JP4888431B2 - Radio communication system and relay method in radio communication system - Google Patents

Description

  The present invention relates to a radio communication system in which a parent fixed station connects to a plurality of relay stations using the same relay wave, and each relay station communicates with a mobile station using the same communication wave, and a relay method in the radio communication system. Is.

  Conventionally, there exists a wireless communication system in which a parent fixed station is connected to a plurality of relay stations using the same relay wave, and each relay station communicates with a mobile station using the same communication wave. In such a wireless communication system, since communication is performed using the same frequency, there is a problem that a beat failure or the like occurs when a plurality of communication overlaps.

  As a solution to this problem, for example, the one disclosed in Patent Document 1 is intended to reduce beat failure caused by relaying simultaneously by a plurality of relay stations. When a station is in multiple overlapping relay station areas, the optimal base station is determined in advance by means of polling, etc., and the relay function of other relay stations is cut off to operate only the optimal relay station. It is made to let you.

  FIG. 14 shows the overall configuration of the wireless communication system in Patent Document 1. In FIG. 14, the parent fixed station is a parent fixed station wireless device that communicates with the mobile station via the relay station. The relay stations A, B, and C are respectively connected between the parent fixed station and the mobile station. A relay station radio device that relays and has a response function for polling from a mobile station, and mobile station D is a mobile station radio device that communicates with a parent fixed station via a relay station and is optimal It has a polling function for collecting base station information.

  Each of the relay stations A, B, and C includes a fixed station responsible for communication with the parent fixed station and a base station responsible for communication with the mobile station, and is the same between the parent fixed station and each fixed station. The base station and the mobile station communicate with each other using the same communication wave between each base station and the mobile station.

  In this configuration, the mobile station transmits a base station identification signal (including a polling code, a base station code, and a mobile station code) to the base station of each relay station manually or by polling. In response to the received base station identification signal, a response signal including field strength information of the mobile station, a code indicating the own station, and a code indicating the mobile station is transmitted. The mobile station records the response information received from each base station, compares the field strength information in the recorded results, determines and selects the optimum relay base station, and determines the optimum base station. By automatically setting and transmitting the station identification signal, only this base station is connected thereafter.

On the other hand, in the relay station, when the base station receives the optimum base station identification signal, the optimum fixed station information is transmitted from the corresponding fixed station to the parent fixed station, and the parent fixed station sets this optimum relay information in its own station. Thereafter, only the set base station is selected, a relay station identification signal is added, and a signal to the mobile station is transmitted. When the relay station identification signal corresponds to the local station, the relay station apparatus relays the communication as it is, and transmits the communication signal from the parent fixed station to the mobile station. When the relay station identification signal corresponds to the other station, the relay station apparatus Disable the relay function.
Japanese Patent Laid-Open No. 08-195710

The technology in this Patent Document 1 transmits a base station identification signal (polling code, base station code, mobile station code, etc.) to each base station by polling sequentially from a mobile station, receives a response signal from each base station, Compared with the received signal strength obtained from the response signal, the optimum base station is determined and selected, but this method is effective when the mobile station is located within the service area of the relay base station, And the case where the station location structure in a service area is recognized beforehand is assumed.
Assuming firefighting operations that are organized in the event of a disaster and dispatched to the disaster site, not all mobile stations are necessarily located within the service area, and relaying to accommodate mobile stations outside the service area There is no guarantee that the base station is located.

  Further, in Patent Document 1, since the parent fixed station and the fixed station in the relay station are connected by a fixed line, stable line quality can always be ensured, and a criterion for selecting a relay base station is set as a criterion for each relay base. Only field strength information at the time of response reception received from the station is used. However, if the parent fixed station and the relay station are not connected by a fixed line, for example, if the mobile station has a relay function, the line quality between the parent fixed station and the relay station becomes unstable. However, there is a problem that only the field strength information at the time of response reception received from the relay base station does not serve as a criterion for selecting an optimum relay station.

  The present invention has been made in view of the above problems, and is optimal while preventing occurrence of a beat failure or the like when a mobile station is provided with a relay function in the absence of a fixed relay base station. An object of the present invention is to provide a radio communication system capable of selecting a relay mobile station.

According to a first aspect of the present invention, in a wireless communication system including a base station and a plurality of mobile stations that communicate with the base station, the mobile station serves as a communication partner stored in advance in a storage unit. The control unit determines whether there is a channel that can be communicated by searching a plurality of channels of the station, and if there is no channel that can be communicated, it is determined that the own station is outside the service area of the base station Then, a "relay communication request" signal is transmitted to the other mobile station from the transmission unit, and the other mobile station receives the "relay communication request" signal from the mobile station at the reception unit, A “relay communication response” signal including information on whether or not relay communication is possible is transmitted from the transmitter to the mobile station, and the “relay communication response” signal includes the “relay communication response” signal Between other mobile stations and base stations When the mobile station receives a “relay communication response” signal from another mobile station within a predetermined period, the mobile station receives the “relay communication” signal. The control unit determines whether the reception level and base wave level of the “response” signal have reached the prescribed values, and if there are a plurality of received “relay communication response” signals, the reception level and base wave level thereof Are selected in the control unit, the optimum relay partner is selected, the selected one other mobile station is designated, and the "relay communication confirmation notification" signal is transmitted, and the receiving unit of the other mobile station is selected. And having one relay mode mobile station and one or more normal operation mode mobile stations that have received the “relay communication confirmation notification” signal, the relay mode mobile station and the normal operation mode mobile station are Between base station When the voice signal from the base station by “Establishment of communication channel” is received / recorded in each storage unit and the transmission end signal from the base station is received, the mobile station in the normal operation mode ends the transmission from the base station. When a synchronous burst signal is received from a mobile station in relay mode within a set time from the reception of the signal, the mobile station in relay mode transmits the recorded voice to a mobile station outside the service area, and the mobile station in normal operation mode. Is a radio communication system characterized in that a voice signal recorded by receiving a skyline signal from a mobile station in relay mode is erased .

