modulation signal to the input of the amplifier 6 via the switch 13 since the circuit is in the << transmit >> mode. Upon reception, the signal supplied by the frequency synthesizer of the modulator 5 is applied to the first input of the frequency transposition device, the second input of which receives the received signal supplied by the low noise amplifier 10. On the one hand, the microphone 14 applies an audio signal to the input port of the processor 4,
It guarantees a digital transmission according to the modulation FSK and, on the other hand, an analog input of the modulator 5 to guarantee a frequency modulation transmission according to the selected operating mode. The high handset 15 receives, on the one hand, the voice signal reconstructed by the processor 4 from the data received by the demodulator 12 when the voice is received by the private channel, and on the other hand the signal by the public channel. Sometimes the demodulator 12 receives the audio signal demodulated.

Reference number TRF6 by the United States company Texas Instruments
This device can be implemented using the components that have been commercialized in 900, which include a processor 4 that can consist of commercially available components.
Except that all elements of FIG. 2 have been reconstructed on the same material.

It is noted that the same antenna 1 is used for transmission and reception at the same time, the transmission and reception module uses the same modulator 5, and the circuit prohibits all simultaneous transmission / reception. Since only two users can communicate in << Full Duplex >>, this problem is solved by using TDMA-type frame temporal multiplexing as shown in the schematic diagram of FIG. . According to this figure, each frame is divided into two time intervals of duration equal to T. With respect to the transmission part, a first time interval of duration T is assigned to a first user arriving on a vacant channel and a second time interval is left for a second user arriving on the same channel. Be saved. Reception is performed at the second time interval for the first user, and reception is performed at the first time interval for the second user. Frame synchronization is achieved by the << top frame >> signal transmitted by the first user's mobile device arriving on the vacant channel. This << top frame >> is transmitted to the portable device of the second user who can be synchronized.

Each frame is composed of several information fields indicated by Z1 to Z4 as shown in FIG. The field Z1 contains the information required for the acquisition and thus the data, the field Z2 contains the data and the field Z4 constitutes a monitoring interval with the following field Z3.

Allocation of resources for private communication is automatically performed at the request of the user. Of course, if all resources are already in use by another user, you can leave nothing behind. This procedure mainly consists of scanning of the frequency band left for private communication with tests on the received power in time and frequency.

Communication communication between two users who are talking to each other on one private channel is zone Z
The signals corresponding to 1 to Z2 are maintained by transmission from the mobile device at respective time intervals. The presence of that signal indicates to another portable device within range that the channel is already occupied. To ensure a minimum energy consumption and a constant autonomy of each mobile device, a timer with a time constant of approximately 20 ms, which can be realized by suitable programming of the processor 4, is provided, and a defined transmission without transmitting a voice. You can disconnect after an hour.

The selection of digital channels is automatically guaranteed. That is, it is guaranteed in a completely clear way for the user according to the frequency usage principle. According to this principle, a channel is considered available if the portable device detects the presence of at most one user. If the tested channel is occupied, the same search principle applies to the next channel.

The presence of a user on the channel is determined by a power estimation for a duration equal to twice the duration Tf of the frame. If the detected signal level is above the defined threshold, the indicator RSSI is placed in the logical state << 1 >> during this measurement, otherwise it is placed in << 0 >>. A free channel search algorithm using this principle is shown in FIG. Execution of this algorithm consists of 8 steps shown in 16-23. The channel scanning process begins in steps 16 and 17 with a level test of the signal RSSI on the channel image of the analog channel in which the two users were placed before deciding to interact on the private channel. If RSSI = 0, the mobile device is transmitting the connection signal of step 18. If the signal RSSI is not zero, a test is performed in steps 17 and 20, and the levels of the signal RSSI are <<0> and <<
If the answer is << Yes >>, it is necessary to confirm in step 20 whether a connection can be established with the second user.
In the opposite case, steps 22 and 23 declare that the channel is unavailable.

