Wireless communication network system and wireless communication device

Abstract

To allow a terminal to automatically return to a network (NW) if the terminal becomes strayed due to channels in use in the NW being changed in the simplex wireless communication network (NW) while some terminals are out of a service area or the like.SOLUTION: In a reception mode, each terminal cyclically scans all available channels, giving time priority to a currently set channel. When a channel in use in a network (NW) is changed, each terminal transmits and receives a G-ID (group identification signal) and a channel change request signal, and each terminal counts the number of times of its transmission and reception. At the time of a call, each terminal also additionally transmits its own count value, and in another terminal, if a receiving channel of the G-ID at cyclic scanning is other than the currently set channel, each terminal updates and stores the receiving channel and a count value (N), and compares its own count value (M) with the count value (N). In a case of M>N, the G-ID and M are transmitted on the currently set channel. In a case of N>M, its own currently set channel is changed to the receiving channel. In a case of M=N, the current state is maintained.SELECTED DRAWING: Figure 15A

Description

[Technical field]

[0001] The present invention relates to a network system and a wireless communication device that, when the communication channel is changed in a simplex group wireless communication network for reasons such as avoiding interference, some of the constituent terminals (wireless communication devices) of the network may deviate from the changed channel for various reasons, but which makes it possible for such "stray terminals" to automatically return to the network. [Background technology]

[0002] Simplex business radio communication devices are used outdoors at various construction sites and other work sites, and indoors at relatively large restaurants and spacious home improvement stores for business-related communication between employees. Furthermore, wireless communication devices that comply with the specific low-power standard are designed to communicate voice over short distances using the 400 MHz band, but as they are now widely used for a variety of business purposes, it is not uncommon for wireless zones to be close to each other or to overlap.

[0003] Non-Patent Document 1 below specifies the type of radio waves, communication method, operating frequency, and antenna power as technical conditions for the system related to the operation of the wireless communication device, and for the operating frequency when the communication method is simplex, 20 channels are allocated, consisting of 11 channels with channel numbers CH20 to CH30, which are divided at 12.5 kHz intervals from 422.0500 to 422.1750 MHz, and 9 channels with channel numbers CH41 to CH49, which are divided at 12.5 kHz intervals from 422.2000 to 422.3000 MHz. In addition, channel number CH31 (422.1875 MHz) is allocated as a frequency control channel, and can be used within a range of 0.5 seconds.

[0004] Therefore, when conducting group communication using the above-mentioned wireless communication device in a simplex system, an available channel will be selected from the above-mentioned 20 channels or from a number of channels pre-selected from those. However, as mentioned above, when wireless zones become dense, interference may occur midway, and when this causes disruption to business operations, it may be necessary to change the communication channel even while the network is in operation.

[0005] In this regard, many wireless communication devices available on the market are equipped with an automatic channel selection function. In the automatic channel selection mode, a specific wireless communication device in the network performing group communication functions as a transmitter, and other wireless communication devices function as receivers. In the transmitting wireless communication device, if the receiving and demodulating unit performs carrier sense and transmission is not possible, the channel is moved by one according to the channel number, etc., and carrier sense is performed, and this procedure is repeated until transmission is possible, and the transmission mode is entered on the channel where transmission is possible. Meanwhile, the receiving wireless communication device constantly scans all channels in the receiving and demodulating unit, and stops scanning and opens the audio playback circuit when a signal with a matching group code is received, and resumes scanning once reception is completed.

[0006] Furthermore, the following techniques have been proposed in patent documents: The following Patent Document 1 discloses a wireless communication network in which, when one wireless communication device in communication detects interference caused by unwanted radio waves, it searches for an available channel and creates a channel switching signal by attaching a switching signal to the detected available channel information, and when it detects that the level of the unwanted radio waves on the channel in communication has dropped to a level where communication is possible, it transmits the channel switching signal and sets the channel to be used by the device to the available channel specified in the channel switching signal, and when the other wireless communication device in communication receives and detects the channel switching signal, it transmits a switching acknowledgement signal and switches to the channel specified by the channel switching signal, and other wireless communication devices in standby mode that are not in communication receive the switching acknowledgement signal and switch to the channel specified by the channel switching signal.

[0007] The following Patent Document 2 discloses a system in which a wireless network is made up of sub-stations which perform data communication and a parent station which controls each of the sub-stations, in which the parent station judges the radio wave conditions of all available wireless channels at the time of startup and determines the optimal channel (the parent station transmits free channel information contained in a beacon), and periodically stops network transmission (the parent station transmits a monitoring beacon which prohibits the sub-stations from transmitting for a certain period of time), and each sub-station monitors the radio wave conditions in the vicinity in a dispersed manner (the sub-station which receives the monitoring beacon measures the received electric field strength during the transmission suspension period and transmits the results to the parent station to notify them), thereby selecting the optimal channel for the wireless network (the parent station selects the optimal channel based on the measurement results of the received electric field strength received from each sub-station, and transmits the optimal channel information contained in a beacon to each sub-station).

[0008] Furthermore, in relation to changing communication channels in a simplex group wireless communication network, the applicant has proposed a wireless communication network system that, "is a simplex wireless communication network system, in which, when any of the constituent terminals transitions to a transmission mode and finds interference in the currently used channel due to carrier sense, scans all channels available in the network during reception / standby mode, and uses channel selection order data created so that each vacant channel is in ascending order of received signal strength, and performs carrier sense sequentially from the top channel to a channel of a predetermined rank, sets the first detected interference-free channel as the transmission / reception channel, and transmits a group identification code and a channel change command for the group network, while each constituent terminal other than the constituent terminal receives / detects the group identification code and channel change command for the group network from a channel determined to be in an interference state during the process of repeatedly scanning all channels available in the group network while in a reception / standby mode" (Patent Application No. 2023-074015). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 10-75194 [Patent Document 2] JP 2002-158667 A [Non-patent literature]

[0010] [Non-Patent Document 1] Association of Radio Industries and Businesses, "Standard for Specified Low-Power Radio Stations / Radio Equipment for Wireless Telephones", RCR STD-20, Version 5.1, revised October 29, 2021 Summary of the Invention [Problem to be solved by the invention]

[0011] As described above, various proposals have been made regarding methods for changing network channels in a group wireless communication network. However, there may be cases where a terminal (wireless communication device) is unable to participate in the change process for reasons such as being out of range when the network channel is changed or not being powered on. Such a terminal (hereinafter referred to as a "stray terminal") is unable to transition to the new network channel after the change, and is therefore unable to communicate with other terminals in the group.

[0012] Furthermore, it is difficult for other wireless communication devices within the network to detect that a stray terminal has been disconnected from the network, and the stray terminal is often unable to immediately confirm that it has been disconnected from the network. As a result, in the case of a network used for business purposes, inconvenient situations can arise, such as the inability to thoroughly communicate business matters.

[0013] Therefore, the present invention aims to provide a network system and a wireless communication device that is a constituent terminal of the network, in which even if a stray terminal occurs in a simplex group wireless communication network, the stray terminal can be automatically transferred to a changed communication channel and returned to the network when a call transmission event or an automatic information transmission event under certain conditions is triggered. [Means for solving the problem]

[0014] <<First Invention>> The present invention relates to a group wireless communication network system in which a wireless communication device, which is a terminal having a common configuration in a simplex group wireless communication network, comprises a modulation / transmission unit and a reception / demodulation unit which cyclically scans all channels available in the network, and in which one terminal transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CCR") on a designated change destination channel, while another terminal receives the G-ID and the CCR (hereinafter both signals are collectively referred to as "G-ID·CCR") during the scanning stage of the designated change destination channel by the reception / demodulation unit, thereby changing the network channel. The present invention relates to a group wireless communication network system in which each terminal in the network has a function A which counts the number of transmissions and receptions of the G-ID·CCR in an incremental manner and updates and stores the count value information, a function B which, in a transmission mode, transmits the G-ID and a call signal together with the count value information of the own terminal which has been updated and stored by function A, over a currently set channel which is the channel used in the previous communication, and a function C which, in a reception mode, transmits and demodulates a signal including the G-ID during the scanning stage of the currently set channel. a function C for receiving and demodulating a call signal and playing back the voice while temporarily stopping the cyclic scanning on the channel, and when a signal including the G-ID is received and demodulated during the scanning stage of an available channel other than the currently set channel, detecting and updating and storing count value information of the transmission source terminal included in the demodulated signal together with the received channel information while temporarily stopping the cyclic scanning on the channel; and a function D for detecting and updating and storing the count value information (M times) of the own terminal updated and stored by the function A and the count value information (M times) of the own terminal updated and stored by the function C each time the information is updated and stored by the function C. and a function E which, when M>N as a result of the comparison by function D, automatically sets the transmission mode of the currently set channel to transmit the G-ID and the count value information (M times) of the own device, and when N>M, changes the currently set channel to a channel indicated by the receiving channel information updated and stored by function C, and rewrites the count value information (M times) of the own device to the count value information (N times) of the transmission source terminal, and when M=N, maintains the current state without executing anything.The present invention relates to a group wireless communication network system, characterized in that each terminal in the network executes the function A, and when any one terminal executes the function B, the other terminal executes the functions C, D, and E, and when M>N occurs in the execution of the function D, the one terminal executes the functions C, D, and E in response to information transmission by the other terminal using the function E.

[0015] This invention relates to a system in which each terminal (wireless communication device) that makes up a simplex group wireless communication network has common functions, and even if a terminal deviates from the network channel, the functions of each terminal work together while communication is being carried out to return it to the network. Each terminal that makes up the network is equipped with a modulation transmission unit and a reception / demodulation unit as a transceiver, and in reception mode, the reception / demodulation unit cyclically scans all channels available on the network.When a G-ID is detected and the call signal is played back, or when required information is obtained and corresponding processing is performed, the cyclic scanning is stopped.

[0016] In the network of this invention, if interference occurs on the network channel currently in use, one terminal transmits the G-ID·CCR on another available channel, while the other terminal receives and demodulates it during the cyclic scanning process of its receiving and demodulating section, and changes its own transmitting and receiving channel to the channel on which the G-ID·CCR was received, thereby changing the network channel. Then, in each terminal of the network, function A detects each time a G-ID·CCR is transmitted / received, counts the number of transmissions / receptions in a sequential increment manner, and updates and stores the count value information.

[0017] In this network, when a terminal goes into transmission mode for a call, it uses function B to transmit the count value information of its own terminal along with the G-ID and the call signal on the currently set channel (the channel used in the previous communication), and transmits the count value information of its own terminal to other terminals. In contrast, in each other terminal in the receiving mode, when the receiving and demodulating unit receives and demodulates a G-ID during the cyclic scanning stage of the currently set channel, function C stops the cyclic scanning on that channel, receives and demodulates the call signal to play the audio, and when a G-ID is received during the cyclic scanning stage of a channel other than the currently set channel, the cyclic scanning is similarly stopped, and the count value information at the sending terminal is detected from the demodulated signal, and updated and stored together with the receiving channel information.

[0018] Here, when the G-ID is received and demodulated on the currently set channel, this corresponds to a state in which the communication channel between the own terminal and the sending terminal is a network channel, or a state in which both terminals are stray terminals and are on the same communication channel; however, this invention is not concerned with these states, and each of the other terminals simply reproduces the speech signal demodulated by the receiving and demodulating unit. On the other hand, if the G-ID is received and demodulated on a channel other than the currently set channel, this corresponds to a situation in which either the own terminal or the sending terminal is a stray terminal, or both are stray terminals on different communication channels. The present invention takes account of this situation and implements an algorithm to return the stray terminal to the network channel.

[0019] First, function C is used to update and store the count value information of the one terminal on the other terminal side, and function D is used to allow the other terminal to compare its own count value information (M times) with the updated and stored count value information of the one terminal (N times). In this case, the longer a terminal remains within the network, the larger the count value associated with the change in network channel will be; conversely, if there is a period of time that the terminal deviates from the network channel, the terminal will not be present when the network channel is changed and the count value will tend to be smaller; and a terminal that remains within the network without deviating will naturally have the largest count value. Therefore, it can be said that the larger the count value updated and stored in the terminal, the higher the estimated probability that the currently set channel is set as the network channel, and conversely, the lower the estimated probability that the terminal is a deviated terminal.

[0020] In the present invention, this situation is utilized rationally, and by function E, other terminals execute the following corresponding processing procedure based on the comparison result between M and N. When M>N, the other terminal has a higher estimated probability of being set to the current network channel than the one terminal, so the other terminal reverses the transmission / reception in order to change the channel set by the one terminal to its own channel, and the other terminal transmits the G-ID and count value information (M times) on its own currently set channel. The information transmitted from other terminals is received and demodulated during the scanning process of the receiving and demodulating section of each terminal in the network, but then, conversely, a terminal which becomes the receiving terminal compares its own count value information (N times) with the demodulated count value information (M times) based on functions C and D. In this case, from the perspective of one terminal, the relationship between N and M is reversed in the corresponding process for the case where N>M described below, and the transmission and reception channel of the one terminal is changed to the channel of the other terminal, and the count value information of the one terminal (N times) is also rewritten to the count value information of the other terminal (M times). Therefore, when one terminal is a stray terminal and the transmitting / receiving unit of the other terminal is a network channel, the transmitting / receiving unit of the one terminal is changed to the network channel and can return to the network, and when both terminals are stray terminals, the count value information of the own terminal is adjusted to the setting channel and count value information of the larger terminal. From the network perspective, the response transmissions from multiple other terminals will overlap, but when carrier sense is required, only the terminal that is first enabled to transmit will be able to transmit a response.

[0021] When N>M, the opposite of the above, the first terminal has a higher estimated probability of being set on the network channel than the other terminals, so the other terminal changes its own transmission / reception channel to the reception channel (the currently set channel on the first terminal side) updated and stored by function C, and at the same time rewrites its own count value information (M times) to the count value information on the first terminal side (N times), thereby formally putting itself in the same history state as the first terminal. In other words, if the currently set channel of one terminal is in a network channel setting state and another terminal is in a stray terminal state, the communication channel of the other terminal is changed to the network channel, enabling it to return to the network, and the count value information is also formally aligned with that of the terminal that remained within the network.

[0022] The case of N=M corresponds to the case where the currently set channels of one terminal and another terminal are both network channels, or where one terminal and another terminal happen to be in a deviated state and have sent and received the same number of G-ID·CCRs. In the former case, there is no need to get involved, while in the latter case, there is no way to resolve the deviated terminal state, and there is no choice but to wait for an opportunity to communicate with a terminal that is not in a deviated state. In the end, no response process is performed and the status quo is maintained.

[0023] Assuming that the functions possessed by the constituent terminals of the above network are possessed by each terminal, when one terminal executes function A, the other terminal executes functions C, D, and E in response to the execution of function B by any one terminal, and when M>N occurs in the execution of function D, the other terminal transmits information using function E, and one terminal executes functions C, D, and E in response to this. During call communication, the communication channel of each terminal is constantly updated and aligned to the currently set channel of the terminal with the larger count value information, so that stray terminals which tend to have smaller count value information are inevitably able to return to the network channel.

[0024] It is desirable that the count value information of the own device in function B of each terminal in the network is transmitted in a manner that the count value information is added to the end of the audio signal portion in a communication frame. This is because mixing an information signal into an audio signal causes distortion in the reproduced sound, making it difficult to hear. For example, this problem can be avoided by adding and transmitting count value information when the PTT button is turned off, and then transmitting a communication end signal.

[0025] Furthermore, with regard to the method of circular scanning of all channels available in the network by the receiving and demodulating unit, it is desirable to set the scanning time for the currently set channel in the wireless communication device longer than the scanning time for each of the other channels, and in particular, it is reasonable and preferable to use a method in which the currently set channel and one other channel are scanned alternately for the same period of time, and different channels are selected in sequence for the one other channel. In the above-mentioned network, terminals are normally in a state where they are communicating with each other using the network channel as the currently set channel, and since the occurrence of a stray terminal is rather a rare case, this is to ensure that the transition to the former normal communication state is executed with priority.

[0026] A wireless communication device applicable to the group wireless communication network system according to the first aspect of the present invention can be configured as follows. The terminal has a common configuration in a simplex group wireless communication network and includes a modulation / transmission unit and a reception / demodulation unit that cyclically scans all channels available in the network, and transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CCR") from the modulation / transmission unit on a designated change destination channel, while receiving the G-ID and the CCR (hereinafter both signals are collectively referred to as "G-ID·CCR") transmitted from other terminals on the designated change destination channel during the cyclic scanning process of the reception / demodulation unit, thereby making it possible to change the network channel. a counting storage means for counting the number of times the G-ID·CCR is transmitted and received in an incrementing manner and updating and storing the count value information; an information transmitting means for, in a transmission mode, transmitting the G-ID and a call signal together with the count value information of the own device which is updated and stored by the counting storage means on a currently set channel which is a channel used in the previous communication; and, in a reception mode, when a signal including the G-ID is received and demodulated during a scanning stage of the currently set channel, transmitting the call signal with the cyclic scanning temporarily stopped on the same channel. a call reproducing means for receiving and demodulating the G-ID and reproducing the voice, an information detecting means for detecting, when a signal including the G-ID is received and demodulated in a stage of scanning an available channel other than the currently set channel in a receiving mode, count value information at the sending terminal included in the demodulated signal together with the receiving channel information, with the cyclic scanning temporarily stopped on the same channel, an information storing means for updating and storing the receiving channel information and count value information detected by the information detecting means, and a count storing means for storing the updated and stored count information of the own terminal each time the information storing means updates and stores the information. a comparison means for comparing the count value information (M times) of the count value information (M times) at the transmission source terminal updated and stored by the information storage means, and if the result of the comparison by the comparison means is M>N, automatically setting the transmission mode of the currently set channel to transmit the G-ID and the count value information (M times) of the count storage means, and if N>M, changing the currently set channel to a channel indicated by the receiving channel information of the information storage means, and rewriting the count value information (M times) of the count storage means to the count value information (N times) of the information storage means, and if M=N,and a corresponding processing means for maintaining the current state without executing any operation.