According to a second aspect of the present invention, in a wireless communication system including a base station and a plurality of mobile stations that communicate with the base station, the mobile station serves as a communication partner stored in advance in a storage unit. The control unit determines whether there is a channel that can be communicated by searching a plurality of channels of the station, and if there is no channel that can be communicated, it is determined that the own station is out of the service area of the base station Then, a "relay communication request" signal is transmitted to the other mobile station from the transmission unit, and the other mobile station receives the "relay communication request" signal from the mobile station at the reception unit, A “relay communication response” signal including information on whether or not relay communication is possible is transmitted from the transmitter to the mobile station, and the “relay communication response” signal includes the “relay communication response” signal Between other mobile stations and base stations When the mobile station receives a “relay communication response” signal from another mobile station within a predetermined period, the mobile station receives the “relay communication” signal. The control unit determines whether the reception level and base wave level of the “response” signal have reached the prescribed values, and if there are a plurality of received “relay communication response” signals, the reception level and base wave level thereof Are selected in the control unit, the optimum relay partner is selected, the selected one other mobile station is designated, and the "relay communication confirmation notification" signal is transmitted, and the receiving unit of the other mobile station is selected. And having one relay mode mobile station and one or more normal operation mode mobile stations that have received the “relay communication confirmation notification” signal, the relay mode mobile station and the normal operation mode mobile station are Between base station When the voice signal from the base station by “Establishment of communication channel” is received / recorded in each storage unit and the transmission end signal from the base station is received, the mobile station in the normal operation mode ends the transmission from the base station. When a synchronous burst signal from a mobile station in relay mode is not received within the set time from the reception of the signal, the mobile station in normal operation mode recorded on a mobile station outside the service area on behalf of the mobile station in relay mode The radio communication system is characterized in that voice is transmitted, and the mobile station in the relay mode is configured to erase the voice signal recorded by receiving the empty line signal from the mobile station in the normal operation mode .

According to claim 3 of the present invention, in addition to claim 1 or 2 , the other mobile station has a means for discriminating the communication state between the own station and the base station at regular intervals, and When the control unit determines that the communication level with the base station has deteriorated below the specified value or communication with the base station is impossible after establishing the relay communication by the “relay communication confirmation notification” signal, A wireless communication system is characterized in that the relay communication is canceled by transmitting a “relay cancellation notification” signal from the transmission unit to the mobile station.

According to a fourth aspect of the present invention, in a wireless communication system comprising a base station and a plurality of mobile stations that communicate with the base station, mobile stations that exist outside the service area of the base station (hereinafter referred to as out-of-range mobile stations) However, it is determined that the own station is out of the service area of the base station and transmits a “relay communication request” signal to another mobile station (hereinafter referred to as a mobile station within the service area) of the base station. 1, and after the in-zone mobile station receives the “relay communication request” signal from the out-of-range mobile station, a “relay communication response” signal including information on whether or not relay communication is possible is sent to the out-of-range mobile station. A second step of transmitting to the third mobile station; a third step in which the out-of-range mobile station waits for a predetermined period of time to receive a “relay communication response” signal from the within-range mobile station; Receive communication response signal It is determined whether the bell has reached the specified value, and when there are multiple “relay communication response” signals including information indicating that the relay communication is received, the reception levels are compared to determine the optimum relay partner. And the fourth step of transmitting a “relay communication confirmation notification” signal by designating one selected mobile station within the selected area, and establishing a relay communication path, and further establishing a relay communication path A fifth step of receiving / recording a voice signal from a later base station to one relay mode mobile station and one or more normal operation mode mobile stations, and the normal operation mode mobile station ending transmission from the base station When a signal is received, a sixth step of setting a timer, and when a synchronous burst signal from a mobile station in relay mode is received within the set time of the timer, the mobile station in relay mode is transferred to a mobile station outside the service area. A seventh step of transmitting the voice and sound, the mobile station in the normal operation mode, and characterized by including an eighth step of erasing the audio signal recorded in an empty line signal received from the mobile station of relay mode This is a relay method in a wireless communication system.

According to a fifth aspect of the present invention, in a wireless communication system comprising a base station and a plurality of mobile stations that communicate with the base station, mobile stations that exist outside the service area of the base station (hereinafter referred to as out-of-service mobile stations) However, it is determined that the own station is out of the service area of the base station and transmits a “relay communication request” signal to another mobile station (hereinafter referred to as a mobile station within the service area) of the base station. 1, and after the in-zone mobile station receives the “relay communication request” signal from the out-of-range mobile station, a “relay communication response” signal including information on whether or not relay communication is possible is sent to the out-of-range mobile station. A second step of transmitting to the third mobile station; a third step in which the out-of-range mobile station waits for a predetermined period of time to receive a “relay communication response” signal from the within-range mobile station; Receive communication response signal It is determined whether the bell has reached the specified value, and when there are multiple “relay communication response” signals including information indicating that the relay communication is received, the reception levels are compared to determine the optimum relay partner. And the fourth step of transmitting a “relay communication confirmation notification” signal by designating one selected mobile station within the selected area, and establishing a relay communication path, and further establishing a relay communication path A fifth step of receiving / recording a voice signal from a later base station to one relay mode mobile station and one or more normal operation mode mobile stations, and the normal operation mode mobile station ending transmission from the base station A sixth step of setting a timer upon receiving a signal, and a mobile station in the normal operation mode when the synchronization burst signal from the mobile station in the relay mode is not received within the set time of the timer; Instead, the seventh step of transmitting the recorded voice to the mobile station outside the service area, and the relay mode mobile station deletes the recorded voice signal by receiving the empty signal from the mobile station in the normal operation mode. It is the relay method in the radio | wireless communications system characterized by comprising these steps .

