Radio Relay System

Abstract

To continue continuous communication with only a small interruption without being subject to a restriction in a wireless relay system that cannot resume relay communication unless a predetermined transmission pause time is set when the relay of continuous communication exceeds a predetermined time limit. [Solution] The repeater 100 switches between two pairs of opposite waves. When relaying continuous communication on one pair of waves begins, a timer is started to measure the time limit of 3 minutes and 30 seconds before that (S217 → S222). When continuous communication exceeds 2 minutes 30 seconds, carrier sense for the other pair of waves is repeated. If a transmission stop or dead state occurs and the result of the most recent carrier sense at that time is an idle state, relaying on the currently used pair of waves is terminated and a beacon signal to switch to the other pair of waves is transmitted, causing communication terminals 201 and 202 to also set the other pair of waves to a use state (S223 to S230 → FIG. 5A). The pair of waves used is changed before the time limit, so the above restriction is not imposed.

Description

[Technical Field]

[0001] This standard for radio stations and radio equipment stipulates that when the continuous communication time reaches a predetermined time limit in relaying radio communication using a semi-duplex method, the communication must be terminated and a predetermined transmission pause must be set before the communication can be resumed. In this case, this standard stipulates that the radio relay system can avoid interruptions to continuous communication by avoiding the constraints without violating the provisions and intent of the standard. [Background technology]

[0002] Wireless communication devices that comply with the specified low-power standard are used for short-distance voice communication using the 400 MHz band, and are also license-free radio stations, so they are used outdoors at various construction sites such as building sites, and indoors at relatively large restaurants and spacious home improvement stores for business-related communication between employees.

[0003] On the other hand, wireless communication devices of this standard are limited to an antenna power of 10mW or less, so the communication distance is approximately 200m to 500m, and communication between different floors or when there is an obstruction in between often becomes difficult even over a short distance of less than 200m. To address the issue of communication distance, a method has been adopted in which wireless repeaters are installed in appropriate locations, effectively doubling the communication distance and ensuring stable communication.

[0004] Radio stations and radio equipment that comply with specific low-power standards are based on the established standards in Non-Patent Document 1 below. According to Volume 1 of the same document, for a communication system using a semi-duplex method for wireless communication terminals via a wireless repeater under conditions of a radio wave type such as F3E and an antenna power of 10mW or less, the upstream and downstream channels for the relayed communication shall use one of the pairs of waves given as channel numbers 1 to 18 in Table 3-2 (p1-5) and channel numbers 32 to 40 in Table 3-4 (p1-6) with a channel spacing of 12.5kHz. Furthermore, according to Part 2 of the same document (concerning the 4-level FSK digital modulation method), for a communication system using a semi-duplex method of a wireless communication terminal via a wireless repeater under the conditions of F1D / F1E wave type and antenna power of 10mW or less and 100mW or less (divided by frequency band), the upstream / downstream frequencies for the relayed communication shall use one of the paired waves given as channel numbers 39 to 73 in Table 3-3 (p2-7) and channel numbers 74 to 90 in Table 3-4 (p2-8) with a channel spacing of 6.25kHz.

[0005] On the other hand, radio equipment with the above antenna power is required to have a carrier sense function, and cannot transmit radio waves of that frequency (and in the case of half-duplex mode, the frequency in the paired wave relationship) unless it has confirmed that there are no radio waves from other radio stations with a received input power value of -96 dBm or more at the feeder line input point.The time required for this carrier sense to determine whether the frequency is free is 200 ms or more, and the response time is within 20 ms.

[0006] Incidentally, for radio stations and radio equipment that comply with specific low-power standards and have the function of automatically limiting communication time to within three minutes and not starting subsequent communication until two seconds have elapsed since the end of communication, carrier sense is not required within the communication time from the first transmission after carrier sense has been performed, and the line connection procedure in a communication system (calling station-relay station-called station) using a semi-duplex method for radio communication terminals via a radio repeater is as shown in Figure 8 [corresponding to Figure 3-7 (p2-19) in Volume 2 of Non-Patent Document 1 below]. It is also stipulated that if transmission stops or the dead state continues for more than two seconds, communication will be terminated.

[0007] The line connection procedure shown in Figure 8 shows a state in which, after a series of connection procedures involving initial carrier sensing, continuous relay communications are repeated such that, from the point at which one-way relay communications ends, a response is received within 2 seconds and reverse communications begin. In this case, there is no need to perform carrier sensing, and smooth communications can be carried out without any cutoff at the beginning of each call. However, when the communication time reaches the three-minute limit, transmission must be automatically terminated and a pause of at least two seconds must be allowed. Then, from standby mode, a series of connection procedures involving carrier sensing must be carried out again to confirm that there is no interference with other communications before transmission can be resumed.

[0008] Next, while the above relates to specific low-power standards, the radio equipment of digital simplex radio stations based on the established standards in Non-Patent Document 2 below uses a digital communication method, which provides good sound quality and high confidentiality, and the antenna power can be output up to 5W, so it is used for communication at event venues and leisure facilities, mainly for security work.

[0009] The standard is formulated in three modulation methods (Part 1: π / 4-shift quadrature phase shift keying, Part 2: real zero-point single sideband modulation, and Part 3: four-level frequency shift keying), and a different radio wave format is used for each. However, "relaying" is limited to licensed stations, and the uplink / downlink frequencies are given as channel numbers D1 to D10 [Table 3-4 (p1-19) in Part 1, Table 3-7 (p2-24) in Part 2, Table 3-5 (p3-19) in Part 3], and relay communication is carried out using the uplink / downlink frequencies (pair waves) associated with any of the channel numbers.

[0010] Furthermore, radio repeaters (licensed stations) under this established standard are also subject to communication time restrictions as radio equipment, with the maximum relay communication time being five minutes, and if radio waves are to be transmitted after the five minutes have been reached, a transmission pause of at least one minute must be inserted. On the other hand, if a transmission stop or dead state continues for more than 3 seconds, the relay communication is considered to have ended, but conversely, even if a transmission stop or dead state lasts less than 3 seconds, it is considered to be one continuous relay communication. In addition, carrier sensing is not required for licensed stations, and flexible response is possible through carrier monitoring and busy display.

[0011] As described above, in relay communications using the semi-duplex method for radio stations and radio equipment of specific low-power standards / digital simplex radio stations, the continuous communication time is limited to 3 minutes / 5 minutes, and if the continuous communication time exceeds the limit, the communication must be terminated and a rest period of at least 2 seconds / 1 minute must be allowed before communication can be resumed.

[0012] In relation to the operation of resuming communication after the expiration of this communication time limit, the following Patent Documents 1 and 2 relate to a mobile communication system based on PHP (Personal Handy Phone) in 1993, and disclose a wireless communication system in which, when a predetermined time (3 minutes) has elapsed between mobile wireless terminals without going through a base station, the terminal automatically disconnects the call, and after a predetermined pause time (2 seconds) has elapsed since the call was disconnected, the terminal automatically initiates a call to the party with whom the call was being made before the call was disconnected. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Publication No. 7-107560 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-32568 [Non-patent literature]

[0014] [Non-Patent Document 1] Association of Radio Industries and Businesses, "Specific Low-Power Radio Stations / Radio Equipment for Radio Telephones / Standard Specifications," RCR STD-20 Version 5.1, revised October 29, 2021 [Non-patent document 2] Association of Radio Industries and Businesses, "Radio Equipment / Standard for Digital Simple Radio Stations," ARIB STD-T98 Version 2.0, revised October 4, 2023 Summary of the Invention [Problem to be solved by the invention]

[0015] First, according to the wireless communication systems of Patent Documents 1 and 2, when it detects that a predetermined time (3 minutes) has elapsed during a call, the communication is forcibly terminated and a call to the previous communication destination is automatically initiated. However, since the call is initiated after a 2-second transmission pause, communication is naturally not possible during those 2 seconds, and in long-term communications, there is always a 2-second transmission pause / deadband state every 3 minutes.

[0016] This is also true for relay communication using semi-duplex method under the specified low-power standard (Figure 8).When the communication ends after the 3-minute communication limit has elapsed, there is a 2-second pause, and then the calling station, relay station, and called station each perform a series of line connection procedures involving carrier sensing, and if the channel to be used is idle, they will transition to continuous relay communication. Furthermore, looking at this in more detail, once the three-minute communication time limit has elapsed, in addition to the two-second pause, three carrier senses (0.2 seconds x 3) and time for other communication operations must be allowed for, meaning that it will take at least 2.6 seconds or more before continuous relay communication, which does not require carrier sense, can begin, and naturally the call will be interrupted.

[0017] Similarly, in the case of relay communication in digital simplex radio, if the communication ends after the five-minute communication limit has elapsed, relay communication cannot be resumed until a one-minute pause has elapsed. This is presumably based on the idea that one continuous call can be completed in five minutes, but depending on the business to which the radio relay system is applied, calls may be exchanged for long periods of time on a regular basis, and in such cases a one-minute relay downtime will definitely result in the loss of call continuity.