[0027] <<Second Invention>> The present invention relates to a group wireless communication network system in which a wireless communication device, which is a terminal having a common configuration in a simplex group wireless communication network, comprises a modulation / transmission unit and a reception / demodulation unit which cyclically scans all channels available in the network, and in which one terminal transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CCR") on a designated change destination channel, while another terminal receives the G-ID and the CCR (hereinafter both signals are collectively referred to as "G-ID·CCR") during the scanning stage of the designated change destination channel by the reception / demodulation unit, thereby changing the network channel. The present invention relates to a group wireless communication network system in which a wireless communication device, which is a terminal having a common configuration in a simplex group wireless communication network, comprises a modulation / transmission unit and a reception / demodulation unit which cyclically scans all channels available in the network, and in which a network channel is changed when one terminal transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CCR") on a designated change destination channel, while another terminal receives the G-ID and the CCR (hereinafter both signals are collectively referred to as "G-ID·CCR") during the scanning stage of the designated change destination channel by the reception / demodulation unit, the network channel is changed by the reception / demodulation unit. and a function C for detecting the detection time information (T1) of the own terminal updated and stored by the function A with the detection time information (T2) of the own terminal updated and stored by the function C every time the information is updated and stored by the function C, and for detecting the detection time information (T1) of the own terminal updated and stored by the function A with the detection time information (T2) of the own terminal updated and stored by the function C, when the signal including the G-ID is received and demodulated in the stage of scanning an available channel other than the currently set channel, and when the signal including the G-ID is received and demodulated in the stage of scanning an available channel other than the currently set channel, the function C detects the detection time information (T1) of the own terminal updated and stored by the function A with the detection time information (T2) of the own terminal updated and stored by the function C, and for detecting the detection time information (T2) of the own terminal updated and stored by the function C, when the information is updated and stored by the function C, and for detecting the detection time information (T2) of the own terminal ... when the information is updated and stored by the function C, and for detecting the detection time information (T2) of the own terminal updated and stored by the function C. and a function E for automatically setting the transmission mode of the currently set channel and transmitting the G-ID and the detection time information (T1) of the own terminal when the comparison by the function D shows that T1 is later than T2, and for changing the currently set channel to the channel indicated by the reception channel information updated and stored by the function C when T2 is later than T1, and rewriting the detection time information (T1) of the own terminal to the detection time information (T2) of the transmission source terminal when T1 and T2 are simultaneous, and for maintaining the current status without performing any operation, each terminal of the network is executing the function A,The present invention relates to a group wireless communication network system, characterized in that, when any one terminal executes the function B, the other terminal executes the functions C, D, and E, and when T1 is later than T2 in the execution of the function D, the one terminal executes the functions C, D, and E in response to information transmission by the other terminal in the function E.

[0028] Like the first invention, this invention also relates to a system in which each terminal (wireless communication device) constituting a simplex group wireless communication network has a common function, and even if a terminal deviates from the network channel, the functions of each terminal work together as communication is being carried out to return it to the network.Each terminal has a modulation transmission unit and a reception / demodulation unit as a transceiver unit, and in reception mode, the reception / demodulation unit cyclically scans all channels available on the network, and the cyclic scanning is stopped when a G-ID is detected and the call signal is played back, or when required information is obtained and corresponding processing is performed.

[0029] Furthermore, in the network of this invention, as in the first invention, if interference occurs on the network channel currently in use, one terminal transmits the G-ID·CCR on another available channel, while the other terminal receives and demodulates it during the cyclic scanning process of its receiving and demodulating section, and changes its own transmitting and receiving channel to the channel on which the G-ID·CCR was received, thereby changing the network channel. Then, in each terminal in the network, function A detects each time a G-ID·CCR is transmitted / received, and updates and stores the detection time information.

[0030] In this invention, when a terminal goes into transmission mode for a call using function B, it transmits the G-ID and call signal along with its own detection time information on the currently set channel (the channel used in the previous communication), and transmits its own detection time information to other terminals. In contrast, in other terminals in receiving mode, when the receiving and demodulating unit receives and demodulates a G-ID during the cyclic scanning stage of the currently set channel, function C stops the cyclic scanning on that channel, receives and demodulates the call signal to play the audio, and when a G-ID is received during the cyclic scanning stage of a channel other than the currently set channel, the cyclic scanning is similarly stopped, and the detection time information of the one terminal is detected from the demodulated signal, and updated and stored together with the receiving channel information.

[0031] Here, when the G-ID is received and demodulated on the currently set channel, this corresponds to a state in which the currently set channel of one terminal and another terminal is a network channel, or when both terminals are deviating terminals and are in the same currently set channel state; however, this invention is not concerned with these states, and the other terminal simply reproduces the speech signal demodulated by the receiving and demodulating unit. On the other hand, if the G-ID is received and demodulated on a channel other than the currently set channel, this corresponds to a state in which either the other terminal or the one terminal is a stray terminal, or both are stray terminals on different communication channels. The present invention takes account of this situation and implements an algorithm to return the stray terminal to the network channel.

[0032] First, function C is used to update and store the detection time information of the one terminal in the other terminal, and function D is used to compare the detection time information (T1) of the other terminal with the detection time information (T2) of the one terminal that has been updated and stored. In this case, it can be said that the later in time a terminal belongs to the network when the network channel is changed, the higher the estimated probability that it is set to the current network channel, and conversely, the lower the estimated probability that it is a deviated terminal.

[0033] In the present invention, this situation is utilized rationally, and by function E, the other terminal executes the following corresponding processing procedure based on the comparison result between T1 and T2. If T1 is later than T2, the other terminal has a higher estimated probability of being set on the network channel than the one terminal, so the other terminal transmits its G-ID and its own detection time information (T1) on its own currently set channel in order to change the currently set channel of the one terminal to its own currently set channel. The information transmitted from the other terminals is received and demodulated during the scanning process of the receiving and demodulating section of each terminal in the network, but then, conversely, a terminal which becomes the receiving terminal compares its own detection time information (T2) with the received and demodulated detection time information (T1) based on functions C and D. In this case, from the perspective of the first terminal, the detection time information (T1) of the other terminal received and demodulated will be later than the detection time information (T2) of the first terminal, so in the corresponding process when T2 is later than T1 described below, the relationship between T2 and T1 will be reversed, and the currently set channel of the first terminal will be changed to the currently set channel of the other terminal, and the detection time information (T2) of the first terminal will also be rewritten to the detection time information (T1) of the other terminal. Therefore, if one terminal is a stray terminal and the communication channel of the other terminal is a network channel, the transmitter / receiver of the one terminal will be changed to the network channel and it will be able to return to the network, and if both terminals are stray terminals, the time indicated by the detection time information will be aligned with the communication channel and detection time information of the later terminal. From the network perspective, it is possible that multiple other terminals may transmit responses at the same time, but when carrier sense is required, only the terminal that is first enabled to transmit can transmit a response.

[0034] If T2 is later than T1, then, conversely to the above, the first terminal has a higher estimated probability of being set on the network channel than the other terminal, so the other terminal changes its own communication channel to the receiving channel (the currently set channel of the first terminal) updated and stored using function C, and at the same time rewrites its own detection time information (T1) to the detection time information (T2) of the first terminal, thereby formally putting itself in the same history state as the first terminal. In other words, if the currently set channel of one terminal is in a network channel setting state and another terminal is in a stray terminal state, the communication channel of the other terminal is changed to the network channel, enabling it to return to the network, and the detection time information is also formally aligned with that of the terminal that remained within the network.

[0035] When T1 and T2 occur simultaneously, this corresponds to the case where the currently set channels of the one terminal and the other terminal are both network channels, or the case where the one terminal and the other terminal happen to be in a deviated state and the last detection times of the G-ID and CCR are simultaneous. In the former case, there is no need to intervene, while in the latter case, there is no way to resolve the deviated terminal state, and there is no choice but to wait for an opportunity to communicate with a terminal that is not in a deviated state. In the end, no response process is performed and the status quo is maintained.

[0036] Assuming that the functions possessed by the constituent terminals of the above network are possessed by each terminal, when one terminal executes function A, the other terminal executes functions C, D, and E in response to the execution of function B by any one terminal, and in such a case that in the execution of function D, T1 becomes later than T2, the other terminal transmits information using function E, and one terminal executes functions C, D, and E in response to such information transmission by the other terminal. As a result, while the telephone communication is being carried out, the communication channel of each terminal is always aligned to the currently set channel of the terminal whose detected time information, which has been updated and stored, indicates a later time, and therefore the stray terminal whose detected time information tends to indicate an earlier time will inevitably be able to return to the network channel.

[0037] It is desirable that the detection time information of the own device in function B of each terminal in the network is transmitted in a manner that the information is added to the end of the audio signal portion in a communication frame. This is because mixing an information signal into an audio signal causes distortion in the reproduced sound, making it difficult to hear. For example, this problem can be avoided by adding and transmitting count value information when the PTT button is turned off, and then transmitting a communication end signal.

[0038] Furthermore, with regard to the method of circular scanning of all channels available in the network by the receiving and demodulating unit, it is desirable to set the scanning time for the currently set channel in the wireless communication device longer than the scanning time for each of the other channels, and in particular, it is reasonable and preferable to use a method in which the currently set channel and one other channel are scanned alternately for the same period of time, and different channels are selected in sequence for the one other channel. In the above-mentioned network, terminals are normally in a state where they are communicating with each other using the network channel as the currently set channel, and since the occurrence of a stray terminal is rather a rare case, this is to ensure that the transition to the former normal communication state is executed with priority.

[0039] A wireless communication device applicable to the group wireless communication network system according to the second aspect of the present invention can be configured as follows. A wireless communication device having a common configuration as a terminal in a simplex group wireless communication network, comprising a modulation transmission unit and a reception / demodulation unit which cyclically scans all channels available in the network, and which transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CCR") from the modulation transmission unit on a designated change destination channel, while enabling a change of network channel by receiving the G-ID and the CCR (hereinafter both signals are collectively referred to as "G-ID·CCR") transmitted from another terminal on a designated change destination channel during the cyclic scanning of the reception / demodulation unit, the wireless communication device comprising: a time storage means which updates and stores detection time information when transmission / reception of the G-ID·CCR is detected; an information transmission means which, in a transmission mode, transmits the G-ID and a call signal together with its own detection time information which has been updated and stored by the time storage means on a currently set channel which is a channel used in the previous communication; and, in a reception mode, when a signal including the G-ID is received and demodulated during the scanning stage of the currently set channel, receives and demodulates the call signal on the same channel with the cyclic scanning temporarily stopped, and plays the voice. A speech reproduction means, an information detection means for detecting, in a reception mode, when a signal including the G-ID is received and demodulated during a scanning stage of an available channel other than the currently set channel, detection time information at the source terminal included in the demodulated signal together with the reception channel information, with the cyclic scanning temporarily stopped on the channel, an information storage means for updating and storing the reception channel information and detection time information detected by the information detection means, and a time storage means for updating and storing the detection time information (T1) at the own terminal and the previous time information (T2) each time the information storage means updates and stores information. a comparison means for comparing the detected time information (T2) at the source terminal which is updated and stored in the information storage means, and if the result of the comparison by the comparison means shows that T1 is later than T2, automatically set the transmission mode of the currently set channel to transmit the G-ID and the detected time information (T1) of the time storage means, and if T2 is later than T1, change the currently set channel to a channel indicated by the receiving channel information of the information storage means, and rewrite the detected time information (T1) of the time storage means to the detected time information (T2) of the information storage means, and if T1 and T2 are simultaneous,and a corresponding processing means for maintaining the current state without executing any operation.

[0040] <<Third Invention>> The present invention relates to a group wireless communication network system in which a wireless communication device, which is a terminal having a common configuration in a simplex group wireless communication network, comprises a modulation / transmission unit and a reception / demodulation unit which cyclically scans a frequency control channel and all channels available in the network, and in which a network channel is changed when one terminal transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CH-CCR") with a designation of a change destination channel on the frequency control channel, while another terminal receives the G-ID and the CH-CCR (hereinafter both signals are collectively referred to as "G-ID·CH-CCR") during the scanning stage of the frequency control channel by the reception / demodulation unit. In this group wireless communication network system, each terminal in the network has a function A which counts the number of times the G-ID·CH-CCR is transmitted and received in an incremental manner and updates and stores the count value information, a function B which sets a normal transmission mode by a predetermined instruction operation and transmits the G-ID and a speech signal, and a function C which, when the reception / demodulation unit does not detect a reception / demodulation signal including the G-ID for a predetermined time in the reception mode, a function C for automatically setting a transmission mode in which the transmission modulation unit is temporarily switched from the currently set channel, which is the channel used in the previous communication (excluding the frequency control channel), to the frequency control channel, and transmitting the G-ID, the currently set channel information, and the count value information of the own terminal updated and stored by the function A; a function D for, in a reception mode, when the reception demodulation unit receives and demodulates a signal including the G-ID on the currently set channel, receiving and demodulating a call signal and reproducing the voice with the cyclic scanning temporarily stopped on the same channel, and when the reception demodulation unit receives and demodulates a signal including the G-ID on the frequency control channel, detecting and updating the currently set channel information and count value information of the transmission source terminal contained in the demodulated signal with the cyclic scanning temporarily stopped on the same channel; and a function E for comparing the count value information of the own terminal updated and stored by the function A (M times) with the count value information of the transmission source terminal updated and stored by the function D (N times) each time the information is updated and stored by the function D, and when the result of the comparison by the function E is M>N,The present invention relates to a group wireless communication network system, characterized in that the modulation transmission unit is automatically set to a transmission mode temporarily changed from the currently set channel to the frequency control channel, and transmits the G-ID, currently set channel information of the own device, and count value information (M times), and when N>M, changes the currently set channel of the own device to the currently set channel of the transmission source terminal, and rewrites the count value information (M times) of the own device to the count value information (N times) of the transmission source terminal, and when M=N, executes nothing and maintains the current status, each terminal of the network executes function A and also executes function B as appropriate, and when any one terminal executes function C, the other terminal executes functions D, E, and F, and when M>N occurs during the execution of function E, the one terminal executes functions D, E, and F in response to information transmission by the other terminal using function F,

[0041] In this invention, like the first and second inventions, each terminal (wireless communication device) that makes up the simplex group wireless communication network has common functions, and even if a terminal deviates from the network channel, the functions of each terminal work together while communication is being carried out to return it to the network. Each terminal that makes up the network is equipped with a modulation transmission unit and a reception / demodulation unit as a transceiver, and in reception mode, the reception / demodulation unit cyclically scans all channels and frequency control channels available in the network. When a G-ID is detected and the call signal is played back, or when required information is obtained and the corresponding processing is performed, the cyclic scanning is stopped.

[0042] In the network of this invention, if interference occurs in the network channel currently in use, one terminal transmits the G-ID·CH-CCR on the frequency control channel, while the other terminal receives and demodulates it during the cyclic scanning process of the receiving and demodulating section, and changes its own transmitting and receiving channel to the channel specified in the CH-CCR, thereby changing the network channel. Then, in each terminal of the network, function A detects each time a G-ID·CH-CCR is transmitted / received, counts the number of transmissions / receptions in a sequential increment manner, and updates and stores the count value information.

[0043] On the other hand, each terminal transmits the G-ID and call signals using the currently set channel in the normal transmission mode based on the instruction operation of the PTT button, etc., using function B, but also transmits control information using the frequency control channel in the transmission mode by function C and function F. In the transmission mode of function C, if the reception demodulation unit does not detect a demodulated signal of the G-ID for a specified period of time in reception mode, that is, if there is no reception from other terminals in the group for a specified consecutive period of time and the terminal is suspected of being in a deviated terminal state, the automatic transmission mode is set in which the currently set channel is temporarily switched to the frequency control channel, and the G-ID, currently set channel information, and the count value information (the number of times transmission and reception of G-ID·CH-CCR has been detected in the terminal) are transmitted to the other terminals. In this case, the "predetermined time" is determined as the period of no communication during which each terminal assumes that it may have become a stray terminal, and may be determined according to the frequency of communication on the network.

[0044] In the first and second inventions, the receiving and demodulating unit is a system that scans communication channels, so that each time a call signal is transmitted, control information is added and transmitted to each terminal, but in this invention, the receiving and demodulating unit is a system that scans communication channels and frequency control channels, and control information is transmitted using a frequency control channel that is frequently used in specific low-power radio, so that the count value information is transmitted only under conditions where the occurrence of a stray terminal is predicted. In addition, the control information transmitted includes not only the G-ID and the count value information but also the currently set channel information of the own terminal. This is because, in the first and second inventions, the control information is transmitted on the currently set channel, so the currently set channel of the transmitting terminal can be confirmed from the receiving channel, whereas in this invention, the control information is transmitted on the frequency control channel, so it is necessary to specifically indicate the currently set channel as information.

[0045] Function D relates to the function in the receiving mode. When the receiving and demodulating unit receives and demodulates a signal including a G-ID on the currently set channel during the cyclic scanning process, the source terminal is a terminal belonging to a group and has the same currently set channel as the terminal itself, and the call signal being received is one that was sent by the source terminal using function B. Therefore, regardless of whether the currently set channel is a network channel, the receiving and demodulating unit reproduces the demodulated call signal. On the other hand, if one terminal does not detect a G-ID reception demodulation signal for a specified period of time and transmits the G-ID, its own currently set channel information, and count value information on the frequency control channel using function C, the reception demodulation unit of another terminal receives and demodulates these control signals during the cyclic scanning of the frequency control channel using function D, and updates and stores them. Therefore, the other terminal (receiving terminal) will have its own count value information (M) updated and stored by function A, and the count value information (N) of one terminal (sending terminal) updated and stored by function D, and the count value information is compared by function E.

[0046] In this case, the longer a terminal remains within the network, the larger the count value relating to the change of network channel will be, and conversely, if the terminal deviates from the network channel for a long period of time, the count value will tend to be smaller as the terminal will not be present when the network channel is changed. Since a terminal that has remained within the network without straying will naturally store the maximum count value information, it can be said that the larger the count value updated and stored by a terminal, the higher the estimated probability that its transmitter / receiver is set to the current network channel and the lower the estimated probability that it is a stray terminal.

[0047] In the present invention, this situation is utilized rationally, and the corresponding process is executed by function F based on the result of the comparison of the count value information by function E. When M>N, the other terminal has a higher estimated probability of being set to the current network channel than the one terminal, so in order to change the channel set by the one terminal to its own channel, the other terminal sets an automatic transmission mode in which the transmission modulation unit is temporarily switched from the currently set channel to the frequency control channel, and transmits the G-ID, its own currently set channel information, and count value information (M times). The transmitted information from the other terminals is received and demodulated when the receiving and demodulating unit of each terminal in the network scans the frequency control channel, but in one terminal, based on functions D and E, the count value information of the own terminal (N times) is compared with the demodulated count value information (M times). In this case, when viewed from the first terminal, the relationship between N and M is reversed in the corresponding process for the case where N>M described below, and based on function F, the communication channel of the first terminal is changed to the currently set channel information of the other terminal, and the count value information (N times) on the first terminal is also rewritten to the count value information (M times) on the other terminal. Therefore, when one terminal is a stray terminal and the transmitting / receiving unit of the other terminal is a network channel, the transmitting / receiving unit of the one terminal is changed to the network channel and can return to the network, and when both terminals are stray terminals, the count value information of the own terminal is adjusted to the setting channel and count value information of the larger terminal. From the network perspective, the response transmissions from multiple other terminals will overlap, but when carrier sense is required, only the terminal that is first enabled to transmit will be able to transmit a response.