According to claim 6 of the present invention, in addition to claim 4 or 5 , the in-zone mobile station includes means for determining a communication state between the own station and the base station at regular intervals. After establishing the relay communication path in the fourth step, if it is determined that the communication level with the base station has deteriorated below a specified value or communication with the base station is impossible, the movement that is the relay partner A relay method in a radio communication system, wherein a relay relay notification signal is transmitted to a station to cancel relay communication.

  According to the present invention, when the mobile station determines that the mobile station is out of the service area range of the base station, the mobile station transmits the “relay communication request” signal to the other mobile stations, so that the mobile station is out of service range. In this case, it becomes possible to search for a relay partner voluntarily. The other mobile station that has received the “relay communication request” signal transmits a “relay communication response” signal including information on whether or not relay communication is possible to the mobile station outside the service area, but the reception level is equal to or higher than a specified value. It is possible to select a relay partner depending on whether or not there is, and further, by including information on the base wave level representing the signal level between the mobile station in the area and the base station in the “relay communication response” signal, In the out-of-service mobile station, base wave level information can also be used as a condition for selecting a relay partner, so that higher-quality relay communication can be performed.

  In addition, when it is determined that the mobile station outside the service area has returned to the service area within the base station, or the communication level with the base station in the mobile station within the service area has deteriorated below the specified value or communication with the base station is not possible. When it is determined that the relay operation is possible, the relay operation is canceled by transmitting a “relay release notification” signal. Therefore, priority is given to returning to the service area, and if it is difficult to continue relaying, Therefore, the relay operation can be canceled.

  According to the present invention, since the mobile station is provided with a relay function to enable relay communication between the base station and the out-of-service area mobile station, it is not necessary to install a separate relay base station, and the introduction cost can be suppressed. With this wireless communication system of the present invention, for example, fire fighting operations can be performed without delay.

According to the present invention, when having a mobile station in the relay mode and the mobile station in the normal operation mode that has received the "relay communication confirmation notification" signal,
When these mobile stations record a voice signal from the base station and receive a synchronization burst signal from the mobile station in the relay mode within a set time after receiving the transmission end signal from the base station, the mobile station Of the mobile station transmits the recorded voice to a mobile station outside the service area.
In addition, when having a mobile station in the relay mode and a mobile station in the normal operation mode that has received the “relay communication confirmation notification” signal, these mobile stations record the audio signal from the base station and receive the signal from the base station. When a synchronous burst signal from a mobile station in relay mode is not received within the set time from reception of the transmission end signal, the mobile station in normal operation mode records on the mobile station outside the service area area on behalf of the mobile station in relay mode Send the sound.
Therefore, even if the mobile station enters the relay mode once and becomes impossible to relay, the mobile station in the normal operation mode can transmit the recorded voice to the mobile station outside the service area instead of the mobile station in the relay mode. , More reliable relay operation.

  The present invention relates to a wireless communication system including a base station and a plurality of mobile stations that communicate with the base station. A mobile station that is outside the service area of the base station (hereinafter referred to as an out-of-service mobile station) A first step of transmitting a “relay communication request” signal to other mobile stations (hereinafter referred to as “in-range mobile stations”) that are outside the service area of the base station and that are within the service area of the base station; The base station level relating to the signal level between the mobile station in the area and the base station, and information on whether relay communication is possible after the mobile station in the area receives the “relay communication request” signal from the mobile station outside the area A second step of transmitting a “relay communication response” signal including the following information to the out-of-area mobile station, and the out-of-area mobile station awaits reception of a “relay communication response” signal from the within-area mobile station for a predetermined period of time Third step And the out-of-service mobile station determines whether the reception level and the base wave level of the received “relay communication response” signal have reached a specified value, and includes the received relay communication enable information. When there are a plurality of “communication response” signals, the reception level and the base wave level are compared, the optimum relay partner is selected, the selected one mobile station within the range is designated, and the “relay communication confirmation notification” signal The relay communication path is established by the fourth step of transmitting. Hereinafter, description will be made based on the drawings.

  A configuration of a wireless communication system according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the overall configuration of a wireless communication system according to the present invention. In FIG. 1, a base station is a digital base station radio apparatus that transmits and receives signals to and from a mobile station in a base station service area and a mobile station in a relay base station service area. The relay base station is a digital relay base station radio device that transmits and receives signals from each other in order to relay communication between the mobile station and the base station in the relay base station service area. The mobile stations a to d are digital mobile station radio apparatuses that transmit and receive signals to and from the base station and the relay base station or other peripheral mobile stations in the base station service area and the relay base station service area.

  As shown in FIG. 2 (a), the transceiver of the base station is configured with one signal having a frequency of FH1 (downlink frequency from the base station) for transmission and FL1 (mobile station) for reception. The diversity method is adopted in which the signal having the higher sensitivity of the reception 1 and the reception 2 is received. As shown in FIG. 2 (b), the mobile station transmitter / receiver is configured with one signal with a frequency of FL1 for transmission and one with a frequency of FH1 for reception. The diversity method of receiving by adopting the better one is adopted, and a signal having a frequency of FL1 can be received in the reception 3 for direct communication between mobile stations.