Two users A using this principle, according to the assumption that they are on the same public channel when they decide to be on the same private channel to continue the dialogue. The connection protocol between B and B will be described below. To do so, users A and B must initiate a manual control generated by a key or push button located on the mobile device. It is very rare for users A and B to initiate manual control at the same time, and generally there is a time gap of tens of seconds between at least two controls, so that according to the process shown in FIG. , Users A and B each initiate scanning of a private channel on their respective mobile device, and then, for example, a first private channel that follows in the order of scanning to occupy the first available channel. To scan. User A is the first person to start scanning the available channels,
Assuming that the resources of the available frequency do not change during the step of establishing the communication, as soon as the mobile device of user A detects a vacant channel while performing a level test of the signal RSSI, While listening to the signal during the time interval T, during the duration Tconnection, start transmitting a signal including the acquired data and the synchronization frame of FIG. 4 without voice data. Meanwhile, user B's mobile device initiates channel scanning to discover the first available channel in a manner similar to that performed by user A's mobile device. If a test carried out on the level of the signal T shows that the signal is present in that channel, the mobile device of the user B synchronizes and analyzes the signal from the moment following the duration, ie the received synchronization signal. To do. If the signal is present, mobile device B considers the frame to be completely occupied. Therefore, without making a connection, the process shifts to the analysis of the following channels. In the opposite case, user B's mobile device considers the channel to be free and begins to send an indicator signal. When two users start the search at almost the same time, the probability that the mobile devices of users A and B are effectively connected is important.

When the mobile device A or B stops transmitting an audio signal, a signal R
The duration T at which the SSI alternates to transition states of the form <<< 1 >> and <<< 0 >>
The signal continues to be transmitted during the down. When this condition is detected and the duration of Tdown or more is exceeded, the communication is considered no longer active. Mobile devices that no longer receive data return to the first public channel. According to another procedure, the means for searching for vacant private channels consists of the electronic circuit of each carrying case that permanently identifies the available private channels, the automatic key << Public /
Identify the available channels transmitted by the first user's mobile device that pressed Private >> (31).

Basically, a portable device according to the invention is in the form of a case as shown in FIGS. 6a and 6b and comprises an electronic card consisting of the previously mentioned functionality, a microphone 14 and a speaker 15. Additionally, a demodulator 12 called FM stereo, RDS, or DAB to weaken or enhance the signal level provided by the receiving tuner when channel activity is transmitted in the RSSI signal. A known type of public radio broadcast reception tuner connected to the can be incorporated into the electronic circuitry of the portable device.

[0025]   By the time the case is shown in Figure 6a, the public channel shown at 24-30 is shown in front of it.
Key unit to select the, as well as a private digital signal from the public analog channel.
Have a public / private key to move to Le Channel. In addition, two people
When communicating on the channel manually selected by the selection keys of channels 24 to 30,
Switch to the private channel as described below. Such switching
Then, if the third user presses the public / private key 31, the electronic circuit of the mobile device will
In some cases it is not possible to connect to the private channel used by the preceding two parties,
Therefore, it is in a state of private communication with the fourth caller. Light emitting diode 24_l~ 30 _l However, in order to show the channel in use to the user,
Rui are associated with push buttons 24-30. Similarly, mobile devices are private
The light emitting diode 311 is installed so that the user can recognize whether or not it is in the mode.
Associated with a public / private key or push button 30. Start / stop key
-Or push button 32 and audio headphone jack 33
, Located on one side of the case shown in FIG. 6b.

The headphone jack is primarily dedicated to the integrated microphone and / or earphones, or otherwise branched in parallel, or instead of the microphone 14 and speaker 15, bicycle headphones. Or, it is exclusively for motorcycle headphones. The benefit of such an arrangement is
This means that users can talk with their hands always free. Similarly, it allows the wearer of the case to listen to the broadcast received by the receiving tuner built into the mobile device. In that case, the user may have a microphone or a connecting cable connecting the headphones to the headphone jack, or a microphone strut, and, if present, all or part of the metal pieces that connect the two headphones to each other. It can be used as a receiving antenna. The headphone jack is also not shown in the case by connecting the same portable device to two microphone / headphone units and simply cabling it, but just press the key provided for that frequency channel. In addition to receiving the, the driver and passenger can talk. Additionally, a key 34 may be provided to confirm the channel selection.

According to another mode of realization of the present invention, public channel access keys 24-30 of different colors, eg blue or red, eg according to the traditional seven colors of the rainbow.
With proper programming of the processor 4 allows access to seven public channels with a simple key press, while on the other hand, for example red and blue,
Pressing two keys simultaneously, green and yellow, allows manual selection of 28 channels. Due to its universal character, the adoption of iridescent colors is due to the simple appearance of the iridescent colors on the key unit of any handheld device that integrates the present invention into multiple handheld devices of different users. There is an advantage that the function and application can be instantly recognized. Also, the present invention can be integrated into a cordless telephone, a cellular mobile telephone, a conventional telephone handset, a portable information terminal, an organizer, a calculator, or any other device used in our current lives.