[0048] When N>M, the opposite of the above is true: the first terminal has a higher estimated probability of being set on the network channel than the other terminals. Therefore, the other terminals use the information they have received, demodulated, and updated to change their own transmission / reception channel to the currently set channel of the first terminal, and also rewrite their own count value information (M times) to the count value information of the first terminal (N times), thereby formally putting themselves in the same history state as the first terminal.

[0049] The case of N=M corresponds to the case where the currently set channels of one terminal and another terminal are both network channels, or the case where one terminal and another terminal happen to be in a deviated state and the number of times G-ID·CH-CCR is sent and received is the same. In the former case, there is no need to get involved, but in the latter case, there is no way to resolve the deviated terminal state, so there is no choice but to wait for an opportunity to communicate with a terminal that is not in a deviated state, and ultimately, no response processing is done.

[0050] Assuming that the functions possessed by the constituent terminals of the above network are possessed by each terminal, when one terminal executes function A, the other terminal executes functions C, D, and E in response to the execution of function B by any one terminal, and when M>N occurs in the execution of function D, the other terminal transmits information using function E, and one terminal executes functions C, D, and E in response to this. During call communication, the communication channel of each terminal is constantly updated and aligned to the currently set channel of the terminal with the larger count value information, so that stray terminals which tend to have smaller count value information are inevitably able to return to the network channel.

[0051] In function C of each terminal of the network, if the receiving and demodulating unit does not detect a receiving and demodulating signal including the G-ID for a predetermined period of time, it is desirable to also perform an operation of displaying on a display means that the terminal is likely to be in a deviated terminal state and / or an operation of notifying that the terminal is in the deviated terminal state by outputting a predetermined sound from an audio output means.

[0052] A wireless communication device applicable to the group wireless communication network system according to the third aspect of the present invention can be configured as follows. A terminal having a common configuration in a simplex group wireless communication network is provided with a modulation / transmission unit and a reception / demodulation unit which cyclically scans a frequency control channel and all channels available in the network, and transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CH-CCR") with a change destination channel designation from the modulation / transmission unit on the frequency control channel, while receiving the G-ID and the CH-CCR (hereinafter both signals are collectively referred to as "G-ID-CCR") transmitted from other terminals on the frequency control channel during the cyclic scanning process of the reception / demodulation unit. a count storage means for counting the number of times the G-ID·CH-CCR is transmitted and received in an incrementing manner and updating and storing the count value information; a normal transmission means for setting a normal transmission mode in response to a predetermined instruction operation and transmitting the G-ID and a speech signal; an information transmission means for, in a reception mode, when the reception demodulation unit does not detect a reception demodulated signal including the G-ID for a predetermined period of time, automatically setting a transmission mode in which the transmission modulation unit is temporarily switched from a currently set channel, which is a channel used in the previous communication (excluding a frequency control channel), to the frequency control channel, and transmitting the G-ID, the currently set channel information, and the count value information of the count storage means; a speech reproduction means for, in a reception mode, when the reception demodulation unit receives and demodulates a signal including the G-ID on the currently set channel, receiving and demodulating the speech signal and reproducing the voice with the cyclic scanning temporarily stopped on the same channel, and a speech reproduction means for, in a reception mode, when the reception demodulation unit receives and demodulates a signal including the G-ID on the frequency control channel, performing the cyclic scanning on the same channel; an information detection means for detecting currently set channel information and count value information at the source terminal contained in the demodulated signal while the signal is temporarily stopped; an information storage means for updating and storing the currently set channel information and count value information at the source terminal detected by the information detection means; a comparison means for comparing the count value information (M times) of the own device updated and stored by the count storage means with the count value information (N times) at the source terminal updated and stored by the information storage means each time information is updated and stored by the information storage means; and, if M>N as a result of the comparison by the comparison means,a processing means for setting a transmission mode in which the modulation transmission unit is temporarily changed from a currently set channel to a frequency control channel, transmitting the G-ID, currently set channel information, and count value information (M times) of the count storage means, and when N>M, changing the currently set channel to a channel indicated by the receiving channel information of the information storage means, and rewriting the count value information (M times) of the count storage means to the count value information (N times) of the information storage means, and when M=N, executing nothing and maintaining the current state.

[0053] <<The fourth invention>> A fourth invention is a group wireless communication network system in which a wireless communication device, which is a terminal of a common configuration in a simplex group wireless communication network, comprises a modulation / transmission unit and a reception / demodulation unit which cyclically scans a frequency control channel and all channels available in the network, and in which a network channel is changed by one terminal transmitting a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CH-CCR") with a change destination channel designation on the frequency control channel while another terminal receives the G-ID and the CH-CCR (hereinafter both signals are collectively referred to as "G-ID·CH-CCR") in a scanning stage of the frequency control channel by the reception / demodulation unit, the group wireless communication network system having a function A for updating and storing detection time information when transmission / reception of the G-ID·CH-CCR is detected, a function B for setting a normal transmission mode by a predetermined instruction operation and transmitting the G-ID and a speech signal, and a function C for temporarily switching the transmission change mode when the reception / demodulation unit does not detect a reception / demodulation signal including the G-ID for a predetermined time. function C automatically sets a transmission mode in which the demodulation unit switches from a currently set channel, which is a channel used in the previous communication (excluding a frequency control channel), to the frequency control channel, and transmits the G-ID, the currently set channel information, and the detection time information updated and stored by function A; in a reception mode, when the reception demodulation unit receives and demodulates a signal including the G-ID in a scanning stage of the currently set channel, the reception demodulation unit receives and demodulates a speech signal and plays back the voice while temporarily stopping the cyclic scanning on the same channel, and when the reception demodulation unit receives and demodulates a signal including the G-ID in a scanning stage of the frequency control channel, the reception demodulation unit detects and updates the currently set channel information and count value information of the transmission source terminal contained in the demodulated signal while temporarily stopping the cyclic scanning on the same channel; and function E compares the detection time information (T1) of the own terminal updated and stored by function A with the detection time information (T2) of the transmission source terminal updated and stored by function D every time information is updated and stored by function D; and when T1 is later than T2 as a result of the comparison by function E,The present invention relates to a group wireless communication network system, characterized in that the modulation transmission unit is automatically set to a transmission mode temporarily changed from the currently set channel to the frequency control channel, and transmits the G-ID, currently set channel information of the own device, and detection time information (T1), and when T2 is later than T1, the currently set channel of the own device is changed to the currently set channel of the source terminal, and the detection time information (T1) of the own device is rewritten to the detection time information (T2) of the source terminal, and when T1 and T2 are simultaneous, nothing is executed and the current status is maintained; each terminal of the network executes the function A and also executes the function B as appropriate; when any one terminal executes the function C, the other terminal executes the functions D, E, and F; and when T1 becomes later than T2 during the execution of the function E, the one terminal executes the functions D, E, and F in response to the information transmission by the other terminal using function F,

[0054] In this invention, like the first and second inventions, each terminal (wireless communication device) that makes up the simplex group wireless communication network has common functions, and even if a terminal deviates from the network channel, the functions of each terminal work together while communication is being carried out to return it to the network. Each terminal that makes up the network is equipped with a modulation transmission unit and a reception / demodulation unit as a transceiver, and in reception mode, the reception / demodulation unit cyclically scans all channels and frequency control channels available in the network. When a G-ID is detected and the call signal is played back, or when required information is obtained and the corresponding processing is performed, the cyclic scanning is stopped.

[0055] In the network of this invention, if interference occurs in the network channel currently in use, one terminal transmits the G-ID·CH-CCR on the frequency control channel, while the other terminal receives and demodulates it during the cyclic scanning process of the receiving and demodulating section, and changes its own transmitting and receiving channel to the channel specified in the CH-CCR, thereby changing the network channel. Then, in each terminal in the network, function A detects each time a G-ID·CH-CCR is transmitted / received, and updates and stores the detection time information.

[0056] On the other hand, each terminal transmits the G-ID and call signals using the currently set channel in the normal transmission mode based on the instruction operation of the PTT button, etc., using function B, but also transmits control information using the frequency control channel in the transmission mode by function C and function F. In the transmission mode of function C, if the reception demodulation unit does not detect a demodulated signal of the G-ID for a specified period of time in reception mode, that is, if there is no reception from other terminals in the group for a specified continuous period of time and it is suspected that the terminal is in a deviated terminal state, it sets an automatic transmission mode in which the currently set channel is temporarily switched to the frequency control channel, and transmits the G-ID, currently set channel information, and the detection time information (the time when the terminal detected transmission and reception of G-ID·CH-CCR in its own terminal) to convey them to the other terminals. In this case, the "predetermined time" is determined as the period of no communication during which each terminal assumes that it may have become a stray terminal, and may be determined according to the frequency of communication on the network.

[0057] In the first and second inventions, the receiving and demodulating unit is a system that scans communication channels, so that each time a call signal is transmitted, control information is added and transmitted to each terminal, but in this invention, the receiving and demodulating unit is a system that scans communication channels and frequency control channels, and control information is transmitted using a frequency control channel that is frequently used in specific low-power radio, so that the detection time information is transmitted only under conditions where the occurrence of a stray terminal is predicted. In addition, the control information transmitted includes not only the G-ID and the detection time information but also the currently set channel information of the own terminal. This is because, in the first and second inventions, the control information is transmitted on the currently set channel, so the currently set channel of the transmitting terminal can be confirmed from the receiving channel, whereas in this invention, the control information is transmitted on the frequency control channel, so it is necessary to specifically indicate the currently set channel as information.

[0058] Function D relates to the function in the receiving mode. When the receiving and demodulating unit receives and demodulates a signal including a G-ID on the currently set channel during the cyclic scanning process, the source terminal is a terminal belonging to a group and has the same currently set channel as the terminal itself, and the call signal being received is one that was sent by the source terminal using function B. Therefore, regardless of whether the currently set channel is a network channel, the receiving and demodulating unit reproduces the demodulated call signal. On the other hand, if one terminal does not detect a received demodulated signal of a G-ID for a specified period of time and transmits the G-ID, its own currently set channel information, and detection time information on the frequency control channel using function C, the receiving and demodulating unit of another terminal uses function D to receive and demodulate these control signals during the cyclic scanning of the frequency control channel, and update and store them. Therefore, the other terminal will have its own detection time information (T1) updated and stored by function A and the detection time information (T2) of the other terminal updated and stored by function D, and these detection time information are compared by function E.

[0059] In this case, it can be said that the later in time a terminal belongs to the network when the network channel is changed, the higher the estimated probability that it is set to the current network channel, and conversely, the lower the estimated probability that it is a deviated terminal.

[0060] In the present invention, this situation is utilized rationally, and the corresponding process is executed by function F based on the result of comparison of the detected time information by function E. If T1 is later than T2, there is an estimated higher probability that the other terminal is set to the current network channel than the one terminal, so in order to change the set channel of the one terminal to its own channel, the other terminal sets an automatic transmission mode in which the transmission modulation unit is temporarily switched from the currently set channel to the frequency control channel, and transmits the G-ID, its own currently set channel information, and detection time information (T1). The information transmitted from the other terminals is received and demodulated when the receiving and demodulating unit of each terminal in the network scans the frequency control channel, but in one terminal, based on functions D and E, the detection time information (T2) of the own terminal is compared with the demodulated detection time information (T1). In this case, from the perspective of the first terminal, the detection time information (T1) received and demodulated by the other terminal will be later than the detection time information (T2) of the first terminal, so in the corresponding processing when T2 is later than T1 described below, the relationship between T2 and T1 will be reversed, and based on function F, the communication channel of the first terminal will be changed to the currently set channel information of the other terminal, and the detection time information (T2) at the first terminal will also be rewritten to the detection time information (T1) at the other terminal. Therefore, when one terminal is a stray terminal and the transmitting / receiving unit of the other terminal is a network channel, the transmitting / receiving unit of the one terminal is changed to the network channel and can return to the network, and when both terminals are stray terminals, the detection time information of the own terminal is aligned with the setting channel and detection time information of the later terminal. From the network perspective, the response transmissions from multiple other terminals will overlap, but when carrier sense is required, only the terminal that is first enabled to transmit will be able to transmit a response.

[0061] If T2 is later than T1, then, conversely to the above, the estimated probability that the first terminal is set to the network channel is higher than the other terminal, so the other terminal uses the information it has received, demodulated, and updated to change its own communication channel to the currently set channel of the first terminal, and at the same time rewrites its own detection time information (T1) to the detection time information (T2) of the first terminal, thereby formally putting itself in the same history state as the first terminal.

[0062] When T1 and T2 occur simultaneously, this corresponds to a case where the currently set channels of the first terminal and the other terminal are both network channels, or where the first terminal and the other terminal happen to be in a deviated state and the detection time information of the G-ID·CH-CCR is identical. In the former case, there is no need to get involved, whereas in the latter case, there is no way to resolve the deviated terminal state, so there is no choice but to wait for an opportunity to communicate with a terminal that is not in a deviated state, and ultimately, no response processing is performed.

[0063] Assuming that the functions possessed by the constituent terminals of the above network are possessed by each terminal, when one terminal executes function A, the other terminal executes functions C, D, and E in response to the execution of function B by any one terminal, and when M>N occurs in the execution of function D, the other terminal transmits information using function E, and one terminal executes functions C, D, and E in response to this. During call communication, the communication channel of each terminal is constantly updated and aligned to the currently set channel of the terminal with the larger count value information, so that stray terminals which tend to have smaller count value information are inevitably able to return to the network channel.

[0064] In function C of each terminal of the network, if the receiving and demodulating unit does not detect a receiving and demodulating signal including the G-ID for a predetermined period of time, it is desirable to also perform an operation of displaying on a display means that the terminal is likely to be in a deviated terminal state and / or an operation of notifying that the terminal is in the deviated terminal state by outputting a predetermined sound from an audio output means.

[0065] A wireless communication device applicable to the group wireless communication network system according to the fourth aspect of the present invention can be configured as follows. A wireless communication device having a common configuration as a terminal in a simplex group wireless communication network, the wireless communication device comprising a modulation / transmission unit and a reception / demodulation unit which cyclically scans a frequency control channel and all channels available in the network, the modulation / transmission unit transmitting a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CH-CCR") accompanied by a change destination channel designation on the frequency control channel, while enabling a change of network channel by receiving the G-ID and the CH-CCR (hereinafter both signals are collectively referred to as "G-ID·CH-CCR") transmitted from another terminal on the frequency control channel during the cyclic scanning process of the reception / demodulation unit, the wireless communication device comprising: a time storage unit which updates and stores detection time information when transmission / reception of the G-ID·CH-CCR is detected; a normal transmission unit which sets a normal transmission mode in response to a predetermined instruction operation and transmits the G-ID and a speech signal; and a current setting which temporarily switches the transmission / modulation unit to a current setting which is a channel used in the previous communication (excluding the frequency control channel) when the reception / demodulation unit does not detect a reception / demodulation signal including the G-ID for a predetermined time in the reception mode. an information transmitting means for automatically setting a transmission mode switched from a channel to the frequency control channel and transmitting the G-ID, the currently set channel information and the detected time information of the time storage means; a speech reproduction means for receiving and demodulating a speech signal and reproducing the voice in a state where the cyclic scanning is temporarily stopped on the currently set channel when the reception demodulation unit receives and demodulates a signal including the G-ID on the currently set channel in a reception mode; and a speech reproduction means for receiving and demodulating a speech signal and reproducing the voice in a state where the cyclic scanning is temporarily stopped on the frequency control channel in a reception mode when the reception demodulation unit receives and demodulates a signal including the G-ID on the currently set channel. information detection means for detecting currently set channel information and detection time information at the source terminal contained in the demodulated signal while the demodulated signal is stopped; information storage means for updating and storing the currently set channel information and detection time information at the source terminal detected by the information detection means; comparison means for comparing detected time information (T1) at the own terminal updated and stored by the time storage means with detected time information (T2) at the source terminal updated and stored by the information storage means every time information is updated and stored by the information storage means; anda processing means for setting a transmission mode in which the modulation transmission unit is temporarily changed from a currently set channel to a frequency control channel, transmitting the G-ID, currently set channel information, and detected time information (T1) of the time storage means, and when T2 is later than T1, changing the currently set channel to a channel indicated by the receiving channel information of the information storage means, and rewriting the detected time information (T1) of the time storage means to the detected time information (T2) of the information storage means, and when T1 and T2 are simultaneous, performing nothing and maintaining the current state. Effect of the Invention

[0066] In the present invention, in a simplex group wireless communication network, even if some terminals are unable to switch to the new channel when the channel in use in the network is changed because they are out of range or their power is turned off, each terminal updates and stores count value information on the change in network channel and information on the detection time of the change, and a specified algorithm using this information is executed during communication, automatically switching the sending and receiving channel of the terminal that has strayed from the network to the channel currently in use in the network, enabling the terminal to quickly and smoothly return to the network. [Brief description of the drawings]