Here, a simple configuration of the base station and the mobile station will be described with reference to the block diagram shown in FIG. As shown in FIGS. 4A and 4B, the base station and mobile station control the digital modulation / demodulation units (11) and (17) that digitally modulate the transmission signal and digitally demodulate the reception signal, and control the overall communication processing. And control units (12) and (18) for storing necessary information in advance and storage units (13) and (19) for storing received information. Also, as shown in FIG. 4A, the base station has one transmitter (14) for transmitting signals and two receivers (15) (16) for receiving signals in a diversity manner. have. As shown in FIG. 4 (b), the mobile station has one transmitter (20) for transmitting a signal, two receivers (21) (22) for receiving a signal in a diversity manner, and The receiver has a total of three receivers, one receiver (23) for direct communication between mobile stations.
In each communication described below, processing is performed while performing modulation / demodulation in the digital modulation / demodulation units (11) and (17). However, for convenience of explanation, description of each digital modulation / demodulation processing is omitted. And
Further, in the description of the flowchart and the control sequence, the main components such as the control unit, the transmission unit, and the reception unit are omitted, but the respective processes shown in FIGS. 4A and 4B are processed. Needless to say, each process is controlled by the control unit, and transmission of signals is performed via the transmission unit, and reception of signals is performed via the reception unit.

In FIG. 1, mobile station a and mobile station b are within the base station service area and there are no obstacles, so that communication with the base station can be satisfactorily, and mobile station c is outside the base station service area. Therefore, communication with the base station is not possible, but direct communication with the mobile stations a and b within the range is possible, and the mobile station d is outside the base station service area but within the relay base station service area. It is in a state where it can communicate with the base station via the relay base station. Regarding the relationship between the relay base station and the mobile station d, since relay communication is performed by a method substantially similar to the conventional technique, description thereof will be omitted below.
Among these, when the mobile station c is out of the base station service area and out of the relay base station service area, the mobile station c recognizes that it is out of the service area and is in the base station service area. A feature of the present invention is that it has a function of making a relay communication request to a mobile station. Hereinafter, the flow of processing when a relay communication request is made will be described.

  FIG. 6 is a flowchart showing a flow when each mobile station searches for a receivable channel in order to receive a signal from the base station. As shown in FIG. 6, in the mobile station, first, in (S401), the frequency data of channels (plurality) of preset base stations are read from the storage unit 19 and the number of channels read in (S402) (for example, 10 channels). Next, in (S403), the reception frequency is adjusted to one channel, and in (S404), it is confirmed whether there is a notification from the base station in a predetermined period. When there is a notification from the base station in (S404), it is set in (S405) that the channel can be received and responded, and the process proceeds to the next (S406). If there is no notification, the process proceeds to (S406). In (S406), it is confirmed whether or not the number of channels has reached the end set in (S402). If not, the number of channels is incremented by 1 in (S407) and the next channel is reached. If it exceeds, the process proceeds to (S408). Thereafter, the loop of (S403) to (S407) is repeated to check whether reception / response is possible for all channels.

In (S408), it is confirmed whether or not there is a channel that can be received and responded, and if so, whether or not the received level is equal to or higher than a specified value, If it is equal to or greater than the specified value, the process proceeds to the next (S409), and if there is no channel that can be received and responded or if it is equal to or less than the specified value, the process proceeds to (S416). In (S409), the reception levels of the channels that are equal to or higher than the specified value are compared, and the channel having the highest reception level in the next (S410) is selected to perform location registration. Thereafter, in (S411), it is confirmed whether or not a response signal from the channel for which location registration has been performed has been received. In (S412), it is determined whether or not the reception level is equal to or higher than a specified value. If so, the process proceeds to (S413). In each of (S411) and (S412), when the response signal is not received or the reception level is equal to or lower than the specified value, the process proceeds to (S416).
If the reception level of the response signal from the channel that performed the location registration is equal to or higher than the specified value, it is determined that communication with the channel is possible, and a communication request is waited in (S413) and (S414). If there is a communication request, the process proceeds to the communication process of (S415). If it is determined that the level is deteriorated while waiting, the process returns to (S401) to search for a communicable channel again, and there is no change in state. Continue to wait.
If it is determined that there is no channel that can be communicated and the process proceeds to (S416), then it is recognized that the own station is out of range and the process proceeds to (S501) in FIG.

  FIG. 7 is a flowchart showing a flow of processing when a relay communication request is made to another mobile station when the mobile station itself recognizes that it is out of range. When recognizing that it is out of service area in (S501), in (S502), the communication mode intended for communication with the base station is switched to a mode for performing direct communication with other mobile stations. In this direct communication mode, message editing for requesting relay communication is performed in (S503), a “relay communication request” signal is transmitted in (S504), and “transmission” is transmitted in (S505) to notify the end of transmission. ". It is assumed that a definition field as shown in FIG. 3A is used when editing a message, and particularly in relay communication, a signal format as shown in FIG. In the case of a “relay communication request” signal, the “* 1” portion is set to “001 = relay communication request” and the originating mobile station number (originating number) of the own station is transmitted.