Also, certain manual channels for one or two colors can be dedicated to well-defined applications. For example, << yellow channel >> is CB
The image is a shared channel of channel 27 of <<, red channel >> is for traffic information only, << green channel >> is for tourist information only, << blue channel >>
> Can be used to call a taxi or as a co-owner of a car. Similarly, cyclists who wish to permanently communicate with another manual channel,
For use by the same group of motorcycle drivers, pedestrians, skiers, << roller skates >> enthusiasts, drivers, more static people (callouts, hospitals, neighbors, children's rooms, etc.) talking in the same neighborhood. You can Also, certain channels can be dedicated to activities that have been designated with priority: blue channels for tourism, red channels for cottage industry, indigo channels for religious information, and so on.

A handheld device with two color channel selection offers more possibilities as it has more channels. In fact, according to the selection criteria or predetermined commonalities, for example, the red and blue channels are assigned to collectors, the orange and green channels are assigned to philosopher lovers, etc. identified by associated color codes. By selecting different channels, one or several persons can contact the one or several persons sufficiently selectively.

The contacting is automatic and in order to save energy, it is sufficient to program the microprocessor 4 to issue a cyclic signal at a high cycle ratio to a predetermined channel, for example every 2 seconds. is there. If the two persons who have selected the channel are in close proximity, an acoustic signal and / or an optical signal can be emitted to establish communication.

In a more complex version, the memory is registered with a profile of the person, and the profile is sent for a predetermined duration to a digital channel dedicated to the application so as to enable searching. The microprocessor 4 can be programmed. Further, if two persons adjacent to each other are programmed with the microprocessor 4 of the mobile device according to the matching criteria or according to the matching providing / searching pair as described above, the microprocessor of each mobile device. The match can be detected by comparing the pre-registered profile performed by the profile received from the special transmission channel dedicated to that application. In this process, the handheld device must ensure that the dedicated channel is available for RSSI signal level testing before transmitting. Upon confirmation of the match with the received profile by the mobile device, the mobile device may, in some cases, send an acknowledgment of receipt containing a copy of the received profile and then switch to the indicated private channel,
If the latter is not available, the above-mentioned private channel scanning process is performed on the first available private channel in numerical order following the indicated channel. When the mobile device, to which the first mobile device has sent the profile of the sought person, receives the receipt, the latter switch to the indicated private channel is also performed, or the latter is the private channel. If not available on the first available channel that follows in the scanning order of, the two people just discovered can communicate on the same automatically assigned private channel. Simultaneously with the connection established in this way, an acoustic or optical signal is emitted by the speaker 15 or by the indicator lamp provided for this, in order to inform the person with whom communication is possible. To avoid collisions of transmissions between different mobile devices on a dedicated channel for that application, the transmission of the profile is done randomly during the predetermined transmission time, within a time matching window of the same duration. The ratio between the transmission duration and the matching window duration is relatively small, for example less than 1/100 due to the low probability of collisions between two transmissions. Downloading by indirect means such as a menu that appears one after another on the display, key operation, or
If desired, the microprocessor 4 can be programmed via a personal computer which can be connected to the input / output ports by any suitable means such as optical, cable or telecommunications. As an illustration of an application, such a mechanism would facilitate the encounter of a person at the same school, an employee of the same company, or someone already in contact and pre-programmed with that name. This mechanism also allows the person making the search and the matching offer to contact each other. Offers and searches are based on services and products. By way of illustration, a person who offers a shared seat in a car can initiate communication with a person who is looking for such a seat; a person who wants to sell the car can communicate with a purchaser.

Also, according to another realization variant of the invention, a << emergency >> key 33 can be added to the mobile device, for example after pressing the key for a few seconds, the device can remain active. it can. In that case, the entire channel is active, and in particular the keys 24 ,. ． ． By pressing 30 or pressing the emergency key 33, a sound signal of a tone color that can be recognized by a group of users who can communicate with a person in an emergency is transmitted. It is useful in emergency situations, for example to find the whereabouts of a person at risk in the mountains quickly, or also when the old man has fallen down and is stuck.

According to another variation of the invention, this device allows the creation of works of art, monuments, or any other subject matter for which information is desired to be broadcast locally by incorporating the device according to the invention into an object. <Speak to an object> can be done,
It also allows all users of nearby mobile devices to hear voice messages emitted by the embedded device. The public channel on which the message is sent is in a visual way, preferably the traditional iridescent color so that the user of the mobile device can see the color code at the foot of the church where they can hear the message about the church, for example. Must be displayed with the color code of the image. The voice message sent is
It can be activated permanently or by detecting the user's voice on a special channel. For example, for a user once connected on a channel that corresponds to a good color code, it is sufficient to say something to start sending a message. In a further developed variation, voice recognition is used to emit on-demand messages.