[0067] [Figure 1] 1 is a block diagram of a wireless communication device according to an embodiment. [Diagram 2] This is a list of frequencies and their channel numbers that can be used by specific low-power radio stations for simplex wireless communication. The channels with numbers enclosed in ovals are the channels that are selectively used in the network of this embodiment, and channel number 31 (CH31) is the frequency control channel. [Diagram 3] 1 is an example of a communication frame format diagram used in a group wireless communication network. [Figure 4] 1 is a diagram showing the cyclic scanning method of a receiving and demodulating unit RX1 of a wireless communication device (each terminal) in the first and second embodiments for each currently set channel. [Diagram 5] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Figure 6] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Figure 7] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Figure 8] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Figure 9] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Figure 10] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Figure 11] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Figure 12] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Figure 13] 5 is a flowchart showing a procedure for counting the number of times a G-ID·CCR (Group Identification Signal·Channel Change Request Signal) transmission and reception is detected by a wireless communication device that is a constituent terminal of a network in the first embodiment. [Figure 14] 5 is a flowchart showing an operation execution procedure in a transmission mode by a wireless communication device that is a constituent terminal of a network in the first embodiment. [Figure 15A] 5 is a flowchart showing the procedure for executing an operation in a reception mode by a wireless communication device that is a constituent terminal of a network in the first embodiment. [Figure 15B] 15B is a flowchart showing details of the operation execution procedure in step S30 of FIG. 15A. [Figure 16] FIG. 2 is a simplified configuration diagram of a network showing a starting state when a stray terminal is automatically returned to the network using transmission from a network-side terminal as a starting event in the first embodiment. [Figure 17] FIG. 2 is a simplified configuration diagram of a network showing a starting state when a stray terminal is automatically returned to the network using a transmission from the stray terminal as a starting event in embodiment 1. [Figure 18] 1 is a simplified configuration diagram of a network showing a state in which a stray terminal has returned to the network in embodiment 1. FIG. [Figure 19] 1 is a simplified configuration diagram of a network showing the communication state after a stray terminal returns to the network in embodiment 1. FIG. [Figure 20] 11 is a flowchart showing a procedure for updating and storing detection time information relating to transmission and reception of G-ID·CCR by a wireless communication device that is a constituent terminal of a network in the second embodiment. [Figure 21] 11 is a flowchart showing the procedure for executing an operation in a transmission mode by a wireless communication device that is a constituent terminal of a network in the second embodiment. [Figure 22A] 11 is a flowchart showing the procedure for executing an operation in a receiving mode by a wireless communication device that is a constituent terminal of a network in the second embodiment. [Figure 22B] 22B is a flowchart showing details of the operation execution procedure in step S70 of FIG. 22A. [Diagram 23] FIG. 11 is a simplified configuration diagram of a network showing a starting state when a stray terminal is automatically returned to the network using transmission from a network-side terminal as a starting event in the second embodiment. [Figure 24] FIG. 11 is a simplified configuration diagram of a network showing the starting state when a stray terminal is automatically returned to the network using a transmission from the stray terminal as a starting event in embodiment 2. [Diagram 25] FIG. 11 is a simplified configuration diagram of a network showing the state in which a stray terminal has returned to the network in embodiment 2. [Figure 26] FIG. 13 is a diagram showing the cyclic scanning method of the receiving and demodulating unit RX1 of the wireless communication device (each terminal) in the third and fourth embodiments for each currently set channel. [Figure 27] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Figure 28] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Figure 29]FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Diagram 30] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Diagram 31] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Diagram 32] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Diagram 33] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Diagram 34] FIG. 1 is a simplified configuration diagram of a simplex group wireless communication network. [Diagram 35] 11 is a flowchart showing a procedure for counting the number of times transmission and reception of a G-ID·CH-CCR (group identification signal·channel change request signal with a destination channel designation) is detected by a wireless communication device that is a constituent terminal of a network in embodiment 3. [Diagram 36] 11 is a flowchart showing the procedure for executing an operation in a transmission mode by a wireless communication device that is a constituent terminal of a network in the third embodiment. [Figure 37A] 13 is a flowchart showing the procedure for executing an operation in a reception mode by a wireless communication device that is a constituent terminal of a network in the third embodiment (however, there is an interrupt process in an automatic transmission mode in steps S117-S119 and step S122). [Figure 37B] 37B is a flowchart showing details of the operation execution procedure in step S122 of FIG. 37A. [Figure 38] FIG. 11 is a simplified configuration diagram of a network showing a starting state when a stray terminal is automatically returned to the network using transmission from a network-side terminal as a starting event in embodiment 3. [Figure 39] FIG. 11 is a simplified configuration diagram of a network showing the starting state when a stray terminal is automatically returned to the network using a transmission from the stray terminal as a starting event in embodiment 3. [Diagram 40] FIG. 11 is a simplified configuration diagram of a network showing the state in which a stray terminal has returned to the network in embodiment 3. [Diagram 41] 13 is a flowchart showing a procedure for updating and storing detection time information of a G-ID·CH-CCR by a wireless communication device that is a constituent terminal of a network in the fourth embodiment. [Diagram 42] 13 is a flowchart showing the procedure for executing an operation in a transmission mode by a wireless communication device that is a constituent terminal of a network in the fourth embodiment. [Figure 43A] 13 is a flowchart showing the procedure for executing an operation in a reception mode by a wireless communication device that is a constituent terminal of a network in the fourth embodiment (however, there is an interrupt process in an automatic transmission mode in steps S177-S179 and step S182). [Figure 43B] 43B is a flowchart showing details of the operation execution procedure in step S182 of FIG. 43A. [Diagram 44] FIG. 13 is a simplified configuration diagram of a network showing a starting state when a stray terminal is automatically returned to the network using transmission from a network-side terminal as a starting event in embodiment 4. [Diagram 45] FIG. 13 is a simplified configuration diagram of a network showing the starting state when a stray terminal is automatically returned to the network using a transmission from the stray terminal as a starting event in embodiment 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0068] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a wireless communication network system and a wireless communication device according to the present invention will be described in detail with reference to the accompanying drawings. First, FIG. 1 is a block diagram of a business wireless communication device according to the embodiment described below, and this wireless communication device corresponds to network constituent terminals 51-55, 61-65 in the simplified configuration diagram of a simplex group wireless communication network in FIG. 5 and subsequent figures.

[0069] The receiving system of this wireless communication device is composed of an antenna 11, a receiving demodulation unit RX1, an amplifier 12, and a speaker (or earphone) 13. The radio wave signal received by the antenna 11 is input to the receiving demodulation unit RX1, which takes in the receiving signal of the controlled set channel, demodulates the receiving signal, and outputs it to the amplifier 12 on the condition that the squelch function is open. The demodulated signal is amplified by the amplifier 12 and reproduced as audio by the speaker (or earphone) 13.

[0070] The channel control in the receiving and demodulating unit RX1 is executed by the system control unit 10. In the receiving mode, in the following embodiments 1 and 2, the control is performed by a method of cyclically scanning five channels (channel numbers 21, 25, 28, 43, and 49) selected from the channels with channel numbers 20 to 30 and 41 to 49 in FIG. 2 that are available for use by specific low-power radio stations / radio telephone radio equipment in the above non-patent document 1, and in the following embodiments 3 and 4, the control is performed by a method of cyclically scanning six channels including the above five channels and a frequency control channel (channel number 31) for transmitting and receiving control information. On the other hand, when a group identification signal is detected and a speech signal or information signal is demodulated, the cyclic scanning is stopped at the detected channel, and in the stopped state, the squelch function is opened to output the demodulated signal to the amplifier 12. The specific order of channels in the cyclic scanning will be described in detail in each embodiment.

[0071] On the other hand, the transmission system of this wireless communication device comprises a microphone 15, an amplifier 16, a modulation transmission section TX1, an amplifier 17 and an antenna 18. The audio signal from microphone 15 is amplified by amplifier 16 and output to modulation transmission unit TX1, which modulates a carrier wave with the audio signal and outputs it to amplifier 17. The modulated carrier wave signal is then power-amplified by amplifier 17 and wirelessly transmitted from antenna 18. The control of the transmission channels and the like related to this transmission system is also performed by the system control unit 10.

[0072] The system control unit 10 controls the receiver / demodulator unit RX1 and the modulator / transmitter unit TX1 by executing a built-in program using events such as command input from the PTT button or various keys on the operation unit 19 or detection of various received and demodulated signals. The system control unit 10 also controls the entire system including the amplifiers 12, 16, 17 and the liquid crystal display unit 20, and executes corresponding processes while updating and storing various data using a counter 21 and a memory 22 when controlling in each of the following embodiments.

[0073] FIG. 3 is a diagram showing an example of a communication frame format used in a group wireless communication network in each of the following embodiments. The transmitting terminal transmits a modulated wave modulated by MSK (Minimum Shift Keying) or the like using the baseband signal of the audio signal section incorporated in the same format, and the receiving terminal demodulates the received signal related to the modulated wave to reproduce the audio signal, while each information signal of the data payload received prior to the audio signal is separated and detected and used as data for operational control by the system control unit 10. The data payload contains a self-identification signal (hereinafter referred to as "self-ID") and a transmission / reception channel information signal, as well as a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CCR") or a channel request signal with a destination channel designation (hereinafter referred to as "CH-CCR"). In the following first and second embodiments, count value information relating to the number of times the CCR or CH-CCR is transmitted and received and a signal relating to transmission and reception time information are added after the audio signal portion.

[0074] <<Embodiment 1>> This embodiment relates to the wireless communication device of FIG. 1 and a group wireless communication network system having the wireless communication device as a constituent terminal, and here, a simplex group wireless communication network consisting of five terminals 51 to 55 as shown in FIG. In the simplified network diagram represented in Fig. 5, "TX1-CH21" in each of the terminals 51 to 55 indicates a state in which the modulation transmission unit TX1 is set to the channel CH21 in Fig. 2, and "RX1-SCAN" indicates a state in which the reception demodulation unit RX1 is performing cyclic scanning of channels. Also, "RX1-CH21" shown in the simplified network diagram later indicates a state in which the reception demodulation unit RX1 has stopped cyclic operation and is set to the channel CH21. It should be noted that modules not hatched are active, and modules hatched are inactive. When the modulation transmission unit TX1 is active, the reception demodulation unit RX1 is inactive.

[0075] In this embodiment, the cyclic scanning performed by the receiving and demodulating unit RX1 of each terminal 51 to 55 is a method of prioritizing the currently set channel (the previous communication channel) among the five channels (CH21, CH25, CH28, CH43, CH49) selected as channels available in the network, as shown in (1) to (5) of Figure 4, and scanning periods of the other channels are sequentially interspersed between scanning periods of the currently set channel. Therefore, if the scanning time per channel is approximately 100 msec, the total scanning time for the currently set channel is approximately 400 msec, and the total scanning time for the other four channels is approximately 400 msec, meaning that the currently set channel is allocated four times the scanning time of each of the other channels.

[0076] The cause of a stray terminal in this network is the following transition of the network state. FIG. 5 shows a state in which the network channel is CH21 and all terminals 51-55 are in receiving (standby) mode, the modulation transmission unit TX1 of each terminal 51-55 is set to CH21 but is in an inactive state, and the receiving demodulation unit RX1-SCAN is performing the cyclic scanning shown in FIG. 4 (1).

[0077] From the state shown in Figure 5, since this is a simplex network, for example, as shown in Figure 6, if terminal 51 performs carrier sense (hereinafter referred to as "CS") on CH21 and is able to transmit, it activates the modulation transmission unit TX1-CH21 and transmits the G-ID and call signal, and in the other terminals 52 to 55, the receiving and demodulating units RX1-SCAN receive and demodulate the G-ID at the scanning stage of CH21 in the cyclic scanning of Figure 4 (1), so that, as shown in Figure 7, the cyclic scanning is stopped at CH21 and the call signal is demodulated.

[0078] Incidentally, a terminal which wishes to switch to transmission mode and transmit an audio signal always sets its transmission channel to the receiving and demodulating unit RX1 and executes CS as described above, and unless it can confirm that there is no interference on that channel, it cannot set the modulation and transmitting unit TX1 to that channel and perform the transmission operation [Ministry of Posts and Telecommunications Notification No. 49 of 1989, Ministry of Internal Affairs and Communications Notification No. 308 of 2021, and (3) Carrier Sense, pages 1-10 of Volume 1 in the above non-patent document 1].

[0079] FIG. 8 shows a state in which the receiving and demodulating unit RX1-CH21 of the terminal 53 has performed CS on the currently set channel CH21 (which is also the network channel), which was the previous communication channel, but interference has occurred. Since the terminal 53 cannot transmit on CH21, it switches the receiving and demodulating unit RX1 to another channel CH28 to perform CS. Regarding the selection of this other channel, a method may be used in which a channel is selected at random and CS is performed, but a method may also be adopted in which better available channels are prioritized in advance as candidate channels, and CS is performed by selecting them in that order, as proposed in Patent Application No. 2023-074015 by the applicant of the present application described in the [Background Art] section above.

[0080] If there is no interference with the CS of CH28, the terminal 53 activates the modulation transmission unit TX1 in CH28 to transmit the GID and CCR, as shown in FIG. Meanwhile, the other terminals 51, 52, 54, and 55 receive and demodulate the G-ID and CCR at the scanning stage of CH28 in the cyclic scanning of the receiving and demodulating unit RX1-SCAN. Based on the fact that the G-ID is an identification signal of the group to which the terminal belongs and the CCR is a channel change request, the terminals change the communication channel from CH21 to CH28, which is the receiving channel for the G-ID and CCR, as shown in FIG. 10.

[0081] As a result, as shown in Figure 10, the communication channel of all terminals 51 to 55 is changed to CH28 and the network channel transitions to CH28, and just as in the case of CH21 before interference (Figures 6 and 7), each terminal 51 to 55 can appropriately activate the modulation transmission unit TX1-CH28 and transmit call signals to other terminals.

[0082] By the way, at the stage in Figure 9, i.e., at the stage when terminal 53 transmits the G-ID and CCR to the other terminals 51, 52, 54, 55 on CH28, if any of terminals 51, 52, 54, 55 happens to be out of range or has its power turned off, that terminal will naturally not be able to receive the G-ID and CCR and will not be able to respond to the change in network channel. For example, FIG. 11 shows a case where terminal 55 is out of range at the stage shown in FIG. 9. Terminals 51, 52, and 54 are able to receive the G-ID and CCR from terminal 53 using the receiving and demodulating unit RX1-SCAN and can change their own communication channel to CH28. However, terminal 55 misses this opportunity, and so, as shown in FIG. 12, only terminal 55 remains on CH21 and becomes an out-of-range terminal. Therefore, even if the terminal 55 returns to the service area or is powered on, it cannot recover communication with the other terminals 51 to 54 and cannot return to the network.

[0083] In this case, terminals 51 to 54 cannot recognize that terminal 55 has been deviated from the network simply because there continues to be no calls from terminal 55. Also, even though the currently set channel for terminal 55 remains CH21 and it continues to be the case that it is not receiving calls from other terminals 51 to 54, in a network with not many calls it will take a considerable amount of time before it recognizes that it has been deviated from the network.

[0084] Therefore, the wireless communication device in this embodiment is applied to the terminals 51 to 55 in the group wireless communication network, so that a terminal that has strayed can always automatically return to the network and regain a communicable state simply by returning to a communication range or by turning the power back on while in the range.

[0085] First, the wireless communication device of this embodiment (FIG. 1) executes the procedure shown in FIG. 13 in the group wireless communication mode. First, when the group wireless communication mode is set from the operation unit 19, the system control unit 10 resets the counter 21 and memory 22 (S1), and then checks whether the modulation transmission unit TX1 of the own terminal has transmitted a G-ID and CCR, and whether the reception and demodulation unit RX1-SCAN has received and demodulated the G-ID and CCR from another terminal (S2, S3), and repeats the operation of incrementing the count value of the counter 21 by +1 each time this is detected (S4, S5 → S2).

[0086] Therefore, comparing the transitions of the network state (Figures 5 to 10), at the stage in Figure 9, terminal 53 transmits G-ID and CCR using modulation transmission unit TX1-CH28, causing the count value of counter 21 of terminal 53 to be incremented by +1, and terminals 51, 52, 54, and 55 receive G-ID and CCR using their respective receiving and demodulating units RX1-SCAN, causing the count value of counter 21 of each terminal 51, 52, 54, and 55 to be incremented by +1. However, as shown in FIG. 11, when terminal 53 transmits the G-ID and CCR from modulation transmission unit TX1-CH28, terminal 55, which is out of range or has its power turned off, is unable to receive the G-ID and CCR, and therefore the count value of counter 21 is not incremented. In other words, as shown in Figure 12, the communication channel of terminal 55 which has become the deviated terminal remains CH21, which is different from the communication channel CH28 of the other terminals 51, 52, 54, and 55, and the count value of counter 21 is smaller than the count values ​​of counters 21 of the other terminals 51, 52, 54, and 55.

[0087] The wireless communication device of this embodiment, as a constituent terminal of a simplex wireless communication network, utilizes the difference in count values ​​that inevitably occurs in the execution procedure of Figure 13 when a stray terminal occurs, and executes the procedures shown in the flowcharts of Figures 14, 15A and 15B to automatically return the stray terminal, whether it is from this terminal or another party, to the network. First, FIG. 14 shows a procedure for transmitting a speech signal in the transmission mode. In the receive mode, in order to send a voice message to another terminal on the network, if the PTT button on the operation unit 19 is turned ON and the transmit mode is set, an interrupt is immediately generated (S10, S11), and the receive demodulation unit RX1 executes CS on the currently set channel, and, provided that there is no interference (hereinafter, an explanation of the procedure related to CS will be omitted), the modulation transmission unit TX1 transmits the G-ID, etc. (including the terminal's own ID in addition to the G-ID), and then the carrier signal is modulated with the input voice signal from the microphone 15 to transmit the voice message (S12, S13).

[0088] In a normal wireless communication device, when the transmission of a voice message is completed and the PTT button is turned OFF, a communication end signal is immediately sent and the transmission of the voice message is terminated. However, in the wireless communication device of this embodiment, the communication is not terminated immediately after the PTT button is turned OFF. Instead, the current count value information of the counter 21 is read and transmitted as an additional signal, and then the communication end signal is transmitted and the interrupt process is terminated (S14, S15, S16).

[0089] In the reception mode, if there is no interrupt process due to the transmission mode setting, the procedure in FIG. 15A is executed. First, the receiving and demodulating unit RX1 performs cyclic scanning of any one of (1) to (5) in FIG. 4, and when a G-ID is received and demodulated during the scanning process, the scanning operation for that receiving channel is stopped (S20 to S22). If the channel that has been stopped is the currently set channel of the own device, the source is another terminal that belongs to the group and is set to the same communication channel, and since this is the other terminal with which normal group communication should be carried out, the call signal is played back as voice, and the device returns to the standby state upon detecting a communication end signal (S23: Y → S24, S25 → S20). In this case, the currently set channel (communication channel) of the receiving terminal itself and the sending terminal of the other party is not necessarily a network channel, and both may be deviated terminals.

[0090] On the other hand, if the stopped channel is not the currently set channel of the own terminal (S23:N), the source terminal belongs to a group but the currently set channel of the own terminal is different from that of the own terminal, which corresponds to either a state in which either the own terminal or the source terminal is a stray terminal, or a state in which both are stray terminals and their currently set channels are different. In this case, if there is a speech signal, it is demodulated to reproduce the voice (S26, S27), and the count value information added to the end of the speech signal is received and demodulated (S28). Also, the demodulated count value information is updated and stored in the memory 22 together with the channel information of the reception demodulation section RX1 that was stopped upon detection of the G-ID (S29). In step 26, the case where there is no speech signal is also considered. This is to take into consideration not only the transmission of voice / information signals from other terminals in steps S11 to S16 of Figure 14, but also the case where the transmission mode is automatically set in Figure 15B described below to transmit count value information after a voice signal frame containing G-ID, etc. and no voice information (S33 to S36).