[0018] Therefore, the present invention aims to provide a radio relay system that enables continuous and smooth communication without long pauses in semi-duplex relay communication by radio stations and radio equipment, which are subject to limits on continuous communication time and transmission pause times set by the standard, while adhering to the spirit of the standard. [Means for solving the problem]

[0019] The first invention is a standard for radio stations and radio equipment, which specifies that the radio station and radio equipment have a carrier sense function, automatically limit the communication time from the start of communication to within a predetermined time T11, and when the communication is terminated based on the limit, a transmission pause time of a predetermined time T12 or more is set after the communication is terminated, no carrier sense is required within the communication time from the first transmission in which carrier sense is performed, and terminate the communication if the transmission stop and dead state continue for a predetermined time t1 or more, and the radio repeater according to the standard specifies that the pair of waves specified by the channel number are to be an uplink channel and a downlink channel. In a radio relay system (hereinafter referred to as "radio relay system in which radio stations and radio equipment are based on the first standard") for relaying communication between a plurality of radio communication terminals by a semi-duplex method using a channel, the radio repeater comprises two receiving and demodulating units in which the uplink channels of each pair of waves corresponding to two channel numbers are respectively set, a signal combining unit which combines and outputs the demodulated signals of the two receiving and demodulating units, a modulation and transmitting unit in which one of the downlink channels of each pair of waves is selectively set variably and transmits a modulated signal modulated by the output signal of the signal combining unit, and a modulation and transmitting unit which transmits the next relay communication during non-relay operation. and a time counting means for counting the time from the start of communication, while each of the wireless communication terminals includes two receiving and demodulating units each having a downstream channel of each of the paired waves set thereto, a signal combining unit for combining and outputting the demodulated signals of the two receiving and demodulating units, an audio reproducing unit for audio reproducing the output signal of the signal combining unit, and a microphone for selectively setting one of the upstream channels of each of the paired waves. a modulation transmitting unit that transmits a modulated signal modulated by an input audio signal; and a channel setting means that, when one of the two receiving and demodulating units receives the beacon signal from the wireless repeater, sets an upstream channel that is in a paired wave relationship with the downstream channel related to the reception in the modulation transmitting unit; and in the wireless repeater, when the timing means has timed the predetermined time T11, the relay operation of the currently used paired wave is automatically stopped, and the beacon transmitting means changes the set channel of the modulation transmitting unit from the downstream channel of the currently used paired wave to the downstream channel of the other paired wave,The wireless relay system is characterized in that if the result of carrier sense performed by the receiver / demodulator in which the uplink channel of the other pair of waves is set is an idle state, the beacon signal is transmitted, and when the receiver / demodulator in each of the wireless communication terminals in which the downlink channel of the other pair of waves is set receives the beacon signal, the set channel of the modulator / transmitter is changed from the uplink channel of the currently used pair of waves to the uplink channel of the other pair of waves.

[0020] In a wireless relay system in which wireless stations and wireless equipment are based on the first standard, during continuous relay communication in which wireless communication terminals alternately respond without any transmission stop or dead time of a predetermined time t1 or more, there is no need to perform carrier sense before transmission, making it possible to smoothly exchange calls.However, since the maximum communication time is set to a predetermined time T11, when the time T11 is reached from the start of relay communication, the wireless repeater automatically stops relaying operation, and relay communication cannot be resumed unless a transmission pause of a predetermined time T12 or more is set. The purpose of imposing such a limit on relay communication time is to prevent a particular group from occupying a particular pair of waves (communication channel) for a long period of time, thereby preventing other groups from using it.

[0021] In this first invention, the wireless repeater has two receiving and demodulating units, and sets the uplink channels of two paired waves with different channel numbers as the receiving channels of these receiving and demodulating units, while each wireless communication terminal also has two receiving and demodulating units, and sets the downlink channels of the same two paired waves as the receiving channels of these receiving and demodulating units.

[0022] When the longest communication time reaches the predetermined time T11, the wireless repeater stops the relaying of the currently used paired wave and immediately starts the beacon signal transmission procedure by the beacon transmitting means. The beacon transmitting means includes information indicating that the beacon signal specifies the paired wave to be used for the next relay communication, changes the transmission channel of the modulation transmitting unit from the downlink channel of the currently used paired wave to the downlink channel of the other paired wave, and transmits the beacon signal. However, since the beacon signal will be transmitted on a new channel, the beacon transmitting means will perform carrier sensing in advance and transmit the beacon signal only after confirming that the result shows an idle state.

[0023] On the other hand, each wireless communication terminal has two receiving and demodulating units, so it can receive the beacon signal transmitted by the wireless repeater on any of the downstream channels of the pair of waves. Upon receiving the signal, the channel setting means changes the channel of the modulation transmitter from the upstream channel of the currently used pair of waves to the upstream channel of the other pair of waves, thereby transitioning the currently used pair of waves to a state in which communication is possible with the other pair of waves.

[0024] In this case, since the current pair of waves has been switched to the other pair of waves, the provision that requires a transmission pause time of at least a predetermined time T12 when the relay time of continuous communication reaches a predetermined time T11 does not apply.As described above, when the radio repeater and each radio communication terminal have transitioned to a state in which they can communicate using the other pair of waves in a semi-duplex manner, the radio repeater can accept calls and transmissions from the radio communication terminal and perform relay communication. Here, if the first standard for radio stations and radio equipment is a specific low-power standard radio station and radio equipment (Non-Patent Document 1 above), the predetermined time T11 is 3 minutes, the predetermined time T12 is 2 seconds, and the predetermined time t1 is 2 seconds. However, according to the radio relay system of the first invention, even if the communication time reaches 3 minutes (T11), there is no need to set a transmission pause time of 2 seconds (T12) or more, and relay communication can be resumed with just the carrier sense time (usually 0.2 seconds) for transmitting a beacon signal and the initial carrier sense time (usually 0.2 seconds) when a radio communication terminal makes a call or transmits on the other pair of waves.

[0025] Therefore, according to this first invention, in the relaying of continuous communication in which responses are repeated alternately without any transmission stop or dead state for a predetermined time t1 or more, by switching the pair of waves to be used each time the accumulated communication time reaches the predetermined time T11, no transmission pause time (predetermined time T12) is required. In principle, there is no restriction on communication time, and if a wireless communication terminal that receives a beacon signal immediately makes a call, after the communication time reaches the predetermined time T11, relayed communication can be resumed with an interruption time of two carrier senses at the wireless repeater and wireless communication terminal, thereby realizing relayed communication with almost no noticeable interruption in voice calls. In addition, the wireless repeater combines the demodulated signals from the two receiving and demodulating units in a signal combining unit and outputs them to the modulating and transmitting unit, and each wireless communication terminal also combines the demodulated signals from the two receiving and demodulating units in a signal combining unit to play back audio, thereby ensuring smooth voice calls.

[0026] The second invention relates to a wireless repeating system in which wireless stations and wireless equipment are based on the first standard, wherein the wireless repeater comprises two receiving and demodulating units in which uplink channels of paired waves corresponding to two channel numbers are respectively set, a signal combining unit which combines and outputs the demodulated signals of the two receiving and demodulating units, a modulation and transmitting unit in which one of the downlink channels of each paired wave is selectively variably set and which transmits a modulated signal modulated with the output signal of the signal combining unit, and a modulation and transmitting unit which transmits a beacon signal for specifying the paired wave to be used for the next relay communication during non-relay operation, to the modulated signal. The beacon transmitting means sets the transmission channel of the transmitting section to the downstream channel of the paired wave related to the specified beacon and transmits the beacon, and the time measuring means measures the time from the start of communication, while each of the wireless communication terminals includes two receiving and demodulating sections to which the downstream channels of the paired waves are respectively set, a signal combining section to combine and output the demodulated signals of the two receiving and demodulating sections, an audio reproducing section to play back the output signal of the signal combining section as audio, and a modulated signal to which either one of the upstream channels of the paired waves is selectively set and modulated with an input audio signal from a microphone. and a channel setting means for setting, when either of the two receiving and demodulating units receives the beacon signal from the wireless repeater, an up channel that is paired with the down channel related to the reception in the modulating and transmitting unit, and in the wireless repeater, after the time when the timekeeping means has timed a predetermined time T13 (where T11-6 seconds ≥ T13 ≥ T11-60 seconds), the receiving and demodulating unit to which the up channel of the other paired wave that is not the paired wave currently in use is set repeatedly performs carrier sense, and When a transmission stop and an insensitive state occur for the currently used paired wave before the means measures the predetermined time T11, if the result of the most recent carrier sense is an idle state, the relay operation by the currently used paired wave is automatically stopped, and the beacon transmitting means changes the set channel of the modulation transmitting unit from the downlink channel of the currently used paired wave to the downlink channel of the other paired wave and transmits the beacon signal, and in each of the wireless communication terminals, when the beacon signal is received by the receiving and demodulating unit to which the downlink channel of the other paired wave is set,The radio relay system is characterized in that the set channel of the modulation transmission unit is changed from the uplink channel of the currently used pair of waves to the uplink channel of the other pair of waves.

[0027] This second invention is similar to the first invention in that the radio stations and radio equipment are related to a radio relay system based on the first standard, and also in the basic configuration of the radio repeater and each radio communication terminal. The difference from the first invention is the timing at which the wireless repeater switches from the currently used paired wave to the other paired wave in relation to the predetermined time T11 relating to the limit on the continuous communication time. That is, in this second invention, the currently used paired wave is switched to the other paired wave in a predetermined procedure before the time limit T11 from the start of communication has elapsed, and the time required for carrier sensing performed when transmitting a beacon signal at the time of switching is not affected by the interruption.

[0028] To this end, in the wireless repeater, from the point when the timing means has clocked a predetermined time T13 (a time set within the time period from 60 seconds to 6 seconds before the predetermined time T11 relating to the limit on continuous communication time has elapsed) from the start of communication, while maintaining relay communication on the currently used paired wave, carrier sensing is repeatedly performed in the receiving and demodulating unit to which the uplink channel of the other paired wave is set. Then, in the relay of continuous communication on the currently used paired wave, if a transmission stop or dead state occurs in the time period from the start of communication until the predetermined time T11 has passed after the predetermined time T13 has passed, the receiver / demodulator checks whether the result of the most recent carrier sense is in an idle state, and if it is in an idle state, the relay operation on the currently used paired wave is automatically stopped, and the beacon transmitting means changes the transmission channel of the modulating / transmitting section from the downlink channel of the currently used paired wave to the downlink channel of the other paired wave and sends out a beacon signal. Furthermore, when transmitting a beacon signal, carrier sensing has already been performed to confirm the idle state, so instead of performing carrier sensing after the predetermined time T11 has elapsed and before sending the beacon signal as in the first invention, the relay operation of the currently used paired wave is automatically stopped and the beacon signal is immediately transmitted.

[0029] On the other hand, since each wireless communication terminal has two receiving and demodulating units, it can receive beacon signals on the downlink channel of either pair of waves, and corresponds to the pair of waves used by the wireless repeater, so that communication is possible on the other pair of waves instead of the currently used pair of waves, i.e., the modulation and transmission unit is changed and set to the uplink channel of the other pair of waves.