In order to better manage the energy, each mobile device has a bipolar
Alternatively, a 3-pole switch is provided, for example, 2 for 100 meters reach.
The transmission power can be changed to mW, or 10 mW for a reach of 300 meters.

In order to reduce the airtime of two users of a private channel, in one variation, a group of private channels, each associated with a group of public channels, was allocated and used by two users. Perform a channel search from a first group of private channels associated with a group of public channels in which there are public channels that are not used by the first private channel in numerical order.

[Brief description of drawings]

FIG. 1 is an illustration of a frequency diagram used to ensure communication between mobile devices according to the present invention.

[Fig. 2]   FIG. 6 is a schematic diagram of an electronic structure that constitutes a portable device according to the present invention.

[Figure 3]   An example of multiplexing of data frames according to the present invention.

[Figure 4]   Data frame format

FIG. 5 is an empty channel search algorithm using the present invention in flow chart form.

[Figure 6]   6a and 6b are embodiments of a case including a portable device according to the present invention.

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ , CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, K E, LS, MW, SD, SL, SZ, TZ, UG, ZW ), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, C R, CU, CZ, DE, DK, DM, DZ, EE, ES , FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, K R, KZ, LC, LK, LR, LS, LT, LU, LV , MA, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, S I, SK, SL, TJ, TM, TR, TT, TZ, UA , UG, US, UZ, VN, YU, ZA, ZW (71) Applicant Dias Bernard             DIAS, Bernard             France, F-92120 Pareiso, Ryu               Alexandre Nero, 36             36, rue Alexander Ner             eau, F-92120 Palaisea             u France (72) Inventor Parianti, Raul             France, F-06000 Nice, Ryu             De Vergique, 5 (72) Inventor Dias Bernard             France, F-91120 Pareiso, Le             Alexander Nero, 36 F term (reference) 5K011 AA07 AA09 BA10 CA02 CA17                       GA03 JA01 JA03 JA12                 5K067 AA21 BB04 DD11 EE02 EE35                       HH11 HH22 JJ21 JJ31

Claims (22)