[0091] Then, every time the channel information and count value information in memory 22 are updated, the count value information (M times) of counter 21 is compared with the updated count value information (N times) of memory 22, and appropriate processing is performed according to the comparison result (S29, S30). This means that the count value information (N times) in memory 22 corresponds to the count value information of the source terminal (i.e., a terminal that belongs to a group but has a different communication channel from the terminal itself), and by comparing this with the count value information (M times) in the counter 21 of the terminal itself, it is determined which terminal is more likely to be a deviating terminal, and the corresponding processing is selected according to the result.

[0092] The comparison result and specific steps related to the corresponding process (S30) are shown in FIG. 15B. If M>N: The transmission mode is automatically set and an interrupt is generated, and the modulation transmission unit TX1 is set as the currently set channel, and the G-ID, etc. and count value information of the counter 21 (M times) are transmitted. Upon completion of this, the mode is automatically returned to the reception mode and the interrupt processing is exited (S31 → S32 to S36). If N>M: The currently set channel of the own device is changed to the channel related to the updated channel information stored in memory 22, and the count value information (M times) of counter 21 is rewritten to the count value information (N times) of memory 22 (S31→S37→S38, S39). For M=N: No action is taken and the status quo is maintained as is (S31→S40).

[0093] The above describes the function of a single wireless communication device applied to a simplex group wireless communication network. Next, we will specifically explain how the stray terminal 55 can be returned to the group network from the network state in which the stray terminal 55 occurred (FIG. 12).

[0094] FIG. 16 relates to a case where a return sequence for the stray terminal 55 to the network is executed with a start event being that any of the terminals 51 to 54 other than the stray terminal 55 (terminal 51 in this case) goes into a transmission mode and starts a call. First, as shown in the figure, the network channel is CH28, but the currently set channel of the stray terminal 55 is CH21. Here, the terminal 51 executes steps S11 to S16 in FIG. 14, switches to the transmission mode, and transmits the count value information of the counter 21 together with the G-ID and the like and the speech signal from the modulation transmission unit TX1-CH 28. In response to this, terminals 52 to 54 execute steps S20 to S23 in FIG. 15A, and when the G-ID is received and demodulated during the cyclic scanning [FIG. 4(3)] in which the currently set channel CH28 is given priority by the receiving and demodulating unit RX1-SCAN, the scanning operation is stopped on that receiving channel. In this case, since the currently set channel of terminals 52 to 54 and terminal 51 is network channel CH28, the stopped channel in terminals 52 to 54 is the same as currently set channel CH28 (S23:Y). Therefore, terminals 52 to 54 execute steps S23 → S24, S25 → S20 in Figure 15A, and the receiving and demodulating unit RX1 receives and demodulates the call signal from terminal 51 on the currently set channel CH28 and plays it back, and receives and demodulates the communication end signal, thereby returning the receiving and demodulating unit RX1 from the stopped state to the cyclic scanning state.

[0095] On the other hand, in the deviating terminal 55, in the cyclic scanning [Figure 4 (1)] of the receiving and demodulating unit RX1-SCAN that prioritizes the currently set channel CH21, the G-ID, etc. are received and demodulated at the scanning stage of CH28, and the scanning operation is stopped (S20-S22), but in this case the stop channel C28 and the currently set channel CH21 are different (S23:N). Therefore, the deviating terminal 55 executes step S23:N→S26 to S30 in FIG. 15A. That is, if there is a speech signal (in this case, there is a speech signal), it is received and demodulated to reproduce the audio, and when the count value information following the audio signal frame is received and demodulated, the reception channel information (in this case, CH28) and the count value information are updated and stored in memory 22, and further, the count value information (M) of counter 21 is compared with the updated and stored count value information (N) of memory 22, and appropriate processing is performed based on the comparison result.

[0096] In the case of the deviated terminal 55, the count value information (N) in memory 22, which is the count value information of terminal 51, is greater than the count value information (M) of the own terminal, and the comparison result is N>M, so in step S30 of Figure 15A, the procedure of steps S31 → S37 to S39 of Figure 15B is executed. Therefore, the currently set channel CH21 of the stray terminal 55 is changed to channel CH28 indicated by the receiving channel information updated and stored in memory 22, and the count value information (M) of counter 21 is also rewritten to the count value information (N) of memory 22, so that the communication channel and count value information become the same as those of terminal 51. As a result, terminal 55 can return to the group communication network from its stray state.

[0097] Next, FIG. 17 shows a case where the stray terminal 55 goes into a transmission mode and transmits a call signal, which becomes a starting event and executes a sequence for returning to the network. First, as shown in the figure, the network channel is CH28, but the currently set channel of the stray terminal 55 is CH21. In this case, the deviated terminal 55 executes steps S11 to S16 in FIG. 14, switches to the transmission mode, and transmits the count value information of the counter 21 together with the G-ID and the voice signal from the modulation transmission unit TX1-CH21.

[0098] In response to this, the terminals 51-54 in the receiving mode execute steps S20-S22 in FIG. 15A, and when the G-ID is received and demodulated during the cyclic scanning [FIG. 4(3)] in which the receiving and demodulating unit RX1-SCAN prioritizes the currently set channel CH28, the scanning operation is stopped on that receiving channel. In this case, however, since the currently set channel of the deviating terminal 55 is CH21, the scanning operation is stopped on CH21. In this case, the currently set channel for the terminals 51 to is CH28, which is different from the channel CH21 on which the scanning operation has been stopped (S23: N).

[0099] Therefore, the terminals 51 to 54 execute steps S23:N → S26 to S30 in Figure 15A, update and record in the memory 22 the count value information received and demodulated following the audio signal from the deviated terminal 55 together with the receiving channel information, compare the count value information (M) of the counter 21 of the own terminal with the count value information (N) of the memory 22, and perform appropriate processing according to the comparison result. In this case, since the count value information (N) in memory 22 relates to deviating terminal 55, the relationship is M>N, and terminals 51 to 54 execute steps S31→S32 to S36 in FIG. 15B at step S30 in FIG. 15A. That is, the terminals 51 to 54 are automatically set to the transmission mode, and in an interrupted state, transmit the G-ID and the count value information (M) of the counter 21 from the modulation transmission unit TX1-CH28 on the currently set channel (CH28), and then return to the reception mode. However, in reality, because transmissions from the terminals 51 to 54 compete on the currently set channel (CH28), only one of the terminals with which CS is established first (hereinafter, referred to as terminal 5X) can transmit.

[0100] On the other hand, in response to the information transmission from the terminal 5X, the deviation terminal 55 then executes steps S20 to S22 in FIG. 15A. In other words, when a G-ID or the like is received and demodulated during the cyclic scanning [Figure 4 (1)] of the receiving and demodulating unit RX1-SCAN, which prioritizes the currently set channel CH21, the scanning operation is stopped on that receiving channel. In this case, however, since the currently set channel of terminal 5X is CH28, the scanning operation is stopped on CH28. In this case, the currently set channel of the deviated terminal 55 is CH21, which is different from the channel CH28 on which the scanning operation is stopped (S23:N), so steps S23:N→S26 to S30 in FIG. 15A are executed. That is, when the deviating terminal 55 receives and demodulates the count value information from the terminal 5X, it updates and stores the count value information in the memory 22 along with the receiving channel CH28, and compares the count value information (M) of its own counter 21 with the updated count value information (N) stored in the memory 22 to execute the corresponding processing.

[0101] The result of the comparison is that N>M, since M is the count value information of the stray terminal, and so steps S31 → S37 to S39 of FIG. 15B are executed in the stray terminal 55, the currently set channel CH21 is changed to channel CH28 indicated by the receiving channel information in memory 22, which is the currently set channel on the terminal 5X side, and the count value information (M) of counter 21 is rewritten to the count value information (N) in memory 22. As a result, the communication channel of the stray terminal 55 is changed from CH21 to CH28, and the stray terminal 55 is able to return to the group network from its stray state. As shown in FIG. 18, the currently set channel (communication channel) of all terminals 51 to 55 is set to network channel CH28, and the detection time information of each terminal 51 to 55 is also consistent. As shown in FIG. 19, no matter which terminal in the network (terminal 53 in the figure) becomes the transmitting terminal, the other terminals (terminals 51, 52, 54, 55 in the figure) can receive and demodulate the G-ID, etc., during the scanning stage of CH28 in the cyclic scanning [(3) in FIG. 4] that prioritizes the currently set channel CH28 of the receiving and demodulating unit RX1-SCAN, and then transition directly to a state of playing the call signal (S20 to S25 in FIG. 15A).

[0102] <<Embodiment 2>> As in the first embodiment, this embodiment relates to a group wireless communication network system having the wireless communication device of FIG. 1 and the wireless communication device as its constituent terminals, and assumes a simplex group wireless communication network consisting of five terminals 51 to 55 as shown in FIG. 5. Furthermore, the five channels selected as available for use in the network in this embodiment and the cyclic scanning conditions of the receiving and demodulating unit RX1-SCAN in each of the terminals 51 to 55 are also the same as those in the first embodiment. Furthermore, the causes of the occurrence of stray terminals in this network are the same as those explained in the first embodiment with reference to FIGS.

[0103] The difference between the wireless communication device of this embodiment and embodiment 1 is that, as a constituent terminal of a group wireless communication network, embodiment 1 uses the magnitude relationship of the count value information of the number of transmissions and receptions of G-ID and CCR as a comparison factor for the estimated probability of being a deviant terminal, whereas embodiment 1 uses the order of the detection time information related to the latest transmission and reception of G-ID and CCR as a comparison factor. This is based on the fact that a terminal with a later latest transmission / reception time of the G-ID and CCR means that it has remained in the network for a longer period of time, and therefore the estimated probability of it being a stray terminal can be considered to be lower.

[0104] Therefore, in the wireless communication device of embodiment 1, Figure 13 shows a procedure for counting the number of times G-ID and CCR are sent and received, while in this embodiment, Figure 20 shows a procedure for updating and storing detection time information related to the sending and receiving of G-ID and CCR. Specifically, when the group wireless communication mode is set from the operation unit 19, the system control unit 10 resets the memory 22 (S41), and then detects whether the modulation transmission unit TX1 of the own terminal has transmitted a G-ID and CCR, and whether the reception and demodulation unit RX1-SCAN has received and demodulated the G-ID and CCR from another terminal (S42, S43).Each time this is detected, the system control unit 10 repeats the operation of updating and storing the time information of the built-in timer in the [A] area of ​​the memory 22 as detected time information (S44, S45 → S42).

[0105] According to the method of updating and storing the detection time of transmission and reception of the G-ID and CCR in this embodiment, in a terminal that is capable of communicating in the group wireless communication network, the latest detection time information relating to the change of network channel due to transmission and reception of the G-ID and CCR is always updated and stored in the [A] area of ​​the memory 22, but in a stray terminal that is out of range or has its power turned off when the G-ID and CCR are transmitted and received, the record will no longer contain the latest detection time information.

[0106] The wireless communication device of this embodiment, as a constituent terminal of a simplex wireless communication network, utilizes the difference in detection time information in area [A] of memory 22 that inevitably occurs in the execution procedure of Figure 20 when a stray terminal occurs, and executes the procedures shown in the flowcharts of Figures 21, 22A and 22B to automatically return the stray terminal, whether it is from this terminal or another party, to the network.

[0107] First, FIG. 21 shows a signal transmission procedure in the transmission mode. In the receive mode, in order to send a voice message to another terminal on the network, if the PTT button on the operation unit 19 is turned ON and the transmit mode is set, an interrupt is immediately generated (S50, S51), and, provided that there is no interference when the receive demodulator RX1 executes CS on the currently set channel, the modulator / transmitter TX1 transmits the G-ID, etc., and then the carrier signal is modulated with the input voice signal from the microphone 15 to transmit the voice message (S52, S53).

[0108] In a normal wireless communication device, when the transmission of a voice message is completed and the PTT button is turned OFF, a communication end signal is immediately sent and the transmission of the voice message is terminated. However, in the wireless communication device of this embodiment, the device does not immediately terminate after the PTT button is turned OFF. Instead, the detection time information is read from the [A] area of ​​memory 22 and transmitted as an additional signal, and then the communication end signal is transmitted and the device exits from the interrupt processing (S54, S55, S56).

[0109] In the reception mode, if there is no interrupt process due to the transmission mode setting, the procedure in FIG. 22A is executed. First, the receiving and demodulating unit RX1 performs cyclic scanning of any one of (1) to (5) in FIG. 4, and when a G-ID is received and demodulated during the scanning process, the scanning operation for that receiving channel is stopped (S60 to S62). If the channel that has been stopped is the currently set channel of the own device, the source is another terminal that belongs to the group and is set to the same communication channel, and since this is the other terminal with which normal group communication should be carried out, the call signal is played back as audio, and the device returns to the standby state upon detecting a communication end signal (S63:Y to S64, S65 -> S60). In this case, the currently set channel (communication channel) of the receiving terminal itself and the sending terminal of the other party is not necessarily a network channel, and both may be deviated terminals.

[0110] On the other hand, if the stopped channel is not the currently set channel of the own terminal (S63:N), the source terminal belongs to a group but the transmission and reception channels are different from the own terminal, which corresponds to either a state in which either the own terminal or the source terminal is a stray terminal, or a state in which both are stray terminals and their currently set channels are different. In this case, if there is a speech signal, it is demodulated to reproduce the audio (S66, S67), and the detection time information added to the end of the speech signal is received and demodulated (S68). Also, together with the channel information of the reception demodulation section RX1 that was stopped upon detection of the G-ID, the demodulated detection time information is updated and stored in the [B] area of ​​the memory 22 (S69). In step 66, the case where there is no speech signal is also considered. This is to take into consideration not only the transmission of voice / information signals from other terminals in steps S51 to S56 of FIG. 21, but also the case where the transmission mode is automatically set in FIG. 22B described below to transmit count value information after a voice signal frame containing no voice information such as a G-ID (steps S73 to S76).

[0111] Then, each time the receiving channel information and detection time information in the [B] area of ​​the memory 22 are updated, the detection time information (T1) in the [A] area of ​​the memory 22 is compared with the updated detection time information (T2) in the [B] area, and appropriate processing is performed according to the comparison result (S69, S70). This means that the detection time information (T2) in the [B] area of ​​memory 22 corresponds to the detection time information of the source terminal (i.e., a terminal that belongs to a group but has a different communication channel from the terminal itself), and by comparing this with the detection time information (T1) in the [A] area of ​​the terminal's memory 22, it is possible to determine which terminal has a higher probability of being a deviating terminal, and to select a corresponding process depending on the result.

[0112] The specific steps of this comparison and response process (S70) are shown in FIG. 22B. If T1 is later than T2: The transmission mode is automatically set and an interrupt is generated, and the modulation transmission unit TX1 is set as the currently set channel, and the G-ID, etc. and detection time information (T1) in the [A] area of ​​memory 22 are transmitted. Upon completion of this, the system automatically returns to the reception mode and exits from the interrupt processing (S71 → S72 to S76). If T2 is later than T1: The currently set channel of the own device is changed to the updated channel stored in the [B] area of ​​memory 22, and the detection time information (T1) in the [A] area of ​​memory 22 is rewritten to the detection time information (T2) in the [B] area of ​​memory 22 (S71 → S77 to S79). When T1 and T2 are simultaneous (T1=T2): No action is taken and the currently set channel is maintained as is (S71→S80).

[0113] The above describes the function of a single wireless communication device applied to a simplex group wireless communication network. Next, we will specifically explain how to return the stray terminal 55 to the group network from the network state in which the stray terminal 55 occurred (FIG. 12).

[0114] FIG. 23 relates to a case where a return sequence for the stray terminal 55 to the network is executed with a start event being that any of the terminals 51 to 54 other than the stray terminal 55 (terminal 51 in this case) goes into a transmission mode and starts a call. As shown in the figure, the network channel is CH28, but the currently set channel of the stray terminal 55 is CH21. Here, the terminal 51 executes steps S51 to S56 in FIG. 21, switches to the transmission mode, and transmits from the modulation transmission unit TX1-CH 28 the G-ID and the like and the speech signal together with the detection time information in the [A] area of ​​the memory 22.

[0115] In response to this, terminals 52 to 54 execute steps S60 to S63 in FIG. 22A, and when a G-ID or the like is received and demodulated during the cyclic scanning [FIG. 4(3)] in which the currently set channel CH28 is given priority by the receiving and demodulating unit RX1-SCAN, the scanning operation is stopped on that receiving channel. In this case, since the currently set channel of terminals 52 to 54 and terminal 51 is network channel CH28, the stopped channel in terminals 52 to 54 is the same as currently set channel CH28. Therefore, terminals 52 to 54 execute steps S63 → S64, S65 → S60 in Figure 22A, and the receiving and demodulating unit RX1 receives and demodulates the call signal from terminal 51 on the currently set channel CH28 and plays it back, and receives and demodulates the communication end signal, thereby returning the receiving and demodulating unit RX1 from the stopped state to the cyclic scanning state.

[0116] On the other hand, in the deviating terminal 55, the receiving and demodulating unit RX1-SCAN receives and demodulates the G-ID at the scanning stage of CH28 in the cyclic scanning [Figure 4 (1)] that prioritizes the currently set channel CH21, and stops the scanning operation (S60-S62). In this case, the stop channel C28 and the currently set channel CH21 are different (S63:N). Therefore, the deviation terminal 55 executes steps S63, S66 to S70 in FIG. 22A. In other words, if there is a speech signal (in this case, there is a speech signal), it is received and demodulated to play back the audio, and when the detection time information following the audio signal frame is received and demodulated, the reception channel information (in this case, CH28) and the detection time information are updated and stored in the [B] area of ​​memory 22, and further, the detection time information (T1) in the [A] area of ​​memory 22 is compared with the updated and stored detection time information (T2) in the [B] area of ​​memory 22, and appropriate processing is performed based on the comparison result.

[0117] In this case, since the detection time information (T1) is from the deviating terminal 55, the comparison result is that "T2 is later than T1", and in step S70 of FIG. 22A, the procedure of steps S71 → S77 to S79 ​​of FIG. 22B is executed. Therefore, the currently set channel CH21 of the stray terminal 55 is changed to channel CH28 indicated by the receiving channel information updated and stored in memory 22, and the detection time information (T1) in the [A] area of ​​memory 22 is also rewritten to the detection time information (T2) in the [B] area of ​​memory 22, so that the communication channel and detection time information become the same as those of terminal 51. As a result, terminal 55 can return to the group communication network from its stray state.