[0030] In this second invention, too, the current pair of waves is switched to the other pair of waves before the accumulated time of continuous communication reaches the predetermined time T11, so the restriction that a transmission pause time of at least the predetermined time T12 must be set when the communication time reaches the predetermined time T11 can be avoided, and when the state transitions to a state where communication is possible on the other pair of waves, the wireless repeater can accept calls and transmissions from the wireless communication terminal and perform relay communication. In this case, the difference from the first invention is that after relay communication on the currently used paired wave has ended, there is no need to perform carrier sensing to transmit a beacon signal, and relay communication can be resumed with only the initial carrier sensing time required when the wireless communication terminal makes a call or transmits on the other paired wave.

[0031] Therefore, in the relay of continuous communication in which responses are repeated alternately without any transmission stop or dead state for a predetermined time t1 or more, if the above-mentioned pair wave change procedure is executed to switch to the other pair wave every time a predetermined time T13 has elapsed since the start of communication using the currently used pair wave, the relay of continuous communication can be resumed with only the carrier sense time when the wireless communication terminal starts communication using the other pair wave, and relay communication with even less noticeable interruption than in the case of the first invention can be realized. In addition, in the wireless repeater, the demodulated signals from the two receiving and demodulating units are combined in a signal combining unit and output to a modulating and transmitting unit, and each wireless communication terminal also adopts a configuration in which the demodulated signals from the two receiving and demodulating units are combined in a signal combining unit to reproduce voice, so smooth voice calls are guaranteed, just like in the first invention.

[0032] In addition, in the wireless repeater of the second invention, even if the timing means has timed the predetermined time T11 without detecting the occurrence of a transmission stop or an insensitive state for the currently used paired wave after the time when the timing means has timed the predetermined time T13 (where T11-6 seconds ≧ T13 ≧ T11-60 seconds), if the result of the most recent carrier sense is an idle state, it is desirable that the relay operation by the currently used paired wave be automatically stopped, and the beacon transmitting means change the setting channel of the modulation transmitting unit from the downlink channel of the currently used paired wave to the downlink channel of the other paired wave and transmit the beacon signal.

[0033] In the case of continuous communication relating to a normal call, transmission stops and a dead state occurs in most cases after a predetermined time T13 has elapsed from the start of the communication and before the predetermined time T11 is reached. However, if the transmission time from one wireless communication terminal becomes long, the cumulative time of the continuous communication may reach the predetermined time T11. In such a case, it is possible to adopt a procedure in which the relay operation of the currently used paired wave is stopped, a transmission pause period of a predetermined time T12 based on the first standard is set, and then the relay operation of the currently used paired wave is started again. However, in this second invention, since the most recent carrier sense result for the other paired wave is obtained at the time the timing means times the predetermined time T11, as in the first invention, if the beacon transmitting means is caused to transmit a beacon signal on the downlink channel of the other paired wave on the condition that the carrier sense result is in an idle state, relay communication for the other paired wave can be started without the transmission pause period.

[0034] The third invention is a wireless repeater system (hereinafter referred to as "wireless repeater") that automatically limits communication time from the start of communication to within a predetermined time T21, and when communication is terminated based on the limit, provides a transmission pause time of a predetermined time T22 or more after the end of communication, and terminates communication when a transmission stop and a dead state continue for a predetermined time t2 or more, and performs relay communication by a semi-duplex method between a plurality of wireless communication terminals using a pair of waves specified by a channel number as an uplink channel and a downlink channel. In a radio repeating system in which a station and radio equipment are based on the second standard, the radio repeater comprises two receiving and demodulating units in which the uplink channels of each pair of waves corresponding to two channel numbers are respectively set, a signal combining unit which combines and outputs the demodulated signals of the two receiving and demodulating units, a modulation and transmitting unit in which one of the downlink channels of each pair of waves is selectively set variably and transmits a modulated signal modulated by the output signal of the signal combining unit, and a modulation and transmitting unit which, during non-relay operation, transmits a beacon signal for specifying the pair of waves to be used for the next relay communication by changing the transmission channel of the modulation and transmitting unit. and a timekeeping means for measuring the time from the start of communication, and each of the wireless communication terminals includes two receiver / demodulators, each of which is set to a downstream channel of the paired wave, a signal synthesizer for synthesizing and outputting the demodulated signals of the two receiver / demodulators, an audio regenerator for audio-regenerating the output signal of the signal synthesizer, a modulation / transmission unit, which is selectively set to one of the upstream channels of the paired wave and transmits a modulated signal modulated by an input audio signal from a microphone, and and a channel setting means for setting, when either one of the transmitting and demodulating units receives the beacon signal from the wireless repeater, an up channel that is in a paired wave relationship with the down channel related to the reception to the modulation and transmission unit, and in the wireless repeater, when the timing means has timed the predetermined time T21, the relaying operation of the currently used paired wave is automatically stopped, and the beacon transmitting means changes the set channel of the modulation and transmission unit from the down channel of the currently used paired wave to the down channel of the other paired wave and transmits the beacon signal, and in each of the wireless communication terminals,When the beacon signal is received by the receiver / demodulator, to which the downlink channel of the other pair of waves is set, the set channel of the modulator / transmitter is changed from the uplink channel of the currently used pair of waves to the uplink channel of the other pair of waves.

[0035] This third invention corresponds to the case where the radio relay system of the first invention is configured under the condition that the radio stations and radio equipment are radio relay systems based on the second standard. The radio stations and radio equipment of the first and second standards have different predetermined times T11 and T21 that limit the cumulative time of continuous communication, predetermined times T12 and T22 that are forced transmission pause times when communication ends based on that limit, and predetermined times t1 and t2 that stop transmission and continue in an insensitive state that is considered to be the end of communication.In addition, the first standard requires carrier sensing to be performed prior to the first transmission, but the second standard does not require carrier sensing at all.

[0036] The difference between the predetermined times is merely the length of the time, and there is no difference in the basic configuration between the third invention and the first invention, but whether or not carrier sensing is required brings about differences in the procedures and operations. That is, in this third invention, when the time of continuous communication in the wireless repeater reaches a predetermined time T21, the repeater stops relaying on the currently used channel and immediately executes the beacon signal transmission procedure using the beacon transmission means, but there is no need to perform carrier sensing prior to transmitting the beacon signal as in the first invention, and the beacon signal is transmitted as is.

[0037] Furthermore, each wireless communication terminal that receives a beacon signal will change from the currently used pair of waves to another pair of waves based on the instructions of the beacon signal, and will make a call and transmit on the uplink channel of the changed pair of waves. In this case, however, there is no need to perform carrier sensing prior to transmitting the beacon signal as in the first invention.

[0038] Therefore, as described above, in the first invention, when relay communication reaches the predetermined time T11 related to the limit on the cumulative time of continuous communication, there is no need to pause transmission for the predetermined time T12. However, since the carrier sense time for transmitting the beacon signal and the initial carrier sense time when the wireless communication terminal makes a call or transmits on the other paired wave are intervened, it takes at least the time for two carrier senses (0.4 seconds) before communication using the changed paired wave can be resumed. However, in the third invention, the time required for carrier sense is eliminated, making it possible to resume relay communication without interruption.

[0039] If the radio station / radio equipment uses the second standard of the digital simplex radio standard (Non-Patent Document 2 mentioned above), the predetermined time T21 is set to 5 minutes, the predetermined time T22 to 1 minute, and the predetermined time t2 to 3 seconds, and if a continuous communication is relayed that reaches the predetermined time T21 related to the transmission time limit, the radio station / radio equipment will be forced to pause transmission for a long time of 1 minute (T22). However, according to the third invention, the transmission pause time (T22) does not apply, and it is particularly significant that long interruptions in calls can be avoided.

[0040] A fourth invention is a wireless repeating system in which wireless stations and wireless equipment are based on the second standard, wherein the wireless repeater comprises two receiving and demodulating units, each set to an uplink channel of each pair of waves corresponding to two channel numbers, a signal combining unit for combining and outputting the demodulated signals of the two receiving and demodulating units, a modulation and transmitting unit in which one of the downlink channels of each pair of waves is selectively variably set and transmits a modulated signal modulated with the output signal of the signal combining unit, beacon transmitting means for setting the transmission channel of the modulation and transmitting unit to the downlink channel of the pair of waves related to the designation and transmitting a beacon signal for designating the pair of waves to be used in the next relay communication during non-relay operation, and a timing means for measuring the time from the start of communication, while each wireless communication terminal comprises two receiving and demodulating units, each set to a downlink channel of each pair of waves, a signal combining unit for combining and outputting the demodulated signals of the two receiving and demodulating units, an audio reproducing unit for audio reproducing the output signal of the signal combining unit, and a modulation and transmitting unit in which one of the uplink channels of each pair of waves is selectively variably set and transmits an input audio signal from a microphone. and a channel setting means for setting, when either of the two receiving and demodulating means receives the beacon signal from the wireless repeater, an upstream channel that is in a paired wave relationship with the downstream channel related to the reception in the modulating and transmitting means, and in the wireless repeater, when a transmission stop and a dead state occur for the currently used paired wave after the time when the time measuring means measures a predetermined time T23 (where T21-6 seconds ≧ T23 ≧ T21-60 seconds) and before the time when the predetermined time T21 is measured, and the beacon transmitting means changes the set channel of the modulation transmitting unit from the downlink channel of the currently used paired wave to the downlink channel of the other paired wave and transmits the beacon signal, and in each of the wireless communication terminals, when the receiving and demodulating unit to which the downlink channel of the other paired wave is set receives the beacon signal, the set channel of the modulation transmitting unit is changed from the uplink channel of the currently used paired wave to the uplink channel of the other paired wave.

[0041] This fourth invention corresponds to the case where the radio relay system of the second invention is configured under the condition that the radio stations and radio equipment are radio relay systems based on the second standard. Therefore, it corresponds to the relationship of the third invention to the first invention, and in relation to the second invention, the limit on the accumulated time of continuous communication is changed from T11 to T21, the transmission pause time that must be set when that limit is reached is changed from T12 to T22, the duration of the transmission stop and insensitive state that is considered to be the end of communication is changed from t1 to t2, and carrier sensing is no longer necessary. If the radio station / radio equipment is a radio station / radio equipment conforming to the second standard digital simplex radio standard (Non-Patent Document 2 above), the predetermined time T21 is 5 minutes, the predetermined time T22 is 1 minute, and the predetermined time t2 is 3 seconds, and no transmission pause time (T22) is applied, so that long interruptions in calls can be avoided, just like the third invention.