  After transmitting the “empty line” in (S505), in (S506), the timer count for a preset timer time, for example, 5 seconds is started. In (S507), “relay communication response from other mobile station” is started. When a response is received while waiting for a signal, in (S508), the base wave level of the mobile station (communication level between the mobile station in the area and the base station), the direct wave level (with the mobile station in the area) Information such as the communication level with the own station) and relayability are stored in a table (see FIG. 5) created in the storage unit 19, and a response is set. Thereafter, the processing of (S507) and (S508) is repeated until the timer time expires in (S509), and after time-out, the process proceeds to (S510). In (S510), it is determined whether or not a valid response exists in the “relay communication response” signal set as a response. Here, the criteria for determining an effective response are, for example, that the base wave level and the direct wave level are each 15 dBμV or more and the relayability is “possible”. If the received response signal is a valid response, the process proceeds to (S511). In (S510), when the response signal is not received or the response is not valid, the process proceeds to (S518), and the process proceeds to (S401) in FIG. In (S511), when there are a plurality of “relay communication response” signals that are valid responses, the signal levels are compared to determine the mobile station with the highest reception level. Specifically, with reference to the signal level table (shown in FIG. 5) created in the storage unit 19, for example, the mobile station having the highest base wave level is selected from the mobile stations determined to be valid responses. . In the example shown in FIG. 5, the mobile station signals that are determined to be valid responses are MSa, MSb, and MSc, and among these, the MSc with a base wave level of 30 dBμV is selected as the mobile station with the highest base wave level. The mobile station with the highest reception level determined here is selected as the partner of relay communication, and the process proceeds to (S512).

  In (S512), message editing is performed based on the signal format of FIG. 3B, and "relay communication confirmation notification" is transmitted in the next (S513). Since this relay communication confirmation notification includes the called number (incoming mobile station number) from the mobile station selected as having the highest reception level, other mobile stations that received the relay communication confirmation notification It is possible to immediately determine whether or not relay communication is requested. After transmitting this relay communication confirmation notice, an “empty line” is transmitted in (S514) and awaits in (S515). Thereafter, until the state changes, the standby is continued in (S515) and (S516), and when a communication request is received from the mobile station that requested the relay communication, the process proceeds to communication processing in (S517), and the local station If it is determined that the mobile station has returned to the service area within the base station, the process proceeds from (S519) to (S601) in FIG.

  FIG. 8 is a flowchart showing the flow of processing when relay cancellation notification is made to another mobile station when the mobile station itself recognizes that it has returned to the service area. Each mobile station searches for a receivable channel by the same processing as in FIG. 6 to determine whether it is within or out of service area even when it is out of service area, and recognizes that it is within service area during relay communication. In this case, the message editing of the “relay cancellation notification” signal is performed in (S601), and the number of retransmissions that is the number of times of transmitting the signal is set (for example, set to 3 times) in (S602). Next, in (S603), a “relay release notification” signal is transmitted, and after transmission is completed, an “empty line” is transmitted in (S604). Thereafter, in (S605), it is confirmed whether a response signal from the relay mobile station has been received. If a response signal is received (S608), the process proceeds to (S401) in FIG. If the response signal cannot be confirmed, the number of retransmissions is confirmed in the next (S606), and if the “relay release notification” signal is transmitted for the set number of times, the process proceeds to (S401) in FIG. 6 in (S608). If the response signal from the relay mobile station is not received, the number of retransmissions is incremented by 1 in (S607), and the processing of (S603) to (S606) is repeated to receive the response signal from the relay mobile station. Alternatively, after transmitting the “relay cancellation notification” signal for the set number of times (S608), the process proceeds to (S401) in FIG.

  In the above, each process in the mobile station has been described using flowcharts. Next, a control sequence until the mobile station that has recognized out of service establishes relay communication will be described with reference to FIG. Here, it is assumed that the base station, the mobile station a within the range, the mobile station b within the range, and the mobile station c outside the service area are in a positional relationship between the base station and the mobile stations a to c in FIG.

  First, mobile station c (hereinafter referred to as out-of-range mobile station c), which has recognized that its own station is out of the base station service area, transmits a relay communication request to another mobile station. A synchronous burst signal SB0 including information on the calling party number is transmitted. At this time, transmission is continuously performed for a certain period. The within-range mobile station a and within-range mobile station b that have received this synchronous burst signal SB0 recognize this signal and lock until receiving an “empty line” signal. Thereafter, the out-of-service mobile station c continuously transmits “empty lines” for a certain period of time to notify the end of transmission of the “relay communication request” signal. Recognize completion of transmission of “relay communication request” signal.

The within-range mobile station a and within-range mobile station b that have recognized the end of transmission of the “relay communication request” transmit the relay communication response, the incoming / outgoing number in order to perform a “relay communication response” that notifies whether or not the local station can relay. Then, the synchronization burst signal SB0 including whether relaying is possible and the base wave level is continuously transmitted for a certain period, and thereafter, “vacant lines” for notifying the end of transmission are continuously transmitted for a certain period. As shown in FIG. 7, there is a difference in the timing at which the “relay communication response” is transmitted from the mobile station a and the mobile station b. This is because the timing at which the “relay communication response” is transmitted is after the standby time uniquely set for each mobile station has elapsed. This prevents interference caused by a plurality of mobile stations transmitting “relay communication response” signals simultaneously. The timing for transmitting the “relay communication response” may be determined randomly according to a variable, or may be determined in inverse proportion to the reception level of the “relay communication request” signal. Also good.
This “relay communication response” signal notifies whether or not the local station can relay, but as an example of a case where a mobile station in the area disables relaying or does not send back a signal, ”(2) When communication with the base station is preceded by timing and the relay communication response cannot be returned, (3) When the mobile phone falls out of service at the moment when it is desired to return the response, And so on.
The out-of-service mobile station c is configured to set a timer after transmitting an “empty line” related to the “relay communication request” and wait for a “relay communication response” from another mobile station until the set time elapses. The content of the received “relay communication response” is stored.