[0118] Next, FIG. 24 shows a case where the stray terminal 55 goes into a transmission mode and transmits a speech signal, which becomes a starting event and causes a return sequence to the network to be executed. As shown in the figure, the network channel is CH28, but the currently set channel of the stray terminal 55 is CH21. In this case, the deviated terminal 55 executes steps S51 to S56 in FIG. 21, switches to the transmission mode, and transmits the G-ID and the like and the audio signal together with the detection time information in the [A] area of ​​the memory 22 from the modulation transmission unit TX1-CH21.

[0119] In response to this, the terminals 51-54 in the receiving mode execute steps S60-S62 in FIG. 22A, and when the G-ID or the like is received and demodulated during the cyclic scanning [FIG. 4(3)] which prioritizes the currently set channel CH28 of the receiving and demodulating unit RX1-SCAN, the scanning operation is stopped on that receiving channel. In this case, however, since the currently set channel of the deviating terminal 55 is CH21, the scanning operation is stopped on CH21. In this case, the currently set channel of the terminals 51 to is CH28, which is different from the channel CH21 on which the scanning operation is stopped (S63:N), so steps S63:N→S66 to S70 in FIG. 22A are executed.

[0120] Therefore, terminals 51 to 54 update and record in area [B] of memory 22 the detection time information received and demodulated following the audio signal from deviated terminal 55 together with the receiving channel information, compare the detection time information (T1) in area [A] of memory 22 of their own terminal with the detection time information (T2) in area [B] of memory 22, and perform appropriate processing according to the comparison result. In this case, since the detection time information (T2) relates to the deviating terminal 55 and has a relationship of "T1 is later than T2", steps S71, S72 to S76 in FIG. 22B are executed in step S70 in FIG. 22A. In other words, the terminals 51 to 54 are automatically set to the transmission mode, and when an interrupt is applied, they transmit the G-ID, etc. and the detection time information in the [A] area of ​​the memory 22 on the currently set channel (CH28) from the modulation transmission unit TX1-CH28, and then return to the reception mode. However, in reality, because transmissions from the terminals 51 to 54 compete on the currently set channel (CH28), only one of the terminals with which CS is established first (hereinafter, referred to as terminal 5X) can transmit.

[0121] On the other hand, in response to information transmission from terminal 5X, deviated terminal 55 then executes steps S60 to S62 of FIG. 22A, and when a G-ID or the like is received and demodulated during the cyclic scanning [FIG. 4(1)] in which the currently set channel CH21 is given priority by the receiving and demodulating unit RX1-SCAN, the scanning operation is stopped on that receiving channel. In this case, since the currently set channel of terminal 5X is CH28, the scanning operation is stopped on CH28. In this case, the currently set channel of the deviated terminal 55 is CH21, which is different from the channel CH28 on which the scanning operation is stopped (S63: N), so steps S63→S66 to S70 in FIG. 22A are executed. In other words, when the stray terminal 55 receives and demodulates the detection time information from terminal 5X, it updates and stores the detection time information in the [B] area of ​​memory 22 along with the receiving channel CH28, and then compares the detection time information (T1) in the [A] area of ​​its own memory 22 with the detection time information (T2) updated and stored in the [B] area of ​​memory 22 to perform appropriate processing.

[0122] In this case, since T1 corresponds to the detection time information of the deviating terminal 55 and T2 corresponds to the detection time information of terminal 5X, the result of the comparison is the relationship in FIG. 22B where “T2 is later than T1”, and steps S71 → S77 to S79 ​​are executed in the deviating terminal 55, the currently set channel CH21 is changed to channel CH28 indicated by the receiving channel information in area [B] of memory 22, which is the currently set channel on the side of terminal 5X, and the detection time information (T1) in area [A] of memory 22 is rewritten to the detection time information (T2) in area [B] of memory 22. As a result, the communication channel of the stray terminal 55 is changed from CH21 to CH28, and the stray terminal 55 is able to return to the group network from its stray state. As shown in FIG. 25, the currently set channel (communication channel) of all terminals 51 to 55 is set to network channel CH28, and the detection time information of each terminal 51 to 55 is also consistent.

[0123] <<Embodiment 3>> Like the above embodiment, this embodiment relates to a group wireless communication network system having the wireless communication device of Figure 1 and the wireless communication device as its constituent terminals, and here we assume a simplex group wireless communication network consisting of five terminals 61 to 65 as shown in Figure 27. In the simplified network diagram represented in Fig. 27, "TX1-CH21" in each of the terminals 61 to 65 indicates a state in which the modulation transmission unit TX1 is set to the channel CH21 in Fig. 2, and "RX1-SCAN" indicates a state in which the reception demodulation unit RX1 is performing cyclic scanning of channels. Also, "RX1-CH21" shown in the simplified network diagram later indicates a state in which the reception demodulation unit RX1 has stopped cyclic operation and is set to the channel CH21. It should be noted that modules not hatched are active, and modules hatched are inactive. When the modulation transmission unit TX1 is active, the reception demodulation unit RX1 is inactive.

[0124] In this embodiment, the cyclic scanning performed by the receiving and demodulating unit RX1 of each terminal 61 to 65 adopts a method of prioritizing the frequency control channel among the five channels (CH21, CH25, CH28, CH43, CH49) selected as channels available in the network and the frequency control channel (CH31), as shown in (1) to (5) of Figure 26, and adopts an alternating scanning method in which a scanning period of one of the five channels, which is the currently set channel (the channel used in the previous communication), is inserted between scanning periods of the frequency control channel. Therefore, if the scanning time per channel is about 100 msec, the total scanning time for the frequency control channel (CH31) and the currently set channel is about 400 msec, and the scanning time for one cycle: about 800 msec is allocated evenly to both channels.

[0125] The cause of a stray terminal in this network is the following transition of the network state. Figure 27 shows a state in which the network channel is CH21 and all terminals 61 to 65 are in receiving (standby) mode, the modulation transmission unit TX1 of each terminal 61 to 65 is set to CH21 but is in an inactive state, and the receiving demodulation unit RX1-SCAN is performing the cyclic scanning shown in Figure 26 (1).

[0126] From the state in Figure 27, since this is a simplex network, for example, as shown in Figure 28, if terminal 61 executes CS on CH21 and is able to transmit, it activates the modulation transmission unit TX1-CH21 and transmits a call signal with the G-ID, etc., and in the other terminals 62 to 65, the receiving and demodulating units RX1-SCAN receive and demodulate the G-ID at the scanning stage of CH21 in the cyclic scanning of (1) in Figure 26, so as shown in Figure 29, the cyclic scanning is stopped at CH21 and the call signal is demodulated and reproduced.

[0127] Incidentally, a terminal which wishes to switch to transmission mode and transmit an audio signal always sets its transmission channel to the receiving and demodulating unit RX1 and executes CS as described above, and unless it can confirm that there is no interference on that channel, it cannot set the modulation and transmitting unit TX1 to that channel and perform the transmission operation [Ministry of Posts and Telecommunications Notification No. 49 of 1989, Ministry of Internal Affairs and Communications Notification No. 308 of 2021, and (3) Carrier Sense, pages 1-10 of Volume 1 in the above non-patent document 1].

[0128] Figure 30 shows a state in which the receiving and demodulating unit RX1-CH21 of terminal 63 has performed CS on the currently set channel CH21 (which is also the network channel), which was the previous communication channel, but interference has occurred. Since terminal 63 cannot transmit on CH21, it switches the receiving and demodulating unit RX1 to the frequency control channel CH31 to perform CS.

[0129] If there is no interference with the CS of CH31, terminal 63 activates modulation transmission unit TX1 on frequency control channel CH31 and transmits G-ID and CH-CCR (the designated change channel is CH28) as shown in FIG. Meanwhile, the other terminals 61, 62, 64, 65 receive and demodulate the G-ID and CH-CCR during the scanning stage of CH31 in the cyclic scanning of the receiving and demodulating unit RX1-SCAN, and change the communication channel from CH21 to the designated destination channel, CH28, based on the fact that the G-ID is an identification signal of the group to which the terminal belongs and that the CH-CCR is a channel change request accompanied by a specification of the destination channel.

[0130] As a result, as shown in Figure 32, the communication channel of all terminals 61 to 65 is changed to CH28 and the network channel transitions to CH28, and just as in the case of CH21 before interference (Figures 28 and 29), each terminal 61 to 65 can appropriately activate the modulation transmission unit TX1-CH28 and transmit call signals to other terminals. In this embodiment, CH-CCR is used instead of CCR used in the first and second embodiments. The reason is that in the first and second embodiments, the destination channel information can be indicated by the transmission channel, whereas in this embodiment, the frequency control channel CH31 is used to transmit the control signal, and therefore the destination channel must be indicated as an information signal.

[0131] By the way, at the stage in Figure 31, i.e., at the stage when terminal 63 transmits G-ID and CH-CCR to other terminals 61, 62, 64, 65 on CH28, if any of terminals 61, 62, 64, 65 happens to be out of range or has its power turned off, that terminal will naturally not be able to receive the G-ID and CH-CCR and will not be able to respond to the change in network channel. For example, Figure 33 shows a case where terminal 65 is out of range at the stage shown in Figure 31. Terminals 61, 62, and 64 are able to receive G-DI and CH-CCR from terminal 63 using the receiving and demodulating unit RX1-SCAN and change their own communication channel to CH28. However, terminal 65 misses this opportunity, and as shown in Figure 34, only terminal 65 remains on CH21 and becomes an out-of-range terminal. Therefore, even if the terminal 65 returns to the service area or is powered on, it cannot recover communications with the other terminals 61 to 64 and cannot return to the network.

[0132] In this case, terminals 61 to 64 cannot recognize that terminal 65 has been deviated from the network simply because there continues to be no calls from terminal 65. Also, even though the currently set channel for terminal 65 remains CH21 and it continues to be the case that it is not receiving calls from other terminals 61 to 64, in a network with not many calls it will take a considerable amount of time before it recognizes that it has been deviated from the network.

[0133] Therefore, the wireless communication device in this embodiment is applied to terminals 61 to 65 in the group wireless communication network, so that a terminal that has strayed can always automatically return to the network and regain a communicative state simply by returning to the range or turning the power back on while in range.

[0134] First, the wireless communication device of this embodiment (FIG. 1) executes the procedure shown in FIG. 35 in the group wireless communication mode. First, when the group wireless communication mode is set from the operation unit 19, the system control unit 10 resets the counter 21 and the memory 22 (S91), and then checks whether the modulation transmission unit TX1 of the own terminal has transmitted a G-ID and CH-CCR, and whether the reception and demodulation unit RX1-SCAN has received and demodulated the G-ID and CH-CCR from another terminal (S92, S93), and each time this is detected, the operation of incrementing the count value of the counter 21 by +1 is repeated (S94, S95 → S92).

[0135] Therefore, comparing the transitions in the network state (Figures 27 to 32), at the stage in Figure 31, terminal 63 transmits G-ID and CH-CCR using modulation transmission unit TX1-CH31, causing the count value of counter 21 of terminal 63 to be incremented by +1, and terminals 61, 62, 64, and 65 receive G-ID and CH-CCR using their respective receiving and demodulating units RX1-SCAN, causing the count value of counter 21 of each terminal 61, 62, 64, and 65 to be incremented by +1. However, as shown in FIG. 33, when terminal 63 transmits G-ID and CH-CCR using modulation transmission unit TX1-CH31, terminal 65, which is out of range or has its power turned off, is unable to receive the G-ID and CH-CCR, and therefore the count value of counter 21 is not incremented. That is, as shown in FIG. 34, the communication channel of terminal 65, which has become the deviated terminal, remains CH21, which is different from the communication channel CH28 of the other terminals 61, 62, 63, and 64, and the count value of counter 21 of terminal 65 is smaller than the count values ​​of counters 21 of the other terminals 61, 62, 63, and 64.

[0136] The wireless communication device of this embodiment, as a constituent terminal of a simplex wireless communication network, utilizes the difference in count values ​​that inevitably occurs in the execution procedure of Figure 35 when a stray terminal occurs, and executes the procedures shown in the flowcharts of Figures 36, 37A and 37B to automatically return the stray terminal, whether it is from this terminal or another party, to the network.

[0137] First, Figure 36 shows the procedure for the normal call transmission mode. When the PTT button on the operation unit 19 is turned ON to set the transmission mode in order to send a voice message from the reception mode to another terminal on the network (S100, S101), the reception demodulation unit RX1 executes CS on the currently set channel, and, provided that there is no interference, the modulation transmission unit TX1 transmits the G-ID, etc. (including the terminal's own ID in addition to the G-ID) and then modulates the carrier signal with the input voice signal from the microphone 15 to transmit the voice message (S102, S103). When the transmission is complete, the PTT button is turned OFF to cancel the transmission mode and transmit a communication end signal (S104, S105). This is a general operation executed as an interrupt process in the transmission mode of a wireless communication device, and does not include adding and transmitting count value information of memory 22 or detection time information to the end of the call signal as shown in steps S14 to S16 of FIG. 14 and steps S54 to S56 of FIG. 21 in embodiments 1 and 2.

[0138] FIG. 37A shows the operation procedure of the wireless communication device of this embodiment, and in the reception mode, an interval timer (3 minutes) is always set (S110, S111). Then, if the receiving and demodulating unit RX1 does not receive and demodulate the G-ID on either the currently set channel (the previous communication channel) or the frequency control channel CH31 within the 3-minute interval (S112:N → S115:N), a timeout is triggered and the transmission mode is automatically set to an interrupt, and the modulation transmitting unit TX1 is changed from the currently set channel to CH31, after which the G-ID, currently set channel information, and count value information of counter 21 are transmitted on the same channel CH31, and a communication end signal is transmitted, after which the modulation transmitting unit TX1 is returned from CH31 to the currently set channel and the interrupt processing is released (S116:Y → S117 to S119). This corresponds to a means for the terminal itself to inquire of the network side, since there is a possibility that a stray terminal has occurred in the network (particularly since there is a high possibility that the terminal itself is a stray terminal). Therefore, although not shown in FIG. 37A, when the timeout occurs, the system control unit 10 may detect this and execute a procedure for displaying on the liquid crystal display unit 20 that the device is in a deviated terminal state and / or a procedure for outputting a special electronic sound from the speaker 14 to notify the user of the terminal.

[0139] On the other hand, if the receiving and demodulating unit RX1 receives and demodulates a G-ID at the currently set channel (previous communication channel) stage during the cyclic scanning process within the 3-minute interval, the cyclic scanning is stopped on that currently set channel and the received and demodulated call signal is played back, and when the communication end signal is received and demodulated, the cyclic scanning returns to the original receiving mode (S112: Y → S113, S114 → S110). This procedure is based on the fact that the sender is another terminal that belongs to a group and is set to the same communication channel, and is the other terminal with which normal group communication should be performed. However, the currently set channel (communication channel) of the receiver terminal itself and the sender terminal is not necessarily a network channel, and both may be stray terminals.

[0140] Furthermore, if the receiving and demodulating unit RX1 receives and demodulates the G-ID at the frequency control channel CH31 stage during the cyclic scanning process within the 3-minute interval, this is reception related to information transmission based on the timeout by another terminal belonging to the group, or information transmission based on the comparison result of the count value information described below, and the channel information and count value information following the G-ID are received and demodulated and updated and stored in memory 22 (S115: Y → S120, S121).

[0141] Then, every time the channel information and count value information in the memory 22 are updated, the count value information (M times) of the counter 21 is compared with the updated count value information (N times) of the memory 22, and appropriate processing is performed based on the result (S121, S122). This is similar to steps S29 and S30 in FIG. 15A in the case of embodiment 1, and the count value information (N times) in memory 22 corresponds to the count value of the source terminal (i.e., a terminal that belongs to a group but has a different transmission / reception channel from the own terminal), and by comparing this with the count value information of the own terminal (M times), it is determined which terminal is estimated to have a higher probability of being a deviating terminal, and appropriate processing is performed based on the comparison result.

[0142] The comparison result and corresponding processing procedure in this embodiment are shown in FIG. 37B and are as follows. If M>N: The transmission mode is automatically set, an interrupt is generated, the modulation transmission unit TX1 is changed from the currently set channel to CH31, and the G-ID, currently set channel information, and count value information of the counter 21 (M times) are transmitted. Upon completion of this, the modulation transmission unit TX1 is changed from CH31 to the currently set channel and returns to the reception mode, thereby exiting from the interrupt processing (S131 → S132 to S136). If N>M: The currently set channel of the own device is changed to the channel related to the updated channel information stored in the memory 22, and the count value information (M times) of the counter 21 is rewritten to the count value information (N times) of the memory 22 (S131→S137 to S139). For M=N: No action is taken and the channel for the transmitter and receiver is maintained as is (S131→S140).

[0143] The above describes the function of a simplex group wireless communication network from the viewpoint of a single wireless communication device applied thereto. Next, we will explain how to return a stray terminal 65 to the group network from a network state in which the stray terminal 65 has occurred, as shown in FIG.

[0144] FIG. 38 relates to a case where a return sequence for the stray terminal 65 to the network is executed with the start event being the transmission of required information by any of the terminals 61 to 64 other than the stray terminal 65 (terminal 61 in this case). First, as shown in the figure, the network channel is CH28, but the communication channel of the stray terminal 65 is CH21. Here, terminal 61 executes steps S117 to S119 according to the condition of steps S111, S112 → S115 → S116: Y (timeout) in Figure 37A, temporarily switches modulation transmission unit TX1 from the currently set channel to CH31, and transmits the G-ID, currently set channel information of the own device, and count value information of counter 21.

[0145] In response to this, the deviating terminal 65 executes S115:Y → S120 to S122 in Figure 37A, and when the G-ID, etc. are received and demodulated during the scanning process of CH31 in the cyclic scanning [(1) in Figure 26] that prioritizes the frequency control channel CH31 of the receiving and demodulating unit RX1-SCAN, the scanning operation on CH31 is stopped, the channel information and count value information are received and demodulated, and these are updated and stored in the memory 22, and the count value information (M) of the counter 21 of the own terminal is compared with the count value information (N) on the terminal 61 side in the memory 22. The comparison result is that N>M because M is the count value of the stray terminal 65, so in step S122, the stray terminal 65 executes steps S131 → S137 to S139 of Figure 37B, the currently set channel is changed from CH21 to CH28, and the count value information (M) of the counter 21 of the own terminal is also rewritten to the count value (N) in memory 22.