[0042] In addition, in the wireless repeater of the fourth invention, even if the timing means has timed the predetermined time T21 without detecting the occurrence of a transmission stop or a dead state for the currently used paired wave after the time when the timing means has timed the predetermined time T23 (where T21-6 seconds ≧ T23 ≧ T21-60 seconds), it is desirable that the beacon transmitting means change the setting channel of the modulating transmitting unit from the downlink channel of the currently used paired wave to the downlink channel of the other paired wave and transmit the beacon signal.

[0043] The operation of this wireless repeater is the same as when the timing means measures the predetermined time T11 in the second invention described above. After the predetermined time T23 has elapsed since the start of continuous communication, if the predetermined time T21 is reached without a transmission stop or dead state occurring, instead of restarting the relay operation using the currently used pair of waves, the relay operation using the currently used pair of waves is stopped and the beacon transmitting means transmits a beacon signal on the downlink channel of the other pair of waves, thereby starting relay communication using the other pair of waves without an intervening transmission pause time T22. However, since the second standard specification relating to this fourth invention does not require carrier sensing, the result of carrier sensing is not a condition as in the case of the second invention, and the relay operation on the currently used paired wave is immediately stopped and a beacon signal is transmitted on the downlink channel of the other paired wave.

[0044] In the wireless repeater of the first to fourth inventions described above, it is desirable that the beacon transmitting means transmits the beacon signal at a predetermined period after the relay operation by the currently used paired wave is automatically stopped until the transmitted radio wave from the wireless communication terminal is received by the receiving and demodulating unit to which the receiving channel that is in a paired wave relationship with the transmitting channel of the beacon signal is set.

[0045] By periodically transmitting a beacon signal from the wireless repeater to each wireless communication terminal, it is possible to thoroughly instruct each wireless communication terminal to change the wave pair to be used. Generally, in a wireless relay system, a beacon signal is transmitted from a relay station to a mobile station to confirm its location information, and is transmitted at a relatively long interval, such as every 30 seconds. However, in the case of the beacon signal in the first to fourth inventions, it is necessary to set the paired wave to be used for the next relay communication as quickly as possible for each wireless communication terminal, so it is desirable to transmit the beacon signal at a short interval, such as every 0.5 seconds. [Effects of the Invention]

[0046] In a semi-duplex radio relay network consisting of radio repeaters and radio communication terminals, which are radio equipment for specified low-power radio stations / radio equipment / digital simplex radio stations (relaying is limited to licensed stations), the standard specifications for these radio stations / radio equipment stipulate that the maximum communication time is a specified time T11 / T21 (3 minutes / 5 minutes), and if the duration of transmission stop and dead state exceeds the specified time t1 / t2 (2 seconds / 3 seconds), communication is considered to have ended, and if the accumulated communication time reaches the specified time T11 / T21, communication cannot be resumed unless a transmission pause of the specified time T12 / T22 (2 seconds / 1 minute) is set. The wireless relay system of the present invention is configured so that the wireless repeater and each wireless communication terminal each have two receiving and demodulating units, and the wireless repeater transmits a beacon signal to switch the pair of waves (upstream channel and downstream channel) used for relay communication.When continuous communication between wireless communication terminals in which transmission stop and dead state do not exceed the predetermined time t1 / t2 continues and the accumulated time reaches the predetermined time T11 / T21, or when a transmission stop and dead state occurs within a certain period of time before the predetermined time T11 / T21 is reached, the wireless repeater transmits a beacon signal to change the currently used pair of waves to the other pair of waves, thereby enabling relay of continuous communication that is not restricted by the transmission pause time T12 / T22. [Brief explanation of the drawings]

[0047] [Figure 1] This is a block circuit diagram of a wireless repeater applied to an embodiment of the wireless repeating system of the present invention, and the description in the lower area shows a list of specific times indicated by the time symbols used in each embodiment and their meanings. [Figure 2] 1 is a block diagram of a wireless communication terminal applied to an embodiment of a wireless relay system of the present invention. [Figure 3] This is a simplified schematic diagram showing a state in which a wireless repeater transmits beacon signals to two wireless communication terminals to change the pair of waves used for relay communication, thereby performing continuous relay communication without any transmission pause time. [Figure 4A] 1 is a diagram illustrating a combination of a flowchart showing an operation procedure of a wireless repeater and a communication sequence flow between the wireless repeater and each wireless communication terminal in the wireless repeating system of the first embodiment. [Figure 4B] 1 is a diagram illustrating a combination of a flowchart showing an operation procedure of a wireless repeater and a communication sequence flow between the wireless repeater and each wireless communication terminal in the wireless repeating system of the first embodiment. [Figure 5A] FIG. 10 is a diagram illustrating a combination of a flowchart showing an operation procedure of a wireless repeater and a communication sequence flow between the wireless repeater and each wireless communication terminal in the wireless repeating system of the second embodiment. [Figure 5B]FIG. 10 is a diagram illustrating a combination of a flowchart showing an operation procedure of a wireless repeater and a communication sequence flow between the wireless repeater and each wireless communication terminal in the wireless repeating system of the second embodiment. [Figure 6A] FIG. 11 is a diagram illustrating a combination of a flowchart showing an operation procedure of a wireless repeater and a communication sequence flow between the wireless repeater and each wireless communication terminal in the wireless repeating system of the third embodiment. [Figure 6B] FIG. 11 is a diagram illustrating a combination of a flowchart showing an operation procedure of a wireless repeater and a communication sequence flow between the wireless repeater and each wireless communication terminal in the wireless repeating system of the third embodiment. [Figure 7A] FIG. 10 is a diagram illustrating a combination of a flowchart showing the operation procedure of a wireless repeater and a communication sequence flow between the wireless repeater and each wireless communication terminal in the wireless repeating system of the fourth embodiment. [Figure 7B] FIG. 10 is a diagram illustrating a combination of a flowchart showing the operation procedure of a wireless repeater and a communication sequence flow between the wireless repeater and each wireless communication terminal in the wireless repeating system of the fourth embodiment. [Figure 8] 1 is a communication sequence flow showing a line connection procedure (published in Volume 2 of Non-Patent Document 1) in a wireless relay communication system using a semi-duplex method between a wireless repeater and a wireless communication terminal based on the standard of a specific low power standard. DETAILED DESCRIPTION OF THE INVENTION

[0048] Hereinafter, an embodiment of a wireless relay system of the present invention will be described in detail with reference to the drawings. <About wireless repeaters> The wireless repeater used in the embodiment of the present invention has a configuration as shown in FIG. This wireless repeater 100 complies with the specified low-power standard or the digital simplex wireless standard, and relays communications between multiple wireless communication terminals using a semi-duplex method by using paired waves specified by channel numbers in each standard as the uplink and downlink channels, and has the following characteristic configuration.

[0049] Two receiver / demodulator units RX01 and RX02 are provided, and uplink channels chA-H and chB-H of two pairs of waves (chA-H / chA-L) and (chB-H / chB-L) with different channel numbers are set to these units. On the other hand, the modulation transmission unit TX0 is selectively set with the downlink channels chA-L and chB-L of the two pairs of waves (chA-H / chA-L) and (chB-H / chB-L) as transmission channels. More specifically, during relay operation, a channel (chA-L or chB-L) that is in a paired relationship with the set channel (chA-H or chB-H) of the receiving demodulation unit (RX01 or RX02) that is taking in the received signal from the receiving antenna 11 and outputting the demodulated signal is set, and when transmitting a beacon signal as described below, the other channel (chB-L or chA-L) that is not the currently used channel (chA-L or chB-L) is set.

[0050] In relay operation, the signal received by receiving antenna 11 is amplified by amplifier 12, and then the signals corresponding to the set channels chA-H and chB-H are demodulated by each receiving demodulation unit RX01, RX02 and combined by signal combiner 13. Modulation transmitter TX0 uses this combined signal as a modulating signal to modulate the carrier of the set channel chA-L or chB-L, and the modulated signal is power-amplified by amplifier 14 and transmitted from transmitting antenna 15.

[0051] In this case, in a wireless relay network consisting of a wireless repeater 100 and wireless communication terminals 201 and 202 described below, if no other communications using chA-H or chB-H are taking place within the communication range, the wireless communication terminals 201 and 202 will only transmit signals on one of the channels, either chA-H or chB-H. Therefore, although the signals are combined in the signal combining unit 13, the modulated signal in the modulation transmitting unit TX0 is a demodulated signal for the signal on one of the channels. As is commonly practiced in wireless relay networks, the transmission signals of the wireless repeater 100 and the wireless communication terminals 201 and 202 may contain a unique identification signal, so that each receiving and demodulating unit RX01 and RX02 does not demodulate received signals that do not contain that identification signal.

[0052] Control of the entire system of the wireless repeater 100 is performed by the system control unit 16, which checks the status signals from each module and adaptively controls each module by managing time using an internal timer as shown in each embodiment described below. In addition, the system control unit 16 also performs selection settings for the pair of waves to be used by the wireless repeater 100 (channel settings for the receiving and demodulating units RX01 and RX02) and other adjustment settings based on input from the operation unit 17, and also controls the turning on / off of various indicator lamps 18 to display the status of the wireless repeater 100.

[0053] <About wireless communication devices> The wireless communication terminals 201 and 202 used in the embodiment of the present invention have the configuration shown in FIG. Each of these wireless communication terminals 201, 202 complies with the specified low power standard or the digital simple radio standard, and performs communication using paired waves specified by channel numbers in each standard as uplink and downlink channels.

[0054] In each wireless communication terminal 201, 202, the receiving system has a structure in which the received signal at antenna 20 is input to two receiving demodulation units RX11, RX12 via a splitter 21 and an amplifier 22, and the demodulated signals from each receiving demodulation unit RX11, RX12 are combined in a signal combining unit 23, and the combined signal is amplified by an amplifier 24 and reproduced as sound through a speaker (or earphone) 25. On the other hand, the transmission system amplifies the audio signal output by the microphone 26 using an amplifier 27, modulates the carrier signal of the transmission channel using the audio signal as a modulating signal in the modulation transmission unit TX1, and after power-amplifies the modulated signal using an amplifier 28, transmits it as radio waves from the antenna 20 via a branching filter 21.