  The out-of-service mobile station c determines whether or not the reception level of each “relay communication response” received before the timeout is notified that relaying is possible is equal to or higher than a specified value. In addition, when there are a plurality of mobile stations that are equal to or greater than the specified value, the reception level of the “relay communication response” and the “base wave level” are compared, and the reception level of the “relay communication response” and The mobile station with the highest “base wave level” is selected. Note that the selection criteria here can be set as appropriate, and may be selected with priority given to either the reception level of “relay communication response” or “base wave level”. With respect to the in-range mobile station (the in-range mobile station a in the example of FIG. 9) as the relay communication partner thus selected, the out-of-range mobile station c uses the relay communication confirmation notification and the relay communication confirmation notification as a signal of “relay communication confirmation notification”. The synchronous burst signal SB0 including the incoming / outgoing number is continuously transmitted for a predetermined period, and thereafter, “vacant lines” for notifying the end of transmission are continuously transmitted for a predetermined period. This “relay communication confirmation notification” signal is received not only by the within-range mobile station “a” but also within the within-range mobile station “b”, but immediately determines whether or not the local station is requested to perform relay communication by the called / calling number. Can be determined. In this way, the mobile station a within the range shifts to the relay mode, and the mobile station b within the range continues normal operation.

  FIG. 10 shows a control sequence at the time of actual relay communication after the relay communication is determined between the within-area mobile station a and the outside-area mobile station c. In this case, first, “establishment of communication path” is performed between the base station and the mobile station “a” in preparation for the transmission of the audio signal. Note that “establishing the communication path” is a technique that has been practiced in the past, and details thereof are omitted. When an audio signal is transmitted from the base station after the “communication path establishment” is completed, the audio signal is received by the in-zone mobile station a and the in-zone mobile station b. At this time, the in-zone mobile station b only receives the voice, but the in-zone mobile station a responsible for relaying receives the voice and records the voice signal and temporarily stores it in the storage unit 19. The base station transmits a TCH: idle signal for notifying the end of transmission when the transmission of the audio signal is completed. Communication between the base station and the in-range mobile station a and the in-range mobile station b is performed in the base station communication mode, and relay communication between the in-range mobile station a and the out-of-range mobile station c is performed in the direct communication mode. After receiving the TCH: idle signal, the mobile station a transmits a synchronization burst signal SB0 indicating that the voice signal from the base station is relayed to the out-of-service mobile station c, and then records the base station Starts to transmit the audio signal from and transmits the empty line after the end. In this way, the relay operation is performed.

In FIG. 9, when the in-zone mobile station a is in the relay mode and the in-zone mobile station b continues the normal operation, FIG. 10 shows a case where the in-zone mobile station a normally performs the relay operation.
FIG. 11 shows a case where the in-range mobile station “a” in the relay mode becomes incapable of relaying in the middle and the in-range mobile station “b” performs the relay operation instead.
In FIG. 11, it is assumed that a voice signal is transmitted from the base station after the “communication channel establishment” is completed and received by the mobile station a and mobile station b. In FIG. 11, unlike FIG. 10, not only the in-range mobile station “a” responsible for relaying but also the in-range mobile station “b” of normal operation receives the voice and records the voice signal and temporarily stores it in the storage unit 19. Remember me. The base station transmits a TCH: idle signal for notifying the end of transmission when the transmission of the audio signal is completed. Upon receiving the TCH: idle signal, the in-service mobile station b in normal operation not relaying sets a timer to monitor the synchronous burst signal SB0 from the mobile mobile station a in charge of relay. When a normal signal is received from within-range mobile station a responsible for relaying within the set time of the timer, within-range mobile station a performs a relay operation as shown in FIG.
However, as shown in FIG. 11, the synchronous burst signal SB0 from the mobile station a that is in charge of relaying even if the mobile station b within the range receives the TCH: idle signal from the base station and the set time of the timer expires. Mobile station b determines that mobile station a is incapable of relaying for some reason, and in turn, mobile station b from out-of-range mobile station c A synchronous burst signal SB0 is transmitted to notify that the voice signal is to be relayed, transmission of the voice signal from the base station recorded after transmission is started, and an empty line is transmitted to the in-range mobile station a and the out-of-range mobile station c after completion. When the nearby mobile station a receives the proxy relay signal from the within-range mobile station b, the within-range mobile station a erases the voice recorded by receiving the empty line signal from the within-range mobile station b.

  FIG. 12 shows a control sequence when it is determined that the out-of-service mobile station c has returned to the service area during relay communication. Each mobile station searches whether there is a channel capable of receiving a signal from the base station at regular intervals regardless of the situation of the mobile station (similar to the flowchart of FIG. 6). If the search is performed while relay communication is performed and it is determined that the mobile terminal has returned to the service area, the synchronous burst signal SB0 as the “relay release notification” signal is transmitted, and “empty line” is transmitted upon completion. On the other hand, the mobile station “a” that has received the “relay cancellation notification” signal transmits a synchronous burst signal SB0 as a “relay cancellation response” signal, and transmits an “empty line” upon completion. In this way, the out-of-service mobile station c that has received the “relay release response” signal ends the relay operation and shifts to the base station mode prepared for communication with the base station.