[Claims] 1. Within a predetermined number of private channels (P ₀ , ... P _m ), a pair of people communicate with each other on the private channel, otherwise another person hears the conversation. A mobile device is a digital private communication means (4,5,12) to allow only communication between two persons, and automatically and optionally alternates from public communication mode to private communication mode. Each mobile device is characterized by a control means (4, 31) for the number of public communication channels (C ₀ , ... C _n ) within a predetermined number. A group of persons can communicate with each other by the same electromagnetic wave layer receiver portable device composed of analog means (1, 2, 3, 14, 15) of public communication for allowing persons to communicate with each other on a public frequency channel, The feature is that each person can hear the conversation of another person. And the short-range wireless communication system. 2. Digital communication means (4, 5, 12) for private communication are programmed for exchanging digital information in alternating mode by temporal multiplexing of frame TDMA. The system according to 1. 3. Each frame TDMA has a first and a second equal duration interval T.
And the first and second intervals are respectively reserved for the transmission of the first person and the second person who have succeeded in arriving on the vacant channel allocated by the automatic search means, and received. System according to claim 2, characterized in that the intervals are left for the second and the first person respectively. 4. A key unit (24, ... 30), each mobile device being arranged to manually select a predefined public channel for use between at least two users, and By pressing the << Auto >> key (31) described above by the two users within a predetermined time period, the two users communicating on the manually selected public channel will be <<<< 4. A public key according to claim 1, 2 or 3, characterized in that it comprises an automatic key << Public / Private >> (31) to allow it to be assigned to a channel. system. 5. A free private channel (16, ... 23) activated by said control means (4, 31) of each mobile device which makes it possible to always identify an available private channel. Said automatic search means, wherein the identification of the available channels is issued by the first user's portable device pressing the automatic key << Public / Private >> (31). The system according to any one of 1 to 4. 6. Scanning of the private channel from the first private channel and no significant power of the signal is measured (RSSI = 0) or significant power is acquired for the first private channel. The power measured only during the transmission interval of the frame TDMA corresponding to the transmission interval of the user's mobile device and the power measured during the second interval of each frame TDMA is not significant (RSSI alternating 0 and 1). System according to claim 5, characterized in that the searching means are programmed to stop scanning on the first private channel encountered, such as (repeat). 7. A signal processor (4) for each mobile device to store a message and deliver it sequentially in real time or with a delay time.
System according to any of claims 1 to 6, characterized in that it comprises a memory connected to the. 8. One on a channel manual selection key unit (24, ... 31).
Pressing one or several keys at the same time provides access to the public channels, and the aforementioned keys are preferably used to identify each channel by color or combination of colors. System according to any of claims 1 to 7, characterized in that it is a different color based on a 7-color image. 9. The private communication digital means (4,5,12) comprises a channel dedicated to searching for a person defined according to the characteristics of a defined profile, said digital means registering the profile, Compare people who can receive it from another handheld device on their search-only channel and automatically switch to the available private channel if the registered and received profiles or offer / search pairs match System according to any of the preceding claims, characterized in that it is configured with a processor (4) programmed for it. 10. System according to claim 9, characterized in that the transmission of the profile on the person-only channel is performed randomly within a matching time window of equal duration. 11. An audio signal when each mobile device establishes a connection, or
System according to any of the preceding claims, characterized in that it comprises means for emitting an optical signal. 12. A person pressing each mobile device's emergency key on its own mobile device by pressing a predetermined key (24, ... 30, 33) corresponding to a predetermined public channel. Must be pressed for a few seconds to send an acoustic signal of a predetermined timbre over all public channels in order to encourage another user of the mobile device communicating on all public channels to initiate communication. System according to any of the claims 1 to 10, characterized in that it comprises a <urgent> key (33) which is inactive. 13. A portable device owner includes a defined number of portable devices permanently allocated to the information terminals so as to obtain the transmitted information, each said terminal defining a channel to select. System according to any of the preceding claims, characterized in that it is assigned a color code as indicated. 14. A key unit (24, ...) Specified to manually select a predefined frequency channel for use by at least two users.
． 30), and during the pre-defined time period, two users may use the automatic key (3
Some, characterized by comprising an automatic key (31) for allowing two users communicating on a manually selected channel to be assigned to a private channel by pressing 1) A short-range wireless communication electronic portable device having a transmission path and a reception path for transmitting or receiving on the frequency-multiplexed channel. 15. A means for searching for available private channels (4, 16, ... 2)
3), scanning from the first private channel and no significant power of the signal is measured (RSSI = 0), or the spacing of another user's mobile device that first acquired the private channel. It seems that the significant power is measured only during the transmission interval of the frame TDMA corresponding to, and the power measured in the second interval of each frame TDMA is not significant (RSSI alternates between 0 and 1). 15. Mobile device according to claim 14, characterized in that said means for stopping scanning on the first private channel encountered are programmed. 16. A high frequency band transmitting (2) and receiving (3) means respectively connected to a microphone (14) and a speaker (15) built in the portable device, respectively. Alternatively, the portable device according to 15. 17. The memory according to claim 14, further comprising a memory connected to the signal processor (4) for storing the message and delivering the message in real time or in sequence with a delay time. 15. The portable device described in 15 or 16. 18. A public channel is accessed by pressing two keys of said key unit at the same time, said key preferably being a traditional key for identifying each channel from a color or combination of colors. 18. The mobile device according to claim 17, wherein the mobile device has different colors according to a seven-color image of a typical rainbow. 19. Registering a profile of a person, comparing it with a profile that can be received from another portable device on the person search dedicated channel, and if the registered and received profile or offer / search pair match. Mobile device according to any one of claims 14 to 18, characterized in that said digital means comprises a processor (4) programmed for automatically switching to an available private channel. 20. Pressing a predetermined key (24, ... 30, 33) corresponding to a predetermined public channel initiates communication with a person who has pressed the emergency key of his mobile device. To prompt another user of a mobile device communicating on the public channel to emit a sound signal of a predetermined timbre to the entire public channel, which can only be activated after a few seconds of pressing << Emergency 20. Mobile device according to any of claims 14 to 19, characterized in that it comprises a >> key (33). 21. A microphone comprising a microphone (14) and a microphone (14), which are substituted or alternatively branched in parallel with a microphone (14) and a speaker (15).
One or two headphone jacks (33
), And optionally, in addition to the transmitting means (2) and the receiving means (3), a selection key for enabling wired communication between the owners of the two headphones. The mobile device according to any one of 20. 22. A cordless telephone, a cellular mobile telephone, or the like, a remote controller, an organizer, a calculator, or any portable information device, according to any one of claims 14 to 21. Mobile device.