[0055] The two receiver-demodulators RX11 and RX12 are set with downlink channels chA-L and chB-L of two pairs of waves (chA-H / chA-L) and (chB-H / chB-L) with different channel numbers, while the modulator-transmitter TX1 is selectively set with uplink channels chA-H and chB-H of the two pairs of waves as transmission channels.

[0056] The entire system of each wireless communication terminal 201, 202 is controlled by a system control unit 29, which receives operation signals from an operation unit 30 and operation signals from each module to adaptively control mode settings, channel settings, etc., and also controls the display of information on a display unit (liquid crystal display unit) 31. The system control unit 29 has a built-in timer, which also manages the total time of continuous communication and the time when carrier sense is performed.

[0057] <Embodiment 1> This embodiment relates to a wireless repeating system made up of the wireless repeater 100 and wireless communication terminals 201 and 202, and particularly to a case where these wireless stations and wireless equipment comply with the specified low power standard. The feature of the wireless relay system of this embodiment is that when continuous communication reaches its time limit T11 (= 3 minutes), the wireless repeater 100 immediately transmits a beacon signal on the downlink channel of the other pair of waves to change the currently used pair of waves to the other pair of waves, and each wireless communication terminal 201, 202 that receives the beacon signal changes the currently used pair of waves to the other pair of waves, thereby allowing the relay of continuous communication to continue without setting a transmission pause time T12 (= 2 seconds).

[0058] In Figure 3, when the wireless repeater 100 transmits a beacon signal on channel chA-L as shown in (A), the usage state of the paired waves in the wireless relay system switches from the (chB-H / chB-L) state shown in (D) to the (chA-H / chA-L) state shown in (B), and when the wireless repeater 100 transmits a beacon signal on channel chB-L as shown in (C), the usage state of the paired waves in the wireless relay system switches from the (chA-H / chA-L) state shown in (B) to the (chB-H / chB-L) state shown in (D).

[0059] The operating procedure of the wireless repeater 100 related to the switching of the pair of waves and the communication sequence flow between the wireless repeater 100 and each wireless communication terminal 201, 202 are shown in Figures 4A and 4B, and below, the overall operation of the wireless repeater system of this embodiment will be explained based on each figure. First, the wireless repeater 100 and each wireless communication terminal 201, 202 are in a standby state, and when the initial relay operation starts, in the wireless repeater 100, the system control unit 16 performs carrier sensing based on the radio wave reception state in the receiving and demodulating unit RX01, and if channel chA-H is in an idle state, it sets the transmission channel of the modulation and transmitting unit TX01 to chA-L and causes a beacon signal to be emitted and transmitted (S101 to S103). Simultaneously with the emission and transmission of the beacon signal, the system control unit 16 starts counting the time of an interval timer (tb=0.5 seconds) (S103). The beacon signal contains code information specific to the network configured by the wireless repeater 100 and each of the wireless communication terminals 201 and 202, and the code information can be demodulated to confirm that it is a beacon signal.

[0060] The beacon signal from the wireless repeater 100 is received and demodulated by the receiving and demodulating unit RX11 (chA-L) of each wireless communication terminal 201, 202, and when the system control unit 29 of each wireless communication terminal 201, 202 confirms that it is a beacon signal, it immediately sets the used pair of waves to (chA-H / chA-L) and sets the channel of the modulation transmitting unit TX1 to chA-H.

[0061] Therefore, at this stage, the wireless relay system is ready for relay communication using paired waves (chA-H / chA-L). That is, one of the wireless communication terminals (201 / 202: 201 in Figure 4A) becomes the calling terminal and performs carrier sensing based on the radio wave reception status at the receiving and demodulating unit RX11 (chA-L), and if the channel chA-L with which it has a paired wave relationship is in an idle state, it starts transmitting an audio signal on channel chA-H. On the other hand, the wireless repeater 100 relays the audio signal from one wireless communication terminal (201 / 202) and transmits it on channel chA-L, and the transmitted signal is received and demodulated by the receiving and demodulating unit RX11 of the other wireless communication terminal (202 / 201) to reproduce the audio.

[0062] As described above, the wireless repeater 100 counts an interval timer (tb = 0.5 seconds) when a beacon signal is emitted and transmitted. However, if a transmission signal is not received from either wireless communication terminal before time tb is counted, the interval timer is reset when time tb is counted, and carrier sensing and the emission and transmission of the beacon signal are repeated (S103, S104: N → S105: Y → S106 → S101, S102). In other words, after the wireless repeater 100 first emits and transmits a beacon signal, it repeatedly emits and transmits the beacon signal at a period tb until it receives a transmission signal from either of the wireless communication terminals (201 / 202).

[0063] On the other hand, in the wireless repeater 100, if the receiving and demodulating unit RX01 receives a signal from either of the wireless communication terminals (201 / 202) before the interval timer reaches time tb, the interval timer (tb) is immediately reset and the interval timer (T11 = 3 minutes) starts timing the limit time for continuous communication (S104 → S107).

[0064] This continuous communication is a communication state in which communication is repeated with a response within two seconds after one communication ends, and the condition is that transmission stop and dead state do not continue for more than two seconds. Specifically, the transmission and reception relationship between each wireless communication terminal 201, 202 via the wireless repeater 100 in Figure 3 (B) or (D) is a communication state in which transmission stop and dead state continue alternating within a range not exceeding 2 seconds, and in this case, carrier sense is not required, allowing smooth voice calls without any cut-off.

[0065] Therefore, in the wireless repeater 100, after the start of relaying continuous communication, the interval timer (t1 = 2 seconds) is started to count each time a transmission stop or dead state occurs, and if there is voice communication at a timing that does not exceed the time t1, the interval timer (t1) is reset and the timer is started to count again. Therefore, when the time counted by the interval timer (t1) exceeds the time t1, it is considered that the continuous communication has ended, and the wireless repeater 100 returns to the procedure for transmitting a beacon signal again with the same settings (S108, S109 → S101).

[0066] On the other hand, if the relay of continuous communication continues (S108, S109: N → S110 → S108), the counting of the interval timer (T11) progresses and reaches time T11. In this case, radio stations and radio equipment that comply with the specified low-power standard must set a transmission pause time of time T12 (= 2 seconds).

[0067] In contrast, in the wireless repeater 100 of this embodiment, when the interval timer (T11) reaches time T11, the relay communication on the currently used pair of channels (chA-H / chA-L) is forcibly terminated and the interval timer (T11) is reset (S110:Y→S111), and carrier sensing is immediately performed based on the radio wave reception status in the receiving and demodulating unit RX02, and if channel chB-H is in an idle state, the transmission channel of the modulation and transmitting unit TX01 is set to chB-L and a beacon signal is emitted and transmitted (S112~S114).

[0068] That is, when the relay time of continuous communication reaches T11 (= 3 minutes), the wireless repeater 100 transmits a beacon signal on chB-L, thereby forcibly terminating the relay communication on the paired wave (chA-H / chA-L), and switching the paired wave used by each wireless communication terminal 201, 202 in standby mode from (chA-H / chA-L) to (chB-H / chB-L). In this case, the procedures for transmitting a beacon signal by the wireless repeater 100 and changing the pair of waves used by each wireless communication terminal 201, 202 are the same as those described above in steps S101 to S106 → S101, except that the pair of waves is different between (chA-H / chA-L) and (chB-H / chB-L).

[0069] According to this embodiment, as described above, when the relay time of continuous communication reaches T11 (= 3 minutes), the currently used pair of waves (chA-H / chA-L) between the wireless repeater 100 and each wireless communication terminal 201, 202 is switched to the other pair of waves (chB-H / chB-L), and there is no obligation to set a transmission pause time T12 (= 2 seconds) imposed by the specified low power standard to resume relay communication using the changed pair of waves (chB-H / chB-L). Therefore, after the relay time of continuous communication reaches T11 (= 3 minutes), the actual required time is less than 0.7 seconds, including the carrier sense time (0.2 seconds) for transmitting a beacon signal by the wireless repeater 100, the carrier sense time (0.2 seconds) by either wireless communication terminal 201 / 202 that will be the calling terminal, and other processing operation times, and it becomes possible to resume relay communication using the paired wave (chB-H / chB-L).

[0070] Of course, this is only the case when one carrier sense is sufficient; if multiple carrier senses are required, the time until communication can be resumed will naturally be longer. However, if the paired waves can be selected and set arbitrarily in advance, and relay communication is started by selecting and setting two paired waves that are in an idle state in advance, relay communication can usually be resumed within the above-mentioned time (0.7 seconds or less).

[0071] As is clear from a comparison of Figures 4A and 4B, steps S101 to S111 and steps S112 to S122 in each figure, which are the operating procedures of the wireless repeater 100, differ only in the paired waves handled by chA and chB, and the procedural flow is the same. Furthermore, with regard to the operation of each wireless communication terminal 201, 202 corresponding to the operating procedure of the wireless repeater 100, after the paired wave is switched upon receiving a beacon signal, it is arbitrary which of the wireless communication terminals 201, 202 becomes the calling terminal, so the transition of their operating states is common.

[0072] Therefore, according to this embodiment, provided that continuous communication continues, the pair of channels used for relay communication are switched between (chA-H / chA-L) and (chB-H / chB-L) each time the accumulated time of the continuous communication reaches the time limit T11 (= 3 minutes) in the specified low-power standard, and continuous communication can, in principle, be continued indefinitely by simply inserting an interruption for a time (0.7 seconds or less) that is significantly shorter than the transmission pause time T12 (= 2 seconds) in the same standard.

[0073] <Embodiment 2> This embodiment also relates to a wireless repeating system made up of the wireless repeater 100 and wireless communication terminals 201 and 202, and like the first embodiment, these wireless stations and wireless equipment comply with the specified low-power standard. The feature of the wireless relay system of this embodiment is that the wireless repeater 100 uses the transmission stop and dead state that occurs during a specified time period [the 30 seconds between 2 minutes 30 seconds (T23) and 3 minutes (T11) from the start of continuous communication] before the accumulated time of continuous communication reaches the time limit T11 (= 3 minutes) as a starting event, and transmits a beacon signal on the downlink channel of the other pair of waves to change the currently used pair of waves to the other pair of waves, and each wireless communication terminal 201, 202 that receives the beacon signal changes the currently used pair of waves to the other pair of waves, thereby allowing the relay of continuous communication to continue without setting a transmission pause time T12 (= 2 seconds). In addition, this embodiment has the feature that by repeatedly performing carrier sensing for the other paired wave in advance during the specified time period, carrier sensing is not required when transmitting a beacon signal after communication with the currently used paired wave has been terminated.