FIG. 13 shows a control sequence when the mobile station a within the range determines that the signal level has deteriorated during relay communication or that the local station is out of range. In such a case, contrary to the case of FIG. 12, the mobile station a within the range transmits a synchronous burst signal SB0 as a “relay release notification” signal, and transmits an “empty line” upon completion. On the other hand, the out-of-service mobile station c that has received the “relay cancellation notification” signal transmits a synchronous burst signal SB0 as a “relay cancellation response” signal, and transmits an “empty line” upon completion. In this way, the mobile station a within the range receiving the “relay cancellation response” signal shifts to the normal operation, and the mobile station c outside the range ends the relay operation and shifts to the base station mode prepared for communication with the base station. To do.
Each signal transmitted in FIG. 12 and FIG. 13 is also received by another base station (such as the mobile station b within the area) that is not involved in the relay operation, but it is determined by the incoming / outgoing number included in each signal. Since it is possible to immediately determine whether the signal is for the station, no problem occurs.

By configuring the wireless communication system as described above, a mobile station that is recognized as being outside the service area of the base station can make a relay communication request to another mobile station by itself. It is possible to communicate with the base station even in an area where there is no station. Although this wireless communication system can be used in various fields, it is particularly suitable for a wireless communication system used for fire fighting and ambulance vehicles. For example, when moving to an area outside the jurisdiction, This is effective when a relay communication request is made to obtain information on a disaster.
If it is applied to fire and ambulance vehicles, the current status such as “out-of-service relay communication” is displayed on the front panel and a speaker is output. It is also possible to notify the user and wait for subsequent communication.

1 is a schematic diagram illustrating an overall configuration of a wireless communication system according to the present invention. It is the figure showing the transmission / reception structure of the base station and mobile station in FIG. (A) is the conceptual diagram showing the definition field for communication control, (b) is the conceptual diagram showing the signal format used at the time of "relay communication" in (a). It is a block diagram showing the simple structure of the base station and the mobile station. It is a conceptual diagram showing the table structure regarding a signal level. It is a flowchart figure showing the flow at the time of searching for the channel which each mobile station can receive in order to receive the signal from a base station. FIG. 5 is a flowchart showing a processing flow when a mobile station itself recognizes that it is out of service area and makes a relay communication request to another mobile station. FIG. 7 is a flowchart showing a flow of processing when a relay cancellation notification is made to another mobile station when it is recognized that the mobile station has returned to the area. It is a control sequence figure until the mobile station which recognized out of service establishes relay communication. It is a control sequence diagram at the time of actual relay communication after the relay communication is confirmed. FIG. 5 is a control sequence diagram when relay communication is performed on behalf of another mobile station when relay communication becomes inoperable. It is a control sequence diagram when it is determined that the out-of-service mobile station has returned to the service area during relay communication. FIG. 10 is a control sequence diagram when a nearby mobile station determines that the signal level is deteriorated or the own station is out of service area during relay communication. It is the schematic diagram showing the whole structure of the conventional radio | wireless communications system.

Explanation of symbols

  11 ... (base station) digital modulation / demodulation unit, 12 ... (base station) control unit, 13 ... (base station) storage unit, 14 ... (base station) transmission unit, 15, 16 ... (base station) Receiving unit, 17 ... (mobile station) digital modulation / demodulation unit, 18 ... (mobile station) control unit, 19 ... (mobile station) storage unit, 20 ... (mobile station) transmission unit, 21-23 ... (movement) (S401) to (S416) ... each step in the flowchart of FIG. 6, (S501) to (S519) ... each step in the flowchart of FIG. 7, (S601) to (S608) ... the flowchart of FIG. In each step.

Claims (6)