[0146] For terminals 62, 63, and 64, S115 → S120 to S122 are executed to similarly compare the count value information (M) of counter 21 of the own device with the count value information (N) of terminal 61 in memory 22. However, since the communication channel between terminal 61 and terminals 62, 63, and 64 is network channel CH28, in step S122, the process goes to step S131 → S140 in Figure 37B, no corresponding processing is performed, and the status quo is maintained. As a result, as shown in FIG. 40, the currently set channel (communication channel) of all the terminals 61 to 65 is set to the network channel CH28, and the count value information of each of the terminals 61 to 65 is also complete.

[0147] On the other hand, Figure 39 relates to a case in which the sequence for returning the stray terminal 65 to the network is executed, with the stray terminal 65 transmitting the required information as the initiating event. In actual operation, this case is thought to be more common than the case of Figure 38. As shown in the figure, the network channel is CH28, and the communication channel of the stray terminal 65 is CH21, as in the case of FIG. Here, the stray terminal 65 executes steps S117 to S119 due to the condition of steps S111, S112 → S115 → S116: Y (timeout) in Figure 37A, temporarily switches the modulation transmission unit TX1 from the currently set channel to CH31, and transmits the G-ID, currently set channel information of the own terminal, and count value information of the counter 21.

[0148] In response to this, terminals 61-64 execute steps S115 → S120-S122 in Figure 37A, and when the G-ID, etc. are received and demodulated during the scanning process of CH31 in the cyclic scanning [Figure 26 (3)] that prioritizes CH31 by the receiving and demodulating unit RX1-SCAN, the scanning operation on CH31 is stopped, the channel information and count value information are received and demodulated, and these are updated and stored in memory 22, and the count value information (M) of the counter 21 of the own terminal is compared with the count value information (N) of the deviated terminal 65 in memory 22, and the corresponding processing is performed. 37B in step S122 of Fig. 37A, the modulation transmission unit TX1 temporarily switches from the currently set channel to CH31, and transmits the G-ID, the currently set channel information of the own device, and the count value information of the counter 21. That is, in response to the transmission of the own device information from the deviating terminal 65, the terminals 61 to 64 conversely transmit their own device information. However, in this case, transmissions by terminals 61 to 64 on CH31 compete with each other, so that only one of the terminals with which CS is established first (hereinafter, referred to as terminal 6X) can transmit.

[0149] On the other hand, the stray terminal 65 executes steps S115 → S120 to S122 in Figure 37A in response to the information transmission from terminal 6X, and in a similar procedure to that executed by terminals 61 to 64 above, receives and demodulates the channel information and count value information on the terminal 6X side, updates and stores them in memory 22, and compares the count value information (M) of its own counter 21 with the count value information (N) in memory 22 to perform corresponding processing. Therefore, the comparison result is that N>M, since M is the count value information in the stray terminal 65, and the stray terminal 65 executes steps S131 → S137 to S139 in FIG. 37B at step 122 in FIG. 37A, and the currently set channel CH21 is changed to the channel indicated by the channel information in memory 22 (currently set channel CH28 on the terminal 5X side), thereby allowing the terminal 65 to return from the stray state to the group network, and the count value information (M) of the counter 21 is also rewritten to the count value information (N) on the terminal 6X side in memory 22. As a result, as shown in FIG. 40, the currently set channel (communication channel) of all the terminals 61 to 65 is set to the network channel CH28, and the count value information of each of the terminals 61 to 65 is also complete.

[0150] <<Embodiment 4>> As in the third embodiment, this embodiment relates to a group wireless communication network system having the wireless communication device of FIG. 1 and its constituent terminals, and assumes a simplex group wireless communication network consisting of five terminals 61 to 65 as shown in FIG. 27. The five channels selected as available for use in the network in this embodiment and the cyclic scanning conditions of the receiving and demodulating unit RX1-SCAN in each of the terminals 61 to 65 are also the same as those in the third embodiment. The causes of the occurrence of stray terminals in this network are also similar to those explained in the third embodiment with reference to FIGS.

[0151] The difference between the wireless communication device of this embodiment and the wireless communication device of embodiment 3 is that, as a constituent terminal of a group wireless communication network, embodiment 3 uses the magnitude relationship of the count value information of the number of times of transmission and reception of G-ID and CH-CCR as a comparison factor for the estimated probability of being a deviant terminal, whereas embodiment 3 uses the order of the latest detection time information related to transmission and reception of G-ID and CH-CCR as a comparison factor. This is based on the fact that a terminal with a later most recent transmission / reception time of the G-ID and CH-CCR has been in the network for a longer period of time, and therefore the estimated probability of it being a stray terminal can be considered to be lower.

[0152] Therefore, in the wireless communication device of embodiment 3, Figure 35 shows a procedure for detecting the transmission and reception of G-ID and CH-CCR and updating and storing the count value information of the number of times this occurs, while in this embodiment, Figure 41 shows a procedure for detecting the transmission and reception of G-ID and CH-CCR and updating and storing the detection time information. Specifically, when the group wireless communication mode is set from the operation unit 19, the system control unit 10 resets the memory 22 (S151), and then detects whether the modulation transmission unit TX1 of the own terminal has transmitted a G-ID and CH-CCR, and whether the reception / demodulation unit RX1-CH31 has received and demodulated the G-ID and CH-CCR from another terminal (S152, S153).Each time such detection is made, the system control unit 10 repeats the operation of updating and storing the time information of the built-in timer in the [A] area of ​​the memory 22 (S154, S155 → S152).

[0153] Furthermore, according to the method of updating and storing the transmission and reception times of the G-ID and CH-CCR in this embodiment, as in the case of embodiment 3, in a terminal that is capable of communicating in the group wireless communication network, the latest time information relating to the change of network channel based on the transmission and reception of the G-ID and CH-CCR is always updated and stored in the [A] area of ​​memory 22. However, in a stray terminal that is out of range or has its power turned off when the G-ID and CH-CCR are transmitted or received, the record will no longer contain the latest time information.

[0154] The wireless communication device of this embodiment, as a constituent terminal of a simplex wireless communication network, utilizes the difference in time information in area [A] of memory 22 that inevitably occurs in the execution procedure of Figure 41 when a stray terminal occurs, and executes the procedures shown in the flowcharts of Figures 42, 43A and 43B to automatically return the stray terminal, whether it is from this terminal or another party, to the network.

[0155] FIG. 42 shows the procedure for the normal call transmission mode, and although it has the same content as FIG. 36, it is included for the sake of functional integration. When the PTT button on the operation unit 19 is turned ON to set the transmission mode in order to send a voice message from the reception (standby) mode to another terminal on the network (S160, S161), the reception demodulation unit RX1 executes CS on the currently set channel, and, provided there is no interference, the modulation transmission unit TX1 transmits the G-ID, etc., and then modulates the carrier signal with the input voice signal from the microphone 15 to transmit the voice message (S162, S163).When the transmission is complete, the PTT button is turned OFF to cancel the transmission mode and transmit a communication end signal (S164, S165). This is a general operation executed as an interrupt process in the transmission mode of a wireless communication device, and as in the case of embodiment 3, the count value of memory 22 and detection time information are not added and transmitted to the end of the call signal as in embodiments 1 and 2.

[0156] FIG. 43A shows the operation procedure of the wireless communication device of this embodiment, and in the reception mode, an interval timer (3 minutes) is always set (S170, S171). Then, if the receiving and demodulating unit RX1 does not receive and demodulate the G-ID on either the currently set channel (the previous communication channel) or the frequency control channel CH31 within the 3-minute interval (S172:N → S175:N), the transmission mode is automatically set due to a timeout, an interrupt is generated, and the modulation transmitting unit TX1 is changed from the currently set channel to CH31, after which the G-ID, currently set channel information, and detection time information in the [A] area of ​​memory 22 are transmitted on the same channel CH31, and a communication end signal is transmitted, after which the modulation transmitting unit TX1 is returned from CH31 to the currently set channel and the interrupt processing is released (S176:Y → S177~S179). This corresponds to a means for the terminal itself to inquire of the network side, since there is a possibility that a stray terminal has occurred in the network (particularly since there is a high possibility that the terminal itself is a stray terminal). Therefore, although not shown in FIG. 43A, when the timeout occurs, the system control unit 10 may detect this and execute a procedure for displaying on the liquid crystal display unit 20 that the device is in a deviated terminal state and / or a procedure for outputting a special electronic sound from the speaker 14 to notify the user of the terminal.

[0157] On the other hand, if the receiving and demodulating unit RX1 receives and demodulates a G-ID at the currently set channel (previous communication channel) stage during the cyclic scanning process within the 3-minute interval, the cyclic scanning is stopped on that currently set channel and the received and demodulated call signal is played back, and when the communication end signal is received and demodulated, the cyclic scanning returns to the original receiving mode (S172:Y → S173, S174 → S170). This procedure is based on the fact that the sender is another terminal that belongs to a group and is set to the same communication channel, and is the other terminal with which normal group communication should be performed. However, the currently set channel (communication channel) of the receiver terminal itself and the sender terminal is not necessarily a network channel, and both may be stray terminals.

[0158] Furthermore, if the receiving and demodulating unit RX1 receives and demodulates the G-ID at the frequency control channel CH31 stage during the cyclic scanning process within the 3-minute interval, this is reception related to information transmission based on the timeout by other terminals belonging to the group, or information transmission based on the comparison result of the detection time information described below, and the channel information and detection time information following the G-ID are received and demodulated and updated and stored in the [B] area of ​​memory 22 (S175:Y → S180, S181).

[0159] Then, each time the channel information and detection time information in memory 22 are updated, the detection time information (T1) in area [A] of memory 22 is compared with the updated detection time information (T2) in area [B] of memory 22, and appropriate processing is performed based on the results (S181, S182). This is similar to steps S69 and S70 in Figure 22A in the case of embodiment 2, and the detection time information (T2) in the [B] area of ​​memory 22 corresponds to the detection time information of the source terminal (i.e., a terminal that belongs to a group but has a different transmission and reception channel from the terminal itself), and by comparing this with the detection time information (T1) of the terminal itself, it is determined which terminal is estimated to have a higher probability of being a deviating terminal, and appropriate processing is performed based on the comparison result.

[0160] The comparison result and corresponding processing procedure in this embodiment are shown in FIG. 43B and are as follows. If T1 is later than T2: The transmission mode is automatically set, an interrupt is generated, the modulating transmission unit TX1 is changed from the currently set channel to CH31, and the G-ID, currently set channel information, and detection time information (T1) in the [A] area of ​​memory 22 are transmitted. Upon completion of this, the modulating transmission unit TX1 is changed from CH31 to the currently set channel and returned to the receiving mode, thereby exiting from the interrupt processing (S191 → S192 to S196). If T2 is later than T1: The currently set channel of the own device is changed to the channel related to the updated channel information stored in memory 22, and the detection time information (T1) in the [A] area of ​​memory 22 is rewritten to the detection time information (T2) in the [B] area of ​​memory 22 (S191 → S197 to S199). When T1 and T2 are simultaneous (T1=T2): No action is taken and the currently set channel is maintained as is (S191→S200).

[0161] The above describes the function of a simplex group wireless communication network from the viewpoint of a single wireless communication device applied thereto. Next, we will explain how to return a stray terminal 65 to the group network from a network state in which the stray terminal 65 has occurred, as shown in FIG.

[0162] FIG. 44 relates to a case where a return sequence for the stray terminal 65 to the network is executed with the start event being the transmission of required information by any of the terminals 61 to 64 other than the stray terminal 65 (terminal 61 in this case). First, as shown in the figure, the network channel is CH28, but the communication channel of the stray terminal 65 is CH21. Here, terminal 61 executes steps S177 to S179 according to the condition of steps S171, S172 → S175 → S176: Y (timeout) in FIG. 43A, temporarily switches modulation transmission unit TX1 from the currently set channel to CH31, and transmits the G-ID, the currently set channel information of the terminal itself, and the detection time information in the [A] area of ​​memory 22.

[0163] In response to this, the stray terminal 65 executes S175 → S180 to S182 in Figure 43A, and when the G-ID, etc. are received and demodulated during the scanning process of CH31 in the cyclic scanning [(1) in Figure 26] that prioritizes frequency control channel CH31 of the receiving and demodulating unit RX1-SCAN, the scanning operation on CH31 is stopped, the channel information and detection time information are received and demodulated, and these are updated and stored in the [B] area of ​​memory 22, and the detection time information (T1) in the [A] area of ​​the memory 22 of the own terminal is compared with the detection time information (T2) in the [B] area. The comparison result shows that T1 is the detection time information at the deviating terminal 65 and T2 is the detection time information at terminal 61, resulting in a relationship of "T2 is later than T1". Therefore, in step S182, the deviating terminal 65 executes steps S191 → S197 to S199 of Figure 43B, the currently set channel is changed from CH21 to CH28, and the detection time information (T1) in the [A] area of ​​the memory 22 of the own terminal is rewritten to the detection time information (T2) in the [B] area.

[0164] For terminals 62, 63, and 64, S175 → S180 to S182 are executed to similarly compare the detection time information (T1) in the [A] area of ​​memory 22 of the own terminal with the detection time information (T2) in the [B] area. However, since the communication channel between terminal 61 and terminals 62, 63, and 64 is network channel CH28, in step S182, the process goes to step S191 → S200 in Figure 43B, no corresponding processing is performed, and the status quo is maintained. As a result, the currently set channel (communication channel) of all the terminals 61 to 65 is set to the network channel CH28, and the count value information of each of the terminals 61 to 65 is also set.

[0165] On the other hand, Figure 45 relates to a case in which the return sequence of the stray terminal 65 to the network is executed, with the starting event being the transmission of required information by the stray terminal 65, and in actual operation, this case is thought to be more common than the case of Figure 44. As shown in the figure, the network channel is CH28, and the communication channel of the stray terminal 65 is CH21, as in the case of FIG. Here, the stray terminal 65 executes steps S177 to S179 due to the condition of steps S171, S172 → S175 → S176: Y (timeout) in Figure 43A, temporarily switches the modulation transmission unit TX1 from the currently set channel to CH31, and transmits the G-ID, the currently set channel information of the own terminal, and the detection time information in the [A] area of ​​memory 22.

[0166] In response to this, terminals 61 to 64 execute steps S175 → S180 to S182 in Figure 43A, and when the G-ID, etc. are received and demodulated during the scanning process of CH31 in the cyclic scanning [Figure 26 (3)] that prioritizes CH31 by the receiving and demodulating unit RX1-SCAN, the scanning operation on CH31 is stopped, the channel information and the detection time information of the deviating terminal 65 are received and demodulated, and these are updated and stored in the [B] area of ​​memory 22, and the detection time information (T1) in the [A] area of ​​memory 22 is compared with the detection time information (T2) in the [B] area. Since the comparison result is that "T1 is later than T2" because T2 is the detection time information of the deviating terminal 65, the terminals 61 to 64 execute steps S191 → S192 to S196 in Fig. 43B in step S182, temporarily switch the modulation transmission unit TX1 from the currently set channel to CH31, and transmit the G-ID, the currently set channel information of the own terminal, and the detection time information. That is, in response to the transmission of the own terminal information from the deviating terminal 65, the terminals 61 to 64 return their own terminal information. However, in this case, transmissions by terminals 61 to 64 on CH31 compete with each other, so that only one of the terminals with which CS is established first (hereinafter, terminal 6X) can transmit.

[0167] On the other hand, in the stray terminal 65, steps S175 → S180 to S182 of FIG. 43A are executed in response to the transmission of the terminal's own information from terminal 6X, and in a similar procedure to that executed by terminals 61 to 64 above, the channel information and detection time information from terminal 6X are received and demodulated, and updated and stored in area [B] of memory 22, and the detection time information (T1) of the terminal's own terminal in area [A] of memory 22 is compared with the detection time information (T2) in area [B]. Thus, the comparison result is that T1 becomes the detection time information in the stray terminal 65, resulting in a relationship of "T2 is later than T1", and steps S191 → S197 to S199 in Figure 43B are executed in the stray terminal 65, and the currently set channel CH21 is changed to the channel indicated by the channel information in memory 22 (currently set channel CH28 on the terminal 6X side), thereby enabling the terminal to return from the stray state to the group network, and at the same time, the detection time information (T1) of the terminal's own terminal in the [A] area of ​​memory 22 is also rewritten to the detection time information (T2) on the terminal 6X side. [Industrial Applicability]

[0168] The present invention can be used in a simplex group wireless communication network and the terminals that constitute the network. [Explanation of symbols]

[0169] 10...system control unit, 11...antenna, 12...amplifier, 13...speaker, 15...microphone, 16...amplifier, 17...amplifier, 18...antenna, 19...operation unit, 20...liquid crystal display unit, 21...counter, 22...memory, RX1...receiving and demodulating unit, TX1...modulating and transmitting unit, 51-55...network constituent terminals (wireless communication devices), 61-65...network constituent terminals (wireless communication devices).

Claims

1. In a group wireless communication network system, a wireless communication device which is a terminal having a common configuration in a simplex group wireless communication network comprises a modulation transmission unit and a reception / demodulation unit which cyclically scans all channels available in the network, and one terminal transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CCR") on a designated change destination channel, while another terminal receives the G-ID and the CCR (hereinafter both signals are collectively referred to as "G-ID-CCR") during the scanning stage of the designated change destination channel by the reception / demodulation unit, thereby changing the network channel, Each terminal of the network has a function A which counts the number of times the G-ID / CCR is transmitted and received in an incremental manner and updates and stores the count value information, a function B which, in a transmission mode, transmits the G-ID and a call signal together with the count value information of the own terminal which has been updated and stored by the function A, through a currently set channel which is the channel used in the previous communication, and a function B which, in a reception mode, when a signal including the G-ID is received and demodulated during a scanning stage of the currently set channel, receives and demodulates the call signal and plays the audio with the cyclic scanning temporarily stopped on the same channel, and when a signal including the G-ID is received and demodulated during a scanning stage of an available channel other than the currently set channel, receives and demodulates the call signal and plays the audio with the cyclic scanning temporarily stopped on the same channel. a function C for detecting count value information at a source terminal and updating and storing the same together with receiving channel information; a function D for comparing the count value information (M times) of the device itself updated and stored by the function A with the count value information (N times) of the source terminal updated and stored by the function C each time information is updated and stored by the function C; and a function E for automatically setting a transmission mode of the currently set channel and transmitting the G-ID and the count value information (M times) of the device itself when the result of the comparison by the function D is M>N, changing the currently set channel to a channel indicated by the receiving channel information updated and stored by the function C, and rewriting the count value information (M times) of the device itself to the count value information (N times) of the source terminal when M=N, and maintaining the current state without executing anything when M=N. A group wireless communication network system characterized in that each terminal in the network is executing function A, and when any one terminal executes function B, the other terminals execute functions C, D, and E, and when M>N occurs during the execution of function D, the other terminal transmits information using function E, and the one terminal executes functions C, D, and E.