[0074] The operating procedure of the wireless repeater 100 related to the switching of the pair of waves and the communication sequence flow between the wireless repeater 100 and each wireless communication terminal 201, 202 are shown in Figures 5A and 5B, and below, the overall operation of the wireless repeater system of this embodiment will be explained based on each figure. However, steps S201 to S209 in Figure 5A and steps S101 to S109 in Figure 4A relating to embodiment 1 differ from step S107 in Figure 4A only in that in step S207 in Figure 5A, the system control unit 16 of the wireless repeater 100 starts timing not only T11 (the time limit for continuous communication) but also T13 (the time from the start of communication to the start of preparation for changing the channel in use), but are otherwise identical, and the corresponding operations of the wireless communication terminals 201 and 202 are also identical.

[0075] Furthermore, steps S216 to S224 of Figure 5B and steps S112 to S120 of Figure 4B in embodiment 1 differ from step S118 of Figure 4B in that in step S222 of Figure 5B, the system control unit 16 starts timing not only T11 but also T13 as described above, and in this embodiment 2, as will be described later, in the wireless repeater 100, carrier sensing before transmitting a beacon signal immediately after switching the currently used paired wave to the other paired wave is no longer necessary, so steps S220 and S221 related to carrier sensing in steps S216 to S221 of Figure 5B are only provided when transmitting a beacon signal for the second or subsequent time, but otherwise they are the same, and the corresponding operations of the wireless communication terminals 201 and 202 are also the same.

[0076] Therefore, in the operating procedures of the wireless repeater 100 and wireless communication terminals 201, 202 in Figures 5A and 5B of this embodiment 2, details regarding the parts that are common to the operating procedures of the wireless repeater 100 and wireless communication terminals 201, 202 in Figures 4A and 4B will be left to the explanation in embodiment 1.

[0077] In the wireless repeater 100 of this embodiment 2, in Figure 5A, after transmitting a beacon signal, when the receiving and demodulating unit RX01 receives a transmission signal from any of the wireless communication terminals 201 / 202, the interval timer (tb) is reset and the interval timer starts counting not only the limit time T11 (= 3 minutes) for continuous communication, but also the time T13 (= 2 minutes 30 seconds) from the start of communication to the start of preparation for changing the channel in use (S203, S204: Y → S207).

[0078] Thereafter, as the relay of continuous communication using the paired waves (chA-H / chA-L) continues, the interval timer will naturally count time T13 (S208, S209: N → S210), and from that point on, the system control unit 16 repeatedly performs carrier sensing based on the radio wave reception status at the receiving and demodulating unit RX02 (chB-H) (S210: Y → S211). The carrier sense is also repeated at a cycle of about 0.3 seconds by the system control unit 16 setting and resetting an interval timer (tc=0.2 seconds).

[0079] Therefore, the wireless repeater 100 continues to repeatedly perform the carrier sense while relaying the continuous communication between each wireless communication terminal 201, 202 using paired waves (chA-H / chA-L) (S208 to S211), and after the repetition of the carrier sense begins, it monitors whether a transmission stop or a dead state occurs in the continuous communication based on the status of the modulation transmission unit TX0 and the reception demodulation unit R01 (S211, S212: N → S213: N → S211) unless the limit time T11 (= 3 minutes) for continuous communication is reached. In this case, there is a 30-second gap between the time T13 (= 2 minutes 30 seconds) from the start of communication to the start of preparation for changing the channel in use and the time limit T11 (= 3 minutes) for continuous communication, and the question is whether a transmission stop or a dead zone will occur during continuous communication in that time period.However, in a typical voice call, the talk time for one call is about 5 to 20 seconds, so the probability of a transmission stop or a dead zone occurring during the 30-second period (T11-T13) is extremely high.

[0080] In the wireless repeater 100, when the system control unit 16 detects a transmission stop and a dead state during the 30-second period (T11-T13), it stops the repeated carrier sense using the receiving and demodulating unit RX02 (chB-H) and immediately checks the results of the most recent carrier sense at the time of detection.If the state is idle, it immediately forcibly terminates the relay of continuous communication using the paired wave (chA-H / chA-L) and resets the interval timer (S213: Y → S214a, S214b: Y → S215). As a result, communication between each wireless communication terminal 201, 202 is temporarily cut off, but in the wireless repeater 100, the system control unit 16 immediately switches the setting channel of the modulation transmission unit TX0 from chA-L to chB-L, transmits a beacon signal on channel chB-L, and starts counting the interval timer (tb) related to the transmission period of the beacon signal (S216).

[0081] Meanwhile, each wireless communication terminal 201, 202 receives the beacon signal at the receiving and demodulating unit RX12 (chB-L), as in the first embodiment, and switches the set channel of the modulation transmitting unit TX1 to the paired wave used as chB-L to (chB-H / chB-L). As a result, if either one of the wireless communication terminals 201 / 202 performs carrier sensing based on the radio wave reception state in the receiving and demodulating unit RX12 (chB-L) as the calling terminal and is in an idle state, it starts transmitting an audio signal on channel chB-H.

[0082] Then, the wireless repeater 100 uses this as the start point for relaying the continuous communication and starts counting the interval timer for the time limit T11 (= 3 minutes) for the continuous communication and the time T13 (= 2 minutes 30 seconds) from the start of communication to the start of preparation for changing the channel being used (S217: Y → S222).

[0083] In this embodiment 2, if the wireless repeater 100 detects a transmission stop or an unresponsive state during the 30-second period (T11-T13), it forcibly terminates the relaying of continuous communication using the paired wave (chA-H / chA-L) without waiting for the continuous communication time limit T11 (= 3 minutes) to expire, and transmits a beacon signal on channel chB-L to switch the paired wave used for relay communication from (chA-H / chA-L) to (chB-H / chB-L). Therefore, at the time of the switch, there is no restriction imposed by the time limit T11 for continuous communication, and naturally there is no obligation to set a transmission pause time T12 when the continuous communication time reaches the time limit T11.

[0084] Furthermore, after the interval timer reaches time T13, carrier sense for channel chB-H is repeatedly performed, and when a transmission stop or dead state is detected during the 30-second period (T11-T13), the results of the most recent carrier sense are checked (S210-S214b), and if the state is idle, communication on the paired channel (chA-H / chA-L) is immediately interrupted and a beacon signal is transmitted on channel chB-L (S215, S216). In this case, when transmitting a beacon signal to set up a new paired wave (chB-H / chB-L), carrier sensing is already performed on chB-H, so carrier sensing is not required, and the interruption time when switching the paired wave used for relay communication is reduced by at least 0.2 seconds compared to embodiment 1.

[0085] The wireless repeater 100 starts relay communication between each wireless communication terminal 201, 202 using the paired wave (chB-H / chB-L) and starts timing the interval timers (T11) and (T13) to relay continuous communication (S217:Y→S222, S223). Thereafter, the operation procedure (S223 to S230) from the start of relay communication on the paired wave (chB-H / chB-L) to the resetting of the interval timer is the same as the previously described steps S208 to S215, except that the channel is different between chA and chB. Then, the wireless repeater 100 forcibly terminates the relay communication on the paired channel (chB-H / chB-L) and resets the interval timer, and then transmits a beacon signal on channel chA-L without performing carrier sensing, and switches the paired channel used for relay communication from (chB-H / chB-L) to (chA-H / chA-L) (S230 → S203, S204).

[0086] Therefore, in this embodiment, provided that continuous communication continues, the transmission stoppage and dead state that occurs in the 30-second time period before the relay of the continuous communication reaches the time limit T11 (= 3 minutes) in the specified low-power standard is used as the starting event, and while switching the paired waves used for relay communication between (chA-H / chA-L) and (chB-H / chB-L), it is possible in principle to continue continuous communication indefinitely with only an extremely short communication interruption (0.5 seconds or less) without being subject to the transmission pause time T12 (= 2 seconds) in the same standard.

[0087] In this embodiment, after the interval timer has counted the predetermined time T13 (=2 minutes 30 seconds) from the start of continuous communication, there may be cases where the call state of either one of the wireless communication terminals 201 / 202 continues for a long time without causing a transmission stop or a dead state, and the interval timer continues to count the predetermined time T11 (=3 minutes) (S212: Y / S227: Y). However, even in this case, carrier sense is repeated using the receiving and demodulating unit RX02 (chB-H) / receiving and demodulating unit RX01 (chA-H). At the same time, the execution is stopped, and the result of the most recent carrier sense execution at the time of detection is immediately checked. If it is in an idle state, the relay of continuous communication using the currently used paired wave (chA-H / chA-L) / (chB-H / chB-L) is immediately forcibly terminated, the interval timer is reset, and the modulation transmitter TX0 is set to the downlink channel (chB-L / chA-L) of the other paired wave to transmit a beacon signal (S213: Y → S214a to S216 / S227: Y → S229a to S230 → S203).

[0088] Therefore, even if the predetermined time T11, which is the time limit, is reached without a transmission stop or dead state occurring after the predetermined time T13 has elapsed since the start of continuous communication, continuous communication can be resumed with the changed pair of waves by transmitting a beacon signal without carrier sense and switching the pair of waves used for relay communication without an intervening transmission pause time T12 (= 2 seconds).

[0089] <Embodiment 3> This embodiment relates to a wireless repeater system consisting of the wireless repeater 100 and wireless communication terminals 201, 202, and particularly to a case where these wireless stations and wireless equipment comply with the digital simplex wireless station standard wireless equipment (wireless repeater 100 is a licensed station). The feature of the wireless relay system of this embodiment is that when the accumulated time of continuous communication reaches the time limit T21 (= 5 minutes), the wireless repeater 100 immediately transmits a beacon signal on the downlink channel of the other pair of waves to change the currently used pair of waves to the other pair of waves, and each wireless communication terminal 201, 202 that receives the beacon signal changes the currently used pair of waves to the other pair of waves, thereby allowing relay communication to continue without setting a transmission pause time T22 (= 1 minute).