In a wireless communication system including a base station and a plurality of mobile stations that communicate with the base station, the mobile station searches for a plurality of channels of the base station as communication partners stored in advance in a storage unit. The control unit determines whether there is a communicable channel. If there is no communicable channel, it determines that the local station is out of the service area of the base station and To send a “relay communication request” signal from the transmitter ,
When the other mobile station receives the “relay communication request” signal from the mobile station at the receiving unit, the other mobile station transmits a “relay communication response” signal including information on whether or not relay communication is possible to the mobile station. Send from the department,
The “relay communication response” signal includes base wave level information indicating the signal level between the other mobile station and the base station related to the “relay communication response” signal, and the mobile station When the reception unit receives a “relay communication response” signal from another mobile station within a predetermined period, whether or not the reception level and base wave level of the “relay communication response” signal have reached a specified value. When there are a plurality of received “relay communication response” signals, the control unit compares the reception level and base wave level to select the optimum relay partner, and the selected 1 Specify the other mobile station to send a “relay communication confirmation notification” signal,
In the case of having one relay mode mobile station and one or more normal operation mode mobile stations that have received the "relay communication confirmation notification" signal at the receiver of the other mobile station, the mobile stations in these relay modes And the mobile station in the normal operation mode receive / record the voice signal from the base station by “establishing the communication path” between the base station and the base station, and receive the transmission end signal from the base station. Then, when the mobile station in the normal operation mode receives the synchronization burst signal from the mobile station in the relay mode within the set time from the reception of the transmission end signal from the base station, the mobile station in the relay mode moves out of the service area. A radio communication system , wherein a recorded voice is transmitted to a station, and a mobile station in a normal operation mode deletes a recorded voice signal upon reception of an empty line signal from a mobile station in a relay mode . In a wireless communication system including a base station and a plurality of mobile stations that communicate with the base station, the mobile station searches for a plurality of channels of the base station as communication partners stored in advance in a storage unit. The control unit determines whether there is a communicable channel. If there is no communicable channel, it determines that the local station is out of the service area of the base station and To send a “relay communication request” signal from the transmitter,
When the other mobile station receives the “relay communication request” signal from the mobile station at the receiving unit, the other mobile station transmits a “relay communication response” signal including information on whether or not relay communication is possible to the mobile station. Send from the department,
The “relay communication response” signal includes base wave level information indicating the signal level between the other mobile station and the base station related to the “relay communication response” signal, and the mobile station When the reception unit receives a “relay communication response” signal from another mobile station within a predetermined period, whether or not the reception level and base wave level of the “relay communication response” signal have reached a specified value. When there are a plurality of received “relay communication response” signals, the control unit compares the reception level and base wave level to select the optimum relay partner, and the selected 1 Specify the other mobile station to send a “relay communication confirmation notification” signal,
In the case of having one relay mode mobile station and one or more normal operation mode mobile stations that have received the "relay communication confirmation notification" signal at the receiver of the other mobile station, the mobile stations in these relay modes And the mobile station in the normal operation mode receive / record the voice signal from the base station by “establishing the communication path” between the base station and the base station, and receive the transmission end signal from the base station. Then, when the mobile station in the normal operation mode does not receive the synchronization burst signal from the mobile station in the relay mode within the set time from the reception of the transmission end signal from the base station, the mobile station in the normal operation mode The recorded voice is transmitted to the mobile station outside the service area on behalf of the mobile station, and the mobile station in the relay mode deletes the recorded voice signal by receiving the empty line signal from the mobile station in the normal operation mode. That Radio communications system to be butterflies. The other mobile station has means for discriminating the communication state between itself and the base station at regular intervals, and after establishing relay communication by the “relay communication confirmation notification” signal, the base station When the control unit determines that the communication level has deteriorated below the specified value or communication with the base station is impossible, a “relay release notification” signal is sent from the transmission unit to the mobile station that is the relay partner. The wireless communication system according to claim 1 or 2, wherein relay communication is canceled by transmission. In a wireless communication system comprising a base station and a plurality of mobile stations that communicate with the base station, a mobile station that is outside the service area of the base station (hereinafter referred to as an out-of-service mobile station) A first step of transmitting a “relay communication request” signal to another mobile station (hereinafter referred to as “in-range mobile station”) that is determined to be outside the service area range and is within the service area range of the base station; A second step of transmitting a “relay communication response” signal including information on whether or not relay communication is possible to the out-of-service area mobile station after the station receives the “relay communication request” signal from the out-of-service area mobile station; A third step in which the out-of-range mobile station waits for a predetermined period of time to receive a “relay communication response” signal from the within-range mobile station; and a reception level of the “relay communication response” signal received by the out-of-area mobile station is Reached the specified value If there are multiple “relay communication response” signals that contain information on whether or not the relay communication is received, compare the reception levels to select the optimum relay partner and select A relay communication path is established by a fourth step of designating one mobile station within a range and transmitting a “relay communication confirmation notification” signal;
A fifth step of receiving / recording a voice signal from the base station after establishing a relay communication path to one relay mode mobile station and one or more normal operation mode mobile stations; and a normal operation mode mobile station When a transmission end signal from the base station is received, a sixth step of setting a timer, and when a synchronous burst signal is received from a mobile station in relay mode within the set time of the timer, the mobile station in relay mode A seventh step of transmitting the recorded voice to a mobile station outside the service area, and an eighth step of erasing the recorded voice signal when the mobile station in the normal operation mode receives an empty line signal from the mobile station in the relay mode. relay method in radio communications systems, characterized in that the. In a wireless communication system comprising a base station and a plurality of mobile stations that communicate with the base station, a mobile station that is outside the service area of the base station (hereinafter referred to as an out-of-service mobile station) A first step of transmitting a “relay communication request” signal to another mobile station (hereinafter referred to as “in-range mobile station”) that is determined to be outside the service area range and is within the service area range of the base station; A second step of transmitting a “relay communication response” signal including information on whether or not relay communication is possible to the out-of-service area mobile station after the station receives the “relay communication request” signal from the out-of-service area mobile station; A third step in which the out-of-range mobile station waits for a predetermined period of time to receive a “relay communication response” signal from the within-range mobile station; and a reception level of the “relay communication response” signal received by the out-of-area mobile station is Reached the specified value If there are multiple “relay communication response” signals that contain information on whether or not the relay communication is received, compare the reception levels to select the optimum relay partner and select A relay communication path is established by a fourth step of designating one mobile station within a range and transmitting a “relay communication confirmation notification” signal;
A fifth step of receiving / recording a voice signal from the base station after establishing a relay communication path to one relay mode mobile station and one or more normal operation mode mobile stations; and a normal operation mode mobile station A sixth step of setting a timer when receiving a transmission end signal from the base station, and a mobile station in the normal operation mode when the synchronization burst signal from the mobile station in the relay mode is not received within the set time of the timer. The seventh step of transmitting the recorded voice to the mobile station outside the service area on behalf of the mobile station in the relay mode, and the mobile station in the relay mode recorded by receiving the sky signal from the mobile station in the normal operation mode relay method in radio communications system characterized by comprising an eighth step of erasing the audio signal. The in-zone mobile station has means for determining the communication state between itself and the base station at regular intervals, and after the in-zone mobile station has established the relay communication path in the fourth step, the base station When it is determined that the communication level has deteriorated below the specified value or communication with the base station is impossible, a “relay cancellation notification” signal is transmitted to the mobile station that is the relay partner, and relay communication is performed. 6. The relay method in a wireless communication system according to claim 4 or 5, wherein: is canceled.

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