2. 2. The group wireless communication network system according to claim 1, wherein the count value information of the own terminal in function B of the network is transmitted by adding the count value information to the end of a voice signal portion in a communication frame.

3. In a group wireless communication network system, a wireless communication device which is a terminal having a common configuration in a simplex group wireless communication network comprises a modulation transmission unit and a reception / demodulation unit which cyclically scans all channels available in the network, and one terminal transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CCR") on a designated change destination channel, while another terminal receives the G-ID and the CCR (hereinafter both signals are collectively referred to as "G-ID-CCR") during the scanning stage of the designated change destination channel by the reception / demodulation unit, thereby changing the network channel, Each terminal of the network has a function A which updates and stores the detection time information when transmission or reception of the G-ID / CCR is detected, a function B which, in a transmission mode, transmits the G-ID and a call signal together with the detection time information of the own terminal which has been updated and stored by the function A, by using a currently set channel which is the channel used in the previous communication, and a function B which, in a reception mode, when a signal including the G-ID is received and demodulated during a scanning stage of the currently set channel, receives and demodulates the call signal and plays the audio with the cyclic scanning temporarily stopped on the same channel, while when a signal including the G-ID is received and demodulated during a scanning stage of an available channel other than the currently set channel, receives and demodulates the call signal and plays the audio with the cyclic scanning temporarily stopped on the same channel. a function C for detecting detection time information at a transmission source terminal and updating and storing the same together with reception channel information; a function D for comparing the detection time information (T1) of the own device updated and stored by the function A with the detection time information (T2) at the transmission source terminal updated and stored by the function C each time the information is updated and stored by the function C; and a function E for automatically setting the transmission mode of the currently set channel and transmitting the G-ID and the detection time information (T1) of the own device when the comparison result by the function D shows that T1 is later than T2, changing the currently set channel to a channel indicated by the reception channel information updated and stored by the function C, and rewriting the detection time information (T1) of the own device to the detection time information (T2) at the transmission source terminal, and for maintaining the current state without executing anything when T1 and T2 are simultaneous, A group wireless communication network system characterized in that each terminal in the network is executing function A, and when any one terminal executes function B, the other terminals execute functions C, D, and E, and when T1 is later than T2 in the execution of function D, the other terminal transmits information using function E, and the one terminal executes functions C, D, and E.

4. 4. The group wireless communication network system according to claim 3, wherein the detection time information of the terminal in function B of the network is transmitted by adding the detection time information to the end of a voice signal portion in a communication frame.

5. A group wireless communication network system as described in claim 1, 2, 3 or 4, in which the receiving and demodulating unit uses a method of circular scanning of all channels available in the network, in which the scanning time for the currently set channel in the wireless communication device is set longer than the scanning time for each of the other channels.

6. 6. A group wireless communication network system according to claim 5, wherein the method of circular scanning of all channels available in the network by the receiving and demodulating unit is a method in which the currently set channel and one other channel are alternately scanned for the same period of time, and different channels are selected in sequence for the one other channel.

7. A group wireless communication network system in which a wireless communication device, which is a terminal having a common configuration in a simplex group wireless communication network, comprises a modulation transmission unit and a reception / demodulation unit which cyclically scans a frequency control channel and all channels available in the network, and one terminal transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CH-CCR") with a designation of a change destination channel on the frequency control channel, while another terminal receives the G-ID and the CH-CCR (hereinafter both signals are collectively referred to as "G-ID-CH-CCR") during the scanning stage of the frequency control channel by the reception / demodulation unit, thereby changing the network channel, Each terminal of the network has a function A which counts the number of times the G-ID-CH-CCR is transmitted and received in an incremental manner and updates and stores the count value information; a function B which sets a normal transmission mode in response to a predetermined instruction operation and transmits the G-ID and a speech signal; and a function C which, in a reception mode, when the reception demodulation unit does not detect a reception demodulated signal including the G-ID for a predetermined period of time, automatically sets a transmission mode in which the transmission modulation unit is temporarily switched from a currently set channel, which is a channel used in the previous communication (excluding a frequency control channel), to the frequency control channel, and transmits the G-ID, the currently set channel information, and the count value information of the own terminal which has been updated and stored by the function A, in a state in which the cyclic scanning is temporarily stopped in the reception mode, when the reception demodulation unit receives and demodulates a signal including the G-ID on the currently set channel, and receives and demodulates the speech signal to play back the audio on the same channel, while a function D for detecting and updating currently set channel information and count value information at the transmitting terminal included in the demodulated signal while temporarily stopping the cyclic scanning on the channel when the signal is received and demodulated; a function E for comparing the count value information (M times) of the transmitting terminal updated and stored by the function A with the count value information (N times) at the transmitting terminal updated and stored by the function D each time the information is updated and stored by the function D; and a function F for automatically setting a transmission mode in which the modulation transmission unit is temporarily changed from the currently set channel to the frequency control channel when the result of the comparison by the function E is M>N, and transmitting the G-ID and the currently set channel information and count value information (M times) of the transmitting terminal; and for changing the currently set channel of the transmitting terminal to the currently set channel of the transmitting terminal when N>M, and rewriting the count value information (M times) of the transmitting terminal to the count value information (N times) at the transmitting terminal; and for maintaining the current state without executing anything when M=N. A group wireless communication network system characterized in that each terminal in the network is executing function A and also executing function B as appropriate, and in response to execution of function C by any one terminal, the other terminals execute functions D, E, and F, and in that case, when M>N occurs during the execution of function E, the other terminal transmits information using function F, and the one terminal executes functions D, E, and F.

8. 8. A group wireless communication network system as described in claim 7, wherein function C of each terminal of the network further comprises, when the receiving and demodulating unit does not detect a receiving and demodulating signal including the G-ID for a predetermined time, an operation of displaying on a display means that the terminal is likely to be in a deviated terminal state and / or an operation of notifying that the terminal is in said state by outputting a predetermined sound from an audio output means.

9. A group wireless communication network system in which a wireless communication device, which is a terminal having a common configuration in a simplex group wireless communication network, comprises a modulation transmission unit and a reception / demodulation unit which cyclically scans a frequency control channel and all channels available in the network, and one terminal transmits a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CH-CCR") with a designation of a change destination channel on the frequency control channel, while another terminal receives the G-ID and the CH-CCR (hereinafter both signals are collectively referred to as "G-ID-CH-CCR") during the scanning stage of the frequency control channel by the reception / demodulation unit, thereby changing the network channel, Each terminal of the network has a function A for updating and storing detection time information when transmission / reception of the G-ID·CH-CCR is detected, a function B for setting a normal transmission mode by a predetermined instruction operation and transmitting the G-ID and a speech signal, and a function C for, in a reception mode, when the reception demodulation unit does not detect a reception demodulated signal including the G-ID for a predetermined time, automatically setting a transmission mode in which the transmission modulation unit is temporarily switched from a currently set channel, which is a channel used in the previous communication (excluding the frequency control channel), to the frequency control channel, and transmitting the G-ID, the currently set channel information, and the detection time information updated and stored by the function A, and a function C for, in a reception mode, when the reception demodulation unit receives and demodulates a signal including the G-ID in a scanning stage of the currently set channel, receiving and demodulating a speech signal and playing back the audio in a state where the cyclic scanning is temporarily stopped on the same channel, while when the reception demodulation unit receives and demodulates a signal including the G-ID in a scanning stage of the frequency control channel, In this case, the present invention is provided with a function D for detecting and updating currently set channel information and count value information at the transmission source terminal contained in the demodulated signal while temporarily stopping the cyclic scanning on the channel, a function E for comparing the detection time information (T1) of the own device updated and stored by the function A with the detection time information (T2) at the transmission source terminal updated and stored by the function D every time the information is updated and stored by the function D, and a function F for automatically setting a transmission mode in which the modulation transmission unit is temporarily changed from the currently set channel to the frequency control channel when T1 is later than T2 as a result of the comparison by the function E, to transmit the G-ID, the currently set channel information of the own device, and the detection time information (T1), and for changing the currently set channel of the own device to the currently set channel of the transmission source terminal when T2 is later than T1, and for rewriting the detection time information (T1) of the own device to the detection time information (T2) at the transmission source terminal, and for maintaining the current status without executing anything when T1 and T2 are simultaneous. A group wireless communication network system characterized in that each terminal in the network is executing function A and also executing function B as appropriate, and when any one terminal executes function C, the other terminal executes functions D, E, and F, and when T1 is later than T2 in the execution of function E, the other terminal transmits information using function F, and the one terminal executes functions D, E, and F.

10. 10. A group wireless communication network system as described in claim 9, wherein function C of each terminal of the network further comprises, when the receiving and demodulating unit does not detect a receiving and demodulating signal including the G-ID for a predetermined time, an operation of displaying on a display means that the terminal is likely to be in a deviated terminal state and / or an operation of notifying the terminal of said state by outputting a predetermined sound from an audio output means.

11. 11. A group wireless communication network system according to claim 7, 8, 9 or 10, wherein the method of circular scanning of the frequency control channel and all channels available in the network by the receiving and demodulating unit is a method in which the scanning time for the frequency control channel is set longer than the scanning time for each of the other channels.

12. 12. The group wireless communication network system according to claim 11, wherein the cyclic scanning method of the frequency control channel and all channels available in the network by the receiver / demodulator is a method in which the frequency control channel and another channel are alternately scanned for the same period of time, and different channels are selected in sequence for the other channel.

13. A wireless communication device as a terminal having a common configuration in a simplex group wireless communication network, comprising a modulation transmission unit and a reception / demodulation unit which cyclically scans all channels available in the network, said modulation transmission unit transmitting a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CCR") on a designated change destination channel, and receiving said G-ID and said CCR (both signals collectively referred to as "G-ID-CCR" hereinafter) transmitted on a designated change destination channel from another terminal during the cyclic scanning process of said reception / demodulation unit, thereby enabling a change of network channel, a count storage means for counting the number of times the G-ID and CCR are transmitted and received in an incrementing manner and updating and storing the count value information; an information transmitting means for transmitting, in a transmission mode, the G-ID and a call signal together with the count value information of the own device which is updated and stored in the count storage means, through a currently set channel which is a channel used in the previous communication; a speech reproduction means for receiving and demodulating a speech signal and reproducing the speech in a state where the cyclic scanning of the currently set channel is temporarily stopped when a signal including the G-ID is received and demodulated in a receiving mode during a scanning step of the currently set channel; In a reception mode, when a signal including the G-ID is received and demodulated during a scanning stage of an available channel other than the currently set channel, an information detection means detects count value information at the transmission source terminal included in the demodulated signal together with the reception channel information while temporarily stopping the cyclic scanning of the channel. an information storage means for updating and storing the reception channel information and the count value information detected by the information detection means; a comparison means for comparing the count value information (M times) of the own device updated and stored by the count storage means with the count value information (N times) of the transmission source terminal updated and stored by the information storage means each time the information is updated and stored by the information storage means; a processing means for automatically setting the transmission mode of the currently set channel to transmit the G-ID and the count value information (M times) of the count storage means when the result of the comparison by the comparison means is M>N, changing the currently set channel to a channel indicated by the receiving channel information of the information storage means when N>M, and rewriting the count value information (M times) of the count storage means to the count value information (N times) of the information storage means when M=N, and maintaining the current state without performing any operation; A wireless communication device comprising:

14. A wireless communication device as a terminal having a common configuration in a simplex group wireless communication network, comprising a modulation transmission unit and a reception / demodulation unit which cyclically scans all channels available in the network, said modulation transmission unit transmitting a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CCR") on a designated change destination channel, and receiving said G-ID and said CCR (both signals collectively referred to as "G-ID-CCR" hereinafter) transmitted on a designated change destination channel from another terminal during the cyclic scanning process of said reception / demodulation unit, thereby enabling a change of network channel, a time storage means for updating and storing detection time information when the transmission / reception of the G-ID / CCR is detected; an information transmitting means for transmitting, in a transmission mode, the G-ID and a call signal together with the detection time information of the own device which is updated and stored in the time storage means, through a currently set channel which is a channel used in the previous communication; a speech reproduction means for receiving and demodulating a speech signal and reproducing the speech in a state where the cyclic scanning of the currently set channel is temporarily stopped when a signal including the G-ID is received and demodulated in a receiving mode during a scanning step of the currently set channel; In a reception mode, when a signal including the G-ID is received and demodulated during a scanning stage of an available channel other than the currently set channel, an information detection means detects detection time information at the transmission source terminal included in the demodulated signal together with the reception channel information while temporarily stopping the cyclic scanning of the channel. an information storage means for updating and storing the reception channel information and the detection time information detected by the information detection means; a comparison means for comparing the detection time information (T1) at the own device updated and stored by the time storage means with the detection time information (T2) at the transmission source terminal updated and stored by the information storage means each time the information is updated and stored by the information storage means; a response processing means for automatically setting the transmission mode of the currently set channel to a channel indicated by the receiving channel information of the information storage means when T1 is later than T2 as a result of the comparison by the comparison means, and rewriting the detected time information (T1) of the time storage means to the detected time information (T2) of the information storage means when T1 and T2 are simultaneous, and for maintaining the current state without carrying out any action; A wireless communication device comprising:

15. A wireless communication device as a terminal having a common configuration in a simplex group wireless communication network, comprising a modulation transmission unit and a reception / demodulation unit which cyclically scans a frequency control channel and all channels available in the network, said modulation transmission unit transmitting a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CH-CCR") accompanied by a designation of a channel to be changed to from said frequency control channel, and receiving said G-ID and said CH-CCR (both signals collectively referred to as "G-ID-CH-CCR") transmitted from another terminal on said frequency control channel during the cyclic scanning process of said reception / demodulation unit, thereby enabling a change of network channel, a count storage means for counting the number of times the G-ID·CH-CCR is transmitted and received in an incrementing manner and updating and storing the count value information; A normal transmission means for setting a normal transmission mode in response to a predetermined instruction operation and transmitting the G-ID and a call signal; an information transmitting means for automatically setting a transmission mode in which the transmission modulation means is temporarily switched from a currently set channel, which is a channel used in the previous communication (excluding a frequency control channel), to the frequency control channel when the reception demodulation unit does not detect a reception demodulated signal including the G-ID for a predetermined time in a reception mode, and transmitting the G-ID, currently set channel information, and count value information of the count storage means; a speech reproduction means for receiving and demodulating a speech signal and reproducing the speech in a state where the cyclic scanning is temporarily stopped on the currently set channel when the reception and demodulation unit receives and demodulates a signal including the G-ID on the currently set channel in a reception mode; In a reception mode, when a signal including the G-ID is received and demodulated on the frequency control channel, an information detection means detects currently set channel information and count value information at the transmission source terminal included in the demodulated signal while temporarily stopping the cyclic scanning on the same channel; an information storage means for updating and storing currently set channel information and count value information at the source terminal detected by the information detection means; a comparison means for comparing the count value information (M times) of the own device updated and stored by the count storage means with the count value information (N times) of the transmission source terminal updated and stored by the information storage means each time the information is updated and stored by the information storage means; a processing means for temporarily changing the transmission mode of the modulation transmission unit from the currently set channel to a frequency control channel when M>N is the result of the comparison by the comparison means, and transmitting the G-ID, the currently set channel information, and the count value information (M times) of the count storage means when N>M, changing the currently set channel to a channel indicated by the receiving channel information of the information storage means, and rewriting the count value information (M times) of the count storage means to the count value information (N times) of the information storage means when M=N, and performing nothing and maintaining the current state; A wireless communication device comprising:

16. A wireless communication device as a terminal having a common configuration in a simplex group wireless communication network, comprising a modulation transmission unit and a reception / demodulation unit which cyclically scans a frequency control channel and all channels available in the network, said modulation transmission unit transmitting a group identification signal (hereinafter referred to as "G-ID") and a channel change request signal (hereinafter referred to as "CH-CCR") accompanied by a designation of a channel to be changed to from said frequency control channel, and receiving said G-ID and said CH-CCR (both signals collectively referred to as "G-ID-CH-CCR") transmitted from another terminal on said frequency control channel during the cyclic scanning process of said reception / demodulation unit, thereby enabling a change of network channel, a time storage means for updating and storing detection time information when the transmission / reception of the G-ID / CCR is detected; A normal transmission means for setting a normal transmission mode in response to a predetermined instruction operation and transmitting the G-ID and a call signal; an information transmitting means for automatically setting a transmission mode in which the transmission modulation means is temporarily switched from a currently set channel, which is a channel used in the previous communication (excluding a frequency control channel), to the frequency control channel when the reception demodulation unit does not detect a reception demodulated signal including the G-ID for a predetermined time in a reception mode, and transmitting the G-ID, currently set channel information, and detection time information of the time storage means; a speech reproduction means for receiving and demodulating a speech signal and reproducing the speech in a state where the cyclic scanning is temporarily stopped on the currently set channel when the reception and demodulation unit receives and demodulates a signal including the G-ID on the currently set channel in a reception mode; In a reception mode, when a signal including the G-ID is received and demodulated on the frequency control channel, an information detection means detects currently set channel information and detection time information at the transmission source terminal included in the demodulated signal while temporarily stopping the cyclic scanning on the same channel; an information storage means for updating and storing currently set channel information and detection time information of the transmission source terminal detected by the information detection means; a comparison means for comparing the detection time information (T1) at the own device updated and stored by the time storage means with the detection time information (T2) at the transmission source terminal updated and stored by the information storage means each time the information storage means updates and stores the information; a response processing means for, when the result of the comparison by the comparison means shows that T1 is later than T2, setting a transmission mode in which the modulation transmission unit is temporarily changed from the currently set channel to a frequency control channel, and transmitting the G-ID, the currently set channel information, and the detected time information (T1) of the time storage means, when T2 is later than T1, changing the currently set channel to a channel indicated by the receiving channel information of the information storage means, and rewriting the detected time information (T1) of the time storage means to the detected time information (T2) of the information storage means, and when T1 and T2 are simultaneous, executing nothing and maintaining the current state; A wireless communication device comprising:

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