[0090] The overall basic operation of the radio relay system is the same as in the first embodiment, but since it complies with the digital simplex radio station standard, the paired waves used for relay communication (channel numbers D1 to D10 in non-patent literature: Table 3-4 in Volume 1, Table 3-7 in Volume 2, and Table 3-5 in Volume 3 are used) are different, and as shown in the list in the lower area of ​​Figure 1, the time limit T21 for continuous relay communication, the transmission pause time T22 when that time limit is reached, and the duration t2 of the transmission stop and insensitive state that is considered to be a communication interruption are different from those in the specific low power standard of the first and second embodiments (T11, T12, t1). In the case of the digital simplex radio station standard, relaying is limited to licensed stations, and carrier sensing is not required for licensed stations, so in this respect the operating procedures of the radio repeater 100 and the radio communication terminals 201 and 202 differ.

[0091] The operation procedure of the wireless repeater 100 and the communication sequence flow between the wireless repeater 100 and each of the wireless communication terminals 201 and 202 in this third embodiment are shown in FIGS. 6A and 6B. As described above, as is clear from a comparison with Figures 4A and 4B of embodiment 1, the procedures related to carrier sensing have been omitted, the time limit for continuous relay communication has been changed from T11 (= 3 minutes) to T21 (= 5 minutes), and the duration of transmission stop and dead state that is considered to be a communication interruption has been changed from t1 (= 2 seconds) to t2 (= 3 seconds), but the overall basic operation is the same. Therefore, the description of the operation of the wireless relay system based on FIGS. 6A and 6B will be omitted here, and the description based on FIGS. 4A and 4B in the first embodiment will be used instead. Although the transmission pause time T22 does not appear in Figures 6A and 6B, this is because, similar to the transmission pause time T12 in the cases of Figures 4A and 4B, only the procedure is shown to avoid the obligation to set the transmission pause times T12 and T22 by changing the paired wave used for relay communication when the time limits T11 and T21 related to the accumulated time of continuous communication are reached.

[0092] According to the wireless relay system of this embodiment 3, provided that continuous communication continues, the pair of waves used for relay communication are alternately switched between (chA-H / chA-L) and (chB-H / chB-L) each time the accumulated time of the continuous communication reaches the time limit T21 (= 5 minutes) in the digital simplex radio station standard. This makes it possible, in principle, to continue continuous communication indefinitely, without having to set the long transmission pause time T22 (= 1 minute) in the same standard, and with almost no communication interruptions because there is no need for carrier sensing.

[0093] <Embodiment 4> This embodiment also relates to a wireless relay system consisting of the above-mentioned wireless repeater 100 and wireless communication terminals 201, 202, and like embodiment 3, these wireless stations and wireless equipment comply with the digital simplex wireless station standard wireless equipment (wireless repeater 100 is a licensed station). A feature of the wireless relay system of this embodiment is that in continuous communication, a transmission stop and dead state that occurs during a specified period of time [30 seconds between 4 minutes 30 seconds (T23) and 5 minutes (T21) from the start of continuous communication] before the accumulated time limit T21 (= 5 minutes) is reached is used as the starting event, and the wireless repeater 100 transmits a beacon signal on the downlink channel of the other pair of waves to change the currently used pair of waves to the other pair of waves, and each wireless communication terminal 201, 202 that receives the beacon signal changes the currently used pair of waves to the other pair of waves, allowing relay communication to continue without setting a transmission pause time T22 (= 1 minute).

[0094] Therefore, the relationship of the operational procedures of this embodiment 4 to embodiment 3 corresponds to the relationship of embodiment 2 to embodiment 1, and the overall basic operation as a wireless relay system is common to embodiment 2. However, since the wireless repeater 100 and wireless communication terminals 201, 202 of this embodiment 4 are compliant with the radio equipment of the digital simplex radio station standard, the pair of waves used for relay communication, the time limit T21 for continuous relay communication, the transmission pause time T22 when the time limit is reached, and the duration t2 of the transmission stop and dead state that is considered to be a communication interruption are the same as in embodiment 3. In addition, it is a digital simplex radio station (licensed station) that relays signals according to the standard, and therefore does not require carrier sensing.

[0095] The operation procedure of the wireless repeater 100 and the communication sequence flow between the wireless repeater 100 and each of the wireless communication terminals 201 and 202 in this fourth embodiment are shown in FIGS. 7A and 7B. As described above, as is clear from a comparison with Figures 5A and 5B relating to embodiment 2, the carrier sense procedure has been omitted, the time limit for continuous relay communication has been changed from T11 (= 3 minutes) to T21 (= 5 minutes), and the duration of transmission stop and dead state considered to be a communication interruption has been changed from t1 (= 2 seconds) to t2 (= 3 seconds), but the overall basic operation is the same. Therefore, the description of the operation of the wireless relay system based on FIGS. 7A and 7B will be omitted here, and the description based on FIGS. 5A and 5B in the second embodiment will be referred to. Although the transmission pause time T22 does not appear in Figures 7A and 7B, just as the transmission pause time T12 does not appear in Figures 5A and 5B, this is because they only show the procedure for avoiding the obligation to set the transmission pause time T22 by changing the paired wave used for relay communication when a transmission stop or dead state occurs in a specified time period (30 seconds) before the limit time T21 (= 5 minutes) is reached in continuous communication.

[0096] According to the wireless relay system of this embodiment 4, provided that continuous communication continues, the transmission stop and dead state that occurs during the 30-second period before the accumulated time of the continuous communication reaches the time limit T21 (= 5 minutes) in the digital simplex radio station standard is used as the starting event, and the paired waves used for relay communication are alternately switched between (chA-H / chA-L) and (chB-H / chB-L).As in the case of embodiment 3, this makes it possible to continue continuous communication indefinitely in principle, without having to set the long transmission pause time T22 (= 1 minute) in the same standard, and with almost no communication interruptions because carrier sensing is not required.

[0097] As described in the second embodiment, also in this fourth embodiment, after the interval timer has counted the predetermined time T23 (= 4 minutes 30 seconds) from the start of the continuous communication, there may be a case where the call state of either one of the wireless communication terminals 201 / 202 continues for a long time without causing a transmission stop or a dead state, and the interval timer continues counting the predetermined time T21 (= 5 minutes) (S410: Y / S422: Y). In such a case, the relay of the continuous communication using the currently used paired wave (chA-H / chA-L) / (chB-H / chB-L) is immediately forcibly terminated, the interval timer is reset, and the modulation transmission unit TX0 is set to the downlink channel (chB-L / chA-L) of the other paired wave to transmit a beacon signal (S410: Y → S412, S413 / S422: Y → S424 → S401).

[0098] Therefore, even if the predetermined time T21, which is the time limit, is reached without a transmission stop or dead state occurring after the predetermined time T23 has elapsed since the start of continuous communication, continuous communication can be resumed with the changed pair of waves by transmitting a beacon signal without carrier sense and switching the pair of waves used for relay communication without an intervening transmission pause time T22 (= 1 minute). This is basically the same as in embodiment 2, but in this embodiment 4, the wireless repeater 100 and wireless communication terminals 201, 202 correspond to relays (licensed stations) in the digital simplex radio station standard, and since carrier sensing is not required, there are no procedures related to it. [Industrial Applicability]

[0099] The present invention can be applied to a wireless relay system in which a limit is set on the cumulative time of continuous relay communication, and when continuous relay communication reaches the limit, the relay communication cannot be resumed unless a predetermined transmission pause period is inserted. [Explanation of symbols]

[0100] 11...receiving antenna, 12...amplifier, 13...signal synthesis section, 14...amplifier, 15...transmitting antenna, 16...system control section, 17...operation section, 18...various indicator lamps, RX01...receiving demodulation section, RX02...receiving demodulation section, TX0...modulation transmission section, 20...antenna, 21...branching filter, 22...amplifier, 23...signal synthesis section, 24...amplifier, 25...speaker (or earphone), 26...microphone, 27...amplifier, 28...amplifier, 29...system control section, 30...operation section, 31...display section, RX11...receiving demodulation section, RX12...receiving demodulation section, TX1...modulation transmission section

Claims

1. The standard for radio stations and radio equipment specifies that they must be equipped with a carrier sense function, that communication time must be automatically limited to within a predetermined time T11 from the start of communication, and that when communication is terminated based on this limit, a transmission pause of a predetermined time T12 or more must be set after the end of communication, that carrier sense is not required within the communication time from the first transmission in which carrier sense is performed, and that communication must be terminated if a transmission stop or dead state continues for a predetermined time t1 or more, and in a radio relay system in which a radio repeater according to the standard relays communication by semi-duplex method between multiple radio communication terminals using paired waves specified by channel numbers for the uplink channel and the downlink channel, The wireless repeater comprises two receiving and demodulating units, each set to an uplink channel of each pair of waves corresponding to two channel numbers; a signal combining unit that combines and outputs the demodulated signals of the two receiving and demodulating units; a modulation and transmitting unit in which one of the downlink channels of each pair of waves is selectively and variably set and that transmits a modulated signal modulated by the output signal of the signal combining unit; beacon transmitting means that, during non-relay operation, sets the transmission channel of the modulation and transmitting unit to the downlink channel of the pair of waves related to the designation and transmits a beacon signal for designating the pair of waves to be used in the next relay communication; and a timing means that measures the time from the start of communication; Each of the wireless communication terminals comprises two receiver-demodulators, each set to a downstream channel of each pair of waves; a signal combiner for combining and outputting the demodulated signals of the two receiver-demodulators; an audio regenerator for audio-regenerating the output signal of the signal combiner; a modulator-transmitter for selectively and variably setting one of the upstream channels of each pair of waves and transmitting a modulated signal modulated by an input audio signal from a microphone; and a channel setting means for, when one of the two receiver-demodulators receives the beacon signal from the wireless repeater, setting the modulator-transmitter to the upstream channel that is in a pair-wave relationship with the downstream channel related to the reception, a beacon transmitting means for transmitting a beacon signal to a communication terminal when the beacon signal is received by the communication terminal and a receiving and demodulating means for receiving and demodulating the beacon signal from ...

2. 2. The wireless repeater system according to claim 1, wherein the beacon transmitting means transmits the beacon signal at a predetermined interval after the relay operation by the currently used paired wave is automatically stopped, until the transmitted radio waves from the wireless communication terminal are received by a receiving and demodulating unit that has a receiving channel set to be paired with the transmitting channel of the beacon signal.

3. The standard for radio stations and radio equipment specifies that they must be equipped with a carrier sense function, that communication time must be automatically limited to within a predetermined time T11 from the start of communication, and that when communication is terminated based on this limit, a transmission pause of a predetermined time T12 or more must be set after the end of communication, that carrier sense is not required within the communication time from the first transmission in which carrier sense is performed, and that communication must be terminated if a transmission stop or dead state continues for a predetermined time t1 or more, and in a radio relay system in which a radio repeater according to the standard relays communication by semi-duplex method between multiple radio communication terminals using paired waves specified by channel numbers for the uplink channel and the downlink channel, The wireless repeater comprises two receiving and demodulating units, each set to an uplink channel of each pair of waves corresponding to two channel numbers; a signal combining unit that combines and outputs the demodulated signals of the two receiving and demodulating units; a modulation and transmitting unit in which one of the downlink channels of each pair of waves is selectively and variably set and that transmits a modulated signal modulated by the output signal of the signal combining unit; beacon transmitting means that, during non-relay operation, sets the transmission channel of the modulation and transmitting unit to the downlink channel of the pair of waves related to the designation and transmits a beacon signal for designating the pair of waves to be used in the next relay communication; and a timing means that measures the time from the start of communication; Each of the wireless communication terminals comprises two receiver-demodulators, each set to a downstream channel of each pair of waves; a signal combiner for combining and outputting the demodulated signals of the two receiver-demodulators; an audio regenerator for audio-regenerating the output signal of the signal combiner; a modulator-transmitter for selectively and variably setting one of the upstream channels of each pair of waves and transmitting a modulated signal modulated by an input audio signal from a microphone; and a channel setting means for, when one of the two receiver-demodulators receives the beacon signal from the wireless repeater, setting the modulator-transmitter to the upstream channel that is in a pair-wave relationship with the downstream channel related to the reception, In the wireless repeater, after the time when the timing means has timed a predetermined time T13 (where T11 - 6 seconds ≥ T13 ≥ T11 - 60 seconds), carrier sense is repeatedly performed by the receiving / demodulating unit to which the uplink channel of the other pair of waves other than the currently used pair of waves is set, and if a transmission stop or an insensitive state occurs for the currently used pair of waves before the timing means has timed the predetermined time T11, and if the result of the most recent carrier sense is an idle state, the relay operation by the currently used pair of waves is automatically stopped, and the beacon transmitting means changes the set channel of the modulating / transmitting unit from the downlink channel of the currently used pair of waves to the downlink channel of the other pair of waves and transmits the beacon signal, and in each of the wireless communication terminals, when the receiving / demodulating unit to which the downlink channel of the other pair of waves is set receives the beacon signal, the set channel of the modulating / transmitting unit is changed from the uplink channel of the currently used pair of waves to the uplink channel of the other pair of waves.

4. In the wireless repeater, even if the timing means has timed the predetermined time T11 without detecting the occurrence of a transmission stop or an insensitive state for the currently used paired wave after the time when the timing means has timed the predetermined time T13 (where T11 - 6 seconds ≥ T13 ≥ T11 - 60 seconds), if the result of the most recent carrier sense is an idle state, the relay operation for the currently used paired wave is automatically stopped, and the beacon transmitting means changes the setting channel of the modulation transmitting unit from the downlink channel of the currently used paired wave to the downlink channel of the other paired wave and transmits the beacon signal.

5. 4. The wireless repeater system according to claim 3, wherein the beacon transmitting means transmits the beacon signal at a predetermined interval after the relay operation by the currently used paired wave is automatically stopped, until the transmitted radio waves from the wireless communication terminal are received by a receiving and demodulating unit that has a receiving channel set to be paired with the transmitting channel of the beacon signal.

6. 6. A wireless relay system according to claim 1, wherein the predetermined time T11 is 3 minutes, the predetermined time T12 is 2 seconds, and the predetermined time t1 is 2 seconds.

7. The standard for radio stations and radio equipment specifies that communication time is automatically limited to within a predetermined time T21 from the start of communication, and when communication is terminated based on this limit, a transmission pause of a predetermined time T22 or more is set after the end of communication, and that communication is terminated if the transmission stop and dead state continues for a predetermined time t2 or more, and in a radio relay system in which a radio repeater according to the standard relays communication by semi-duplex method between multiple radio communication terminals using paired waves specified by channel numbers as uplink and downlink channels, The wireless repeater comprises two receiving and demodulating units, each set to an uplink channel of each pair of waves corresponding to two channel numbers; a signal combining unit that combines and outputs the demodulated signals of the two receiving and demodulating units; a modulation and transmitting unit in which one of the downlink channels of each pair of waves is selectively and variably set and that transmits a modulated signal modulated by the output signal of the signal combining unit; beacon transmitting means that, during non-relay operation, sets the transmission channel of the modulation and transmitting unit to the downlink channel of the pair of waves related to the designation and transmits a beacon signal for designating the pair of waves to be used in the next relay communication; and a timing means that measures the time from the start of communication; Each of the wireless communication terminals comprises two receiver-demodulators, each set to a downstream channel of each pair of waves; a signal combiner for combining and outputting the demodulated signals of the two receiver-demodulators; an audio regenerator for audio-regenerating the output signal of the signal combiner; a modulator-transmitter for selectively and variably setting one of the upstream channels of each pair of waves and transmitting a modulated signal modulated by an input audio signal from a microphone; and a channel setting means for, when one of the two receiver-demodulators receives the beacon signal from the wireless repeater, setting the modulator-transmitter to the upstream channel that is in a pair-wave relationship with the downstream channel related to the reception, In the wireless repeater, when the timing means has clocked the predetermined time T21, the relay operation of the currently used paired wave is automatically stopped, and the beacon transmitting means changes the set channel of the modulation transmitting unit from the downlink channel of the currently used paired wave to the downlink channel of the other paired wave and transmits the beacon signal, and in each of the wireless communication terminals, when the receiving and demodulating unit to which the downlink channel of the other paired wave is set receives the beacon signal, the set channel of the modulation transmitting unit is changed from the uplink channel of the currently used paired wave to the uplink channel of the other paired wave.

8. The wireless repeater system of claim 7, wherein the beacon transmitting means in the wireless repeater is configured to transmit the beacon signal at a predetermined period after the relay operation by the currently used paired wave is automatically stopped, until the transmitted radio waves from the wireless communication terminal are received by a receiving and demodulating unit that has a receiving channel set to be paired with the transmitting channel of the beacon signal.

9. The standard for radio stations and radio equipment specifies that communication time is automatically limited to within a predetermined time T21 from the start of communication, and when communication is terminated based on this limit, a transmission pause of a predetermined time T22 or more is set after the end of communication, and that communication is terminated if the transmission stop and dead state continues for a predetermined time t2 or more, and in a radio relay system in which a radio repeater according to the standard relays communication by semi-duplex method between multiple radio communication terminals using paired waves specified by channel numbers as uplink and downlink channels, The wireless repeater comprises two receiving and demodulating units, each set to an uplink channel of each pair of waves corresponding to two channel numbers; a signal combining unit that combines and outputs the demodulated signals of the two receiving and demodulating units; a modulation and transmitting unit in which one of the downlink channels of each pair of waves is selectively and variably set and that transmits a modulated signal modulated by the output signal of the signal combining unit; beacon transmitting means that, during non-relay operation, sets the transmission channel of the modulation and transmitting unit to the downlink channel of the pair of waves related to the designation and transmits a beacon signal for designating the pair of waves to be used in the next relay communication; and a timing means that measures the time from the start of communication; Each of the wireless communication terminals comprises two receiver-demodulators, each set to a downstream channel of each pair of waves; a signal combiner for combining and outputting the demodulated signals of the two receiver-demodulators; an audio regenerator for audio-regenerating the output signal of the signal combiner; a modulator-transmitter for selectively and variably setting one of the upstream channels of each pair of waves and transmitting a modulated signal modulated by an input audio signal from a microphone; and a channel setting means for, when one of the two receiver-demodulators receives the beacon signal from the wireless repeater, setting the modulator-transmitter to the upstream channel that is in a pair-wave relationship with the downstream channel related to the reception, In the wireless repeater, if a transmission stop or an insensitive state occurs for the currently used paired wave after the timing means has timed a predetermined time T23 (where T21 - 6 seconds ≥ T23 ≥ T21 - 60 seconds) and before the timing of the predetermined time T21, the wireless repeater automatically stops the relay operation of the currently used paired wave, and the beacon transmitting means changes the set channel of the modulation transmitting unit from the downlink channel of the currently used paired wave to the downlink channel of the other paired wave and transmits the beacon signal, and in each of the wireless communication terminals, when the beacon signal is received by the receiving and demodulating unit to which the downlink channel of the other paired wave is set, the set channel of the modulation transmitting unit is changed from the uplink channel of the currently used paired wave to the uplink channel of the other paired wave.

10. In the wireless repeater, even if the timing means has timed the predetermined time T21 after the time T21 - 6 seconds ≧ T23 ≧ T21 - 60 seconds without detecting the occurrence of a transmission stop or a dead state for the currently used paired wave, the beacon transmitting means changes the setting channel of the modulation transmitting unit from the downlink channel of the currently used paired wave to the downlink channel of the other paired wave and transmits the beacon signal.

11. The wireless repeater system of claim 9, wherein the beacon transmitting means in the wireless repeater is configured to transmit the beacon signal at a predetermined period after the relay operation by the currently used paired wave is automatically stopped, until the transmitted radio waves from the wireless communication terminal are received by a receiving and demodulating unit that has a receiving channel set to be paired with the transmitting channel of the beacon signal.

12. 12. A wireless relay system according to claim 7, claim 8, claim 9, claim 10 or claim 11, wherein the predetermined time T21 is 5 minutes, the predetermined time T22 is 1 minute, and the predetermined time t2 is 3 seconds.

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